PVElite-Manual.pdf

PVElite 2006 January 2006, Issued January 2006 PVElite is a Windows (2000/XP) based program. This version has been developed and tested on Windows 2000 and XP. It will not run or install on earlier versions of Windows. Note that Microsoft has discontinued development and support for these older operating systems. NOTES: Launching the program PVE.EXE starts PVElite. Some of the new features in this version are: • ASME Code 2005 Updates, including changes to the material tables 1A.1B, 2A, 2B and the Yield Stress Table Added 2 new External Pressure charts • Added change for the Flange Rigidity requirement in Appendix 2 • Added Wind and Seismic Load Scalars • Added Additional UG-39 checks for Nozzles on Flat Heads (Ligaments, edge spacing etc) • Integrated ASME App 26 Thin Bellows calculation into the tubesheet input • Added to program most Sections of ASME Code Case 2286 • Added ability to address nozzles in flat heads for PD 5500 and EN 13445 • Added ability to switch between ANSI Metric and ANSI Imperial Nozzle sizes • Added ability to add full penetration pad welds and nozzle welds using the list feature • Added Nozzle Cut Length calculations • Added ability to add platforms to horizontal vessels • Plus several other new features • Component (CodeCalc) Analysis Features:

• ASME Code 2005 Updates, including changes to the material tables 1A.1B, 2A, 2B and the Yield Stress Table • Added 2 new External Pressure charts • Added change for the Flange Rigidity requirement in Appendix 2 • Added ASCE 7-2002/95/98 and UBC-1997 Wind Codes for the Support Lug and Legs. • Added ASCE 7-2002/95/98 and UBC-1997 Wind Codes for the horizontal vessels. • Added the option of entering the loads in Sustained, Expansion and Occasional categories using the WRC-107 convention system. Once, the loads are categorized they can be combined per ASME Sec. VIII Div. 2 rules and compared with the allowables. The loads can be converted from one convention to another with a click of a button from the input screen.

• Added an autosave feature that allows you to specify a time period in between saves. Saves can be silent or prompted. This feature is in the Tools->Configuration Menu Miscellaneous tab. • Modified the input echo and output results from the Flange and Floating Head modules to be consistent with ASME nomenclature.

• Added the recommendation for the minimum gasket width in Floating Head calculations. If the program is installed on the network, the batch file netuser.bat should be run from each user’s machine to register the required dlls. Otherwise some parts of PVElite will not function. Please note that periodically we will post fixes to the software on our web site at the location sited below. If you are having trouble with a particular calculation, check the COADE web site to see if there is a later version available that may fix your problem (also available from the PVElite Help menu). You should always run the latest version of the software.

www.cadfamily.com EMail:[email protected] The document is for study only,if tort to your rights,please inform us,we will delete

Contacting COADE We welcome your comments and suggestions regarding PVELITE. Problems, comments, and suggestions should be directed to the PVELITE development staff. Our current contact information is: • • • •

(Phone) (Fax) (E-mail) (Web)

281-890-4566 281-890-3301 [email protected] http://www.coade.com

Best Regards. PVElite Development Staff


2006 PVElite User Guide


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PREFACE PVElite LICENSE AGREEMENT Licensor: COADE/Engineering Physics Software, Inc., 12777 Jones Road, Suite 480, Houston, Texas 77070

ACCEPTANCE OF TERMS OF AGREEMENT BY THE USER YOU SHOULD CAREFULLY READ THE FOLLOWING TERMS AND CONDITIONS BEFORE USING THIS PACKAGE. USING THIS PACKAGE INDICATES YOUR ACCEPTANCE OF THESE TERMS AND CONDITIONS. The enclosed proprietary encoded materials, hereinafter referred to as the Licensed Program(s), are the property of COADE and are provided to you under the terms and conditions of this License Agreement. You assume responsibility for the selection of the appropriate Licensed Program(s) to achieve the intended results, and for the installation, use and results obtained from the selected Licensed Program(s).

LICENSE GRANT In return for the payment of the license fee associated with the acquisition of the Licensed Program(s) from COADE, COADE hereby grants you the following non-exclusive rights with regard to the Licensed Programs(s): 1

Use of the License Program(s) on one machine. Under no circumstance is the License Program to be executed without a COADE External Software Lock (ESL).

2

To transfer the Licensed Program(s) and license it to a third party if the third party acknowledges in writing its agreement to accept the Licensed Program(s) under the terms and conditions of this License Agreement; if you transfer the Licensed Program(s), you must at the same time either transfer all copies whether printed or in machine-readable form to the same party or destroy any copies not so transferred; the requirement to transfer and/or destroy copies of the Licensed Program(s) also pertains to any and all modifications and portions of Licensed Program(s) contained or merged into other programs.

You agree to reproduce and include the copyright notice as it appears on the Licensed Program(s) on any copy, modification or merged portion of the Licensed Program(s). THIS LICENSE DOES NOT GIVE YOU ANY RIGHT TO USE COPY, MODIFY, OR TRANSFER THE LICENSED PROGRAM(S) OR ANY COPY, MODIFICATION OR MERGED PORTION THEREOF, IN WHOLE OR IN PART, EXCEPT AS EXPRESSLY PROVIDED IN THIS LICENSE AGREEMENT. IF YOU TRANSFER POSSESSION OF ANY COPY, MODIFICATION OR MERGED PORTION OF THE LICENSED PROGRAM(S) TO ANOTHER PARTY, THE LICENSE GRANTED HEREUNDER TO YOU IS AUTOMATICALLY TERMINATED.

TERM This License Agreement is effective upon acceptance and use of the Licensed Program(s) until terminated in accordance with the terms of this License Agreement. You may terminate the License Agreement at any time by destroying the Licensed Program(s) together with all copies, modifications, and merged portions thereof in any form. This License Agreement will also terminate upon conditions set forth elsewhere in this Agreement or automatically in the event you fail to comply with any term or condition of this License Agreement. You hereby agree upon such


PREFACE

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termination to destroy the Licensed Program(s) together with all copies, modifications and merged portions thereof in any form.

LIMITED WARRANTY The Licensed Program(s), i.e. the tangible proprietary software, is provided "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED AND EXPLICITLY EXCLUDING ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. The entire risk as to the quality and performance of the Licensed Program(s) is with you. Some jurisdictions do not allow the exclusion of limited warranties, and, in those jurisdictions the above exclusions may not apply. This Limited Warranty gives you specific legal rights, and you may also have other rights, which vary from one jurisdiction to another. COADE does not warrant that the functions contained in the Licensed Program(s) will meet your requirements or that the operation of the program will be uninterrupted or error free. COADE does warrant, however, that the CD(s), i.e. the tangible physical medium on which the Licensed Program(s) is furnished, to be free from defects in materials and workmanship under normal use for a period of ninety (90) days from the date of delivery to you as evidenced by a copy of your receipt. COADE warrants that any program errors will be fixed by COADE, at COADE's expense, as soon as possible after the problem is reported and verified. However, only those customers current on their update/maintenance contracts are eligible to receive the corrected version of the program.

ENTIRE AGREEMENT This written Agreement constitutes the entire agreement between the parties concerning the Licensed Program(s). No agent, distributor, salesman or other person acting or representing themselves to act on behalf of COADE has the authority to modify or supplement the limited warranty contained herein, nor any of the other specific provisions of this Agreement, and no such modifications or supplements shall be effective unless agreed to in writing by an officer of COADE having authority to act on behalf of COADE in this regard.

LIMITATIONS OF REMEDIES COADE's entire liability and your exclusive remedy shall be: 1

the replacement of any CD not meeting COADE's "Limited Warranty" as defined herein and which is returned to COADE or an authorized COADE dealer with a copy of your receipt, or

2

if COADE or the dealer is unable to deliver a replacement CD which is free of defects in materials or workmanship you may terminate this License Agreement by returning the Licensed Program(s) and associated documentation and you will be refunded all monies paid to COADE to acquire the Licensed Program(s).

IN NO EVENT WILL COADE BE LIABLE TO YOU FOR ANY DAMAGES, INCLUDING ANY LOST PROFITS, LOST SAVINGS, AND OTHER INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE LICENSED PROGRAM(S) EVEN IF COADE OR AN AUTHORIZED COADE DEALER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES, OR FOR ANY CLAIM BY ANY OTHER PARTY.


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SOME JURISDICTIONS DO NOT PERMIT LIMITATION OR EXCLUSION OF LIABILITY FOR INCIDENTAL AND CONSEQUENTIAL DAMAGES SO THAT THE ABOVE LIMITATION AND EXCLUSION MAY NOT APPLY IN THOSE JURISDICTIONS. FURTHERMORE, COADE DOES NOT PURPORT TO DISCLAIM ANY LIABILITY FOR PERSONAL INJURY CAUSED BY DEFECTS IN THE DISKETTES OR OTHER PRODUCTS PROVIDED BY COADE PURSUANT TO THIS LICENSE AGREEMENT.

GENERAL You may not sublicense, assign, or transfer your rights under this License Agreement or the Licensed Program(s) except as expressly provided in this License Agreement. Any attempt otherwise to sublicense, assign or transfer any of the rights, duties or obligations hereunder is void and constitutes a breach of this License Agreement giving COADE the right to terminate as specified herein. This Agreement is governed by the laws of the State of Texas, United States of America. The initial license fee includes 1 year of support, maintenance and enhancements to the program. After the first 1year term, such updates and support are optional at the then current update fee. Questions concerning this License Agreement, and all notices required herein shall be made by contacting COADE in writing at COADE, 12777 Jones Road, Suite 480, Houston, Texas, 77070, or by telephone, 281-890-4566.

DISCLAIMER Copyright (c) COADE/Engineering Physics Software, Inc., 2006, all rights reserved. This proprietary software is the property of COADE/Engineering Physics Software, Inc. and is provided to the user pursuant to a COADE/Engineering Physics Software, Inc. program license agreement containing restrictions on its use. It may not be copied or distributed in any form or medium, disclosed to third parties, or used in any manner except as expressly permitted by the COADE/Engineering Physics Software, Inc. program license agreement. THIS SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED. COADE/ENGINEERING PHYSICS SOFTWARE, INC. SHALL NOT HAVE ANY LIABILITY TO THE USER IN EXCESS OF THE TOTAL AMOUNT PAID TO COADE UNDER THE COADE/ENGINEERING PHYSICS SOFTWARE, INC. LICENSE AGREEMENT FOR THIS SOFTWARE. IN NO EVENT WILL COADE/ENGINEERING PHYSICS SOFTWARE, INC. BE LIABLE TO THE USER FOR ANY LOST PROFITS OR OTHER INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF USE OR INABILITY TO USE THE SOFTWARE EVEN IF COADE/ENGINEERING PHYSICS, INC. HAS BEEN ADVISED AS TO THE POSSIBILITY OF SUCH DAMAGES. IT IS THE USERS RESPONSIBILITY TO VERIFY THE RESULTS OF THE PROGRAM.

HOOPS' License Grant COADE grants to PVElite users a non-exclusive license to use the Software Application under the terms stated in the Agreement. PVElite users agree to not alter, reverse engineer, or disassemble the Software Application. PVElite users will not copy the Software except: (i) as necessary to install the Software Application onto a computer(s)...or (ii) to create an archival copy. PVElite users agree that any such copies of the Software Application shall contain the same proprietary notices which appear on and in the Software Application.


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Title to and ownership of the intellectual property rights associated with the Software Application ADA any copies remain with COADE and its suppliers. PVElite user are hereby notified that Tech Soft America, L.L.C. 1301 Marina Village Parkway, Suite 300, Alameda CA 94501 ("Tech Soft America") is a third-party beneficiary to this Agreement to the extent that this Agreement contains provisions which relate to PVElite users' use of the Software Application. Such provisions are made expressly for the benefit of Tech Soft America and are enforceable by Tech Soft America in addition to COADE. In no event shall COADE or its suppliers be liable in any way for indirect, special or consequential damages of any nature, including without limitations, lost business profits, or liability or injury to third persons, whether foreseeable or not, regardless of whether COADE or its suppliers have been advised of the possibility of such damages.

TRADEMARKS HOOPS' is a trademark of Tech Soft America, L.L.C. Windows (95/98/ME/NT/2000/XP), Access, SQL Server, Excel, Word are trademarks of Microsoft Corporation. Oracle is a trademark of Oracle Corporation. Other trademarks are the property of their respective owners.



Contents PREFACE .........................................................................................................................................1 PVElite LICENSE AGREEMENT....................................................................................................2 ACCEPTANCE OF TERMS OF AGREEMENT BY THE USER...................................................2 LICENSE GRANT ............................................................................................................................2 TERM................................................................................................................................................2 LIMITED WARRANTY...................................................................................................................3 ENTIRE AGREEMENT ...................................................................................................................3 LIMITATIONS OF REMEDIES ......................................................................................................3 GENERAL ........................................................................................................................................4 DISCLAIMER...................................................................................................................................4 HOOPS' License Grant......................................................................................................................4 TRADEMARKS................................................................................................................................5

Chapter 1

Introduction

1-1

What is PVElite?....................................................................................................................................... 1-2 What is the Purpose and Scope of PVElite? ............................................................................................. 1-3 What Distinguishes PVElite From our Competitors? ............................................................................... 1-4 What Applications are Available? ............................................................................................................ 1-5 About the Documentation ......................................................................................................................... 1-9 Program Support / User Assistance ........................................................................................................ 1-10 Updates ................................................................................................................................................... 1-11 COADE Technical Support Phone Numbers.......................................................................................... 1-12

Chapter 2

The Installation/Configuration Process

2-1

Overview .................................................................................................................................................. 2-2 System and Hardware Requirements ........................................................................................................ 2-3 External Software Lock ............................................................................................................................ 2-4 Starting the Installation Procedure............................................................................................................ 2-5 Installing PVElite...................................................................................................................................... 2-7 Network Installation / Usage .................................................................................................................. 2-10 Software Installation on a Network Drive ................................................................................... 2-10 ESL Installation on a Network................................................................................................................ 2-11 Novell File Server ESL Installation............................................................................................. 2-11 Novell Workstation ESL Installation........................................................................................... 2-11 Windows Server Installation ....................................................................................................... 2-11 Notes on Network ESLs ......................................................................................................................... 2-12

Chapter 3

Tutorial/Master Menu

3-1

Program Structure and Control ................................................................................................................. 3-2 A Road Map for PVELITE ....................................................................................................................... 3-3 The Input Processor .................................................................................................................................. 3-4 Other Input Processors.............................................................................................................................. 3-7 Error Checking........................................................................................................................................ 3-10 Analysis .................................................................................................................................................. 3-11 Tools Menu............................................................................................................................................. 3-12


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Contents Output Review and Report Generation................................................................................................... 3-13 Design and Analysis of Vessel Details ................................................................................................... 3-15 Input Menu.............................................................................................................................................. 3-18 Main Menu.............................................................................................................................................. 3-21 File Menu................................................................................................................................................ 3-22 Analyze Menu......................................................................................................................................... 3-25 Output Menu........................................................................................................................................... 3-26 Tools Menu............................................................................................................................................. 3-27 Create / Review Units.................................................................................................................. 3-33 Edit / Add Materials .................................................................................................................... 3-33 Calculator .................................................................................................................................... 3-35 Diagnostics Menu ................................................................................................................................... 3-36 View Menu ............................................................................................................................................. 3-37 Inspecting the Model in 3D .................................................................................................................... 3-40 ESL Menu............................................................................................................................................... 3-42 Help Menu .............................................................................................................................................. 3-43 PVElite Quick Start ................................................................................................................................ 3-44 Entering PVElite.......................................................................................................................... 3-44 Defining the Basic Vessel............................................................................................................ 3-45 Adding Details ........................................................................................................................................ 3-46 Recording the Model - Plotting the Vessel Image .................................................................................. 3-47 Specifying Global Data - Loads and Design Constraints........................................................................ 3-49 Performing the Analysis ......................................................................................................................... 3-53 Reviewing the Results ............................................................................................................................ 3-54 Analyzing Individual Vessel Components Details ................................................................................. 3-55 DXF File Generation Option .................................................................................................................. 3-58 Setting Up the Required Parameters ....................................................................................................... 3-59 User Border Creation................................................................................................................... 3-59 DXF File Generated by PVElite During Runtime .................................................................................. 3-61 Invoking the Drawing.................................................................................................................. 3-61

Chapter 4

Element Data

4-1

Introduction............................................................................................................................................... 4-2 Element Basic Data................................................................................................................................... 4-3 Element's From Node .................................................................................................................... 4-3 Element's To Node ........................................................................................................................ 4-4 Element's Diameter........................................................................................................................ 4-4 Distance or Straight Flange Length ............................................................................................... 4-4 Finished Thickness ........................................................................................................................ 4-5 Corrosion Allowance..................................................................................................................... 4-5 Wind Load Diameter Multiplier .................................................................................................... 4-5 Material Name ............................................................................................................................... 4-5 Joint Efficiency for Longitudinal and Circumferential Seams ...................................................... 4-6 Design Internal Pressure................................................................................................................ 4-6 Design Temperature for Internal Pressure ..................................................................................... 4-6 Design External Pressure............................................................................................................... 4-7 Design Temperature for External Pressure .................................................................................... 4-7 Swap Diameter Basis..................................................................................................................... 4-7 Element Additional Data .......................................................................................................................... 4-8 Cylindrical Shell ............................................................................................................................ 4-8 Elliptical Head ............................................................................................................................... 4-8 Head Factor ................................................................................................................................... 4-8 Inside Head Depth ......................................................................................................................... 4-9


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Sump Head?................................................................................................................................... 4-9 Torispherical Head.................................................................................................................................. 4-10 Crown Radius .............................................................................................................................. 4-10 Knuckle Radius ........................................................................................................................... 4-10 Sump Head?................................................................................................................................. 4-10 Spherical Head........................................................................................................................................ 4-11 Conical Head or Shell Segment................................................................................................... 4-11 To Node Diameter ....................................................................................................................... 4-11 Cone Length ................................................................................................................................ 4-11 Half Apex Angle.......................................................................................................................... 4-12 Toriconical................................................................................................................................... 4-12 Toricone Dialog........................................................................................................................... 4-12 Large End Knuckle Radius.......................................................................................................... 4-12 Large End Knuckle Thickness..................................................................................................... 4-13 Small End Knuckle Radius.......................................................................................................... 4-13 Sump Head?................................................................................................................................. 4-13 Welded Flat Head ................................................................................................................................... 4-14 Attachment Factor ....................................................................................................................... 4-14 Non-Circ. Small Diameter ........................................................................................................... 4-15 Appendix 14 Large Opening ....................................................................................................... 4-15 Flange Analysis ...................................................................................................................................... 4-16 Body Flange................................................................................................................................. 4-16 Skirt Support with Basering.................................................................................................................... 4-17 Inside Diameter at Base............................................................................................................... 4-18 Basering Dialog ........................................................................................................................... 4-19 Flange Input Data ................................................................................................................................... 4-20 Basering Analysis ................................................................................................................................... 4-21 Brownell and Young Method of Design...................................................................................... 4-21 Tailing Lug Analysis .............................................................................................................................. 4-22 Tailing Lug Input Data ........................................................................................................................... 4-23 Perform Tailing Lug Analysis ..................................................................................................... 4-23 Tail Lug Type .............................................................................................................................. 4-23 Centerline Offset ......................................................................................................................... 4-23 Lug Thickness ............................................................................................................................. 4-23 Pin Hole Diameter ....................................................................................................................... 4-23 Weld Size Thickness ................................................................................................................... 4-23 Lug Height (only if no Top Ring)................................................................................................ 4-23 Discussion of Results................................................................................................................... 4-24

Chapter 5

Vessel Detail Data

5-1

Introduction............................................................................................................................................... 5-2 Assigning Detail ....................................................................................................................................... 5-4 Detail Definition Buttons.......................................................................................................................... 5-5 Defining the Details .................................................................................................................................. 5-7 Rings......................................................................................................................................................... 5-8 Inside Diameter of Ring ................................................................................................................ 5-9 Outside Diameter of Ring.............................................................................................................. 5-9 Thickness of Ring.......................................................................................................................... 5-9 Ring Material................................................................................................................................. 5-9 Moment of Inertia.......................................................................................................................... 5-9 Cross Sectional Area ................................................................................................................... 5-10 Distance to Ring Centroid ........................................................................................................... 5-10 Name of Section Type ................................................................................................................. 5-10


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Contents Nozzle Dialog Data................................................................................................................................. 5-11 Nozzle Analysis ...................................................................................................................................... 5-12 Nozzle Input Data ................................................................................................................................... 5-13 Nozzle Description ...................................................................................................................... 5-13 Angle Between Nozzle and Shell ................................................................................................ 5-13 Offset Distance from Cylinder/Head Centerline (L1) ................................................................. 5-13 Class for Attached B16.5 Flange ................................................................................................. 5-13 Grade for Attached B16.5 Flange ................................................................................................ 5-13 Modification of Reinforcing Limits............................................................................................. 5-14 Physical Maximum for Nozzle Diameter Limit........................................................................... 5-14 Physical Maximum for Nozzle Thickness Limit ......................................................................... 5-14 Do you want to set Area1 or Area 2 to 0 ..................................................................................... 5-14 Nozzle Material Specification ..................................................................................................... 5-14 Nozzle Diameter Basis ................................................................................................................ 5-15 Actual or Nominal Diameter of Nozzle....................................................................................... 5-15 Nozzle Size and Thickness Basis ................................................................................................ 5-15 Actual Diameter and Thickness................................................................................................... 5-15 Nominal Diameter and Thickness ............................................................................................... 5-15 Minimum Diameter and Thickness ............................................................................................. 5-15 Actual Thickness of Nozzle......................................................................................................... 5-15 Nominal Schedule of Nozzle ....................................................................................................... 5-16 Nozzle Corrosion Allowance....................................................................................................... 5-16 Joint Efficiency of Shell Seam through which Nozzle Passes..................................................... 5-16 Joint Efficiency of Nozzle Neck.................................................................................................. 5-16 Insert Nozzle or Abutting Nozzle ................................................................................................ 5-16 Nozzle Outside Projection ........................................................................................................... 5-16 Weld Leg Size for Fillet Between Nozzle and Shell or Pad ........................................................ 5-16 Depth of Groove Weld Between Nozzle and Vessel ................................................................... 5-17 Nozzle Inside Projection.............................................................................................................. 5-17 Weld Leg Size Between Inward Nozzle and Inside Shell ........................................................... 5-17 Local Shell Thickness.................................................................................................................. 5-17 Shell Tr Value.............................................................................................................................. 5-17 Tapped Hole Area Loss ............................................................................................................... 5-17 Overriding Nozzle Weight........................................................................................................... 5-18 Nozzle Orientation....................................................................................................................... 5-18 Additional Reinforcing Pad Data........................................................................................................... 5-27 Pad Outside Diameter along Vessel Surface ............................................................................... 5-27 Pad Width .................................................................................................................................... 5-27 Pad Thickness.............................................................................................................................. 5-27 Pad Weld Leg Size as Outside Diameter ..................................................................................... 5-27 Depth of Groove Weld between Pad and Nozzle Neck ............................................................... 5-27 Pad Material................................................................................................................................. 5-27 ASME Code Weld Type.............................................................................................................. 5-27 Flange Type ................................................................................................................................. 5-28 Flange Material............................................................................................................................ 5-28 Lugs ........................................................................................................................................................ 5-29 Distance from Vessel OD to Lug Midpoint................................................................................. 5-29 Lug Bearing Width ...................................................................................................................... 5-29 Radial Width of Bottom Support Plate........................................................................................ 5-29 Length of Bottom Lug Support Plate........................................................................................... 5-30 Thickness of Bottom Plate........................................................................................................... 5-30 Distance between Gussets ........................................................................................................... 5-30 Mean Width of Gussets ............................................................................................................... 5-30 Height of Gussets ........................................................................................................................ 5-30 Thickness of Gussets ................................................................................................................... 5-30


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Radial Width of Top Plate/Ring .................................................................................................. 5-30 Thickness of Top Plate/Ring ....................................................................................................... 5-30 Overall Height of Lug.................................................................................................................. 5-30 Overall Width of Lug .................................................................................................................. 5-30 Weight of One Lug ...................................................................................................................... 5-30 Number of Lugs........................................................................................................................... 5-31 Perform WRC 107 Calc............................................................................................................... 5-31 Pad Width .................................................................................................................................... 5-31 Pad Thickness.............................................................................................................................. 5-31 Pad Length................................................................................................................................... 5-31 Weights ................................................................................................................................................... 5-32 Miscellaneous Weight ................................................................................................................. 5-32 Offset from Centerline................................................................................................................. 5-32 Is this a Welded Internal .............................................................................................................. 5-32 Forces and Moments............................................................................................................................... 5-33 Force in X, Y, or Z Direction ...................................................................................................... 5-33 Moment about X, Y, or Z Axis.................................................................................................... 5-33 Acts During Wind or Seismic...................................................................................................... 5-33 Force/Moment Combination Method .......................................................................................... 5-33 Platforms................................................................................................................................................. 5-34 Platform Start Angle (degrees) .................................................................................................... 5-34 Platform End Angle (degrees) ..................................................................................................... 5-34 Platform Wind Area..................................................................................................................... 5-35 Platform Weight .......................................................................................................................... 5-35 Platform Railing Weight.............................................................................................................. 5-35 Platform Grating Weight ............................................................................................................. 5-35 Platform Width ............................................................................................................................ 5-35 Platform Height ........................................................................................................................... 5-35 Platform Clearance ...................................................................................................................... 5-35 Platform Force Coefficient .......................................................................................................... 5-35 Platform Wind Area Calculation [Installation \ Misc. Options] .................................................. 5-35 Platform Length (Non- Circular) ................................................................................................. 5-36 Saddles.................................................................................................................................................... 5-37 Width of Saddle........................................................................................................................... 5-37 Centerline Dimension (B)............................................................................................................ 5-37 Saddle Contact Angle (degrees) .................................................................................................. 5-38 Height of Composite Stiffener..................................................................................................... 5-38 Width of Wear Plate .................................................................................................................... 5-38 Thickness of Wear Plate .............................................................................................................. 5-38 Wear Plate Contact Angle (degrees)............................................................................................ 5-38 Saddle Dimension A.................................................................................................................... 5-38 Perform Saddle Check ................................................................................................................. 5-38 Material Yield Stress ................................................................................................................... 5-38 E for Plates .................................................................................................................................. 5-38 Baseplate Length ......................................................................................................................... 5-38 Baseplate Width........................................................................................................................... 5-38 Baseplate Thickness .................................................................................................................... 5-39 Number of Ribs ........................................................................................................................... 5-39 Rib Thickness .............................................................................................................................. 5-39 Web Thickness ............................................................................................................................ 5-39 Web Location .............................................................................................................................. 5-39 Height of Center Web.................................................................................................................. 5-39 Trays ....................................................................................................................................................... 5-40 Number of Trays.......................................................................................................................... 5-40 Tray Spacing................................................................................................................................ 5-40


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Contents Tray Weight Per Unit Area.......................................................................................................... 5-40 Height of Liquid on Tray............................................................................................................. 5-40 Density of Liquid on Tray ........................................................................................................... 5-40 Legs ........................................................................................................................................................ 5-41 Distance from Outside Diameter: or Diameter at Leg Centerline ............................................... 5-41 Leg Orientation............................................................................................................................ 5-41 Number of Legs ........................................................................................................................... 5-42 Section Identifier ......................................................................................................................... 5-42 Length of Legs............................................................................................................................. 5-42 Vessel Translates During Occasional Load ................................................................................. 5-42 Packing ................................................................................................................................................... 5-43 Height of Packed Section ............................................................................................................ 5-43 Density of Packing ...................................................................................................................... 5-44 Liquid...................................................................................................................................................... 5-45 Height/Length of Liquid .............................................................................................................. 5-45 Liquid Density ............................................................................................................................. 5-45 Insulation ................................................................................................................................................ 5-47 Height/Length of Insulation / Fireproofing ................................................................................. 5-47 Thickness of Insulation or Fireproofing ...................................................................................... 5-47 Insulation Density........................................................................................................................ 5-47 Lining...................................................................................................................................................... 5-49 Height/Length of Lining .............................................................................................................. 5-49 Thickness of Lining ..................................................................................................................... 5-49 Density of Lining......................................................................................................................... 5-49 Half Pipe Jacket ...................................................................................................................................... 5-50 Introduction ................................................................................................................................. 5-50 Purpose, Scope and Technical Basis............................................................................................ 5-50 Discussion of Input Data ............................................................................................................. 5-50

Chapter 6

General Vessel Data

6-1

Introduction............................................................................................................................................... 6-2 Design Data .............................................................................................................................................. 6-3 Installation Options................................................................................................................................... 6-8 Design Modification ............................................................................................................................... 6-11 Nozzle Design Modifications ................................................................................................................. 6-14 Wind & Seismic Data ............................................................................................................................. 6-16 Wind Data............................................................................................................................................... 6-17 ASCE Wind Data.................................................................................................................................... 6-18 UBC Wind Data...................................................................................................................................... 6-20 NBC Wind Data...................................................................................................................................... 6-22 ASCE 95 Wind Data............................................................................................................................... 6-24 IS 875 Wind Code .................................................................................................................................. 6-27 User-Defined Wind Profile ..................................................................................................................... 6-29 Percent Wind for Hydrotest ......................................................................................................... 6-29 Wind Profile Data........................................................................................................................ 6-29 Mexican Wind Code 1993 ...................................................................................................................... 6-30 British Wind Code BS-6399 ................................................................................................................... 6-37 Seismic Data ........................................................................................................................................... 6-41 Seismic Design Code................................................................................................................... 6-41


Contents

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ASCE 7-88 Seismic Data........................................................................................................................ 6-42 ASCE7-93 Seismic Data......................................................................................................................... 6-44 UBC Seismic Data .................................................................................................................................. 6-45 NBC Seismic Data .................................................................................................................................. 6-47 India's Earthquake Standard IS-1893 RSM and SCM ............................................................................ 6-49 ASCE - 95 Seismic Data......................................................................................................................... 6-50 Seismic Load Input in G's....................................................................................................................... 6-51 UBC 1997 Earthquake Data.................................................................................................................... 6-52 IBC-2000 Earthquake Parameters........................................................................................................... 6-54 Response Spectrum................................................................................................................................. 6-56

Chapter 7

PVElite Analysis

7-1

Introduction............................................................................................................................................... 7-2 Calculating and Displaying Vessel-Analysis Results ............................................................................... 7-3 Optional Steps........................................................................................................................................... 7-9 Component Analysis............................................................................................................................... 7-11

Chapter 8

Output/Review

8-1

Generating Output .................................................................................................................................... 8-2 The Review Screen ................................................................................................................................... 8-3 Using Review............................................................................................................................................ 8-4 Component Analysis................................................................................................................................. 8-5

Chapter 9

HEAT EXCHANGERS

9-1

Introduction............................................................................................................................................... 9-2 Purpose, Scope and Technical Basis......................................................................................................... 9-3 Analyzing Heat Exchangers...................................................................................................................... 9-4 Building Heat Exchangers ........................................................................................................... 9-11

Chapter 10

Component Analysis Tutorial

10-1

Purpose of this Chapter........................................................................................................................... 10-2 Starting CodeCalc from PVElite............................................................................................................. 10-3 Main Menu.............................................................................................................................................. 10-4 File Menu .................................................................................................................................... 10-5 Edit Menu .................................................................................................................................... 10-7 Analysis Menu............................................................................................................................. 10-8 Output Menu................................................................................................................................ 10-9 Tools Menu................................................................................................................................ 10-10 Diagnostic Menu ....................................................................................................................... 10-20 View Menu ................................................................................................................................ 10-21 ESL Menu.................................................................................................................................. 10-22 Help Menu ................................................................................................................................. 10-23 Performing an Analysis ........................................................................................................................ 10-24 Reviewing the Results - The Output Option ......................................................................................... 10-30 Printing or Saving Reports to a File .......................................................................................... 10-31


8

Contents Summary - Seeing Results for a Whole Vessel .................................................................................... 10-32 Tutorial Problem Printout ..................................................................................................................... 10-33

Chapter 11

SHELLS

11-1

Introduction............................................................................................................................................. 11-2 Purpose, Scope and Technical Basis....................................................................................................... 11-3 Discussion of Input Data......................................................................................................................... 11-5 Main Input Fields ........................................................................................................................ 11-5 Pop-up Input Fields ..................................................................................................................... 11-8 Results .................................................................................................................................................. 11-12 API 579 Introduction ............................................................................................................................ 11-14 Purpose, Scope, and Technical Basis.................................................................................................... 11-15 Discussion of Input Data....................................................................................................................... 11-18 Discussion of Results............................................................................................................................ 11-27 Example ................................................................................................................................................ 11-28 Jacket .................................................................................................................................................... 11-29

Chapter 12

NOZZLES

12-1

Introduction............................................................................................................................................. 12-2 Purpose, Scope, and Technical Basis...................................................................................................... 12-3 Discussion of Input Data......................................................................................................................... 12-4 Main Input Fields ........................................................................................................................ 12-4 Pop-Up Input Fields .................................................................................................................. 12-10 Discussion of Results............................................................................................................................ 12-14 Actual Nozzle Diameter Thickness ........................................................................................... 12-14 Required Thickness of Shell and Nozzle................................................................................... 12-14 UG-45 Minimum Nozzle Neck Thickness ................................................................................ 12-14 Required and Available Areas ................................................................................................... 12-14 Selection of Reinforcing Pad ..................................................................................................... 12-15 Large Diameter Nozzle Calculations......................................................................................... 12-15 Effective Material Diameter and Thickness Limits ................................................................... 12-15 Effective Material Diameter and Thickness Limits ................................................................... 12-15 Minimum Design Metal Temperature ....................................................................................... 12-15 Weld Size Calculations.............................................................................................................. 12-15 Weld Strength Calculations ....................................................................................................... 12-16 Failure Path Calculations........................................................................................................... 12-16 Iterative Results Per Pressure, Area , And UG-45.................................................................... 12-16 Example ................................................................................................................................................ 12-17

Chapter 13

FLANGES

13-1

Introduction............................................................................................................................................. 13-2 Purpose, Scope, and Technical Basis...................................................................................................... 13-3 Discussion of Input Data......................................................................................................................... 13-5 Main Input Fields ........................................................................................................................ 13-5 Pop-Up Input Fields .................................................................................................................. 13-14


Contents

9

Discussion of Results............................................................................................................................ 13-18 Example ................................................................................................................................................ 13-22

Chapter 14

CONICAL SECTIONS

14-1

Introduction............................................................................................................................................. 14-2 Purpose, Scope and Technical Basis....................................................................................................... 14-3 Discussion of Input Data......................................................................................................................... 14-4 Main Input Fields ........................................................................................................................ 14-4 Pop-Up Input Fields .................................................................................................................... 14-8 Discussion of Results............................................................................................................................ 14-10 Internal Pressure Results ........................................................................................................... 14-10 External Pressure Results .......................................................................................................... 14-10 Reinforcement Calculations Under Internal Pressure................................................................ 14-10 Reinforcement Calculations Under External Pressure............................................................... 14-11 Example ................................................................................................................................................ 14-12

Chapter 15

FLOATING HEADS

15-1

Introduction............................................................................................................................................. 15-2 Purpose, Scope and Technical Basis....................................................................................................... 15-3 Discussion of Input Data......................................................................................................................... 15-4 Main Input Fields ........................................................................................................................ 15-4 Pop-Up Input Fields .................................................................................................................. 15-13 Discussion of Results............................................................................................................................ 15-14 Internal Pressure Results for the Head:...................................................................................... 15-14 External Pressure Results for Heads:......................................................................................... 15-14 Intermediate Calculations for Flanged Portion of Head: ........................................................... 15-14 Required Thickness Calculations: ............................................................................................. 15-14 Soehren's Calculations:.............................................................................................................. 15-14 Example ................................................................................................................................................ 15-16

Chapter 16

HORIZONTAL VESSELS

16-1

Introduction............................................................................................................................................. 16-2 Discussion of Input ................................................................................................................................. 16-3 Main Input Fields ........................................................................................................................ 16-3 Pop-Up Input Fields .................................................................................................................... 16-7 Discussion of Results............................................................................................................................ 16-16 Saddle Wear Plate Design..................................................................................................................... 16-17 Example ................................................................................................................................................ 16-20

Chapter 17

TUBESHEETS

17-1

Introduction............................................................................................................................................. 17-2 Purpose, Scope, and Technical Basis...................................................................................................... 17-3 Discussion of Input Data......................................................................................................................... 17-6 Main Input Fields ........................................................................................................................ 17-6 Pop-Up Input Fields .................................................................................................................. 17-18 Discussion of Results............................................................................................................................ 17-31 Example ................................................................................................................................................ 17-36


10

Contents

Chapter 18

WRC 107\FEA

18-1

Introduction............................................................................................................................................. 18-2 Discussion of Input ................................................................................................................................. 18-3 Main Input Fields ........................................................................................................................ 18-3 Pop-Up Input Fields .................................................................................................................... 18-8 WRC 107 Additional Input........................................................................................................ 18-15 FEA Additional Input ................................................................................................................ 18-16 Discussion of Results............................................................................................................................ 18-18 WRC 107 Stress Calculations.................................................................................................... 18-18 WRC107 Stress Summations..................................................................................................... 18-20 ASME Section VIII Division 2 - Elastic Analysis of Nozzle .................................................... 18-21 Finite Element Analysis (FEA): ................................................................................................ 18-23 Example ................................................................................................................................................ 18-25 Example ................................................................................................................................................ 18-27

Chapter 19

LEGS and LUGS

19-1

Introduction............................................................................................................................................. 19-2 Discussion of Input ................................................................................................................................. 19-3 Main Input Fields ........................................................................................................................ 19-3 Pop-Up Input Fields .................................................................................................................... 19-6 Vessel Leg Input ................................................................................................................................... 19-12 Leg Results ........................................................................................................................................... 19-14 Support Lug Input................................................................................................................................. 19-15 Lifting Lug Input .................................................................................................................................. 19-18 Output ................................................................................................................................................... 19-21 Baseplate Input ..................................................................................................................................... 19-22 Main Input Fields ...................................................................................................................... 19-22 Baseplate Results .................................................................................................................................. 19-25 Trunnion Input ...................................................................................................................................... 19-26 Main Input Fields ...................................................................................................................... 19-26 Trunnion Results................................................................................................................................... 19-29 Example ................................................................................................................................................ 19-30

Chapter 20

PIPES and PADS

20-1

Introduction............................................................................................................................................. 20-2 Discussion of Input ................................................................................................................................. 20-3 Main Input Fields ........................................................................................................................ 20-3 Pop-Up Input Fields .................................................................................................................... 20-5 Output ..................................................................................................................................................... 20-8 Example .................................................................................................................................................. 20-9

Chapter 21

BASE RINGS

21-1

Introduction............................................................................................................................................. 21-2 Calculations ............................................................................................................................................ 21-3 Calculation Techniques ............................................................................................................... 21-3 Discussion of Input ................................................................................................................................. 21-9 Main Input Fields ........................................................................................................................ 21-9


Contents

11

Pop-up Input Fields ................................................................................................................... 21-14 Tailing Lug Analysis ............................................................................................................................ 21-16 Discussion of Input ............................................................................................................................... 21-17 Tailing Lug Input....................................................................................................................... 21-17 Discussion of Results............................................................................................................................ 21-18 Example ................................................................................................................................................ 21-19

Chapter 22

THIN JOINTS

22-1

Introduction............................................................................................................................................. 22-2 Purpose, Scope and Technical Basis....................................................................................................... 22-3 Discussion of Input Data......................................................................................................................... 22-4 Main Input Fields ........................................................................................................................ 22-4 Pop-Up Input Fields .................................................................................................................... 22-8 Example ................................................................................................................................................ 22-11

Chapter 23

THICK JOINTS

23-1

Introduction............................................................................................................................................. 23-2 Discussion of Input Data......................................................................................................................... 23-4 Main Input Fields ........................................................................................................................ 23-4 Pop-Up Input Fields .................................................................................................................... 23-9 Discussion of Results............................................................................................................................ 23-10 Example ................................................................................................................................................ 23-11

Chapter 24

ASME TUBESHEETS

24-1

Introduction............................................................................................................................................. 24-2 Purpose, Scope, and Technical Basis...................................................................................................... 24-3 Discussion of Input Data......................................................................................................................... 24-4 Main Input Fields ........................................................................................................................ 24-4 Pop-Up Input Fields .................................................................................................................. 24-16 Discussion of Results............................................................................................................................ 24-26 Example ................................................................................................................................................ 24-28

Chapter 25

HALF-PIPES

25-1

Introduction............................................................................................................................................. 25-2 Purpose, Scope, and Technical Basis...................................................................................................... 25-3 Discussion of Input Data......................................................................................................................... 25-4 Main Input Fields ........................................................................................................................ 25-4 Discussion of Results.............................................................................................................................. 25-7 Example .................................................................................................................................................. 25-9

Chapter 26

LARGE OPENINGS

26-1

Introduction............................................................................................................................................. 26-2 Purpose, Scope and Technical Basis....................................................................................................... 26-3 Discussion of Input Data......................................................................................................................... 26-4 Main Input Fields ........................................................................................................................ 26-4 Example Problem.................................................................................................................................... 26-5


12

Contents

Chapter 27

RECTANGULAR VESSELS

27-1

Introduction............................................................................................................................................. 27-2 Purpose, Scope and Technical Basis....................................................................................................... 27-3 Discussion of Input Data....................................................................................................................... 27-10 Main Input Fields ...................................................................................................................... 27-10 Pop-Up Input Fields .................................................................................................................. 27-14 Discussion of Results............................................................................................................................ 27-18 Ligament Efficiency Calculations ............................................................................................. 27-18 Reinforcement Calculations ...................................................................................................... 27-18 Stress Calculations..................................................................................................................... 27-18 Allowable Calculations.............................................................................................................. 27-19 Highest Percentage of Allowable Calculations.......................................................................... 27-19 MAWP Calculations.................................................................................................................. 27-19 External Pressure Calculations .................................................................................................. 27-19 Example Problem.................................................................................................................................. 27-20

Chapter 28

WRC 297/ANNEX G

28-1

Introduction............................................................................................................................................. 28-2 Discussion of Input Data......................................................................................................................... 28-3 Main Input Fields ........................................................................................................................ 28-3 Additional Input for PD 5500, Annex G...................................................................................... 28-7 Sample Calculation ................................................................................................................................. 28-9 Discussion of Results............................................................................................................................ 28-10

Chapter 29

Appendix Y

29-1

Introduction............................................................................................................................................. 29-2 Purpose, Scope, and Technical Basis...................................................................................................... 29-3 Gasket and Gasket Factors...................................................................................................................... 29-4 Example .................................................................................................................................................. 29-5

Chapter 30

Miscellaneous Topics

30-1

Heading Edit ........................................................................................................................................... 30-2 Heading Manipulation and Material Properties ...................................................................................... 30-3 Discussion of Input ................................................................................................................................. 30-6 Input Data .................................................................................................................................... 30-6 Nominal Density of this Material ................................................................................................ 30-9 P Number Thickness.................................................................................................................... 30-9 Yield Stress, Operating................................................................................................................ 30-9 UCS-66 Chart Number ................................................................................................................ 30-9 External Pressure Chart Name..................................................................................................... 30-9 Carbon Steel Materials .............................................................................................................. 30-10 Heat Treated Materials .............................................................................................................. 30-10 Stainless Steel (High Alloy) Materials ...................................................................................... 30-10 Non Ferrous Materials ............................................................................................................... 30-11


Contents

Chapter 31

13

Vessel Example Problems

31-1

Vessel Example ...................................................................................................................................... 31-2



CH AP TER

1

Chapter 1 Introduction

In This Chapter What is PVElite?.........................................................................1-2 What is the Purpose and Scope of PVElite? ...............................1-3 What Distinguishes PVElite From our Competitors? .................1-4 What Applications are Available? ..............................................1-5 About the Documentation ...........................................................1-9 Program Support / User Assistance.............................................1-10 Updates .......................................................................................1-11 COADE Technical Support Phone Numbers ..............................1-12


1-2

Introduction

What is PVElite? PVElite is a PC-based pressure vessel design and analysis software program developed, marketed and sold by COADE Engineering Software. PVElite is a package of nineteen applications for the design and analysis of pressure vessels and heat exchangers, and fitness for service assessments. The purpose of the program is to provide the mechanical engineer with easy to use, technically sound, well documented reports with detailed calculations and supporting comments, which will speed and simplify the task of vessel design, re-rating or fitness for service. The popularity of PVElite is a reflection of COADE's expertise in programming and engineering, as well as COADE's dedication to service and quality.



1-3

What is the Purpose and Scope of PVElite? Calculations in PVElite are based on the latest editions of national codes such as the ASME Boiler and Pressure Vessel Code, or industry standards such as the Zick analysis method for horizontal drums. PVElite offers exceptional ease of use, which results in dramatic improvement in efficiency for both design and re-rating. PVElite features include: Graphical User Interface, which lists model data and control with a vessel display. Horizontal and vertical vessels may be composed of cylinders, conical sections, body flanges as well as elliptical, torispherical, hemispherical, conical and flat heads. Saddle supports for horizontal vessels. Leg and skirt supports at any location for vertical vessels. Extensive on-line help. Deadweight calculation from vessel details such as nozzles, lugs, rings, trays, insulation, packing and lining. Wall thickness calculations for internal and external pressure in accordance with the rules of ASME Section VIII Divisions 1 and Division 2, PD 5500 and EN-13445. Stiffener rings are evaluated for external pressure. Wind and seismic data using the American Society of Civil Engineers (ASCE) standard, the Uniform Building Code (UBC), and the National (Canadian) Building Code, India Standards as well as British, Mexican, Australian and European Standards. User-defined unit system. A complete examination of the vessel’s structural loads combining the effects of pressure, deadweight and live loads in the empty, operating and hydrotest conditions. Logic to automatically increase wall thickness to satisfy requirements for pressure and structural loads and introduce stiffener rings to address external pressure rules. Structural load evaluation in terms of both tensile and compressive stress ratios (to the allowable limits). Detailed analysis of nozzles, flanges, and base rings. Material library for all three-design standards. Component library containing pipe diameter and wall thickness, ANSI B16.5 flange pressure vs. temperature charts, and section properties for AISC, British, Indian, Japanese, Korean, Australian and South African structural shapes. Printed output from PVElite is clear and complete, with user definable headings on each page. User comments and additions may be inserted at any point in the output.


1-4

Introduction

What Distinguishes PVElite From our Competitors? COADE treats PVElite more as a service than a product. Our staff of experienced pressure vessel engineers are involved in day-to-day software development, program support and training. This approach has produced a program, which most closely fits today's requirements of the pressure vessel industry. Data entry is simple and straightforward through annotated input screens and/or spreadsheets. PVElite provides the widest range of modeling and analysis capabilities without becoming too complicated for simple system analysis. Users may tailor their PVElite installation through default setting and customized databases. Comprehensive input graphics confirms the model construction before the analysis is made. The program's interactive output processor presents results on the monitor for quick review or sends complete reports to a file, printer or Word document. PVElite is an up-to-date package that not only utilizes standard analysis guidelines but also provides the latest recognized opinions for these analyses. PVElite is a field-proven engineering analysis program. It is a widely recognized product with a large customer base and an excellent support and development record. COADE is a strong and stable company where service is a major commitment.



1-5

What Applications are Available? The following applications are available in PVElite.

General Vessels Enables users to perform wall thickness design and analysis of any vessel for realistic combinations of pressure, deadweight, nozzle, wind and seismic loads in accordance with ASME Section VIII Division 1 rules, Division 2 rules, PD 5500, and EN-13445. These calculations address minimum wall thickness for pressure and allowable longitudinal stress (both tension and compression) in the vessel wall for the expected structural load combinations.

Complete Vertical Vessels Enables definition of vessels supported by either skirts, legs or lugs for complete dead load and live load analysis. Stacked vessels with liquid are also addressed. Enables specification of Hydrotest conditions for either vertical or horizontal test positions. Vessel MAWP includes hydrostatic head and ANSI B16.5 flange pressure limitations.

Complete Horizontal Vessels Enables stress analysis of horizontal drums on saddle supports using the method of L. P. Zick. Results include stresses at the saddles, the midpoint of the vessel and in the heads. The following applications are available in PVElite:

Shells & Heads Performs internal and external pressure design of vessels and exchangers using the ASME Code, Section VIII, Division 1 rules. Components include cylinders, conical sections, elliptical heads, torispherical heads, flat heads, spherical shells and heads. This program calculates required thickness and maximum allowable internal pressure for the given component. It also calculates the minimum design metal temperature per UCS-66, and evaluates stiffening rings for external pressure design. Jackets covering the shell can also be analyzed. These jackets are addressed in Appendix 9 of the ASME Sec. VIII Div. 1. Implements API-579 for Fitness For Service evaluations (FFS). Sec. 4, Local Thinning, Sec. 5, General Metal Loss and Sec. 6 Pitting Corrosion.

Nozzles Calculates required wall thickness and reinforcement under internal pressure for nozzles in shells and heads, using the ASME Code, Section VIII, Division 1 rules and including tables of outside diameter and wall thickness for all nominal pipe diameters and schedules. The program checks the weld sizes, calculates the strength of reinforcement and evaluates failure paths for the nozzle. Hillside, tangential and Y-angle nozzles can also be evaluated.


1-6

Introduction

Conical Sections Performs internal and external pressure analysis of conical sections and stiffening rings using the ASME Code, Section VIII, Division 1 rules. Complete area of reinforcement and moment of inertia calculations for the cone under both internal and external pressure are included.

Floating Head Performs internal and external pressure analysis of bolted dished heads (floating heads) using the ASME Code, Section VIII, Division 1, Appendix 1 rules. The program also enables users to use an additional calculation technique allowed by the Code - Soehrens calculation.

Flanges Performs stress analysis and geometry selection for all types of flanges using the ASME Code, Section VIII, Division 1 rules. This program both designs and analyzes the following types of flanges: All integral flange types Slip on flanges and all loose flange types with hubs Ring type flanges and all loose flange types without hubs Blind flanges, both circular and non-circular TEMA channel covers Reverse geometry weld neck flanges Flat faced flanges with full face gaskets Users can input the external forces and moments acting on the flange and alternate mating flange loads.

Tubesheets (TEMA and PD 5500) PVElite performs an analysis of all types of tubesheets using the 8th Edition of the Standards of the Tubular Exchanger Manufacturers Association and PD 5500. The program takes full account of the effects of tubesheets extended as flanges, and for fixed tubesheets also includes the effects of differential thermal expansion and the presence of an expansion joint. Expansion joint can be designed within this module. For a fixed tubesheet exchanger the program can analyze multiple loads cases for both the corroded and uncorroded conditions. If an expansion joint is added, then corresponding expansion joint load cases will also be run.

Horizontal Vessels Performs stress analysis of horizontal drums on saddle supports using the L.P. Zick method. Results include stresses at the saddles, the midpoint of the vessel and in the heads. Stiffening rings used in the design of the vessel are also evaluated. Wind and seismic loadings are also considered. Additionally, the saddle, webs and baseplate are checked for external seismic and wind loads. Users can also specify friction and additional longitudinal forces on the vessel.

Legs & Lugs Performs analysis of vessel support legs, support lugs, trunnions and lifting lugs based on industry standard calculation techniques, and the resulting stresses are compared to the AISC Handbook of Steel Construction or the



1-7

ASME Code. A full table of 929 AISC beams, channels and angles is included in the program. WRC 107 analysis to check local vessel stresses around the trunnion and the support lug is also available from within this module. Various wind and seismic codes are available for Leg and Lug supported vessels.

Pipes & Pads Calculates required wall thickness and maximum allowable working pressure for two pipes, and branch reinforcement requirements for the same two pipes considered as a branch and a header. Based on ANSI B31.3 rules, this program includes tables of outside diameter and wall thickness for all nominal pipe diameters and schedules.

WRC 107/FEA Calculates stresses in cylindrical or spherical shells due to loading on an attachment, using the method of P.P. Bijlaard as defined in Welding Research Council Bulletin 107, including a stress comparison to VIII Div. 2 allowables for 3 different loading conditions. This module also contains an interface to the Finite Analysis Program (Nozzle Pro from The Paulin Research Group).

Baserings Performs stress and thickness evaluation for skirts and baserings. Results from both the neutral axis shift and simplified method for basering required thickness is reported. Required skirt thickness due to weight loads and bending moments are also displayed. Tailing Lugs attached to the basering can also be analyzed.

Thin Joints Performs stress and life cycle evaluation for thin walled expansion joints (bellows kind) in accordance with ASME VIII Div. 1 appendix 26.

Thick Joints Performs stress, life cycle and spring rate calculations for flanged and flued expansion joints in accordance with ASME VIII Div. 1 appendix 5. The spring rate computation is per TEMA eighth edition.

ASME Tubesheets Determines required thickness of tubesheets for fixed, floating or U-tube exchangers per the ASME Code Section VIII division 1 section UHX. You can use the program to analyze multiple loads cases for both the corroded and uncorroded conditions.

Half-Pipe Determines required thickness and MAWP for half-pipe jacketed vessels per the ASME Code Section VIII division 1 appendix EE.


1-8

Introduction

Large Openings Analyzes large openings in integral flat heads per the ASME Code Section VIII division 1 appendix 2 and appendix 14. Required thickness, MAWP and weights are computed for geometries with or without an attached nozzle.

Rectangular Vessels Analyzes non-circular pressure vessels using the rules of the ASME Code, Section VIII, Division 1 and Appendix 13. Most of the vessel types in Appendix 13 are analyzed for internal pressure, including reinforced or stayed rectangular vessels with a diametral staying plate. All membrane and bending stresses are computed and compared to the appropriate allowables.

WRC 297 / PD5500 Annex G Performs the stress analysis of loads and attachments according to the Welding Research Council bulletin 297 and the British Standard Annex G PD:5500. The WRC 297 bulletin, published in 1984, attempts to extend the existing analysis of WRC 107 for cylinder-to-cylinder intersections. PD:5500 Annex G provides an analysis of stress in cylindrical or spherical shells due to attachment loads. Complete material databases for ASME Sec VIII and Div-1, 2; and PD 5500 are available.

Appendix Y Flanges Performs a stress evaluation of Class1 category 1, 2, or 3 flanges that form identical flange pairs, according to the latest version of the ASME Code Section VIII Division 1 Appendix Y.

Summary Displays a description and evaluation of all the components of a pressure vessel or heat exchanger. Design pressure, temperature, material, actual thickness and Maximum Allowable Working Pressure are shown for each component.



1-9

About the Documentation Chapter 2 gives you information on the hardware and software required to run PVElite, instructions on how to install the program, and how to prepare your computer to run the program. Chapter 3 tells you how to launch PVElite on your computer. Use Chapter 3 to learn the structure of the program, and the keystrokes needed to operate the software. Each of the applications operates the same way, so you will only need to learn these skills one time. Chapter 4 discusses the PVElite element input data for each basic element. The details added to these elements are explained in Chapter 5. Chapter 6 describes the general vessel input data. Chapter 7 discusses the Analyze options of PVElite while Chapter 8 discusses how to review or generate output for the job. This chapter also focuses on the capabilities of the review processor Chapter 9 contains information needed to analyze shell and tube type heat exchangers. . Chapter 10 contains a complete tutorial, which leads you through the use of one application of the PVElite Component Analysis Module. Chapter 11 gives a more detailed description of several features associated with the spreadsheet input program merging shell data, selecting materials, editing materials properties, and inserting or deleting analyses. Chapters 11 through 29 contain the technical descriptions for each of the PVElite module applications. The information provided for each application includes: The purpose and scope of the application and its technical basis Notes on the input to the program and results of the program A figure showing the relevant geometry One or more example problems Chapter 30 describes miscellaneous topics included in PVElite. Chapter 31 provides additional information, which will be helpful as you use PVElite. These include heat exchanger design cases, hand calculations for selected programs, a bibliography of pressure vessel texts and standards.


1-10

Introduction

Program Support / User Assistance COADE's staff understands that PVElite is not only a complex analysis tool but also, at times, an elaborate process — one that may not be obvious to the casual user. While our documentation is intended to address the questions raised regarding pressure vessel/heat exchanger/FFS analyses, system modeling, and results interpretation, not all the answers can be quickly found in these volumes. COADE understands the engineer's need to produce efficient, economical, and expeditious designs. To that end, COADE has a staff of helpful professionals ready to address any PVElite issues raised by all users. PVElite support is available by telephone, e-mail, fax, Website discussion forum, and by mail; literally hundreds of support calls are answered every week. COADE provides this service at no additional charge to the user. It is expected, however, that questions focus on the current version of the program. Users who wish to be informed of the latest build/updates for the program can register their copy of PVElite at www.coade.com/updates.htm. Formal training in PVElite and pressure vessel analysis is also available from COADE. COADE conducts regular training classes in Houston and provides in-house and open attendance courses around the world. These courses focus on the expertise available at COADE — modeling, analysis, and design. For more information about these courses visit www.coade.com.



1-11

Updates The version number identifies the PVElite update set. The current release of PVElite is Version 2006. COADE schedules and distributes these updates every January. The purchase price includes unlimited access to PVElite and one year of updates, maintenance, and support. Updates, maintenance, and support are available on an annual basis after the first year.


1-12

Introduction

COADE Technical Support Phone Numbers Phone: 281-890-4566

Email: [email protected]

Fax: 281-890-3301

WEB: www.coade.com


CH AP TER

2

Chapter 2 The Installation/Configuration Process In This Chapter Overview .................................................................................... 2-2 System and Hardware Requirements .......................................... 2-3 External Software Lock .............................................................. 2-4 Starting the Installation Procedure.............................................. 2-5 Installing PVElite........................................................................ 2-7 Network Installation / Usage ...................................................... 2-10 ESL Installation on a Network.................................................... 2-11 Notes on Network ESLs ............................................................. 2-12


2-2


Overview PVElite is installed on the system hard disk using the program setup located on the CD. The installation program has been designed to allow total installations, diagnostic checks of the installation and ease of updating. This section will explain the process of running the PVElite setup application. For users upgrading to a new version of PVElite, the installation program can be instructed to place the new files in the same directory where the current version resides. The new version files will overwrite the old version files where appropriate. PVElite can be run from anywhere on the system hard disk. It is recommended that job files be kept in one or more data or project directories separate from the installation directory. The installation process consists of the following steps: 1

Copying of files from the program CD to the hard disk.

2

Extraction of PVElite from these compressed files.

3

Verification of the extracted files.

4

Installation of the External Software Lock (ESL) drivers.

5

Configuring of PVElite.


Chapter 2 The Installation/Configuration Process

2-3

System and Hardware Requirements The specific system resources necessary to run PVElite are listed below: Intel Pentium processor (or equivalent) Microsoft Windows (2000 or higher) Operating System 128 Mbytes RAM (recommended) 80 Mbytes of disk space CD-ROM Drive 1.5 GigaHertz CPU or better Note: PVElite is designed for 1024x768 or higher resolution. All of the dialogs may not fit on the screen at lower resolutions.


2-4


External Software Lock The External Software Lock (ESL) is the security protection method used by COADE. The program cannot execute unless an appropriate ESL (green USB) is attached to the PC locally, or to another computer in the network (red USB ESL). The ESL contains the PVElite licensing data, and other client-specific information. This information includes the client company name and user ID number. Additional data may be stored on the ESL depending on the specific program and the specific client. The ESL can be attached to the USB port in a matter of seconds.



2-5

Starting the Installation Procedure Insert the program CD into the CD drive. The installation program should start automatically. If so, proceed to the section entitled "Installing PVElite". If not, it may be started manually using the following procedure.

Installing PVElite Manually Click the Windows Desktop Start button and select SETTINGS/ CONTROL PANEL.

Opening Control Panel

From the Control Panel window click Add/Remove Programs.


2-6


Control Panel Window

Click the Install button to start the installation process.

Add/Remove Programs Window

The next screen prompts for the folder where PVElite is to be installed. Users may modify and control the folder by clicking Browse. The folder may be the location of an existing PVElite installation, or a new location. This starts the installation process by prompting you to place the CD in the CD drive and clicking Next. Add/Remove Programs searches for the SETUP.EXE file located on the CD and prompts the user for verification of the file to be installed. Clicking Finish runs the setup program.



2-7

Installing PVElite Launch the installation routine by responding to the on-screen prompts and then clicking Next.

The Destination Folder dialog prompts users for the folder where PVElite will be installed. Click Change...&to specify a different folder than the default folder C:\Program Files\COADE\PVElite\. The folder may be the location of an existing PVElite installation or a new location.


2-8


Destination Folder Window

Select the ESL color. Selecting the correct ESL color ensures that the correct drivers are loaded during installation.

Select ESL Color Window

After selecting the ESL color, the Next button becomes enabled and allows users to continue the installation.



2-9

Ready to Install the Program Window

Click Install and installation will begin. When installation is complete, the InstallShield Wizard Complete dialog displays.

Final Installation Screen

Click Show me the readme file if you wish to review information regarding the new version or click Finish to conclude the installation


2-10


Network Installation / Usage COADE products can be run on network file servers as easily as on stand-alone workstations. There are two different installation configurations, which must be considered. Network drive installation – The software is installed on a network drive and a network ESL is installed and accessed by multiple users. Network drive installation (each user has a ESL) – The software is installed on a network drive and both local ESLs and network ESLs are present. COADE software supports two ESLs. The green USB devices are intended for local usage. The red USB devices are intended for network usage. Do not attempt to put a local green USB ESL on a network server - the system will crash.

Software Installation on a Network Drive Setup treats a network drive no differently than a local hard drive. Simply specify the target installation drive and directory and the software will be installed as specified. Some networks protect installation directories from subsequent modification by users. This involves setting the access rights in the installation directory to usually "read", "share" and "scan". Since COADE software utilizes data files specific to the installation (i.e., accounting, files, material files, etc.), which a user may need to modify, these files cannot be located in the "protected" installation directory. These data files are located in a sub-directory named SYSTEM, under the installation directory. Users should be given all access rights to this SYSTEM directory. While the person installing the software can specify the actual name of the program's installation directory, the SYSTEM sub-directory name is fixed, and is automatically created. Renaming this sub-directory will cause the software to fail and generate an error report. Note: The SYSTEM sub-directory is not the primary top level SYSTEM directory containing the network operating system. Once the software has been installed on the network drive, the installation program invokes the configuration program, which generates a default configuration file. Once the installation directory is write protected this file cannot be modified. Leaving this file as read only would insure the configuration file can then only be used as a starting template to generate other configuration files located in the various user data directories.



2-11

ESL Installation on a Network COADE software supports two different ESL types, local and network. Both types of ESLs are intended to be attached to the USB ports of the applicable computers. Local ESLs provide the maximum flexibility in using the software, since these devices can be moved between computers (for example, between desktops and laptops). If your computer uses a local ESL, the remainder of this section can be skipped. Network ESLs must be attached to the USB port of any machine on the network (this can be a workstation or the file server). The file server is a better location for this ESL, since it will usually be up and running. If the network ESL is attached to a workstation, the workstation must be running and/or logged onto the network before anyone can use the software. In order for the network to recognize the ESL, a utility program must be loaded on the machine controlling the ESL. The actual utility used depends on whether the ESL is on the file server or a workstation and the type of network. The drivers for network ESL usage can be found in the sub-directory ASSIDRV beneath the PVElite program directory. The documentation files in this sub-directory contain instructions for a variety of networks and operating systems. Note that there are periodic updates to these ESL drivers and they can be downloaded from the COADE website.

Novell File Server ESL Installation If the network ESL is to be located on a Novell file server, the driver HASPSERV.NLM is needed. This driver should be copied onto the file server, into the top level SYSTEM directory. Then, the system start-up file (AUTOEXEC.NCF) should be modified to include the command: LOAD HASPSERV

This modification can be accomplished with SYSCON (or equivalent) assuming supervisor rights.

Novell Workstation ESL Installation If the network ESL is to be located on a workstation, the driver HASPSERV.EXE is needed. This driver should be copied onto the workstation. The actual location (directory) on the workstation is not important, as long as the program can be located for start-up. Place the command: HASPSERV

in the AUTOEXEC.BAT file of the workstation, after the commands which load the network drivers. The workstation does not need to be logged in. Note however, the workstation must always be up and running for users to access the software.

Windows Server Installation For Windows Server installation, please refer to the documentation files NETHASP.TXT and ESL_RED.TXT found in the ASSIDRV subdirectory for network specific instructions.


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Notes on Network ESLs There are advantages and disadvantages in utilizing a network ESL. The prime advantage is that many users (up to the number of licenses) have access (from a variety of computers) to the software on a single server. The prime disadvantage is that users cannot transfer the ESL between machines in order to take PVElite home or to another remote location. Since both a network and several local ESLs may be initialized on the same system (there is no network-specific version of the software), it is suggested that only 70 to 80 percent of the desired licenses be assigned to a network ESL. The remaining 20 to 30 percent of the licenses should be assigned to local ESLs. This enables the local ESLs to be moved between computers, to run the software at remote locations. Alternatively, if all of the licenses are on the ESL, a user must then be logged into the network to access the software. A few local ESLs provide much greater operating flexibility. Note: The number of licenses assigned to a network ESL is not a parameter that can be modified remotely by COADE software. Local users running the software from a network drive should run the file "Netuser.bat" one time to update all locations.


CH AP TER

3

Chapter 3 Tutorial/Master Menu In This Chapter Program Structure and Control ................................................... 3-2 A Road Map for PVELITE......................................................... 3-3 The Input Processor .................................................................... 3-4 Other Input Processors................................................................ 3-7 Error Checking............................................................................ 3-10 Analysis ...................................................................................... 3-11 Tools Menu................................................................................. 3-12 Output Review and Report Generation....................................... 3-13 Design and Analysis of Vessel Details ....................................... 3-15 Input Menu ................................................................................. 3-18 Main Menu ................................................................................. 3-21 File Menu.................................................................................... 3-22 Analyze Menu............................................................................. 3-25 Output Menu............................................................................... 3-26 Tools Menu................................................................................. 3-27 Diagnostics Menu ....................................................................... 3-36 View Menu ................................................................................. 3-37 Inspecting the Model in 3D ........................................................ 3-40 ESL Menu................................................................................... 3-42 Help Menu .................................................................................. 3-43 PVElite Quick Start .................................................................... 3-44 Adding Details ............................................................................ 3-46 Recording the Model - Plotting the Vessel Image ...................... 3-47 Specifying Global Data - Loads and Design Constraints............ 3-49 Performing the Analysis ............................................................. 3-53 Reviewing the Results ................................................................ 3-54 Analyzing Individual Vessel Components Details ..................... 3-55 DXF File Generation Option ...................................................... 3-58 Setting Up the Required Parameters ........................................... 3-59 DXF File Generated by PVElite During Runtime ...................... 3-61


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Program Structure and Control A typical PVElite hard disk configuration is structured as follows: PVELITE:

Root Installation PVElite directory

Project #1:

Data files for Project #1

Project #2:

Data files for Project #2

\SYSTEM:

Program database & control files

\EXAMPLES:

Sample input files

Most files in the data subdirectories are identified by a user-defined filename with a given extension. The remaining files hold data controlling the program's operation. These files and their description follow: jobname.PVI

PVElite input file

jobname.TAB

Temporary results file

jobname.T80

Results file used by the output review processor

jobname.CCI

Input file for component analysis

units.FIL

User units file (relating user's units and program units)

*.BIN

PVElite Material Database

UMAT1.BIN

Binary file holding the user-defined materials


Chapter 3 Tutorial/Master Menu

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A Road Map for PVELITE There are many PVElite functions that are not addressed here. This section focuses on the structure and control of the fundamental units of the program - input, analysis and output. By understanding these basic concepts, a firm foundation for understanding PVElite is assured. Input, analysis, output; it is as simple as that. Input - collect information required to define the vessel, its service requirements and its design guidelines. Analysis - translate the input into appropriate data for the design and analysis algorithms, correctly apply the rules of appropriate Code or Standard and generate results. Output - present those results with explanation in a way that the final report is comprehensive and meaningful.


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The Input Processor Input is broken down into basic elements—heads, shells, cones, etc. A quick look at the default PVElite input screen (below) shows the data defining one element. Except for the From Node and To Node, the data is common to all vessel wall thickness calculations. The From and To Nodes are necessary to assemble the individual elements into the complete vessel and are automatically assigned by PVElite. A complete vessel is required if all dead and live loads are to be included in the design or analysis however, PVElite will run wall thickness calculations on elements without constructing the entire vessel.

PVElite Completed Input Screen

The Input screen has a Main Menu across the top, which controls navigation through the processor. These items — File, Input, Analyze, Output, Tools, etc. — may be accessed directly from this menu at any point in the processor. In a row directly below the Main Menu is a series of toolbars and buttons specific to the current screen. In the screen above, the buttons manipulate the elements (Insert, Delete, Update), specify unique data (Material, Share), or change the view or input method (Zoom, Layout view). The three toolbars control the data file, add elements and add details to the current element. These toolbars and buttons may be relocated on the screen.



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The body of the screen contains either two or three areas - a table of the Element Basic Data, a table of the Element Additional Data (when required) and the graphic area which contains an image of the current status of the entire vessel or the current element. A status bar displays across the bottom of the screen and displays the element count, the position and orientation of the current element, quick internal pressure calculations for the current element. How are the menu selections made? How are the buttons pushed? How is the data entered? Most operations are obvious when using a mouse; point to the item and click the left mouse button to open drop down menus from the menu line, activate the button commands, pick a tool or move control to one of the screen areas. All buttons and toolbars have tool tips, which are activated when the mouse rests on the button. When users click in the data area(s), the Tab key moves the highlight (and control) through its input cells. In most element data areas, Enter registers the data and will move the focus to the next field. The exception is at combo boxes where clicking the arrow displays the available choices. An example of a combo box is found on the Input screen shown on the previous page where the element is chosen from a list of available types. Throughout the program, [F1] displays help for the highlighted data item. Once familiar with these screen controls, a combination of mouse and keystroke commands will provide the most efficient navigation through the program. Some of the data input in PVElite is controlled through a data grid. To enter the data click the mouse on the data text, such as Inside Diameter, and type the input value. The cursor will not blink over the numeric/alphanumeric values until typing has begun. After the data is entered, press the Enter or Tab to proceed. Arrow keys can also be used to navigate between the input fields. Note: The right mouse button is used to select vessel details on the vessel graphic. Combo boxes have the down arrow button at the right end of the input cell.

Input Screen Layout


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When the graphics area of the Input screen is active, a few more keys are available. No special highlight will appear but the string PgUp/PgDn/Home/End will display at the bottom graphics area. This indicates that these keys are now active. The image in the graphics area shows the current state of the input for the vessel model with its elements and the details on these elements. One element is highlighted. This is the current element and the element data (Element Basic Data and Element Additional Data) shown on the screen defines this element. By pressing PgUp or PgDn, the highlight changes from one element to the next through the vessel. Press the Home and End keys to move the highlight to the first and last elements in the vessel. Clicking the left mouse button while selecting the element will also highlight it. Once an element is highlighted detail information for that element may be accessed. With the mouse, click the right mouse button for the existing detail image to display. To add details to the current element, click the appropriate detail on the toolbar and enter the necessary data.

Detail Pop-up Screen

Once the control of this screen is understood, all the remaining input processors will present no difficulties as they all have the same control structure with mouse and keyboard commands.



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Other Input Processors The other menu items listed under Input indicate the other types of data that may be necessary for an analysis.

Input Menu

Other than the Vessel Data there are four other categories of vessel input, which must be addressed - Component Analysis Data, Report Headings, the Vessel Design or Analysis guidelines, and live (Wind and Seismic) load definitions. These input topics are part of the tabbed input data view. Please note that these tabs can be organized and moved. The Design/Analysis Constraints data is important here as this is where the overall analysis for this vessel is defined and controlled. Finished thickness is a required input for each vessel element but users may allow the program to increase the element thickness so that each element passes the requirements for internal pressure, external pressure, the combined loads of pressure, dead and live loads. Remember that the status bar lists internal pressure information about the current element including the required thickness. A switch is also available to locate stiffener rings on the vessel to satisfy the external pressure requirements. The Component Analysis Data option allows users to enter data and analyze without building a vessel. These are COADE's CodeCalc analysis modules, some of which are not incorporated directly into PVElite. CodeCalc, COADE's popular vessel component analysis package is included in PVElite through the Component Analysis menu option. Users can launch the input data screens by clicking the tab associated with a specific item. Notice the tabs at the bottom of the Design/Analysis Constraints Screen graphic shown below.

Report Headings Screen


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Design/Analysis Constraints Screen



Wind Data Screen

Seismic Data Screen


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Error Checking The input processor makes many data consistency checks during the input session. For example, the processor will create an error message if the user tries to specify a nozzle 20 feet from the bottom of a 10-foot shell element. Not all data can be confirmed on input. For that reason, a general error processor is executed prior to the analysis. This error processor can be run in a stand-alone mode as well. The error checker may be accessed from the Analyze menu. In addition to the notes that are presented on the screen during error checking, these error messages appear in the output report, are accessible through the output review processor. As with all engineering and designing, the vessel analyst must use common sense to insure the model is basically correct. This is a great advantage of the 3D graphics as it reveals obvious errors.



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Analysis PVElite can be used to confirm a safe design for a proposed or existing vessel. The program also provides direct design capabilities with which the wall thickness of individual elements is increased to meet the code requirements for internal and external pressure and longitudinal stress from a variety of dead and live loads. Whether or not the program changes wall thickness during the analysis is controlled through a DESIGN/ANALYSIS CONSTRAINT specification under Design Modification. For more information see DESIGN/ANALYSIS CONSTRAINTS. A simple analysis run (no design) occurs when the flags for Select t for ... are all unchecked. If any of these boxes are checked, the program will automatically increase the wall thickness until the constraint is satisfied. The user's input in the resulting output report is automatically updated to reflect any changes made during the analysis. In addition to wall thickness, a fourth flag can be set - Select Stiffener Rings for External Pressure. In this case, rather than increasing the wall thickness, stiffener rings are located along the vessel to satisfy the external pressure requirements. As with the wall thickness changes, these stiffener rings are added to the model input for this analysis. PVElite will analyze each element to determine the required wall thickness for internal and external pressure based on the Section VIII Division 1 rules, Division 2, PD:5500 or EN-13445 rules. The program then calculates the longitudinal stresses in the wall due to four categories of vessel loads: pressure, deadweight, deadweight moments from vessel attachments or applied loads, and moments due to the live loads - wind and earthquake. These four categories are set for three different load conditions: empty, operating, and hydrotest. The sensible combination of these various categories and conditions produce the default set of 17 load cases that are found in the DESIGN/ANALYSIS CONSTRAINTS processor. For each load case, PVElite will calculate the maximum longitudinal stress around the circumference of the elements and compare these values to the allowable stress for the material, both tensile and compressive. If stresses in the vessel wall exceed the design limits, PVElite will proceed according to the design modification settings in the input. Once the program finishes a pass through the analysis, a check is made for any program design modifications. If PVElite changed any data, then the program automatically re-runs the complete analysis to review the impact of the changes. There are several additional analysis controls that should be reviewed here. These controls, however, are more general in nature and are not defined for the individual job. Instead, these seven computational control directives are set for all jobs executed in the Data sub-directory. These controls are viewed and modified through the Tools menu item on the Main Menu. Here, click Configuration to display the Setup Parameters dialog.


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Tools Menu

Tools Menu

Setup Parameters and DXF Options Screens:



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Output Review and Report Generation Output is stored in a binary file having the same name as the input file but with the extension of ".T80". Once the output file is created, it can be examined through the Review item under the Output option from the Main Menu. Each analysis module creates its own report in the output file. The reports of interest are selected with the mouse and can be sent to the screen, a printer or a file. Most of the reports take the form of tables with the rows related to the elements and the columns holding the values such as thickness, MAWP, and stress.

PVElite Output Review Screen Internal Pressure Report

These are some reports available from PVElite. Depending on the type, position and geometry the list of reports will vary.


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Step 0

Vessel Element Error Checking

Cover

Cover Sheet

Title

Title Page

Step 1

Vessel Input Echo

Step 2

XY Coordinate Calculations

Step 3

Internal Pressure Calculations

Step 4

External Pressure Calculations

Step 5

Weight of Elements & Details

Step 6

ANSI Flange MAWP

Step 7

Natural Frequency Calculations

Step 8

Forces & Moments Applied to Vessel

Step 9

Wind Load Calculation

Step 10

Earthquake Load Calculation

Step 11

Wind and Earthquake Shear, Bending

Step 12

Wind Deflection

Step 13

Longitudinal Stress Constants

Step 14

Longitudinal Allowable Stresses

Step 15

Longitudinal Stresses Due to Load Components

Step 16

Stress Due to Combined Loads

Step 17

Basering Calculations

Step 18

Center of Gravity Calculation

Cone 1-N

Conical Sections

Nozl 1-N

Nozzle Calculations

Step 21

Nozzle Summary

Step 22

Vessel Design Summary



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Design and Analysis of Vessel Details At this point in the analysis the vessel details have been defined only so that their weights could be included in vessel calculations. With the structural analysis of the vessel complete and the wall thickness set, vessel details can be evaluated. To access the Input Processor for these vessel details, use the pull down menu under Input and select COMPONENT ANALYSIS DATA. This will bring up the processor from which the component is selected and defined.

Component Selection Screen from the Component Pull-down Menu


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WRC 107 Input Screen



WRC 107 Results


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Input Menu

Input Menu

The Input menu controls the general input processes. The following options are available:

Input File Menu Options

Description

Vessel Data, Report Headings, Data items located on the tabbed dialog pallette as shown Design/Analysis Constraints, Load below. Click the desired tab to view of change the input for Cases, Wind Loads, and Seismic that set of data items. Loads Component Analysis Data

Includes those (CodeCalc) processors, which are not integrated into the main vessel analysis. These processors are described in Chapters 9 thorough 28.

Report Headings

Allows users to input and edit a three line heading, which will be placed in the first three lines of each report page. It will also print on the title page of the report. A 60-line heading can also be entered.

Design/Analysis Constraints

Allows users to input and edit the global data, which includes the general vessel description, design control data and the structural load analyses to be performed. This is where ASME Section VIII Division 1, Division 2, PD:5500 or EN-13445 is specified as the design code. If the user does not select this option, the program will set the default data. Note that the vessel design code can be changed from the Design Code pull down on the Units/Code toolbar.

Display the List Dialog

Displays the detail data in Excel grid style format.



Design/Analysis Constraints Dialog


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Tutorial/Master Menu Live Load Data—This option switches to the wind or seismic data edit mode where the wind loads and seismic loads are defined through the specification of the appropriate load parameters.

Live Load Wind Data Dialog



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Main Menu PVElite starts with the Vessel Data Input screen. Across the top of this screen is a line of items called the Main Menu. The Main Menu controls the major functions of the program. This chapter reviews the functions available in each of these menu items.


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File Menu

File Menu

File options control the general operations of PVElite files. Options that are displayed in the menu with an ellipsis (…) cause a file manage window to appear when selected. The following options are available from the Main Menu item - File:



New - There is a choice for selecting the design code. When one is selected this will start a new file.

File New...

File Open Dialog


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Save—Causes the current file to be saved in its present condition.

Save As Dialog

Option

Description

Save As

Allows the user to either save a file that has not been named or to save the current file under another name.

Print

Sends the current vessel graphic image directly to a printer.

Print Preview

Displays the page that will be sent to the printer (see above)

Print Setup

Displays the standard Windows printer setup screen.

Exit

Exits PVElite. A message window will display prompting to save any changes to the current job.

Export Menu Option

Description

Graphics to PCX

Stores the vessel image in a standard PCX format file. This file can be printed at a later date or added to other documents. The name of the PCX file defaults to the name of the current job with the extension of PCX.

Screen to PCX

Builds a PCX file for later manipulation and printing. In this case, the entire contents of the screen are saved in the file.

The File Menu will also list the last several vessel input files. Any of these files may be opened with a mouse click.



Analyze Menu

Analyze Menu

The Analyze menu has the following options:

Menu Option

Description

Analyze

This option saves the input data and begins error checking. If no errors are detected, the program will continue the analysis process. A description of the PVElite analysis is found in Chapter 7 of this user guide. The output from the analysis processor, whether error messages or results, may be examined in the Output Processor. Once an analysis is completed, the program will automatically switch to the Output Review processor.

Error Check Only

This option will only process the error checking, and will not implement the analysis process. The error report may be examined in the Review option found in the Output item from this Main Menu.


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Output Menu

Output Menu

The Output menu enables users to review the analysis results and print the graphics of the vessel using the following options:

Field Name

Description

Review

Reviews the analysis results of the current job, if these results are already available.

Review the DXF file

Launches any program capable of viewing this file type on the computer system.

Review the Access Database If a database has been created, it can be reviewed directly using Microsoft Access.



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Tools Menu

Tools Menu

The Tools menu controls utility processors. Options that display on the menu with '...' cause a window to appear when selected. Configuration allows the user to define a variety of system variables for the program:


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Configuration Dialog

These controls let you set some options in some programs that control the results of some computations. Following is a description of the options:

Print Water Volume in Gallons? Normally the volumes computed by the program are in diameter units. If you want to use US gallons instead of cubic diameter units check this directive. The program will use cubic units if the default value if it is not checked.

Round Thickness to Nearest Nominal Size? If you would like to have your thicknesses rounded to the nearest 1/16 of an inch (if you are in English units) or the nearest 1mm if you are in MM units, then check this directive.



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The program will increase the thickness of an element if you specify for it to do so in the Design/Analysis Constraints, and the element thickness is inadequate. If this directive is not checked then no thickness rounding will be performed.

Print Equations and Substitutions? By default PVElite will provide you with formulas and substitutions for internal and external pressure calculations. If you do not want these formulas and substitutions, do not check this box.

Increase Blind Flange Thickness for Reinforcement? For Section VIII Division 1, paragraph UG-39(d)(2) provides a consideration for bypassing reinforcement of a single opening of a flat end connection. This effectively increases the required thickness of the blind flange cover. Please note that this can only be used if there is only 1 nozzle located in the blind flange.

Use OD as the Basis for the Shell Radius in Zick? By default PVElite uses the ID basis on which to perform Zick analysis calculations. In general, this is more conservative than using the OD. However if you wish to use the OD as the basis, then check this box. Checking this box will change the "r" value used in the stress calculation equations.

Do Not Use the Bolt Correction Factor. For the design of heat exchanger flanges and tubesheets, TEMA (like Taylor-Forge) provide a correction factor when the actual bolt spacing exceeds the allowable bolt spacing. The correction factor is then multiplied by the moment to design a thicker flange. The use of this term is very standard in industry and is used in other pressure vessel design Codes such as PD:5500 however, ASME Section VIII does not specifically address this subject. Thus, for a pure flange design per Appendix 2, there is no bolt-spacing correction factor. If you do not wish to use the factor, then check this box. The default is to use the bolt space correction factor.

Use ASME Code Case 2260/2261. Use of this code case calculates required thickness of elliptical and torispherical heads. The required thickness is less than that of the equations in UG-32 or Appendix 1 for these heads.

Use EigenSolver The natural frequency of a structure can be calculated using more than 1 method. The traditional method is the analysis technique of Freese or Rayleigh-Ritz. For the skirt-supported freestanding structure, this method provides acceptable results. When the support configuration is not the skirt/base type such as legs, lugs, or intermediate skirt, this analysis may not provide accurate results. To solve this problem generically, PVElite has a natural frequency solver that uses numerical methods to solve the general equations motion. Namely, the program must solve the following: [ [K] - w 2[M]] {a}={0}. Which for the


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general case is a set of n homogeneous (right hand side equal to zero, in this case abs[ [K] - w 2[M]] {a}=0. This requires an iterative solution. After building a stiffness [K] and mass [M] matrix of the model with appropriate boundary conditions (anchors at skirts, bottom of legs, at support lugs etc.) the program can extract a number of modes that is meaningful in the solution of the dynamics problem, particularly the modal response spectrum analysis. Using this generic frequency Eigensolution method, PVElite can accurately extract modes of vibration for models that do not fit neatly into the cantilever beam model required for the Freese integration codes. The natural frequency of the vessel is used in several of the wind and seismic method. For PVElite files earlier than 4.3, the default is to use the Freese method. The default version for 4.3 and later is to use the EigenSolver. Enable or disable this box as necessary.

Use Pre-99 Addenda Division 1 only. As of January 2000, the 1999 addenda of the ASME Code are mandatory. This mandatory revision includes changes to the material properties of many materials used for Division 1 vessel construction found in Section 2 Part D. Namely; the allowable stresses were increased in certain ranges. PVElite contains 2 databases of material properties. The default behavior is to use the current higher allowable stress database. If you are re-rating an older vessel to the pre 99 addenda and would like to use the older material allowables, then you should check this box. Since the program uses this directive to connect to the database, it should be checked before any vessel modeling occurs. This directive will not affect other design codes.

No MDMT / No MAWP Calculations To disable the MAWP or MDMT check the corresponding check box as required.

Use Bolt Load Instead of Bolt Area Times Bolt Allowable Stress This option may be used in the design of annular baserings. Choosing this option will instruct PVElite to use the computed value of the bolt load instead of the bolt area times its allowable stress. Checking this box will lead to a less conservative basering/bolting/chair cap thickness calculation.

Syntax Highlighting in Output Reports By default PVElite will color the data reports to highlight failures and illustrate problem areas more clearly. If this action is not desired, un-check this box.

No Extended ASCII Characters in Output Some equations that PVElite prints use extended ASCII characters such as the single character ½ and others. For some non-English versions of Windows these characters may not be displayed correctly. If that is the case, then uncheck this box. The extended characters will be replaced multiple characters that represent the same value.

Metric Output is in Consistent Units Entering data in Metric and in English units causes it to be inconsistent. For example units of stress may be displayed in MPa and pressure in Bar. For coherent output these units should be the same. Enabling this box allows PVElite to change the units so that they are consistent.



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Use Code Case 2286 This ASME Code Case uses a different methodology for determining allowable external pressure and allowable compressive stress for combinations of external pressure, bending and axial stress. Users of this option should be very familiar with this Code Case before using it. Note that this option is not compatible with the ASME STS Steel Stack design option.

No Corrosion on Inside Welds By default PVElite will always corrode the inner fillet weld when computing the area available in the inside weld. If the inside weld will not corrode or you do not wish to remove the corrosion allowance when computing the area, and then check this box. The default method is the most conservative because the area under the weld is corroded in accordance with figure UG-37 of the ASME Code. This directive has no effect when using the PD:5500 or EN Codes.

Use AD-540.2 Sketch B and Not Sketch D For Normal? This setup parameter is used for computation of the vertical thickness limit. The formulas for computing these limits are found in paragraph AD-540.2 of the ASME Code Section VIII Division 2. Sketch (b) of Fig. AD-540.1 shows an integral connection with a smooth radius. Figure (d) shows a similar geometry with an alternative pad plate and fillet. By default PVElite uses sketch (d) to compute the vertical thickness limit. However, if you would like to use sketch (b) then check this directive.

Compute Increased Nozzle Thickness? In many cases pressure vessels are designed and built long before the piping system is attached to them. This means that the nozzle loadings are unknown. If this field is checked, then your minimum nozzle thickness (trn) will be the maximum of: trn = max (.134, trn for internal pressure ) <=Nps 18 trn = max (OD/150, trn for internal pressure) > Nps 18 By using such a requirement in addition to UG-45, the piping designers will have some additional metal to work with to satisfy thermal bending stresses in systems these vessels are designed for. Note carefully, that these formulae are not in the ASME Code. They are used in industry. You can also specify the minimum wall thickness of the nozzle (Trn) in the Nozzle input. If you do so, that will override this calculation.

Compute and Print Areas for Small Nozzles? The Code paragraph UG-36 discusses the requirement of performing area replacement calculations when small nozzles are involved. The Code states:


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Openings in vessels not subject to rapid fluctuations in pressure do not require reinforcement other than that inherent in the construction under the following conditions: 3.5" finished opening in a shell or head .375 inches thick or less 2.375" finished opening in a shell or head greater than .375 inches If your geometry meets this criteria and this parameter is not checked, then the nozzle reinforcement areas and MAWPs will not be computed.

Compute Chord Length in Hillside Direction By default PVElite will use the actual length of removed material for hillside nozzle calculations. If you wish to use the chord length to compute the included angle, check this box. Generally, the difference is very minor.

Compute Areas per PD 5500:2003 3.5.4.9 If you wish to perform the pressure times area calculations per 3.5.4.9 then check this box. Please note that the standard calculations per the design section 3 will always be computed.

Allowable Tower Deflection This setup directive applies to vertical tower geometries. By default PVElite uses a criteria of 6 inches per 100 feet for the allowable tower deflection. If your design specification requires a different value of allowable deflection then enter it here.

Wind Shape Factor Based on the wind design specification, PVElite will compute the wind shape factor. If your design requirement calls for a specific value for the shape factor that does not correspond to the calculated value, then enter that number here. For cylindrical structures it is typically 0.7.



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Create / Review Units

Create/Review Units Dialog

Edit / Add Materials Enables users to create and edit a user-defined material in the PVElite material database. Clicking this menu option displays the dialog below:


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Edit/Add Materials Dialog

To use the processor, click the areas. Click the

button. Next enter the material properties under the General and the Stresses

button to add another material if desired. When all of the materials have been entered, click

the button to add these materials to the end of the materials supplied in the PVElite material database. The material list from the main database can also be imported into this processor. A material from this list can be imported into the user material database. Use the

button on the toolbar to accomplish this task.

In addition to adding materials to the ASME Databases, it is also possible to add materials to the PD 5500 / EN 13445 database. When the option to edit this database is selected, the following screen appears:



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To use this processor, click the button. Next enter the Material Name, Yield Strength and other fields. Next fill in the table of stress versus temperature. This processor creates a user material database that is stored in the PVElite\System subdirectory. Once the database has been saved after the initial use, those materials will be available for editing.

Calculator Launches the Windows calculator and optionally pastes the results in the input at the cursor location.

Windows Calculator - Scientific View


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Diagnostics Menu

Diagnostics Menu

Field Name

Description

CRC Check

This option performs a cyclic redundancy check on each of the supplied PVElite files.

Build Version Check

This option checks the revision level of the PVElite executable files.



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View Menu

View Menu

The View menu allows users to specify the toolbars to be displayed. The following options are available: Standard Bar—Allows the user to open, save and print. Additionally, users can access PVElite version and contact information. The contains

Standard Bar

Element Bar—Allows users to create a vessel with the default data by clicking an icon on the Element Toolbar. The following options are available:

Element Bar

Detail Bar—Allows users to add certain details i.e., stiffeners, nozzles, forces, moments, lining, half-pipe jackets and tubesheets etc. to the current element when applicable. The following options are available:


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Detail Bar

Utility Bar—Enables users to insert, delete, update, share and flip elements.

Utility Bar

Auxiliary Bar—Allows manipulation of the model, create drawings and databases and others.

Auxiliary Bar

Pipe Properties - Enables users to access the database of pipe dimensions. After clicking OK, the current diameter and thickness will be replaced with the current selection. List Dialog - Obtain a list of the vessel's details. Items can be added or removed from the list.

List Dialog



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The List dialog allows the editing of some types of vessel details. One feature of the list is that the location of the detail can be specified from the datum position. To use the list dialog, select the type of detail to edit by pressing its tab. Then simply enter the data as necessary for each cell. If the list is empty, then press the plus button (+) to add a row. The entry of the "From Node" is optional. The program will assign that value automatically. The description is a required mandatory input. If it is not entered, the program will treat that row as if it did not exist and that data will be lost. All of the other data must be entered as required. Rows of data can be duplicated from one row to the next. Click on the listing number of the item to copy. That row should turn black (selected). Next copy the data to the clipboard by pressing [Ctrl-C]. Next paste it to a blank line by using [Ctrl-V]. Next change any data that might be different for that detail. Status Bar - Displays a variety of critical information about the current vessel component such as MAWP and required thickness.

Status Bar

Split - Allows the user to split the screen for simultaneous viewing of the 2D and 3D graphics as well as the information for the current element.

Analyze Bar - Allows the user to analyze the current model, review previous results, error-check the model, or review the previously created DXF file.

Analyze Bar


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Inspecting the Model in 3D Enable or disable 3D viewing by clicking on the PVElite Auxiliary toolbar. A vessel model will display ready for viewing after the button is clicked. The 3D model displays next to the 2D model. The 3D viewer is an integrated application that can render any PVElite input file showing the actual vessel geometry in 3 dimensions. In addition to showing the outer surfaces, the model can also be viewed in wire frame and hidden line mode. Different shading modes such as flat shaded, Gourard and Phong are all supported. Other operations such as panning, zooming and model rotation are also supported. You can also double click on various details to display that detail's dialog box. Pressing the right mouse button anywhere on the 3D View window will display a floating menu through which a variety of commands can be executed. These same commands are also active from the 3D Menu option when the 3D View window has the focus. The toolbar for performing some basic operations should appear in a vertical position on the right side of the applications frame. Listed below is an explanation of the buttons on the toolbar. By default, this toolbar displays vertically on the right side of the 3D graphics window.

3D View Icons

Option

Description

Predefined Views

Changes the current view to front, back, top, bottom, left, or right view.

Zoom Extents

Resizes the model so that it fits in the current window.

Zoom Window

Allows users to use the mouse to draw a window around the portion of the model that you want to zoom in on. This is a rubber band zoom. Alternately, spin the mouse wheel to zoom in and out.

Orbit

Allows users to rotate the model using the mouse. Click the right mouse button and move the mouse to rotate the model.

Pan

Allows users to translate the model in the direction the mouse is dragged. Pressing the mouse wheel and holding it down while moving the mouse will also pan the model.

Zoom Camera

Enables users to zoom in or out. Click this button then press the left mouse button and move the mouse diagonally across the screen to zoom in or out. Alternately, spin the mouse wheel to zoom in and out.

Select by Click

Allows the selection of a detail for further manipulation. This is the cursor icon.



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Option

Description

Insert Cutting Plane

Enables users to insert a cutting plane when you click this button and then click anywhere in the window. Users can then rotate the cutting plane after it has been initiated. The rotating plane will then expose the various layers of the vessel. The visibility of the cutting plane can then be turned off once the view is set. To restore the model, right click in the 3D window and choose the Delete Cutting Plane option.

Options

Many operations are supported using the Options menu. After being set, the program will recall them in subsequent sessions. This option is also available by right clicking on the model window and selecting properties. The Options dialog displays below.

3D Options

While in 3D view a detail's dialog can be requested by double clicking on it. It may be necessary to click the cursor icon beforehand.


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ESL Menu The ESL Menu provides access to utilities, which interact with the External Software Lock.

ESL Menu

The options are as follows:

ESL Menu Option

Description

Show Data

Displays the data stored on the ESL.

Phone Update

Allows the user to obtain phone update authorization information or other ESL changes, to be made over the phone.

Generate Access Codes

Generates access codes for remote ESL updating. These access codes should be sent to COADE for generation of authorization codes.

Enter Fax Authorization Codes

Allows users to choose this option to enter the remote authorization codes you received from COADE. Each set of four codes will make one change to the data stored on your ESL.

Check Hasp Driver Status

Installs the software needed check for the standalone ESL

Install Hasp Device Driver

Installs the HASP device driver



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Help Menu

Help Menu

The Help menu displays on-line help and information on how to obtain technical support for PVElite. The options available are as follows: Tip of the Day

Provides tips for running PVElite.

PVElite Help Topics

Starts the help facility.

On-Line Documentation

View this manual online.

PVElite Quick Start

A quick start guide for new users.

Foundation 3D Help

Review the foundation 3D interface specification.

Check for Updates

This option will check COADE's web site for a later build of the current version. You must have live Internet connection for this to work.

On-Line Registration

Register this product electronically with COADE.

About PVElite

Provides information on the best ways to contact COADE personnel for technical support, and provides a link to COADE's Web Site.


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PVElite Quick Start Entering PVElite Before starting PVElite, most users will collect the necessary data for the vessel design or analysis. PVElite breaks the vessel into an assemblage of individual elements—heads, shells, cones, body flanges, and/or a skirt—and the components on these elements. Vessels are defined one element to the next - from bottom to top for vertical vessels and from left to right for horizontal vessels. Collecting data to define these elements before starting the program is not required but it will make the most efficient use of the designer's time. Typical input items include actual or proposed values for vessel material, inside diameter, operating temperatures and pressures, wind and seismic site data, nozzle and ring location to name a few. If necessary, the input processor can be terminated at any time and restarted later if any missing data need be collected. With the program's graphic display of the vessel input, it is easy to recall the current state of an unfinished model or identify where data is missing or incomplete. Start PVElite by clicking on the icon on the desktop or selecting the item from Programs. PVElite will start with a Vessel Input Screen for the job currently called "Untitled."



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Defining the Basic Vessel PVElite displays the Element Basic Data, empty graphic areas, three toolbars (File Handling, Elements, and Details) and a button bar. Disabled items cannot be used. Users should build vertical vessels from bottom to top and horizontal vessels from left to right. It is not necessary to build an entire vessel if only thickness for pressure is desired. The Element Basic Data must be specified before the first element can be placed on the screen. Start with the Inside Diameter, as both the Node Numbers and the Element Type will be set by using the element tool bar. Once the Basic Data is entered, elements are quickly assembled one after another by clicking the Element toolbar and making any changes to the Basic Data. The complete vessel is created from the following elements (in their toolbar order): Shell Elliptical Head Torispherical Head Spherical Head Cone Welded Flat Head Body Flange Skirt If the vessel begins with a skirt element it will be a vertical vessel. Both vertical vessels on legs and horizontal vessels would start with a head element. If that first head element is improperly oriented for the vessel in mind (horizontal or vertical), simple click the FLIP button to correct the orientation. Once the second element is added, the vessel can no longer be flipped between horizontal and vertical. Later, if heads, body flanges or cone elements show incorrect orientation, use the FLIP button to fix them. From Nodes and To Nodes are automatically assigned by the program; they start with node 10 and are incremented by 10's throughout the model. The element data set at the beginning of the session carries forward from one element to the next. Any data changes on the last element will carry forward onto any new elements to be added. The element data displayed belongs to the highlighted element in the vessel image. Use the mouse to change the highlighted and displayed element by clicking on the element of interest. The Page Up and Page Down keys can also be used to scroll through the vessel elements. Data may be updated one element at a time but there are more efficient ways to change an item through several elements. Say, for example, the circumferential weld joint efficiency for the skirt (from node 10 to 20) is set at 0.7. If this value was not changed to 1.0 on the bottom head as it was created, this (incorrect) value is carried from one element to the next in the Build Mode to the top of the vessel element (say, From Node 50 To Node 60). In this situation, it is easiest to change the data on the bottom head element (20 to 30) and then use the SHARE button to "share" this item through the elements in the list with "From Node" 30 through "From Node" 50. Certain data is automatically "shared". Inside diameter, for example is automatically changed for all elements (stopping at cones) attached to the element where the change occurs. Some changes to the element data do not immediately appear on the vessel image. To refresh the image press [F5]. There is a detailed Quick Start guide available on the Help menu.


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Adding Details With the elements defined, enough information exists to run through the pressure calculations but the total vessel weight is not yet set. Much of this information is specified as element details. Nozzles, insulation, operating fluid, platforms and the like are all entered as details on the various elements. PVElite will calculate the weight of each of these items and account for them in the various analyses. Details such as saddles, lugs and legs are also used to locate support points on the vessel—important data for load calculations. Details can only be specified on the current element. To enter the first detail, highlight (make current) the element, which will hold the detail and click the appropriate DETAIL button. Allowing the cursor to rest on the toolbar button will produce a fly out definition of the button. Select the detail and enter the data in the screen that follows. Use the Help button on the detail screen or press [F1] to learn more about the requested data. Define all details necessary to develop the proper total vessel load.



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Recording the Model - Plotting the Vessel Image At any point during the input process a standard PCX file with the vessel image is available through the Output item on the Menu Bar. This file can then be incorporated into reports or printed directly (on all printers) through most Microsoft Windows™ packages with graphics capabilities (such as Microsoft's Word for Windows™ or Paintbrush™). Examples of the graphic dump and screen dump appear below following the illustration of the pulldown menu under File.

The vessel graphic may also be sent directly to the printer by clicking Print on the File menu.


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Graphics to PCX



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Specifying Global Data - Loads and Design Constraints Although default values allow the analysis to proceed, other data should be set before the analysis continues. These data are the required live loads & design constraints and the optional vessel identification and report headings. These data are accessed and entered through the Input item on the Menu Bar. The pull down menu under Input shows the Report Headings, Design/Analysis Constraints, and Live Load Data along with the vessel and component analysis data. The heading input allows the specification of three lines of data, which will appear at the top of each page in the printed output. The heading data also includes title page entry, which will appear at the beginning of the input echo report. Clicking the Design Constraints tab on the floating input data grid will instantiate the design data. Design Data includes vessel identification along with items, which will affect the design and analysis of the vessel; items such as type of hydrostatic testing and degree of radiographic examination appear here. It is important to note that this is where the design code is set - Division 1, Division 2, PD:5500 or EN 13445. The Design Modification area holds four flags, which control the redesign of the vessel should the user-entered wall thickness be insufficient for the analyzed loads. If a box is checked, the program will increase the element's wall thickness so that it meets or exceeds the requirements for that load category. There are four boxes for three load types - one box for internal pressure, two boxes for external pressure (either increase the wall thickness or locate stiffener rings along the vessel to satisfy the buckling requirements), and one box for the variety of structural loads which develop longitudinal stresses in the vessel wall. The program provides the option of rounding up a required thickness to a nominal value (such as the next 1/16 inch or 1 mm). (Use the Configuration item from the Utility menu on the Menu Bar. The Load Case tab displays seventeen default structural load cases for the analysis. These twelve cases cover the extent of structural loads on the vessel wall. Each case contains a pressure component (axial) 1, a weight component (both axial and bending), and a live load component (bending). The axial stresses are combined with the bending stresses to produce a total stress in the vessel wall. Both tensile and compressive stresses are compared to their allowable limits. Refer to the table and screen image below for a definition of terms used in the Load Case input. Note: These pressure calculations should not be confused with those used for the wall thickness requirements defined in ASME Section VIII and PD:5500. Here, internal and hydrostatic pressures are used to calculate a longitudinal, tensile stress in the vessel wall and the external pressure a similar compressive stress in the wall. The fourth area, Nozzle Design Modification, is used to set the overall pressure requirements for the nozzles on this vessel and also to include the maximum allowable pressure - new and cold (MAP nc) case in the nozzle checks. There is also a button on this screen - Install Option. Clicking this button will produce a screen which allows the user to specify where certain vessel details will be added - either at the fabrication shop or in the field. This data is used to properly set the detail weights for the empty and operating conditions.


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Pressure

Weight

Live Load

NP - No Pressure

EW - Empty Weight

WI - Wind

IP - Internal Pressure

OW - Operating Weight

EQ - Earthquake

EP - External Pressure

HW - Hydrostatic Weight

HI - Wind at Hydrostatic Weight conditions

HP - Hydrostatic Pressure

CW - Empty Weight No CA

HE - Earthquake at Hydrostatic Weight conditions VF - Vortex Shedding Filled VO - Vortex Shedding Operating VE - Vortex Shedding Empty WE - Wind Bending Empty New and Cold WF - Wind Bend Filled New and Cold CW - Axial Weight Stress New and Cold FS - Axial Stress, seismic PW - Axial Stress Wind



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Design Analysis Constraints Screen

Wind and earthquake information can be entered by clicking the Wind Data or Seismic Data tabs. PVElite generates live loads based on the criteria established by one of many standards, including - the American Society of Civil Engineers (ASCE), the Uniform Building Code (UBC), the (Canadian) National Building Code (NBC), and the Indian National Standard. Wind loads may also be specified directly by the user as a wind pressure profile. PVElite references these codes for live loads only. ASME Section VIII or PD 5500 rules apply for all other calculations. The screen below shows the data required for the default codes. PVElite will use these criteria to set the magnitude of the live load and bending moment on each element of the vessel.


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Live Load Data Screen

Once the element, detail, and global data is entered and checked, the model is ready for error processing and analysis.



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Performing the Analysis The pull down menu under Analyze on the Menu Bar shows two options - Error Check Only and Analyze. Use the Error Check Only option immediately after any questionable data is entered. Analyze automatically performs an Error Check before the analysis starts. Comments from an Error Check may be examined through the Review function under Output on the Menu Bar (discussed below). Note: Errors must be corrected before the analysis can proceed. As the analysis proceeds, PVElite displays the step or component being analyzed. If any Design Modifications were set (e.g. Select Wall Thickness for Internal Pressure), PVElite resets the thickness to the necessary value and exports these increased thicknesses to all output reports and in all other calculations. For example, if the user-entered wall thickness of 1/2 inch is insufficient for the load and the design flag is enabled, the program will calculate the required thickness (say, 5/8 inch) and replace the user-entered input value (1/2) in the output report with the calculated required thickness (here, 5/8). The program does not change the original model data. PVElite will check the element wall thicknesses for the various pressure cases (internal, external, and hydrostatic) and then assemble the axial and bending loads to construct each load case defined in the Global Design data. PVElite will also calculate the longitudinal stress on both sides of the vessel (e.g. both windward and leeward for loads with wind) and compare the calculated stresses with the allowable stresses, both tensile and compressive. PVElite will display the windward or leeward side stress, which is closest by ratio to the allowable limit, again either tension or compression. Once the analysis is complete, the Review processor displays the results of the analysis on the screen.


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Reviewing the Results The PVElite output is stored in a binary data file, which requires interpretation by a processor. In PVElite this processor is called Output. Output is invoked at the end of the analysis and may also be accessed directly from the Output item on the Menu Bar. Review lists every report contained in the output from input echo through stress reports. One or more reports are selected by highlighting their titles through mouse clicks. Reports can be reviewed on the screen or sent to a printer or file by using the appropriate toolbar button. Note that the screens are configurable and the default position for the Report List is on the right side of the screen



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Analyzing Individual Vessel Components Details PVElite provides for the analysis of a variety of vessel components that are not included in the overall vessel analysis: Appendix Y Flange, Floating Heads, Lifting Lug, Pipe & Pad, WRC 107 and 297, Thin Joints, Thick Joints, ASME Tubesheets, TEMA Tubesheets, Halfpipe Jackets, Large Openings, and Rectangular Vessels. To enter the component data select Component Analysis Data from the Input Menu. On the Component screen select a component type from the Component Menu and build the input for the analysis. Each component, once entered, may be analyzed and reviewed by selecting Analyze from the Tools Menu.

Component Analysis Menu


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Component Analysis Shell/Head Input Screen



Shell/Head Results


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DXF File Generation Option As of Version 4.00 PVElite provides an option to write out Data Interchange Files (3 all together). This type of file is termed a DXF file. The DXF file is a text file that contains commands for generating a 2D CAD drawing of the vessel. This drawing is on a one to one scale and the border and text are scaled by the diameter conversion constant and the scale factor generated by the program or typed in be the user. Many popular drawing programs such as AutoCad ® and MicroStation ® read and process these files. The DXF files produced by PVElite are release 12 compatible. Any version of AutoCad including release 12 and after should be able to read the DXF file. Three files will be produced: the vessel drawing, the nozzle schedule, and the Bill of Material. The files will be written in the directory where the input file for the vessel file is located. These files are written at the end of the program's calculation execution. Please note that nearly every individual has his/her own way of drafting. A conscious effort was made not to be too specific. This approach allows the drafter to take the vessel drawing file and edit it as necessary.



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Setting Up the Required Parameters In order for PVElite to generate these files, you must instruct it to do so. This is accomplished by clicking the red CAD Icon on the Auxiliary toolbar, its look like a red letter A. Optionally, you can use the menu option FILE>EXPORT->GENERATE DXF FILE to set this option. If the scale factor is not set the DXF Options dialog will appear prompting for the scale factor and any other necessary options. These options should be entered after the vessel has been completely modeled. This is due to the fact that the scaling factor is based on the overall height/length of the vessel. It is best to check the scaling factor at the conclusion of the data input and before the model is analyzed. The DXF Options are available under the TOOLS->CONFIGURATION menu. This is a tabbed dialog. Click the second tab and set the options as necessary. The following options are in the dialog. Create a Default Border—Checking this box instructs the program to put a border around the drawing. The border style differs based on the border size. You can create your own border styles. The borders are located in the PVElite\System subdirectory. They are named ANSI_A.txt and so fourth. These text files are essentially the core of ACAD Release 12 DXF files. See the user border creation instructions below. Create a Nozzle Schedule

Check this to create a Nozzle Schedule. The nozzle schedule contains information pertaining to the size and thickness of nozzles, their mark number and the necessity of reinforcing.

Create a Bill of Material

Causes the program to generate a Bill of Material for the major components of the vessel including shells, heads, conical sections etc.

OD Lines Shown Only

Normally the DXF file will contain ID as well as OD lines for the major shell sections. If you do not want to see the ID lines, then check this box.

Show Dimensions

If you would like tail dimensions for the major shell courses, then check this box. The element diameters and thicknesses are shown in the BOM.

Drawing Size

Select A, B, C or D. Each size has a different style.

Scale Factor

It is best to let the program select this value. We then recommend rounding up to the nearest typical scale factor.

User Border Creation In order to do the following, you must be able to use your Windows Explorer, AutoCad and Notepad. If you cannot, seek help from a seasoned support person. Start AutoCad and open your border. The border should be ANSI standard dimensions 8 ½ by 11 and so fourth scaled for the non-printable area of the paper. After the border drawing is open, save it as a release 12 DXF file. After the file has been saved it will be necessary to edit it with a text editor such as Notepad. Since the main drawing will have a DXF header, it will be necessary to delete the one in the border drawing. The DXF header ends on about line 960 with the word Entities. Delete through this line. Next delete the last 4 lines in the file. This is the end of file marker. Save the file with a txt extension. Next rename the file in the PVElite\system directory that you will be replacing. We suggest putting a new extension on it. Save/Copy your border in the PVElite\system directory and then rename it replacing our default border. You should now have new ANSI_?.txt file in the PVElite\System subdirectory. It may be wise to review our border drawing text files before you start. Also please note that the border drawings must not contain any block attributes. These are not supported in our current implementation. A typical drawing displays on the next page


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DXF File Generated by PVElite During Runtime Invoking the Drawing If you have a drawing tool on your computer that supports DXF files, PVElite can invoke it directly. On the Analyze toolbar, there is a blue "A" button. If the button is active, the DXF file for this job was created during the last run. Clicking the button will submit the file to Windows, which will launch your drawing tool. If the input is altered, the analysis must be run in order to generate a new DXF file.



CH AP TER

4

Chapter 4 Element Data In This Chapter Introduction ................................................................................ 4-2 Element Basic Data..................................................................... 4-3 Element Additional Data ............................................................ 4-8 Torispherical Head...................................................................... 4-10 Spherical Head............................................................................ 4-11 Welded Flat Head ....................................................................... 4-14 Flange Analysis .......................................................................... 4-16 Skirt Support with Basering........................................................ 4-17 Flange Input Data ....................................................................... 4-20 Basering Analysis ....................................................................... 4-21 Tailing Lug Analysis .................................................................. 4-22 Tailing Lug Input Data ............................................................... 4-23


4-2

Element Data

Introduction PVElite has eight basic element types from which all vessels are constructed. PVElite terms for these elements are as follows: Cylindrical

Cylindrical Shell

Elliptical

Elliptical Head

Torispherical

Torispherical Head

Spherical

Spherical Head or Shell

Conical

Conical or Shell Segment

Welded

Welded Flat Head

Flange

Body Flange

Skirt

Skirt Support with Base Ring

PVElite does not require the complete construction of a vessel for the analysis. Individual elements or groups of elements may be defined and at least partially analyzed. Only complete vessels, that is, vessels with proper supports, can be analyzed for deadweight and live loads. Except for the skirt element, all elements can be used to create either horizontal or vertical vessels. Models for vertical vessels are built from bottom to top and models for horizontal vessels are built from left to right. The vessel orientation is established with the first element. If starting with a skirt, it's a vertical vessel. If starting with a head, the head may be "flipped" between a bottom head (vertical model) and a left head (horizontal model) by clicking the FLIP button. Once the second element is added to the model, the orientation is fixed. Skirts are the only vessel supports that are modeled as elements. Other supports such as legs and lugs for vertical vessels and saddles for horizontal vessels are modeled as "details" on the elements. These vessel details are in the next chapter.


Chapter 4 Element Data

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Element Basic Data

All elements share a common set of parameters:

Element's From Node Enter a number associated with the starting point and ending point of this element. For Heads, the From and To Nodes mark the straight flange attachment to the head, not the overall extent of the head. (The straight flange length cannot equal zero.)


4-4

Element Data

Head From and To Nodes

The 'From' node number for this element will also be used to define details such as nozzles, insulation, and packing which are associated with this element. The location of the 'To' node will be calculated by the program by adding the length of this element to the location of the 'From' node. The From and To nodes establish the overall organization of the vessel. When creating a vessel model in the BUILD mode, node numbers are automatically assigned to each element. The BUILD mode starts with node 10 and increments by 10 throughout the vessel. When DELETEing elements, the program will "reconnect" the vessel elements by changing the From node of the following element to the To node of the previous element. When INSERTing elements, PVElite will ask for the new (added) To node number and again "reconnect" the elements so that the From and To nodes match with the previous and next elements in the model. The program defines a vertical vessel from the bottom to the top. If the vertical vessel were on a skirt, the first element would be the skirt. If it is on legs or lugs, the first element would be a head and the legs or lugs are defined as details on the appropriate shell element. The program defines a horizontal vessel from the left end to the right end. The first element in a horizontal vessel is usually a head, and the support saddles are defined as details on the appropriate shell element.

Element's To Node This is the number associated with the starting point of this element, the 'From' node. Note that the program will generate this value automatically.

Element's Diameter Enter the appropriate diameter of the element. The diameter may be specified as either ID or OD. Click Swap Diameter Basis to flip in between ID and OD. For elliptical, torispherical and spherical heads, this should be the diameter of the straight flange. For cones, this is the diameter at the From node end. For flanges, this is the diameter of the body flange. For blind flanges this should always be the OD. For skirts, this is the diameter at the top of the skirt.

Distance or Straight Flange Length Enter the distance between the 'From' Node and 'To' Node.



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For a cylindrical shell, enter the length of the shell from seam to seam. For an elliptical or torispherical head enter the length of the straight flange. The straight flange length cannot equal zero. For a spherical head the distance can be zero. For a conical head or shell segment, enter the length of the cone (including tori-conical sections, if any) from seam to seam. For a welded flat head, enter the thickness of the head. For a body flange, enter the through thickness of the flange including the weld neck, if any. For a skirt support, enter the distance from the bottom of the basering to the skirt/head/shell seam.

Finished Thickness Enter the finished thickness of the element. This is typically the nominal thickness minus any mill undertolerance, and taking into account any thinning due to forming. Note that the corrosion allowance is automatically subtracted from this thickness by the program and should not be subtracted by the user. For elliptical, torispherical and spherical heads, you may have to reduce the nominal thickness of the plate used in order to take into account the thinning of the head due to forming. For cylindrical shells made from pipe, you will have to subtract the maximum possible mill undertolerance from nominal pipe wall thickness. For welded flat heads, enter the through thickness of the flange portion, but do not include the hub and weld neck. For a skirt, this is typically the nominal thickness minus any mill undertolerance, and taking into account any thinning due to forming. For cylindrical skirts made from pipe, you will have to subtract the maximum possible mill undertolerance from the nominal pipe wall thickness.

Corrosion Allowance Enter the corrosion allowance. The analysis program will subtract this value from the entered thickness and add this value to inside diameter.

Wind Load Diameter Multiplier The value entered here will be multiplied by the element outside diameter in order to determine the overall element diameter to be used in wind load calculations. The element outside diameter will include the insulation. When a number greater than 1 is used, it should be carefully chosen to account for the tributary area of external attachments such as nozzles, piping, or ladders. The typical multiplier used to determine wind load diameter is 1.2. Thus if the actual element OD was 50 inches, the overall wind load diameter for this element would be 50 * 1.2 = 60. The range of this value is normally greater than 1 and less than 2. However in some cases it can be used to turn the wind loads off of certain elements. You can disable the wind load on the current element by setting this value to 0. A vessel that is supported by an intermediate skirt whose lower elements are protected from the wind would see no wind load on those elements.

Material Name Enter the material specification as it appears in the material allowable tables. Alternatively, the material can be selected from the Material Database by clicking the [Mat] button from the toolbar. Selecting one of the material


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Element Data

names from the list will display the significant material parameters for the analysis. If the current element temperature is outside the valid temperature range for the material, the material may not be specified or selected. (Likewise, a temperature may not be entered if it exceeds the limits for the material.) Pressing Enter while on this field will display the material properties of the current element or detail. Note that if the material is newly selected, the data displayed here are directly from the program's material database; otherwise the data is from the data structure of the current element or detail. If a newly selected material can not be found in the program's material database, the program will assume that it is a user-defined material, in this case the user must define all material properties in this window.

Joint Efficiency for Longitudinal and Circumferential Seams Enter the efficiency of the welded joint for shell section with welded longitudinal seams. This will be the efficiency of the longitudinal seam in a cylindrical shell or any seam in spherical shell. Elliptical and torispherical heads are typically seamless but may require a stress reduction, which may be entered as a joint efficiency. Refer to Section VIII, Div. 1 Table UW-12 for help in determining this value. The Joint Efficiency in this (and all other) ASME Code formula is a measure of the inspection quality on the weld seam. In general, weld seams that receive full radiography have a joint efficiency of 1.0. Weld seams that receive spot radiography have a joint efficiency of 0.85. Weld seams that receive no radiography have a joint efficiency of 0.7. Seamless components have a joint efficiency of 1.0. In addition to the basic rules described above, the Code requires that no two seams in the same vessel differ in joint efficiency by more than one category of radiography. For example, if circumferential seams receive no radiography (E=0.7) then longitudinal seams have a maximum E of 0.85, even if they receive full radiography. The practical effect of this rule is circumferential seams, which are usually less highly stressed may be spot radiographed (E=0.85) while longitudinal seams are fully radiographed. This results in the same metal thickness at some savings in inspection costs. Except for the skirt, these values should be set to 1.0 for PD:5500 and Division II. For EN-13445 they are defined and should be greater than 0 and less than or equal to 1.

Design Internal Pressure Enter the design internal pressure for the component. This pressure need not include any pressure due to liquid head, as that value is calculated automatically by the program through the liquid Detail definition. For skirts, this value is preset to zero and cannot be modified.

Design Temperature for Internal Pressure Enter the metal design temperature for the internal pressure condition. This value will be used to collect the material allowable stress in the operating condition. PVElite will check the entered value against the valid temperature range for the current element material. The program will not allow the entry of a temperature outside the material's range. This value will be used to determine the material allowable stress.



4-7

Design External Pressure Enter the design pressure for external pressure analysis. This should be a positive value, i.e. 15 psig. If you enter a zero in this field the program will not compute required thickness due to external pressure, but will compute the external MAWP for each of the elements. For skirts, this value is preset to zero and cannot be modified. Examples of external pressure: 0

No external pressure calculation for the element

15 psig

External pressure of one atmosphere (full vacuum)

Design Temperature for External Pressure Enter the design temperature for external pressure. This value will be used as the metal design temperature for external pressure calculations. When performing these calculations, the program will use the external design temperature along with the external chart name (found on the material edit window) to access the material tables and thus determine the allowable external pressure. The maximum design temperature will be used for the allowable compressive stress on each element unless this has been overridden on the Load Case parameters tab.

Swap Diameter Basis Changing this selection will change the diameter basis from the inside diameter basis to the outside diameter basis or vice versa. This function is only active for ASME VIII Division 1. Division 2 formulas are based strictly on ID formulas.


4-8

Element Data

Element Additional Data Several elements require more information for complete definition. Once the element is set, the Element Additional Data window appears below the Element Basic Data.

Cylindrical Shell There is no additional data for cylinders.

Elliptical Head

Elliptical Head Additional Data

Head Factor Enter the aspect ratio for the elliptical head. A value of 2 is typical, that is, the major axis (vessel diameter) is twice the minor axis (two times the head height). For example, a 60-inch diameter elliptical head would extend 15 inches beyond the straight flange.



4-9

Inside Head Depth Enter the inside depth of the elliptical in this field. This value is in the new condition and does not include the corrosion allowance. PVElite will compute the outer depth H and uses this item in the calculation of the parameters needed to compute the required thickness of the ellipse. This depth value is only required for PD:5500.

Sump Head? Check the box to indicate that this element is a sump head. When the pulldown is active the program will list all available nozzles. All of the nozzles on the vessel must be defined before the sump head. The best strategy is to completely define all of the elements and details and then create the sump element last.


4-10

Element Data

Torispherical Head

Torispherical Head Additional Data

Crown Radius Enter the crown radius of the torispherical head. For a standard ASME Flanged and Dished head, this is equal to the outside diameter of the shell. See the ASME Code, Section VIII, Division 1, Appendix 1-4, figure 1-4(b). The crown radius is 'L' in this figure. For PD:5500, this is equal to the outside diameter of crown section of torispherical end measured to tangent between crown and knuckle, as shown in Figure 3.5.2.1.

Knuckle Radius Enter the knuckle radius for the toroidal portion of the torispherical head. For a standard ASME Flanged and Dished head, this is equal to 6 percent of the crown radius. Allowable values range from 6 percent of the crown radius to 100 percent of the crown radius (hemispherical head). See the ASME Code, Section VIII, Division 1, Appendix 1-4, figure 1-4(b). The knuckle radius is r' in this figure.

Sump Head? Check the box to indicate that this element is a sump head. When the pulldown is active the program will list all available nozzles. All of the nozzles on the vessel must be defined before the sump head. The best strategy is to completely define all of the elements and details and then create the sump element last.



4-11

Spherical Head Conical Head or Shell Segment

Conical Additional Data

To Node Diameter The diameter entered in the Element Basic Data for a cone is the inside diameter of the cone at the 'From' end of the cone. Enter the inside diameter of the cone at the 'To' end here. For a conical head, either the 'From' node or 'To' node will have a diameter equal to zero or two times the small end knuckle radius. Note that this should not be the diameter at the point where a knuckle or flare intersects the conical section, but at the point where the knuckle or flare intersects the cylindrical section.

Cone Length Enter the design length of the cone along the axis of the vessel. The program will calculate the effective length of the cone for internal and external pressure calculations. For a regular transition cone, the cone length will be equal to the element length. For the case of a conical head this will be the length of the sloped section while the element distance is the length of the straight flange.


4-12

Element Data

Half Apex Angle Based on the geometry PVElite can determine the half apex angle of the cone. Refer to the ASME Code, Section VIII, Division 1, paragraph UG-33, figure UG-33.1 for a sketch of the half apex angle for some typical geometries. For internal pressure calculations the half apex angle should not be greater than 30 degrees, though the program will give results for up to 60 degrees. For external pressure calculations it must not be greater than 60 degrees. If the conical section and the cylinders attached do not have a common centerline, it may be necessary to compute the greater of the angles and enter it in this field.

Toriconical Check this field if this cone has either a flare (at the small end) or a knuckle (at the large end). See ASME Code, Section VIII, Division 1, Paragraph UG-33, Figure UG-33.1 for an illustration of a toriconical section. By checking the field, the Cone Knuckle Data Edit window will appear.

Toricone Dialog

Additional Data for toriconical sections (Flare and Knuckle) The Toricone dialog lets the user input and edit the data of the knuckles, which are parts of a cone component. The following options are available: DELETE

Resets the input fields to values of 0.

OK

Saves the data then closes the window.

CANCEL

Exits the window without saving the data.

HELP

Displays the button definitions.

Large End Knuckle Radius Enter the bend radius of the toroidal knuckle at the large end. Note that the Code requires this radius to be no less than 6 percent of the outside diameter of the head, nor less than three time the knuckle thickness (ASME Code, Section VIII, Division 1, Paragraph UG-31(h)).



4-13

Large End Knuckle Thickness Enter the minimum thickness after forming the toroidal knuckle at the large end.

Small End Knuckle Radius Enter the bend radius of the toroidal knuckle at the small end. Note that the Code requires this radius to be no less than 6 percent of the outside diameter of the head, nor less than three times the knuckle thickness (ASME Code, Section VIII, Division 1, Paragraph UG-31(h)).

Sump Head? Like ellipsoidal and torispherical heads, spherical heads can also be sump heads. Check the box to indicate that this element is a sump head. When the pull down is active the program will list all available nozzles. All of the nozzles on the vessel must be defined before the sump head. The best strategy is to completely define all of the elements and details and then create the sump element last.


4-14

Element Data

Welded Flat Head

Welded Flat Head Additional Data

Attachment Factor Enter the flat head attachment factor, calculated or selected from the ASME Code, Section VIII, Division 1, or the British Standard PD:5500. For PD:5500, enter the factor C computed per figures 3.5.5(1-2). Typical values are 0.35 or 0.41. For ASME Code, refer to Paragraph UG-34, Figure UG-34. Some typical attachment factors are as follows: 0.17

(b-1)

Head welded to vessel with generous radius

0.20

(b-2)

Head welded to vessel with small radius

0.20

(c)

Lap welded or brazed construction

0.13

(d)

Integral flat circular heads

0.20

(e f g)

Plate welded inside vessel (check 0.33*m)

0.33

(h)

Plate welded to end of shell

0.20

(i)

Plate welded to end of shell (check 0.33*m)

0.30

(j k)

Bolted flat heads (include bending moment)

0.30

(m n o)

Plate held in place by screwed ring

0.25

(p)

Bolted flat head with full face gasket

0.75

(q)

Plate screwed into small diameter vessel

0.33

(r s)

Plate held in place by beveled edge



4-15

Non-Circ. Small Diameter If the flat head is circular, you can leave this field at zero. However, if the flat head is non-circular, the program can still calculate the required thickness, etc., using the formulas in the ASME Code, Section VIII, Division 1, Paragraph UG-34. In this case the program assumes that you entered the larger dimension of the flat head in the Diameter field, and that you will enter the smaller dimension of the head here.

Appendix 14 Large Opening If the selected Code is ASME VIII - 1, you can specify that you have a large centrally located opening per Appendix 14. Check the box and a dialog will appear that will allow the specification of the opening size, material, hub dimensions and other parameters that the program needs to perform the large opening calculation.


4-16

Element Data

Flange Analysis Body Flange

Body Flange Additional Data

PVElite calculates actual and allowable stresses for all types of flanges designed and fabricated to the ASME Code, Section VIII, Division 1. The program uses the Code rules found in Appendix 2 of the ASME Code, latest addenda. Click the Perform Flange Calculation check box to describe the input of a custom body flange or fill in the flange class and grade below. For a discussion of Flange input, design and analysis, refer to The Flange Module (see "FLANGES" on page 13-1).



Skirt Support with Basering

Skirt Support with Base Ring


4-17

4-18

Element Data

Inside Diameter at Base Enter the inside diameter at the bottom of the skirt. This value must be larger than or equal to the inside diameter at the top of the skirt.



Basering Dialog

The Basering dialog allows the input of basering data. Note:

Use the Plot button to get a detailed sketch of the geometry you entered.


4-19

4-20

Element Data

Flange Input Data For a discussion of Flange input, design and analysis, refer to The Flange Module (see "FLANGES" on page 13-1).



4-21

Basering Analysis The PVElite Basering module performs thickness calculations and design for annular plate baserings, top rings, bolting, and gussets found on skirts for vertical vessels. These calculations are performed using industry standard calculation techniques as described in, The Base Ring Module. This chapter also describes the theory and method of analysis as well as the input values.

Brownell and Young Method of Design The Brownell and Young Method computes the required thickness of the baseplate, the gussets and the top plate or top ring (if there is one). Brownell and Young discuss this method in the book, Process Equipment Design. Dennis R. Moss also discusses it in the book, Pressure Vessel Design Manual. This baseplate design method is based on the neutral axis shift method and will in general design a thinner basering than the method discussed in the previous paragraphs.


4-22

Element Data

Tailing Lug Analysis

Tailing Lug Input Data

The tailing lug calculation is included in the basering analysis for a single or dual type design as depicted in the figure on the following page. The design is based on a lift position where no bending occurs on the tailing lug. The main considerations for the design are the section modulus, shear and bearing stress at the pinhole and the weld strength. The location of the center of the pin hole will be assumed radially at the edge of the outer most of the top ring or the basering, which ever is larger. In the absence of the top ring/plate the height of the tailing lug is required. The tailing lug material is assumed to be the same material as the gusset or basering. Note that all input fields pertain to one tail lug. In order for the program to perform this analysis it must be instructed to perform the rigging analysis. To do this select the Input menu option, then select Design/Analysis Constraints and then click the Installation/Misc Options button. Then enter in the lug distances and impact factor. When this is complete, PVElite will compute the tailing lug force.



4-23

Tailing Lug Input Data Perform Tailing Lug Analysis Select this check box to perform the Tailing Lug analysis.

Tail Lug Type Select the type of tailing lug (single or dual) used.

Centerline Offset Enter the offset dimension (OS) for the dual tailing lug design only.

Lug Thickness Enter the thickness of the tailing lug.

Pin Hole Diameter Enter the pin hole diameter. The center of the pin hole will be placed radially in line with the larger of the outer most edge of the top ring or the basering (OD).

Weld Size Thickness Enter the leg weld size.

Lug Height (only if no Top Ring) Enter the tailing lug height measured from the top of basering.


4-24

Element Data

Tailing Lug Geometry

Discussion of Results The tailing lug design consists of a three-part analysis: the basering assembly (basering, skirt and top ring), the strength of the weld the tailing lug itself It is assumed that there is no bending in the tailing lug. In the absence of the top ring only the basering and the decay length (e) are considered for the section modulus calculation. The table below lists the allowable stresses used to check the design strength. Stress Type

Allowable Value

Shear at Pin Hole

0.4 Sy

Bearing Stress

0.75 Sy

Weld Stress

0.49 Sallow


CH AP TER

5

Chapter 5 Vessel Detail Data In This Chapter Introduction ................................................................................ 5-2 Assigning Detail ......................................................................... 5-4 Detail Definition Buttons............................................................ 5-5 Defining the Details .................................................................... 5-7 Rings........................................................................................... 5-8 Nozzle Dialog Data..................................................................... 5-11 Nozzle Analysis .......................................................................... 5-12 Nozzle Input Data ....................................................................... 5-13 Additional Reinforcing Pad Data............................................... 5-27 Lugs ............................................................................................ 5-29 Weights....................................................................................... 5-32 Forces and Moments................................................................... 5-33 Platforms..................................................................................... 5-34 Saddles........................................................................................ 5-37 Trays ........................................................................................... 5-40 Legs ............................................................................................ 5-41 Packing ....................................................................................... 5-43 Liquid.......................................................................................... 5-45 Insulation .................................................................................... 5-47 Lining.......................................................................................... 5-49 Half Pipe Jacket .......................................................................... 5-50


5-2

Vessel Detail Data

Introduction PVElite vessel models are composed of the basic elements (heads, shells, cones, etc.) with details added to these elements. Vessel details are included for two reasons—to develop the total vessel deadweight loads, and to collect information for the analysis of vessel components. Not all of these details are sensible additions to every element. The following table defines the application of these vessel details to the different elements. Cylinder

Elliptical Head

Tori Head

Sph Head

Flat Head

Cone

Body Flange

Skirt

Ring

#1

Nozzle

#

#

#

#

#

#

Lugs

#

#

#

#

#

#

#

#

Weight

#

#

#

#

#

#

#

#

Forces/Moments

#

#

#

#

#

#

#

#

Platform2

#

#

#

#

#

Saddle3

#

Tray2

Y/N

Legs5

Y/N4

Y/N

Y/N

Y/N

Y/N

Packing

Y/N

Y/N

Y/N

Y/N

Y/N

Liquid

Y/N

Y/N

Y/N

Y/N

Y/N

Insulation

Y/N

Y/N

Y/N

Y/N

Y/N

Y/N

Y/N

Y/N

Lining

Y/N

Y/N

Y/N

Y/N

Y/N

Y/N

Y/N

Y/N

#

#

Relationship of Elements and Details 1

# Indicates that this element type may have several of these details defined

2

Vertical vessels only

3

Horizontal vessels only

4

Y/N (Yes or No) indicates that this element may have this detail enabled or disabled

5

Vertical vessels only and only if no skirt is defined

It is also useful to note here the positioning of certain vessel "details" are applied at a point, such as over a length of the element. A good example is insulation. For a bottom (or left) head, the insulation (element detail) actually starts before the "From" node and covers the head to the "To" node. For a 60-inch diameter elliptical bottom head, the start point of the insulation is 15 inches below the "From" node (enter -15 for the "Distance from From Node"). If the head has the standard 3-inch straight flange, then the insulation covers 18 inches of the element (enter 18 for the "Height/Length of the Insulation"). See the chapter on Details for more information.


Chapter 5 Vessel Detail Data

Insulation Details


5-3

5-4

Vessel Detail Data

Assigning Detail Details may be assigned to elements by selecting them from the Detail toolbar located at the top of the vessel input screen. The first step in this process is to make the element of interest the current element by clicking on it. Next, click the appropriate detail icon for the detail you need to add. A dialog box will display. Enter all of the information then click OK and PVElite will update the graphic image showing your new detail. Since the image is scaled you can see if you placed your detail in the correct location.

Detail Toolbar



5-5

Detail Definition Buttons Details are selected by pressing the appropriate button on the detail toolbar. The stiffening ring dialog is shown below:

The individual detail windows generally have the following buttons available: Prev

Saves the current details data and displays the previous details data. If there is no previous detail, an error message will be displayed.

Next/Add

Saves the current details data and displays the next detail of the same type for the element. If no additional detail of this type exists, the program will create a default detail for the user's modification. PVElite registers details by the Detail ID. If the current detail does not have a Detail ID defined, the program will display an error message if this button is used.

Delete

Deletes the current detail and displays the data of the next detail of this type, if it exists. If there is not a next detail, the data of the previous detail, if it exists, will be displayed on the window. If no previous detail exists for the element, a new detail listing will be created.

OK

Saves the data of the current detail and closes the window. Note that the program will generate an error and not save the data if no Detail ID is specified.

Cancel

Closes the window without saving the current data.


5-6

Vessel Detail Data

Ring Material

Launches the material database. Clicking on a material name from the program's database will close the material selection window and bring that material name into the detail data. As not all details require a material definition, not all detail edit windows contain this button.

Help

Displays general help for the detail window.

Other buttons not shown in the illustration above: SECTIONID

Displays the database names for the wide variety of cross section data stored in PVElite. As with MATERIAL..., clicking on a name in the database will close the database and copy the selected name to the Section ID field. This option is available for leg details.

FULL

Appears with those details, which involve some length such as insulation, packing and liquid. These details require a start position and end position (entered as a distance from the From node and height/length of detail). If the detail extends throughout the element, clicking this button will automatically calculate and enter these values so that the detail "covers" 'the entire element. This feature is very useful for heads where these two terms (distance and height/length) may not be obvious. Remember that the From node and To node mark the ends of the straight flange portion of the head element and the head itself starts before or extends beyond this node pair. This leads to negative distances from the From node or a larger height/length of the detail.

ALL

Allows some detail types such as insulation to be applied over the entire vessel at one time. Of course the detail type can be edited on an individual basis on any element if the ALL feature has been used.

Note that only the details of the current element are accessible. To review or define details on other elements, the element of interest must be made current by clicking on it first. Note: Users may also access the Detail Edit window directly from the graphic image found in the Build and Define modes. Click the left mouse button on the element to make it current and then click the right mouse button on the detail of interest. For details that cannot be right clicked such as liquid, click the detail on the detail toolbar and its associated edit dialog will display.



5-7

Defining the Details Three items appear with every element detail. The From Node of the current element, the distance from the element's From Node (or Offset from Vessel Centerline for heads), and the label given to the detail or Detail ID.

From Node The From Node is an element identifier that cannot be entered or modified. The From Node (and the highlighted element on the graphic) indicates the element which contains the detail.

Distance from "From" Node or Offset from Vessel Centerline Enter the axial or longitudinal distance from the "From" Node to the start of the item to be defined. Be aware that for heads this may be a negative value; for example, insulation on a bottom head starts before the "From" node since the "From" node marks the beginning of the straight flange. For nozzles on heads, enter the radial distance between the vessel centerline and the centerline of the nozzle.

For the Detail...

Enter axial distance between From node and the following location:

Ring

Centerline of the ring

Nozzle

Centerline of the nozzle

Lug

Centroid of the lug attachment weld

Weight

Point at which the weight acts

Force/Moment

Point at which the force or moment acts

Platform

Axial distance from the node to the bottom of the platform

Saddle

Vertical centerline of the saddle

Trays

Bottom of the lowest tray

Legs

Centroid of the leg attachment weld

Packing

Start of the packed section

Liquid

Start of the liquid section

Insulation

Start of the insulated section

Lining

Start of the lined section

Detail ID Enter any alphanumeric string to identify the detail. While not required, it is suggested to assign unique names for unique items for clear reporting. For example, nozzles should be unique as their individual identification is important while insulation on all elements, if consistent throughout, may be named INSUL on each element. Some consistency will help your naming process. You may wish to use the From node number with an alphabetical extension showing the detail type and the number of such details if needed. For example, for a nozzle, insulation and ring defined on the element From node 20 To node 30 you may have Detail IDs of "NOZL A", "INSUL", and "20 RING 1 of 2", respectively. No two details should have the same name.


5-8

Vessel Detail Data

Rings The Stiffening Ring dialog lets the user input and edit the data of the rings, which are attached to the current element. These data are used in the calculation of the weight of the ring and, for external pressure checks, in the calculation of the ring area and inertia. When using the ASME Code, the Stiffening Ring dialog displays.

As the stiffening ring data is entered, PVElite automatically computes the inertias required and available, provided it is not a cone to cylinder junction ring. For bar rings, the program will size a new ring based on a default thickness of 0.375 inches or the value given in the Miscellaneous Options dialog located on the Design/Analysis dialog. The Section Calculator button allows inertia, area and centroidal distance to be computed for non-standard or built up sections. This button is only available when the Section Type ring is being analyzed. The Check Standards Bars button helps users select a suitable ring. As you cursor through the rings, the program computes the results and places them in the display area near the bottom of the dialog. Rings that meet Code requirements display in blue and failed rings display in red along with a failed message. Users should verify that the entire vessel is modeled prior to placing and sizing the rings. The Bar Selection dialog is shown below. Use the mouse, space bar, and/or arrow keys to navigate this tree.



5-9

Inside Diameter of Ring Enter the inside diameter of the stiffening ring. This value is usually equal to the outside diameter of the shell, except for the relatively rare case of a stiffening ring inside of the vessel.

Outside Diameter of Ring Enter the outside diameter of the stiffening ring. This value is usually greater than the outside diameter of the shell.

Thickness of Ring Enter the axial thickness of the stiffening ring.

Ring Material Enter a name of the ring material from the program's material database or select the material name by first clicking on the Ring Material button. Individual material parameters may be viewed and modified by pressing Enter when the cursor is in this field. PVElite allows entry of the generic entry of any type of stiffener. To do this you must know the cross sectional area of the stiffener as well as the moment of inertia and the distance from the shell surface to the ring centroid. If you are using an American type structural shape simply click the Section Type button and then click the type of geometry being used. If a non-American type section ring is being used, enter in the properties for your section type.

Moment of Inertia A property of the stiffener typically taken from a structural handbook. Units of inertia are length to the 4th power.


5-10

Vessel Detail Data

Cross Sectional Area This is the cross sectional metal area of the ring.

Distance to Ring Centroid This is the distance from the surface of the shell to the center of the rings area. This property is typically taken from a structural handbook.

Name of Section Type This value is used for documentation purposes and it is used to look up the total height of the stiffener for the horizontal vessel analysis if it was left as zero or not specified. When using British Standard PD:5500 for a cylindrical section, the following screen displays:



5-11

Nozzle Dialog Data The Nozzle Dialog allows input and editing of the nozzles, which are attached to the current element. These nozzles will add to the total deadweight of the vessel. Even if the deadweight is not significant, entering the nozzles may be very important as the data entered here will be used to evaluate the flange's and vessel's maximum allowable pressure (MAWP). The nozzle flange MAWP will be set according to the element temperature, the nozzle class and the flange grade according to ANSI B16.5. If one of the nozzles controls the vessel's MAP and a vertical hydrotest is carried out in accordance with ASME UG 99(c), be sure to enter the correct "Flange Distance to Top" in the Global Design Data. Flange distance to top will be the distance from the controlling flange to the top of the vessel. See the Global Data chapter for more information. The orientation of the nozzle is also controlled by the user in the radial and hillside directions. This feature gives the user versatility in the use of this program. The Layout button can also be used to enter in hillside nozzles whose centerline does not correspond with a global direction.


5-12

Vessel Detail Data

Nozzle Analysis PVElite calculates required wall thickness and area of reinforcement for a nozzle in a pressure vessel shell or head, and compares this area to the area available in the shell, nozzle and optional reinforcing pad. The program also calculates the strength of failure paths for the nozzles. This calculation is based on the ASME Code, Section VIII, Division 1, Paragraph UG-37 through UG-45. The calculation procedure is based on figure UG-37.1. The program calculates the required thickness (for reinforcement conditions) based on inside diameter for the following vessel components:

Component

Paragraph

Limitations

Cylinder

UG-27 (c) (1)

None

2:1 Elliptical Head

UG-32 (d) (1)

None

Torispherical Head

UG-32 (e) (1)

None


UG-27 (d) (3)

None

Note: PVElite also analyzes a large nozzle in a welded flat head, which is found in this user manual where the flat head is discussed. The program evaluates nozzles at any angle (less than 90 degrees) away from the perpendicular, allowing evaluation of off angle or hillside nozzles. NOZZLE takes full account of corrosion allowance. You enter actual thickness and corrosion allowance, and the program adjusts thicknesses and diameters when making calculations for the corroded condition. NOZZLE also performs UCS-66 Minimum Design Metal Temperature (MDMT) calculations for nozzles. As the nozzle data is entered, PVElite will automatically perform the ASME area of replacement or PD:5500 nozzle compensation calculations. A calculation is performed every time the cursor is moved in between input cells. If there is any error in the input that will not allow the analysis to be performed, a status of failed will appear at the bottom of the Nozzle dialog. The calculation is initiated once the pipe size is specified. If you are changing data, such as the pad thickness and are not moving between cells, press F5 to force PVElite to recalculate and display the results. If the calculation has failed, the result will appear in red. A nozzle that has passed will have blue results. The result is typically the area and minimum nozzle overstress per 1-7. The program will display the text failed in brackets, even though the area of replacement may be sufficient. To effectively use this feature, we suggest that the entire vessel be modeled first, along with the liquid and nozzle pressure design options set. Also for vessels that have ANSI flanges note that the ANSI flange rating will be shown on the main Status bar. The figure below displays the Nozzle Module geometry.



5-13

Nozzle Input Data Nozzle Description Enter a 15 character or less description of this nozzle. If you type in the description "MANWAY" the UG-45 check for minimum nozzle neck thickness will not be performed. The text #SN in the description will cause PVElite to compute the areas if this is a small nozzle.

Angle Between Nozzle and Shell Enter the angle between the centerline of the nozzle and a tangent to the vessel at the point where the nozzle centerline intersects the vessel outside diameter. If left blank, and an offset is entered, the program will compute the angle. Please refer to the section below: Nozzle Orientation, where the alternative method of entering hillside and radial nozzles is discussed in detail. Please refer to this chapter, as it gives the user greater control over the positioning of nozzles, especially hillside nozzles that point in any direction. Much greater versatility is available by using the alternative method of orientating nozzles in heads and cylinders.

Offset Distance from Cylinder/Head Centerline (L1) Enter the distance from the center of the head to the nozzle centerline.

Class for Attached B16.5 Flange From the pull down, select the class of nozzle flange you will be using. The following flange classes are available: CL 150, CL 300, CL 400, CL 600, CL 900, CL 1500, CL 2500 PVElite will use the class and grade to determine the MAWP of the ANSI flange.

Grade for Attached B16.5 Flange Enter the letters "GR" followed by a space and the number corresponding to the flange material grade. The following flange grades are available: GR 1.1 GR 1.2 GR 1.4

Med Carbon Steel High Carbon Steel Low Carbon Steel

Austenitic Steels: GR 2.1 GR 2.2 GR 2.3 GR 2.4 GR 2.5 GR 2.6 GR 2.7

Type Type Type Type Type Type Type

304 316 304L,316L 321 347,348 309 310


5-14

Vessel Detail Data

Alloy Steels: GR 1.5 GR 1.7 GR 1.9 GR 1.10 GR 1.13 GR 1.14

C-1/2Mo 1/2Cr-1/2Mo, Ni-Cr-Mo 1-1/4Cr-1/2Mo 2-1/4Cr-1Mo 5Cr-1/2Mo 9Cr-1Mo

High Alloy Steels GR 3.1 GR 3.2 GR 3.4 GR 3.5 GR 3.6 GR 3.7 GR 3.8

NI-FE-MO-CB NI Alloy 200 NI CU 400, 500 NI-CR-FE 600 NI CR-FE 800 NI-MO B2 Nickel Alloys

Modification of Reinforcing Limits You may enter any physical limitation, which exists, on the thickness available for reinforcement or the diameter available for reinforcement. An example of a thickness limitation would be a studding pad or nozzle stub which would not extend normal to the vessel wall as far as the thickness limit of the nozzle calculation. An example of a diameter limitation would be two or more nozzles close together, or a vessel seam for which you did not want to take an available area reduction.

Physical Maximum for Nozzle Diameter Limit Enter the maximum diameter for material contributing to nozzle reinforcement. An example of a diameter limitation would be two nozzles close together, or a vessel seam for which you did not want to take an available area reduction.

Physical Maximum for Nozzle Thickness Limit Enter the maximum thickness for material contributing to nozzle reinforcement. An example of a thickness limitation would be a studding pad or nozzle stub which would not extend normal to the vessel wall as far as the thickness limit of the nozzle calculation.

Do you want to set Area1 or Area 2 to 0 In some vessel design specifications it is mandated that no credit be taken for the area contributed by the shell or nozzle. You can enter the text "A1" or "A2" in this field. If you do so, that area will be set equal to 0. You can also enter "A1 A2". This would give you no credit for Area1 - available area in the vessel wall or Area2 - available area in the nozzle wall. Another option is to neglect the area available in the cover weld (ACWLD).

Nozzle Material Specification Enter the ASME code material specification as it appears in the ASME material allowable tables. Alternatively, the material can be selected from the Material Database by pressing D when the cursor is in the material field. If a material is not contained in the database, its specification and properties can be entered manually.



5-15

Nozzle Diameter Basis Select the appropriate basis from the pull down menu. Nozzles can be specified on either the Inside or Outside diameter basis.

Actual or Nominal Diameter of Nozzle Enter the diameter of the nozzle. If you specify nominal or minimum for the nozzle size and thickness basis, then you must enter the nominal diameter of the nozzle in this field. Valid nominal diameters are: 0.125

0.25

0.375

0.5

0.75

1

1.25

1.5

2

2.5

3

3.5

4

5

6

8

10

12

14

16

18

20

24

30

Note that if you are using Metric or non-English units, then the diameter when converted must end up as a value in the table above. For example if the size were 10 inch nominal, this would correspond to 254 mm. In the nozzle dialog, press the button next to the pipe size to select it from the list. In the list, both the ANSI nominal and Metric Nominal are shown.

Nozzle Size and Thickness Basis Select the appropriate basis for the nozzle diameter and thickness, Actual, Nominal or Minimum.

Actual Diameter and Thickness The program will use the actual diameter entered in the field above and the actual thickness entered in the field below.

Nominal Diameter and Thickness The program will look up the actual diameter based on the nominal diameter entered in the nozzle size and thickness basis field, and will look up the nominal thickness based on the schedule entered in the nominal schedule of nozzle field.

Minimum Diameter and Thickness The program will look up the actual diameter based on the nominal diameter entered in the nozzle size and thickness basis field, and will look up the nominal thickness based on the schedule entered in the nominal schedule of nozzle field. It will then multiply the nominal thickness by a factor of 0.875.

Actual Thickness of Nozzle Enter the minimum actual thickness of the nozzle wall. Enter a value in this field only if you selected ACTUAL for the nozzle diameter and thickness basis. Otherwise enter a schedule in the field below.


5-16

Vessel Detail Data

Nominal Schedule of Nozzle Enter the schedule for the nozzle wall. Enter a value in this field only if you selected NOMINAL or MINIMUM for the nozzle diameter and thickness basis. Otherwise enter a thickness in the thickness field. Select the nozzle schedule from the pulldown. Available nozzle schedules are: SCH 10

SCH 60

SCH 140

SCH 80S

SCH 20

SCH 80

SCH 160

SCH STD

SCH 30

SCH 100

SCH 10S

SCH X-STG

SCH 40

SCH 120

SCH 40S

SCH XX-STG

Note that all schedules of pipe may not have a corresponding diameter associated. In this case, PVElite will return an error stating the thickness of the nozzle was not found.

Nozzle Corrosion Allowance Enter the corrosion allowance. The program adjusts both the actual thickness and the inside diameter for the corrosion allowance you enter.

Joint Efficiency of Shell Seam through which Nozzle Passes Enter the seam efficiency. The seam efficiency is used in the 'area available' calculations to reduce the area available in the shell. Note that for shell and nozzle wall thickness calculations, the seam efficiency is always 1.0.

Joint Efficiency of Nozzle Neck Enter the seam efficiency of the nozzle. The seam efficiency is used in the UG-45 calculation to determine the minimum required thickness of the nozzle due to internal pressure. Note that for shell and nozzle wall internal pressure thickness calculations, the seam efficiency is always 1.0.

Insert Nozzle or Abutting Nozzle The nozzle type and depth of groove welds are used to determine the required weld thicknesses and failure paths for the nozzle. If the nozzle is welded to the outside of the vessel wall, it is abutting the vessel wall. If the hole in the vessel is bigger than the nozzle OD and the nozzle is welded into the hole, it is inserted. Figure UW-16.1 shows typical insert and abutting nozzles.

Nozzle Outside Projection Enter the distance the nozzle projects outward from the surface of the vessel. This will usually be to the attached flange or cover. This length will be used for weight calculations and for external pressure calculations. Also, if this value is less than the calculated thickness limit, this value is used when computing the area available in the nozzle wall.

Weld Leg Size for Fillet Between Nozzle and Shell or Pad Enter the size of one leg of the fillet weld between the nozzle and the pad or shell.



5-17

Depth of Groove Weld Between Nozzle and Vessel Enter the total depth of the groove weld. Most groove welds between the nozzle and the vessel are full penetration welds. Thus the depth of the weld would be the same as the depth of the component, that is the thickness of the nozzle. If the nozzle is attached with a partial penetration weld, or just a fillet weld, enter the depth of the partial penetration or a zero, respectively, in this field.

Nozzle Inside Projection Enter the projection of the nozzle into the vessel. The program uses the least of the inside projection and the thickness limit with no pad to calculate the area available in the inward nozzle. Therefore, you may safely enter a large number such as six or twelve inches if the nozzle continues into the vessel a long distance.

Weld Leg Size Between Inward Nozzle and Inside Shell Enter the size of one leg of the fillet weld between the inward nozzle and the inside shell.

Local Shell Thickness Some vessels have insert plates, which are thicker than the surrounding shell. If your vessel uses insert plates, enter the thickness of the plate here. This value will be thicker than the shell course thickness this nozzle is located on. The maximum of this value and the element thickness will be used in the nozzle reinforcement calculations. A basic assumption here is that the diameter of the insert plate is greater than the diameter limit of reinforcement, which is roughly twice the diameter of the finished opening. On the other hand, if the area immediately adjacent to the opening is corroded to a greater degree or locally thinner than the rest of the shell, the thinner value can be entered in as well.

Shell Tr Value For some vessel designs the nozzle reinforcement is governed by bending and normal stresses in the local shell area where the nozzle is located. Normally the value of Tr (shell required thickness) is based on internal pressure requirements. Some specifications call out for "Full Replacement." If this is the case, enter in the actual shell thickness less the corrosion allowance. For another option, review the Nozzle Design Modification Section in the Design/Analysis Constraints. The Base Nozzle tr on Max. Stress ratio check box can also satisfy external loading criteria by computing the exact requirement for tr. If you enter the Shell Tr, this is the value the program will use. If you do not wish to use this value, enter a 0. This directive is for vertical vessels only. This option should not be checked if the vessel is a horizontal vessel.

Tapped Hole Area Loss This entry is for the exclusion of area needed when holes are tapped into studding outlets and other similar connection elements. The traditional industry standard is to increase the area required by the tapped area loss. Values for tapped area loss are shown in the table below adapted from the Pressure Vessel Design Manual. Please note that PVElite will not multiply the tapped area loss by 2. It will simply use the value that has been supplied.


5-18

Vessel Detail Data

Overriding Nozzle Weight Normally the program calculates the weight of the nozzle from the information the user has already entered and from internal tables of typical weights. If your nozzle is significantly different from a standard weight nozzle, you can enter the weight here, and it will override the program calculated weight.

Nozzle Orientation The Alternative (more versatile) Method This alternative method of orientating nozzles, especially in cylinders gives the user complete control over the direction in which the nozzle points. By using this method, the user is not confined to only having nozzles point in the coordinate system of the 3D model. By this, we mean that nozzles may only point in the X, Y and Z directions like this:

In the above figure, the hillside nozzles are only pointing in four directions, aligned with the major co-ordinates of the cylinder. The alternative method presented in this section shows how the nozzles can be placed to point in any hillside direction with greater ease.



5-19

Using the Layout Button in the Nozzle Dialog Screen - Alternative Method We discuss how a hillside nozzle may be made to point in any direction as indicated below:

The above figure shows that the direction of the nozzle is not controlled by the four axis directions of the cylinder, but may be made to point in any direction within the 360º position around the cylinder. Note the difference between the Reference Angle, and the Layout Angle.

Starting the Alternative Nozzle Layout Method At the bottom of the Nozzle dialog in the Nozzle Properties frame is the Layout... button. Clicking this button displays the Nozzle Layout screen. Enter the nozzle description, size, schedule and other parameters before clicking Layout.


5-20

Vessel Detail Data

Nozzle In a Cylinder Radial and Hillside Nozzles in Cylinders If the nozzle is to be installed in a cylinder, the following opens :

Three different orientations are available for the nozzle: Radial Nozzle Hillside Nozzle Lateral Nozzle These orientations are controlled by clicking the appropriate radio button:



5-21

Radial Nozzle in Cylinder - Data Entry Reference Angle Alpha

Enter the reference angle alpha. As this is a radial nozzle, the centerline of the nozzle passes through the centerline of the parent cylindrical shell. Projection Dimension "Proj"

Enter the projection from the centerline of the parent cylinder to the end of the nozzle as illustrated on the screen. Once this is entered, PVElite automatically calculates the projection ho, and this value replaces the red message Please enter a valid "Proj" value to compute ho with the computed value of ho. Return to the main Nozzle dialog by clicking OK, the appropriate values have been filled in the layout angle and projection. Hillside Nozzle Cylinder - Data Entry

Reference Angle Alpha Enter the reference angle. Note, the reference angle is not the layout angle. The reference angle displays in the figure on th next page.


5-22

Vessel Detail Data

Nozzle Offset Dimension Enter the Offset Dimension. To clarify matters, the figure below displays the offset dimension.

Projection Dimension "Proj"

Enter the projection from the centerline of the parent cylinder to the end of the nozzle as illustrated on the screen. Once this is entered, PVElite automatically calculates the projection ho, and this value replaces the red message Please enter a valid "Proj" value to compute ho with the computed value of ho. On returning to the main Nozzle dialog by clicking OK, the appropriate values have been filled in the layout angle and projection. To clarify matters, the figure below displays the layout angle the program calculates:



5-23

Lateral Nozzle in Cylinder - Data Entry

Reference Angle Alpha Enter the reference angle alpha. This is the angle between the nozzle centerline and the parent cylinder centerline. It is illustrated on the input screen. Note: You have to return to the main Nozzle dialog to enter the projection from the surface of the cylinder.


5-24

Vessel Detail Data

Nozzle In a Head Radial and Hillside Nozzles and Heads If the nozzle is to installed in a head, the following dialog box will display:

The available nozzle orientations are: Radial Nozzle Hillside Nozzle These orientations are controlled by clicking the appropriate radio button:



5-25

Radial Nozzle in Head - Data Entry

Reference Angle Alpha - The Direct Method Enter the reference angle alpha as indicated in the following illustration:

Data Entry - Computing the Reference Angle Alpha

Using this method to derive the reference angle, PVElite will compute the reference angle alpha from the coordinate X-Y location chosen by the user. This method is useful, as nozzle locations on heads are often given in the X-Y coordinate system. Enter the appropriate values of X and Y in any of the four angle quadrants.


5-26

Vessel Detail Data

Projection Dimension "Proj"

Enter the projection from the centerline of the parent cylinder to the end of the nozzle as illustrated on the screen. Once this is entered, PVElite automatically calculates the projection ho, and this value replaces the red message Please enter a valid "Proj" value to compute ho with the computed value of ho. On returning to the main Nozzle dialog by clicking OK, the appropriate values have been filled in the layout angle and projection. Hillside Nozzle in Head - Data Entry For more information, refer to Radial Nozzle in Head in the previous section for entry of this data. Notes and Advantages for Hillside Nozzles Often, hillside nozzles in heads are arranged such that the flange faces are all level in the same plane, as in the illustration below:

Using the alternate method of entry for hillside nozzles in a head makes this arrangement very simple.



5-27

Additional Reinforcing Pad Data Pad Outside Diameter along Vessel Surface Enter the outside diameter of the pad. The diameter of the pad is entered as the length along the vessel shell - not the projected diameter around the nozzle, although these two values will be equal when the nozzle is at 90 degrees.

Pad Width In many cases the desired pad width is known and the diameter is not known. When the pad width is entered, the program will compute the Pad outer diameter and update the screen accordingly. Internally PVElite works with the pad diameter and not the width.

Pad Thickness Enter the thickness of the pad. Any allowances for external corrosion should be taken into account for the pad thickness.

Pad Weld Leg Size as Outside Diameter Enter the size of one leg of the fillet weld between the pad OD and the shell. Note that if any part of this weld falls outside the diameter limit, the weld will not be included in the available area.

Depth of Groove Weld between Pad and Nozzle Neck Enter the total depth of the groove weld. Most groove welds between the pad and the nozzle are full penetration welds. Thus the depth of the weld would be the same as the depth of the component, that is the thickness of the pad. If the pad is attached with a partial penetration weld, or just a fillet weld, enter the depth of the partial penetration or a zero, respectively, in this field.

Pad Material Enter the applicable code material specification as it appears in the material allowable tables. Alternatively, the material can be selected from the Material Database by clicking the Pad Material button. If a material is not contained in the database, its specification and properties can be entered manually.

ASME Code Weld Type In many cases the Code does not require weld strength/path calculations for full penetration groove welds for pressure loadings. If your weld detail is per UW-16.1 sketch (a), (b), (c), (d), (e), (f-1), (f-2), (f-3), (f-4), (g), (x-1), (y-1) or (z-1) and you do not wish the program to perform the weld strength calculation, enter in a designation such as A. If you wish PVElite to perform this calculation regardless of the type of weld, leave this field blank. If it is a type I, J, K, L, X-2, Y-2, Z-2 weld, then PVElite will perform the additional weld size calculations per UW-16(d)(1). This field is not applicable for PD 5500 or EN-13445.


5-28

Vessel Detail Data

Flange Type This is the type of nozzle flange. This value is not used by the program, but is echoed out for documentation purposes.

Flange Material This is the material the flange is constructed of. This value is not used by the program, but is echoed out for documentation purposes. The flange material should correspond to the type listed for the flange grade.



5-29

Lugs The Lug Dialog allows the entry of the sets of support lugs, which are attached to the current element. If no skirt or legs are defined for a vertical vessel, the lowest set of lugs will be used as the vessel support point for dead load and live load calculations.

PVElite allows the entry of one of three types of support lug geometries: 1 - simple geometry with gussets 2 - gusseted geometry with top plate 3 - gusseted geometry with continuous top ring Depending on the type of geometry selected, additional data will need to be entered.

Distance from Vessel OD to Lug Midpoint This is the radial distance from the wall of the vessel to the point where the lug attaches to the structural steel.

Lug Bearing Width This is the width of the structure that is in contact with the bottom lug support plate.

Radial Width of Bottom Support Plate This is the distance the bottom support plate extends from the OD of the vessel. This value must be greater than or equal to the average gusset width.


5-30

Vessel Detail Data

Length of Bottom Lug Support Plate This value is typically equal to the distance between gussets plus two times the gusset plate thickness.

Thickness of Bottom Plate This value is the thickness of the bottom support plate.

Distance between Gussets This is the distance between the insides of the gusset plates.

Mean Width of Gussets This value is equal to the gusset width at the top plus the gusset width at the bottom divided by two. PVElite uses the mean gusset width in order to compute the actual stresses in the gusset plates.

Height of Gussets Enter the height of one gusset.

Thickness of Gussets Enter the thickness of the gusset plate.

Radial Width of Top Plate/Ring This is the radial dimension from the OD of the shell to the edge of the top plate. This value should be less than or equal to the mean gusset width.

Thickness of Top Plate/Ring Enter the thickness of the top plate, which sits above the gussets.

Overall Height of Lug Enter the distance from the bottom of the support lug to the top.

Overall Width of Lug Enter the width of the support lug.

Weight of One Lug The program does not gather enough information to be able to do the detailed calculation of the support lug weight. Therefore you must enter the actual weight of one support lug.



5-31

Number of Lugs Enter the number of support lugs around the periphery of the vessel at this location.

Perform WRC 107 Calc If the box is checked to perform the WRC 107 local stress and analysis, you will need to fill out the pad dimensions (if there is a pad) and the allowable stress increase factor.

Pad Width The reinforcing pad width is measured along the circumferential direction of the vessel. The pad width must be greater than the attachment width. The length of the attachment is measured along the axis of the vessel. If the box is checked to perform the analysis and the pad properties are filled in, the program will compute the stresses at the edge of the attachment and the edge of the pad.

Pad Thickness Enter the thickness o of the pad. Any allowances for the external corrosion should be taken in to account for the pad thickness.

Pad Length Enter the outside diameter of the pad. The diameter of the pad is entered as the length along the vessel shell - not the projected diameter around the nozzle, though these two values will be equal when the nozzle is at 90 degrees.


5-32

Vessel Detail Data

Weights The Weight Dialog allows the entry of miscellaneous weight that cannot be entered by using any of the other methods. Note that this is not an applied force, but a static mass that will affect the natural frequency of the vessel and axial stress calculations. Piping can be modeled using the Weight Dialog. The area and mass of the piping will be considered in the same manner as a weight.

Miscellaneous Weight Enter a weight value. This could be generated by an attached piece of equipment such as a motor, by internals such as piping, or by externals such as structural elements. Note that this value will affect the seismic analysis.

Offset from Centerline Enter the distance of this generic weight from the centerline of the vessel. The value will be multiplied by the weight to obtain a moment that will be a part of the stress calculations.

Is this a Welded Internal This parameter informs PVElite in which category to add the weight.



5-33

Forces and Moments The Force/Moment Edit window allows the user to input and edit the data of the sets of forces and moments, which are added to the current element. In most cases these are operating loads imposed on the vessel; usually piping loads on nozzles.

Force in X, Y, or Z Direction Enter the force in the selected direction. Note that the Y direction is always vertically up, the X direction is from left to right, and the Z direction is out of the page. Loads perpendicular to the vessel will be resolved into a single vector and applied to create the worst combination with the live load. Unlike miscellaneous weight, this force is not included in the seismic analysis.

Moment about X, Y, or Z Axis Enter the moment about the selected axis. The rules stated for the forces apply here as well.

Acts During Wind or Seismic If the force or moment acts during either the Wind or Seismic case, check the appropriate box. Please note you can check both boxes but you must at least check one.

Force/Moment Combination Method The Algebraic method gives the most accurate results. It accounts for signs on the forces that cause bending about the skirt, lugs or legs. The SRSS method disregards the signs and will generate more conservative results. This option is not used when the vessel is horizontal.


5-34

Vessel Detail Data

Platforms The Platform Dialog allows the user to input and edit data of the platforms, which are attached to the current vertical vessel element.

Platform Start Angle (degrees) Enter the angle between the designated zero degree line of the vessel, and the start angle of the platform.

Platform End Angle (degrees) Enter the angle between the designated zero degree line of the vessel, and the ending angle of the platform.



5-35

Platform Wind Area Enter the tributary wind area of the platform if you do not agree with the program's computed value. Typically this value will be the greatest span of the platform perpendicular to the vessel multiplied by a nominal platform height, between 12 and 36 inches on the handrails and other equipment on the platform.

Platform Weight Enter the weight of the platform if you wish to override the program's computed weight value.

Platform Railing Weight Enter the weight of the railing in units of force/length in this field. The platform width, grating weight and railing weight are used to compute the weight of the platform automatically when entering data on the dialog.

Platform Grating Weight The grating is the plate that one stands on while standing on a platform. The platform width, grating weight and railing weight are used to compute the weight of the platform automatically when entering data on the dialog.

Platform Width Enter the radial width of the platform. The platform width, grating weight and railing weight are used to compute the weight of the platform automatically when entering data on the dialog.

Platform Height The platform height is the distance from the floor plate to the top handrail. This dimension is usually 42 inches. The program uses this value to compute the wind area when one of the Wind area calculation buttons is clicked.

Platform Clearance The platform clearance is distance between the outer shell surface and the inner diameter of the platform. The value is used to compute the floor area of the platform.

Platform Force Coefficient The force coefficient is a term used to compute the wind area and consequently the wind force acting on a platform. This value is taken from ASCE7-95 from Table 6-9 and is referred to as Cf. A typical value for Cf is 1.2. This value should always be greater than or equal to 1.0.

Platform Wind Area Calculation [Installation \ Misc. Options] PVElite can perform platform area wind calculations in one of four ways. The methods are


5-36

Vessel Detail Data The height times the width times the force coefficient (conservative). One half of the floor plate area times the force coefficient. The height times the width times the force coefficient divided by 3. The projected area of the platform times the force coefficient divided by 3. Note that this option will yield the same results as option 3 for platforms that have a sweep angle of greater than 180 degrees.

To have the program compute the area, simply fill in the required data such as the platform height, width, start and end angles and the force coefficient. As you enter the data the program will compute the result and insert it into the wind area cell. If you want to use your own values, type it in and do not press one of the area options. Note: This option is not available on the Platform dialog, but is globally available in the Installation / Miscellaneous Options dialog.

Platform Length (Non- Circular) If the platform is the non-circular top head type, enter the long dimension of the platform.



5-37

Saddles The Saddle Dialog lets the user input and edit data of the saddles, which are attached to the current horizontal cylinder. The size and location of the saddles are important for the Zick calculations of local stresses on horizontal vessels with saddle supports. For proper Zick analysis, only two saddles may be defined and they do not have to be symmetrically placed about the center of the vessel axis. If no saddles are defined for a horizontal vessel, the dead load and live load calculations will not be performed.

Width of Saddle Enter the width of the saddle support. This width does not include any wear pad on the vessel side.

Centerline Dimension (B) Enter the distance from the base of the saddle to the centerline of the vessel. This is referred to as dimension "B" in some pressure vessel texts. This value is used in determining additional saddle loads due to wind or seismic events.


5-38

Vessel Detail Data

Saddle Contact Angle (degrees) Enter the angle contained between the two 'horns' (contact points) of the saddle, measured from the axial center of the vessel. Typically this value ranges from 120 to 150 degrees.

Height of Composite Stiffener Enter the overall height of the composite stiffener over the saddle (if there is one).

Width of Wear Plate Enter the width of the wear plate between the vessel and the saddle support.

Thickness of Wear Plate Enter the thickness of the wear plate between the vessel and the saddle support.

Wear Plate Contact Angle (degrees) Enter the angle contained from one edge of the wear plate to the other edge, measured from the axial center of the vessel. Typically this value is approximately 130 degrees.

Saddle Dimension A This distance is the length between the centerline of the saddle support and the tangent line of the nearest head. This dimension is usually labeled A in most pressure vessel texts.

Perform Saddle Check By checking this box and entering the following information PVElite will perform a structural design check on the saddle supports.

Material Yield Stress Enter the yield stress for the saddles at their design temperature.

E for Plates Enter the modulus of elasticity for the material used to make the saddles.

Baseplate Length This is the long dimension of the baseplate, which is in contact with the supporting surface. This value is comparable with the vessel diameter.

Baseplate Width This is the short dimension (Width) of the baseplate.



5-39

Baseplate Thickness This is the thickness of the baseplate support.

Number of Ribs The ribs run parallel to the long axis of the vessel. Enter the number of ribs on one saddle support.

Rib Thickness Enter the thickness of the rib supports.

Web Thickness The web is the part of the support structure to which the ribs are attached. Enter the thickness of the web here.

Web Location There are 2 possible locations for the webs, center or side. Pull down the appropriate selection.

Height of Center Web Enter the distance from the bottom of the center rib to the top plus the thickness of the shell.


5-40

Vessel Detail Data

Trays The Tray Dialog allows the user to enter and edit one set of equally spaced trays with a set liquid height for the current element. The Distance from "From" Node will be to the bottom of the lowest tray. Trays may only be entered for vertical vessels.

Number of Trays Enter the number of trays for the current element.

Tray Spacing Enter the vertical distance between trays.

Tray Weight Per Unit Area Enter the unit weight of each tray. Do not enter the total weight, since the program will multiply the unit weight by the cross sectional area of the element.

Height of Liquid on Tray Enter the height of the liquid on each tray.

Density of Liquid on Tray Enter the density of the liquid on each tray.



5-41

Legs The Leg Dialog allows the user to input data for the legs that are attached to the current element. Legs may be entered for vertical vessels that have no skirt element.

Distance from Outside Diameter: or Diameter at Leg Centerline For shell elements enter the distance between the centerline of the leg to the element outside diameter. Usually, this data is the half value of the leg's width. For heads where the legs may not necessarily attach at the vessel OD but somewhere else along the head, enter the distance between the centerlines of two legs that are opposite to one another. If there are an odd number of legs (therefore no two are opposite), then enter the diameter of a circle drawn through the centerlines of the legs; this would be the outside diameter at the head attachment elevation plus the depth of the leg.

Leg Orientation Select the orientation of the leg to the centerline. Weak, Strong and diagonal are acceptable selections.


5-42

Vessel Detail Data

Number of Legs Enter the number of legs. This value should be greater than or equal to 3.

Section Identifier Enter the section identifier for the vessel. The program has several databases of structural shapes. The Section ID database may be displayed by clicking the Section ID button or press [Alt-S] keystroke combination. The section identifier can be selected directly from the database.

Length of Legs Enter the distance from the attachment point of the leg to the base.

Vessel Translates During Occasional Load If the Perform WRC 107 Analysis check box has been enabled, the translation check box will be active. The state of this check box informs PVElite how the longitudinal moment is to be calculated. When the box is checked, this will produce a more conservative longitudinal moment than when the box is left unchecked. If you are unsure, verify the box is checked.



5-43

Packing The Packing Dialog allows the user to input and edit the data for the packing, which is attached to the current element.

Height of Packed Section Enter the height of the packed section on this element. This value is used only to calculate the weight of the packed section. For seismic calculations the weight center of the packed section will be taken at half this height. Note that if you have a packed horizontal vessel (rare) the value entered in this cell will be the length of the packed section.


5-44

Vessel Detail Data

Density of Packing Enter the density of the packing. The following table lists some typical densities, shown in lbs/ft3. Note that the densities should be converted if you are using another units system.

Size (in.)

Density (lb/ft3)

Size (in.)

Density (lb/ft3)

Ceramic Raschig Ring

Carbon Raschig Ring

1/4

60.0

1/4

46.0

3/8

61.0

1/2

27.0

1/2

55.0

3/4

34.0

5/8

56.0

1

27.0

3/4

50.0

1 1/4

31.0

1

42.0

1 1/2

34.0

1 1/4

46.0

2

27.0

1 1/2

46.0

3

23.0

2

41.0

Carbon Steel Pall Ring

3

37.0

5/8

37.0

4

36.0

1

30.0

Carbon Steel Raschig Ring

1 1/2

26.0

1/4

133.0

2

24.0

3/8

94.0

Plastic Pall Ring

1/2

75.0

5/8

7.25

5/8

62.0

1

5.50

3/4

52.0

1 1/2

4.75

1

39.0

2

4.50

1 1/2

42.0

3

4.50

2

37.0

3

25.0



5-45

Liquid The Liquid Dialog allows entry and editing of liquid data in the model.

Height/Length of Liquid Enter the height or length of the liquid on this element. This value is used only to calculate the weight of the liquid section. For seismic calculations the weight center of the liquid section will be taken at half this height. This value is also used to calculate the operating pressure at all points below the liquid.

Liquid Density Enter the density of the liquid. Some typical specific gravities and densities are shown below in lbs/ft3. Note that the densities should be converted if you use another units system.


5-46

Vessel Detail Data

Name

Gravity

Density (lb/ft3)

Ethane

0.3564

22.23

Propane

0.5077

31.66

N-butane

0.5844

36.44

Iso-butane

0.5631

35.11

N-Pentane

0.6247

38.96

Iso-Pentane

0.6247

38.96

N-hexane

0.6640

41.41

2-methypentane

0.6579

41.03

3-methylpentane

0.6689

41.71

2,2-dimethylbutane

0.6540

40.78

2,3-dimethylbutane

0.6664

41.56

N-heptane

0.6882

42.92

2-methylheptane

0.6830

42.59

3-methylheptane

0.6917

43.13

2,2-dimethylpentane

0.6782

42.29

2,4-dimethylpentane

0.6773

42.24

1,1-dimethylcyclopentane

0.7592

47.34

N-octane

0.7068

44.08

Cyclopentane

0.7504

46.79

Methylcyclopentane

0.7536

46.99

Cyclohexane

0.7834

48.85

Methylcyclohexane

0.7740

48.27

Benzene

0.8844

55.15

Toluene

0.8718

54.37

Alcohol

0.7900

49.26

Ammonia

0.8900

55.50

Benzine

0.6900

43.03

Gasoline

0.7000

43.65

Kerosene

0.8000

49.89

Mineral oil

0.9200

57.37

Petroleum oil

0.8200

51.14



5-47

Insulation The Insulation Edit Dialog allows the user to input and edit the data of the insulation, which is attached to the current element.

Height/Length of Insulation / Fireproofing Enter the height or length of the insulation on this element. This value is used only to calculate the weight of the insulation. For seismic calculations the weight center of the insulated section will be taken at half this height. Note that if you have insulation on a horizontal vessel the value entered in this cell will be the length of the insulated section. Note also that the only distinction between insulation and lining, from the program's point of view, is that insulation is on the OD of the element, while lining is on the ID of the element. Therefore, use the insulation field to enter OD fireproofing, and the lining field to enter ID fireproofing.

Thickness of Insulation or Fireproofing Enter the thickness of the insulation or fireproofing.

Insulation Density Enter the insulation density. The following table lists some typical densities, shown in lbs/ft3. Note that the densities should be converted if you are using another units system.


5-48

Vessel Detail Data

Name

Density

Calcium Silicate

22.5

Foam Glass

16.0

Mineral Wool

14.0

Glass Fiber

11.0

Asbestos

30.0

Careytemp

18.0

Kaylo 10

22.0

Perlite/Celo-temp 1500

23.0

Polyurethane

4.0

Styrofoam

3.0



5-49

Lining The Lining Edit Dialog allows the user to input and edit the data of the lining, which is attached to the current element.

Height/Length of Lining Enter the height or length of the lining on this element. This value is used only to calculate the weight of the lined section. For seismic calculations the weight center of the lined section will be taken at half this height. Note that if you have lining in a horizontal vessel the value entered in this cell will be the length of the lined section.

Thickness of Lining Enter the thickness of the lining or fireproofing. Note that the only distinction between insulation and lining, from the program's point of view, is that insulation is on the OD of the element, while lining is on the ID of the element. Therefore, use the insulation field to enter OD fireproofing, and the lining field to enter ID fireproofing.

Density of Lining Enter the density of the insulation, lining, or packing. The following table lists some typical densities, shown in lbs/ft3. Note that the densities should be converted if you are using another units system.

Name

Density (lbs/ft3)

Alumina Brick

170.0

Fire Clay

130.0

High Alumina

130.0

Kaolin

135.0

Magnesite

180.0

Silica

110.0

Concrete

140.0

Cement

100.0


5-50

Vessel Detail Data

Half Pipe Jacket Introduction PVElite is capable of performing the analysis of half-pipe jackets in accordance with ASME Code, Section VIII, Division 1 rules Appendix EE. The half-pipe jacket can be installed on cylindrical shells, and the jacket pitch, total length and half-pipe nominal diameter are taken into account.

Purpose, Scope and Technical Basis PVElite performs required thickness and Maximum Allowable Working Pressure calculations for cylindrical shells with half-pipe jackets attached. The module is based on the ASME Boiler and Pressure Vessel Code, Section VIII, Division 1. Specifically, the calculation is based on the rules in Paragraph EE-1, Appendix EE. It is important to note the limitations of this analysis. First, the half-pipe jacket analysis performed is only valid for the cylindrical geometries shown in Figure EE-4. These are the only two geometries addressed by paragraph EE-1. The second limitation of the HALF-PIPE analysis is the acceptable Nominal Pipe Sizes. Appendix EE only includes charts for Nominal Pipe Sizes 2, 3, and 4. Nominal Pipe Sizes greater than 4 or less than 2 will not be accepted in the input. Although there are no charts for Nominal Pipe Sizes 2.5 and 3.5, the HALF-PIPE Module will accept these sizes and perform iterations between the given charts. Additionally, if the half-pipe is a nonstandard pipe size or has a formed radius, the actual radius is used in the calculations. The HALF-PIPE module takes full account of corrosion allowance. Actual thickness values and corrosion allowances are entered, and the program adjusts thicknesses and diameters when making calculations for the corroded condition.

Figure A - HALF-PIPE Module Acceptable Geometries

Discussion of Input Data Before attempting to add a half-pipe, ensure the component to which the half-pipe is to be attached is a cylindrical shell; otherwise, PVElite will not be able to work.

Click

to activate the Half Pipe Jacket Input screen.



5-51

Main Input Fields Jacket Description Enter a description that will be used in the report generated by PVElite. Distance from "From" Node Use the illustration below to enter the distance in this field.

Length along Shell of Jacket section Enter the Length along the shell as illustrated above. Pitch Spacing Enter the pitch between the centers of adjacent half-pipes. Jacket Design Temperature Enter the Design Temperature of the half-pipe jacket (this is not necessarily the design temperature of the parent shell).


5-52

Vessel Detail Data

Jacket Design Pressure Enter the Design Pressure of the fluid inside the half-pipe jacket. Jacket Material Clicking

enables users to select the desired material from the drop down list.

Jacket Corrosion Allowance Enter the internal corrosion allowance of the half-pipe jacket.

Pipe Dimension from the PVElite Internal Pipe Dimension Database Click Pipe... to display the Pipe Selection dialog and select a standard pipe.

Pipe Selection Dialog

Nominal Pipe Diameter (in) Select the nominal diameter of the pipe.



5-53

Pipe Schedule Select the pipe schedule number Deduct Mill Tolerance from Thickness? If the mill undertolerance (usually 12-1/2% on pipe thickness), then check this box. PVElite will then reduce the thickness by the mill undertolerance. For Users Preferring to Enter the Pipe Dimensions follow these instructions: Jacket Thickness Enter the actual half-pipe wall thickness.

Inside Radius of Formed Jacket / or / Nominal Pipe Size The user is given the option of choosing a nominal pipe diameter from the PVElite internal pipe database,

or users may enter the actual internal radius of the half-pipe.

Nominal Pipe Size

This is an alternative drop down list box where users can select a standard pipe from the PVElite internal pipe database. Contents Specific Gravity Enter the specific gravity (SG) of the fluid inside the half-pipe jacket. This value is used when PVElite computes the vessel weights. Calculator Enables users to see the half-pipe analysis computation without having to analyze the whole vessel. A mini-screen displays containing the calculation results, thus allowing the user to see where problems with the design may exist.



CH AP TER

6

Chapter 6 General Vessel Data In This Chapter Introduction ................................................................................ 6-2 Design Data ................................................................................ 6-3 Installation Options..................................................................... 6-8 Design Modification ................................................................... 6-11 Nozzle Design Modifications ..................................................... 6-14 Wind & Seismic Data ................................................................. 6-16 Wind Data................................................................................... 6-17 ASCE Wind Data........................................................................ 6-18 UBC Wind Data.......................................................................... 6-20 NBC Wind Data.......................................................................... 6-22 ASCE 95 Wind Data................................................................... 6-24 IS 875 Wind Code ...................................................................... 6-27 User-Defined Wind Profile......................................................... 6-29 Mexican Wind Code 1993 .......................................................... 6-30 British Wind Code BS-6399 ....................................................... 6-37 Seismic Data ............................................................................... 6-41 ASCE 7-88 Seismic Data............................................................ 6-42 ASCE7-93 Seismic Data............................................................. 6-44 UBC Seismic Data ...................................................................... 6-45 NBC Seismic Data ...................................................................... 6-47 India's Earthquake Standard IS-1893 RSM and SCM ................ 6-49 ASCE - 95 Seismic Data............................................................. 6-50 Seismic Load Input in G's........................................................... 6-51 UBC 1997 Earthquake Data ....................................................... 6-52 IBC-2000 Earthquake Parameters............................................... 6-54 Response Spectrum..................................................................... 6-56


6-2

General Vessel Data

Introduction The information on the Design Constraint tab allows entry of global design data that the program will use as defaults before the model is created. Depending on the design code, the information gathered may differ slightly examples could include the hydrotest type, construction type and degree of radiography.


Chapter 6 General Vessel Data

6-3

Design Data Following is a discussion of the design data parameters that are used for overall vessel analysis:

Design Internal Pressure Enter the specified design internal pressure for the vessel. This value is used as general design data and also to set the UG-99(b) footnote 33 hydrotest pressure.

Design External Pressure If the vessel is required to be rated for vacuum conditions, enter the design external pressure here. PVElite will use this value as a default when the model is constructed.

Design Internal Temperature This value is used by the input echo to help insure the correct design data was entered. The analysis portion of the program does not use this value.

Design External Temperature If the vessel is required to be rated for vacuum conditions, enter the design external pressure here. PVElite will use this value as a default when the model is constructed.

Datum Line Distance Enter the location of the datum line from the first elements from node. After this is done you can use the list command to enter the locations of nozzles, platforms, etc. from the datum line.

Hydrotest Type The Internal Pressure Calculations report from PVElite will list hydrotest pressures for all three test types described below. It is important to properly identify the information requested throughout this input group. That is, even though Hydrotest Test Position, Projection from Top, Projection from Bottom, and Flange Distance to Top are not used for ASME UG-99(b) or for ASME UG-99(b) footnote 33, these data are necessary to report the proper hydrostatic test pressure for ASME UG-99(c). Select the hydrotest type. The analysis program provides three different ways to determine hydrotest pressure:

1 - ASME UG-99(b) The hydrotest pressure will be 1.3 times the maximum allowable working pressure for the vessel multiplied by the lowest ratio of the stress value Sa for the test temperature to the stress value S for the design temperature. This type of hydrotest is normally used for non-carbon steel vessels where the allowable stress changes with temperature


6-4

General Vessel Data

starting even at a somewhat low temperature. If Appendix body flanges have been specified, the bolt allowable stresses are included in determining Sa/S.

2 - ASME UG-99(c) The hydrotest pressure will be determined by multiplying the minimum MAP by 1.3 and reducing this value by the hydrostatic head on that element or flange. If the vessel is tested in the horizontal position, the hydrostatic head will be based on the maximum shell diameter plus the Projection from Top plus the Projection from Bottom specified later in this input group. If the vessel is tested in the vertical position and a vessel element sets the minimum MAP, then the hydrostatic head is set by the distance of that element from the top of the vessel plus the Projection from Top. If the vessel is tested in the vertical position and a flange has the minimum MAP, the hydrostatic head is composed of the Flange Distance to Top plus the Projection from Top.

3 - ASME UG-99(b) footnote 33 The hydrotest pressure will be 1.3 times the Design Internal Pressure specified at the beginning of this input group, multiplied by the lowest ratio of the stress value Sa for the test temperature to the stress value S for the design temperature.

Hydrotest Position This input is required so that the total static head can be determined and subtracted in accordance with UG-99(c). This field is used in conjunction with the Projection from Top, Projection from Bottom, and Flange Distance to Top fields to determine the total static head. Select one of the following Hydrotest Positions.

Hydrotest Position

Description

Vertical

The vessel would be tested in the upright or vertical position. Note that not very many vessels are tested in the vertical position.

Horizontal

This is the position for the majority of vessels tested. The vessel would normally be on its side (in the case of a vertical vessel) or in its normal position (for a horizontal vessel).

Projection from Top Enter the distance from the outer surface of the vessel in its test position to the face of the highest flange in the test position. This distance is added to the height (for vertical test positions) or to the maximum diameter of the vessel (for horizontal test positions) to determine the static head for the UG-99(c) hydrostatic test.

Projection from Bottom Enter this distance from the outer surface of the vessel in its test position to the face of the lowest flange in the test position. This distance is added to the height (for vertical test positions) or to the maximum vessel diameter (for horizontal test positions) to determine the static head for the UG-99(c) hydrostatic test.



6-5

Min. Metal Temperature Enter the specified minimum design metal temperature for the vessel. This value is listed in the Internal Pressure Calculations report for comparison with the calculated UCS-66 minimum temperature.

Flange Distance to Top If a flange controls the MAP of the vessel, the hydrostatic head associated with that flange may be important in determining the overall MAP of the vessel. The value entered here will be used by PVElite to calculate the hydrostatic head at this point and adjust the UG-99(c) MAP for vertically tested vessels. Once the controlling flange is identified (usually through a previous analysis) the distance from that flange to the top of the vessel is entered in this field. If the vessel is to be tested in the vertical position in accordance with UG-99(c), this value and the "Projection from Top" will be used to adjust hydrostatic test pressure should a (the) flange govern.

Construction Type Select the type of construction to be included on the nameplate. This data is for information only; it is reported in the input echo. Available types of construction display below: Type

Description

Welded

Welded

Pressure Welded

Pressure Welded

Brazed

Brazed

Resistance Welded

Resistance Welded

Special Service Select the type of special service in which the vessel will be used. This data is for information only; it is reported in the input echo. Available types of special service display below:

Field Name

Description

None

None

Lethal

Lethal Service

Unfired Steam

Unfired Steam Boiler

Direct Firing

Direct Firing

Non-stationary

Non-stationary Pressure Vessel

Degree of Radiography Select the symbolic representation of the degree of radiography. This data is for information only; it is reported in the input echo. Options include:


6-6

General Vessel Data

ASME VIII-1

Description

RT-1

When the complete vessel satisfies the full radiography requirements of UW-11(a) and when the spot radiography provisions of UW-11(a)(5)(b) have not been applied.

RT-2

When the complete vessel satisfies the full radiography requirements of UW-11(a)(5) and when the spot radiography provisions of UW-11(a)(5)(b) have been applied.

RT-3

When the complete vessel satisfies the spot radiography requirements of UW-11(b).

RT-4

When only part of the vessel has met the other category requirements, or when none of the other requirements are applied.

Miscellaneous Weight Many designers like to include extra weight to account for vessel attachments and internals not otherwise included in the models. The total weight of the vessel is multiplied by 1.0 plus this percent (i.e., 1.03, 1.05). The two most common choices are 3.0 or 5.0.

Use Higher Longitudinal Stresses? Checking this selection will increase the allowable stresses for vessel loads which include wind or earthquake by twenty percent. The ASME Code (Section VIII, Division 1, Paragraph UG-23(d)) allows the allowable stress for the combination of earthquake loading, or wind loading with other loadings to be increased by a factor of 1.2.

Hydrotest Allowable Un-modified By default PVElite uses the hydrotest stress times the stress increase factor for occasional loads ( times the joint eff. on the tensile side ). If you wish to use 90 percent of the material yield stress for the hydrostatic test allowable, check the box to do so.

Consider Vortex Shedding? For vertical vessels, which are susceptible to wind induced oscillations, check this field. This will cause the program to compute fatigue stresses based on loads generated by wind flutter. The program will then go on to compute the number of hours of safe operation remaining under the wind vibration conditions.

User Defined MAWP/MAPnc Normally PVElite computes the MAWP and the MAPnc based on pressure ratings for the elements and ANSI flanges. In some cases it may be necessary to override the program's generated results with a pre-defined value. If this value is zero it will be ignored by the program. This is the default behavior.

User Defined Hydrostatic Test Pressure Normally the program computes the hydrostatic test pressure. It is then used to determine the stresses on the elements when subjected to this pressure. If this value is greater than 0, PVElite will use this pressure plus the applicable hydrostatic head, which will be computed based on the hydrotest position. If this value is 0, the program will use the computed value based on the hydrotest type and position.



6-7

Corroded Hydrotest? By default PVElite uses the uncorroded wall thickness when the stresses on the elements during the hydrotest are computed. In some cases it is necessary to hydrotest the vessel after it has corroded. If you wish to use a corroded thickness in the calculations, check this box. Please note that longitudinal stresses due to Hydrostatic test pressure will also be computed in a similar manner.

Is This a Heat Exchanger If the Dimensional Solutions 3D file interface button is checked, PVElite will write out an ASCII text file that contains the geometry and loading information for this particular vessel design. If this box is checked, the program will simply write this data out to the Jobname.ini file created in the current working directory.

Hydrotest Allowable is 90 percent of Yield If you wish to ignore using 1.3 times Sa for the allowable, then check this box. This applies only for Division 1 vessel designs. Checking and un-checking this box will cause PVElite to recompute the hydrotest allowable.

ASME Steel Stack If you are designing a cylindrical ASME Steel Stack and wish to have PVElite analyze allowables and stress combinations per ASME STS-2003(a), then check this box. Please note the design code must be set to ASME VIII1. Otherwise, the program will not attempt to analyze per STS-2003(a). Note that on the grid, next to the ASME Steel Stack heading there is a list expansion button. When pressed it will either collapse or expand the remaining stack entries. These are the ASCE wind exposure and the importance factor. Please note that other wind codes can be used, but the exposure is a required entry.


6-8

General Vessel Data

Installation Options The installation options shown below allow the specification of where the equipment such as platforms, insulation, lining, etc. will be installed. This information is used to calculate the center of gravity of the vessel in both the shop and the field (operating) positions. Additionally, when computing such items as the fabricated weight, operating weight, empty weight, etc., PVElite will consider these detail weights as appropriate for the various weight cases.

Platform Area Calculation Method PVElite uses the area of the platforms in the computation of forces that are applied to the vessel during the wind loading analysis. Unfortunately, there is no standard method for computing the amount of area that a platform provides for wind load calculations. Select one of the 4 options in the pull down box: This selection will be used to compute the wind area for all platforms specified in this job. If you decide to change this option after the model has been created, you will need to recompute the areas for these platforms. Click the list button and one the list dialog appears, all of the platform wind areas can be recomputed with the touch of a button.

Stiffener Type For ASME VIII-1 and VIII-2 the program has the ability to determine the maximum stiffener spacing and add rings to the model. If you have selected this position to model, it can select an appropriate stiffener from the AISC or selected database. If you have a non-AISC database selected, be sure the selected Stiffener type exists in the database. The stiffener types are: Equal Angle Unequal Angle (hard way shown) Double Angles with large or small sides back to back Channels Wide Flanges Structural Tees Bar For the bar ring design, the program will design a ring with an aspect ratio of 10 to 1.00. The height of the ring is 10 times its thickness. The minimum ring width the program will start out with is 0.5 inches or 12mm.

For Angle Sections Rolled the Hard Way If the stiffener above is an angle type, they are frequently rolled to have the strong axis of the ring perpendicular to the vessel wall. If they are rolled the hard way check this box.



6-9

Bar Thickness to Use Designing When the bar ring option is selected the program must have a thickness to use when computing a suitable ring. For the ring design, the program will generate a ring with a 10 to 1 aspect ratio. In other words, the width of the ring will be 10 times bigger. This value can be left blank. If it is blank, the program will use a default thickness of 0.375 inches or 9 mm. When computing the ring width to meet the moment of inertia requirements.

Rigging Data The rigging analysis calculates and locates the bending and shear stresses created during erection process. Where the vessel is lifted from the horizontal position at two lifting points up to the vertical position where the vessel is set onto the foundation. The safety of the maximum combined stresses is also analyzed using the unity check method. This analysis however, does not evaluate the design of any rigging attachment such as, lugs, shackles, cables etc Rigging analysis is performed when the vessel is in the horizontal position where the combinations of stresses are at its maximum. The torsional effect is not considered in this analysis. The vessel is erected using two lifting points where the tail and lifting lugs are located. The design weight of the vessel is calculated by multiplying the erected empty weight, including internals and externals, with an impact factor to simulate the initial lift. The rigging analysis reports the field and design weight of the vessel, the center of gravity, the reaction forces at the lifting points, the location for the maximum bending and shear stresses, and the unity check. As a comparison, the allowable bending (per UG-23) and shear (0.4 Sy @ ambient) stresses are also reported, and can be plotted with the fore-mentioned parameters. The stresses are calculated in 1-foot increments along the vessel taking into account the varying diameter and thickness of the shell. A circular cross sectional shape is assumed throughout the vessel sections with no corrosion allowance included for the thicknesses. Node numbering starts at the base of the vessel and ends at the top section of the vessel where the straight line ended. For elliptical heads, the end node is the end of the straight-line portion. Thus the total height of the vessel is the elevation of the last node.

Impact Factor PVElite can perform a rigging (combined shear plus bending stress) analysis granted that the vessel has a support such as a skirt and the impact factor and lug elevations defined. When the vessel is lifted from the ground, it may be yanked suddenly. The impact factor takes this into account. This value typically ranges from 1.5 to 2.0, although values as high as 3.0 may be entered in. The impact factor effectively increases the overall weight of the vessel by the impact factor. If you do not wish to perform the rigging analysis, set the impact factor to 0.

Lug Distances from Base You will have to enter two distances (one in each field) to perform the rigging analysis. These distances are measured from the bottom of the vertical vessel or from the left end of the horizontal vessel. It does not matter which dimension goes in which box. The lesser distance will be the minimum of the two values.


6-10

General Vessel Data

Select from Standard Bar Ring List If this box is checked and the program is set to add reinforcing rings during runtime, PVElite will check all rings from smallest to largest and determine the minimum ring that will satisfy the moment of inertia requirements per UG29(a) or Appendix 1-5 or 1-8 in the case of cone cylinder junction ring design. A list of sizes is shown in the table below: Ring Thickness (in.)

Ring Width (in.)

1/4

1.5

1.75

2.0

2.5

...

3/16

2.5

...

...

...

...

3/8

2.0

2.5

3.0

3.5

4.0

1/2

3.5

4.0

4.5

5.0

5.5

5/8

5.0

6.0

...

...

...

3/4

5.0

5.5

6.0

8.0

...

7/8

6.0

8.0

...

...

...

1

6.0

8.0

10.0

11.0

...

1.25

8.0

10.0

12.0

...

...

1.5

8.0

10.0

12.0

...

...

2

12.0

18.0

...

...

...

4

30.0

...

...

...

...

Saddle Calculation Option Choose the appropriate option, Zick or PD-5500. Either option will work for any code.

Use New Metal Weights for Saddle Calcs. By default PVElite uses the corroded metal weight when determining saddle loads for the operating condition. If you wish to use the new metal weight to determine the saddle load, check the box.

Number of Intermediate Support to be used during the Hydrotest When some larger vessels are hydrotested after construction, a number of intermediate supports may be placed under the vessel to keep the saddle stresses below their allowables. If this is the case, type in the number of intermediate supports that will be used. This value can range from 0 to 20.



6-11

Design Modification Select Wall Thickness for Internal Pressure If the user toggles on this button and the required element thickness for internal pressure exceeds the user's finished thickness for the element, the program will increase the user's finished thickness to meet or exceed the thickness required for internal pressure. PVElite will exceed the required thickness only if the round off switch is activated in the program configuration (the round off will bump the thickness up to the next 1/8 inch in English units or to the next millimeter in metric units). The program will perform this calculation automatically as the model data is being typed in. Check this box before any part of the vessel has been modeled. If the given thickness is greater than the required thickness, then the program will not alter the given value. Note that during the input phase, the program cannot check the required thickness for flanges. That check will be performed during the analysis phase.

Select Wall Thickness for External Pressure If this check box is checked the program will calculate the required thickness of each element (or group of elements) and increase the given thickness appropriately for the external pressure. Note that if the user selects this button, the program will not calculate stiffening rings for the external pressure. After the analysis the program may prompt stating that the input file has been modified. If any of the elements have been thickened, simply select "yes" to the prompt and your model will be updated with the current changes.

Select Stiffening Rings for External Pressure If the user toggles on this button, the program will calculate the location and size stiffening rings needed for the external pressure. Note that if the user selects this button, the program will not modify thickness for the external pressure. After the analysis the program may prompt stating that the input file has been modified. If any rings have been added, simply select "yes" to the prompt and your model will be updated with the current changes. Please note that in order to do this the program computes the allowable length between stiffeners. This result must come out to be some reasonable value. If the maximum stiffened is too small, the program will not be able to add rings. In that case, you must increase the thickness of the shell and try the design again. Also note that the heads must also be properly designed for external pressure. Please verify that the thickness for external pressure is adequate.

Select Wall Thickness for Axial Stress If the user toggles on this button he program will calculate the required thickness of each element (or group of elements) for longitudinal loadings (wind, earthquake, weight of vertical vessels) and increase the given thickness appropriately for the axial stress. PVElite will exceed the required thickness only if the round off switch is activated in the program configuration (the round off will bump the thickness up to the next 1/8 inch in English units or to the next millimeter in metric units).


6-12

General Vessel Data

Load Case The program performs calculations for various combinations of internal pressure, external pressure, hydrotest pressure, wind load, and seismic load. You can define up to twelve combinations of these loadings for the program to evaluate. Load cases are defined by a string that shows the loads to be added, i.e. "IP+OW+WI", which would be the sum of internal pressure plus operating weight plus wind. Typical definitions for the load cases are shown below, followed by the definition of the load case abbreviations:

Load Case Abbreviations NP

No Pressure

IP

Internal Pressure

EP

External Pressure

HP

Hydrotest Pressure

EW

Empty Weight

OW

Operating Weight

HW

Hydrotest Weight

WI

Wind Load

EQ

Earthquake Load

HE

Hydrotest Earthquake

HI

Hydrotest Wind

WE

Wind Bending Empty New and Cold

WF

Wind Bending Filled New and Cold

CW

Axial Weight Stress New and Cold

FS

Axial Stress due to Applied Axial Forces (Seismic Case)

FW

Axial Stress due to Applied Axial Forces (Wind Case)

BW

Bending Stress due to Lat. Forces for the Wind Case, Corroded

BS

Bending Stress due to Lat. Forces for the Seismic Case, Corroded

BN

Bending Stress due to Lat. Forces for the Wind Case, UnCorroded

BU

Bending Stress due to Lat. Forces for the Seismic Case, UnCorroded

If you checked the box to perform vortex shedding calculations, the following load case descriptors may be used:



6-13

Load Case Descriptors VO

Bending Stress due to Vortex Shedding Loads (Ope)

VE

Bending Stress due to Vortex Shedding Loads (Emp)

VF

Bending Stress due to Vortex Shedding Loads (Test No CA.)

The live loads (wind and earthquake) are calculated for two conditions - operating and hydrotest. In both cases, the basic loads calculated are identical but the hydrotest live loads are usually a fraction of the operating live load. These hydrostatic fractions (percents) are entered in the live load definitions.


6-14

General Vessel Data

Nozzle Design Modifications PVElite has three mutually exclusive options for determination of the pressure where the nozzle is located. The fourth design option allows reinforcing calculations for the geometry to be made in the new and cold condition helping to satisfy hydrotest requirements. The last option deals with compliance with nozzle design for wind and seismic considerations. Check the option(s) you wish the program to use.

Nozzle Design Modifications, Design Pressure, M.A.W.P. + Static Liquid Pressure Computes the internal pressure on the nozzle on the bottom of the element where the nozzle is located. This pressure is the MAWP of the vessel plus the static head to the bottom of that element. Thus, the design pressure can vary for nozzles located on different elements. This option is OK to use if you know for certain that your nozzle locations will not vary during the design process. If you use this option and a nozzle is lowered in the vessel and under additional pressure due to liquid head, you need to rerun the analysis in order to determine if your nozzle geometry is satisfactory.

Nozzle Design Modifications, Design Pressure, Design Pressure + Static Liquid Pressure Computes the exact internal pressure at the nozzle location. Normally, this option would be used for re-rating vessels. This would allow one to get the exact results for each nozzle, because the overall pressure on each nozzle is computed on an individual basis.

Nozzle Design Modifications, MAWP + Static Liquid Pressure to the bottom of the Element that is governing the MAWP Computes one single design internal pressure for all of the nozzles located on the vessel. If the nozzle location on a vessel changes due to a client request, there would be no need to rerun nozzle calculations since the pressure used in the calculations would not change. This design option is ideal for designing new vessels.

MAWP + Static Liquid Pressure to the Nozzle Computes the MAWP of the vessel and then adds the static liquid pressure from the liquid surface to the nozzle location. For nozzles at different elevations, the design pressure will vary.

Nozzle Design Modifications, Consider MAP nc in Analysis Some design specifications require that nozzle reinforcement calculations are performed for the MAP new and cold condition. PVElite will check to see if the nozzle is reinforced adequately using the MAPnc generated during the internal pressure calculations. When the area of replacement calculations are made for this case, cold allowable stresses are used and the corrosion allowance is set to 0. Designing nozzles for this case helps the vessel to comply with UG99 or appropriate (hydrotest) requirements. Check your design requirements to see if your client requires this case.

Modify Tr Based on the Maximum Stress Ratio Some Nozzle designs need to comply with ASME Section VIII Division 1 paragraph UG-22 that deals with supplemental loadings. One factor in ASME nozzle design is the required thickness of the shell (tr). Usually internal pressure (hoop stress) governs. In some cases, such as when a nozzle is located on a shell course at the bottom of a



6-15

tall tower, longitudinal stresses will govern. In this case the shell required thickness must be based on longitudinal stresses and not the hoop stress. If you check this option, PVElite will look at all of the defined load cases and select the highest stress ratio. It will then use this number as a multiplier on the shell thickness. Thus the nozzle design is based on the precise loading at the bottom of that shell course. Note: Optionally, for full replacement options, you can type in your own value of tr for each nozzle. That value will override this directive.

Consider Code Case 2168 for Nozzle Design For Div. 1 nozzles of integral construction, the Code in Code Case 2168 allows a different set of rules to be used from those in UG-37. If it is within the project specifications to use these rules enable this box.

Redesign Pads to Reinforce Openings If this box is checked and pad defined geometries are inadequately reinforced, PVElite will determine the diameter and thickness of the pad required to reinforce the opening. If the program has changed the pad data during the analysis, it will prompt you to reload the file so that you can view the new changes. Note that this functionality is restricted to ASME VIII analysis at this time.


6-16

General Vessel Data

Wind & Seismic Data The Wind data is available when the wind tab is pressed. The seismic data works in the same manner.



6-17

Wind Data Wind Design Code Select one wind of the design codes: ASCE

American Society of Civil Engineers Standard 7 (formerly ANSI A58.1) The program implements ASCE 793.

UBC

Uniform Building Code. The program implements the 1991 edition.

NBC

National Building Code of Canada. The program implements the 1990 edition.

User Defined Wind Profile.

Instead of supplying the wind parameters required by the above codes, the user may specify the elevation vs. wind pressure directly.

ASCE-1995/98

The American Society of Civil Engineers Standard 7 1995/1998. This revision includes a new calculation for the gust factor as well as the wind pressure at height Z. These calculations are based on a 3 second gust.

Mexico 1993

Mexico's National Wind Code

BS-6399 1997

Standard Wind Code of Britain, replaces CP3

AS/NZ

Design Wind Code of Australia and New Zealand, 2002 edition

Euro Code

This is the Design Wind Code for several European Countries including France.

IS-875

This is India's National Standard Wind design code. The year of this code is 1987.

The remaining wind load data required by PVElite changes based on which Wind Design Code is selected. These data requirements are reviewed here according to the design code specification.


6-18

General Vessel Data

ASCE Wind Data Design Wind Speed Enter the design value of the wind speed. These will vary according to geographical location and according to company or vendor standards. Typical wind speeds range from 85 to 120 miles per hour. Enter the lowest value reasonably allowed by the standards you are following, since the wind design pressure (and thus force) increases as the square of the speed.

Exposure Constant Enter an integer indicating the ASCE-7 Exposure Factor:

Entry

Definition

1

Exposure A, Large city centers

2

Exposure B, Urban and suburban areas

3

Exposure C, Open terrain

4

Exposure D, Flat unobstructed coastal areas

Note that most petrochemical sites use a value of 3, exposure C.

Base Elevation Enter the elevation at the base of the vessel. This value will be used to calculate the height of each point in the vessel above grade. Thus, for example, if the vessel is mounted on a pedestal foundation, or on top of another vessel, it will be exposed to higher wind pressures than if it were mounted at grade.

Percent Wind for Hydrotest Enter the fraction of the wind load (not wind speed) that will be applied during the hydrotest. This is typically as low as one-third the design wind load, since it can be assumed that the vessel will not be hydrotested during a hurricane or severe storm.

ASCE 7-93 Importance Factor Enter the value of the importance factor that you wish the program to use. Please note the program will use this value directly without modification. In general this value ranges from .95 to 1.11. It is taken from Table 5 of the ASCE standard.



Category

6-19

100 mi. from Hurricane Oceanline

< 100 mi. from Hurricane Oceanline

I

1.00

1.05

II

1.07

1.11

III

1.07

1.11

IV

0.95

1.00

Category

Classification

I

Buildings and structures not listed below

II

Buildings and structures where more than 300 people congregate in one area.

III

Buildings designed as essential facilities, hospitals etc.

IV

Buildings and structures that represent a low hazard in the event of a failure.

Note that most petrochemical structures are Importance Category I.

ASCE Roughness Factor Enter an integer indicating the ASCE-7 Roughness Factor (from ASCE 7-93, Table 12 Force Coefficients for Chimneys, Tanks, and Similar Structures, Cf)

Entry

Definition

1

Round, moderately smooth

2

Round, rough (D'/D = 0.02)

3

Round, very rough (D'/D = 0.08)

Where: D' is the depth of protruding elements such as ribs and spoilers and D is the diameter or least horizontal dimension. Note that most petrochemical sites use a value of 1, moderately smooth, except that some designers use a value of 3, very rough, to account for platforms, piping, ladders, etc. instead of either entering them explicitly as a tributary wind area or implicitly as an increased wind diameter. The value Cf will vary between 0.5 and 1.2 depending on the type of surface and height to diameter ratio.


6-20

General Vessel Data

UBC Wind Data Design Wind Speed Enter the design value of the wind speed. These will vary according to geographical location and according to company or vendor standards. Typical wind speeds range from 85 to 120 miles per hour. Enter the lowest value reasonably allowed by the standards you are following, since the wind design pressure (and thus force) increases as the square of the speed.

Exposure Constant Enter an integer indicating the UBC Exposure Factor as defined in Section 2312:

Entry

Definition

2

Exposure B, Terrain with buildings, forest or surface irregularities 20 feet or more in height covering at least 20 percent or the area extending one mile or more from the site.

3

Exposure C, Terrain, which is flat and generally open, extending one-half mile or more from the site in any full quadrant.

4

Exposure D, The most severe exposure with basic wind speeds of 80 m.p.h. or more. Terrain, which is flat and unobstructed facing large bodies of water over one mile or more in width relative to any quadrant of the building site. This exposure extends inland from the shoreline 1/4 mile or 10 times the building (vessel) height, whichever is greater.

Note that most petrochemical sites use a value of 3, exposure C. This value is used to set the Gust Factor Coefficient (Ce) found in Table 23-G.



UBC Wind Importance Factor Enter the value of the UBC Importance Factor. Please note the program will use this value directly without modification. This value is taken from Table 23-L of the UBC standard:



Entry

Definition

1.15

Category I: Essential facilities

1.15

Category II: Hazardous facilities

1.0

Category III: Special occupancy structures

1.0

Category IV: Standard occupancy structures

6-21

Most petrochemical structures have an Importance Factor of 1.0. The four Occupancy Categories (I-IV) are defined in Table 23-K of the code.


6-22

General Vessel Data

NBC Wind Data Design Wind Speed Enter the design value of the wind speed. These will vary according to geographical location and according to company or vendor standards. Typical wind speeds range from 85 to 120 miles per hour. Enter the lowest value reasonably allowed by the standards you are following, since the wind design pressure (and thus force) increases as the square of the speed.

Exposure Constant Enter an integer indicating the NBC Exposure Factor: Entry

Definition

1

Exposure A, open or standard exposure

2

Exposure B, urban and suburban areas

3

Exposure C, centers of large cities

Note that most petrochemical site use a value 1, Exposure A. Note also that these exposure factors are reversed from those of ASCE-7 or UBC.



Critical Damping Ratio The dynamic gust evaluation in NBC requires that the user assign a critical damping ratio for the tower. NBC recommends the use of the value 0.0016 (dimensionless) for tall metal unlined stacks, but says that these values will go up for shorter towers. We recommend the following: Entry

Definition

0.0016

For tall towers ( L/D > 7 )

0.0032

For moderately tall towers

0.0064

For short towers ( L/D < 1) or horizontal



6-23

Roughness Factor Enter an integer indicating the NBC Roughness Factor as found in Figure B-15. Entry

Definition

1

Round, moderately smooth surface

2

Round, rough surface (rounded ribs, h = 2%d)

3

Round, very rough surface (sharp ribs, h = 8%d)

Note that most petrochemical sites use a value of 1, moderately smooth, except that some designers use a value of 3, very rough, to account for platforms, piping, ladders, etc. instead of either entering them explicitly as a tributary wind area or implicitly as an increased wind diameter.


6-24

General Vessel Data

ASCE 95 Wind Data Percent Wind for Hydrotest Enter the fraction of the wind load (not wind speed) that will be applied during the hydrotest. This is typically as low as one-third the design wind load, since it can be assumed that the vessel will not be hydrotested during a hurricane or severe storm.

Design Wind Speed Enter the design value of the wind speed. These will vary according to geographical location and according to company or vendor standards. Typical wind speeds range from 85 to 120 miles per hour. Enter the lowest value reasonably allowed by the standards you are following, since the wind design pressure (and thus force) increases as the square of the speed.


Exposure Constant Enter an integer indicating the ASCE Exposure Factor:

Entry

Definition

1

Exposure A, large city centers

2

Exposure B, urban and suburban areas

3

Exposure C, open terrain

4

Exposure D, flat unobstructed coastal areas

Note that most petrochemical site use a value 1, Exposure A. Note also that these exposure factors are reversed from those of ASCE-7 or UBC.

Importance Factor This value varies between .087 and 1.15 and is found in Table 6-2 of ASCE 95.



6-25

Roughness Factor Enter an integer indicating the Roughness Factor as found in Table 6-7: Entry

Definition

1

Round, moderately smooth surface

2

Round, rough surface

3

Round, very rough surface

Note that most petrochemical sites use a value of 1, moderately smooth, except that some designers use a value of 3, very rough, to account for platforms, piping, ladders, etc. instead of either entering them explicitly as a tributary wind area or implicitly as an increased wind diameter.

Height of Hill (H) Height of Hill or Escarpment relative to the upwind terrain.

Distance to Site (x) Enter the distance ( upwind or downwind ) from the crest to the building site

Height above Ground ASCE defines this value as height above local ground level.

Crest Distance This is the distance upwind of the crest where the difference in ground elevation is half the hill or escarpment height.

Type of Hill None 2-D ridge 2-D escarpment 3-D axisymmetric hill

Damping Factor Enter the structural damping coefficient (percentage of critical damping). The damping factor is used in the calculation of the gust response factor. Additionally, if you wish to run another case empty or filled (or both), specify the values of the damping factor (beta) for these cases. By entering these values PVElite will compute the gust response factor for each case and the subsequent wind loads. The results will be displayed in the Wind Load Calculation and Wind Shear and Bending reports.


6-26

General Vessel Data

Technical Note: Computation of h/d from table 6-7. For vessels that have a constant diameter the value of h/d is straightforward. The ratio is merely the total height of the vessel divided by the insulated outside diameter. This computation is more difficult for vessels of more than 1 diameter (i.e.: vessels that have cones). The first step is to compute the total height h. Next the total cross sectional area of the vessel is computed. To get a properly weighted value for h/d we square the maximum height and divide by the total area. Finally to get Cf we index into the table as needed and interpolate for the final value. If you have a shape factor specified and do not wish to use the computed value, specify your own shape factor in the Tools, Configuration option from the Main Menu.



6-27

IS 875 Wind Code Percent Wind for Hydrotest Enter the fraction of the wind load (not wind speed) that will be applied during the hydrotest. This is typically as low as one-third the design wind load, since it can be assumed that the vessel will not be hydrotested during a hurricane or severe storm. Enter the design value of the wind speed. These will vary according to geographical location and according to company or vendor standards. Typical wind speeds range from 85 to 120 miles per hour. Enter the lowest value reasonably allowed by the standards you are following, since the wind design pressure (and thus force) increases as the square of the speed.


Wind Zone Number India is divided into 6 wind zones. Refer to figure 1 in the IS-875 code to determine which wind zone the vessel will operate in. The program will gather the basic wind speed based on the zone. However, this value can be overridden by typing in a basic wind speed in the Design Wind Speed field.

Risk Factor This is the value of K1 and it varies between 1.05 and 1.08 depending on which zone has been entered above.

Terrain Category The terrain category varies between 1 and 4.

Category 1 Exposed open terrain with few or no obstructions including open sea coasts and treeless plains.

Category 2 Open terrain with scattered obstructions having heights between 1.5 to 10 meters. This category is generally used for design purposes.


6-28

General Vessel Data

Category 3 This is terrain with numerous closely spaced obstructions, which have buildings up to 10 M in height. This includes well-wooded areas, towns and industrial areas fully or partially developed.

Category 4 Terrain consisting of large closely spaced obstructions. This category includes large urban centers and well developed industrial centers.

Equipment Class This field accepts a value of 1, 2, or 3. Class A - 1 Class B - 2 Class C - 3

Consider Gust Response Factor If you wish to include the gust response factor per IS-875, check this box. However, since this factor increases the wind load 3 to 6 times, it may lead to a very conservative wind design.



6-29

User-Defined Wind Profile Percent Wind for Hydrotest Enter the fraction of the wind load (not wind speed) that will be applied during the hydrotest. This is typically as low as one-third the design wind load, since it can be assumed that the vessel will not be hydrotested during a hurricane or severe storm.

Wind Profile Data With this selection, PVElite will forego all code calculations and simply use the user's profile of height versus wind pressure. Enter the profile in the area below the standard wind design code data. Enter the height above grade (in length units) in the left cell, and the wind pressure at that height in the right cell. If you have more cells available than you need to describe the profile, simply enter zeros in all the remaining cells. Zero elevation corresponds to the bottom of the skirt or leg supports for a vertical vessel and to the bottom of the saddle, which supports a horizontal vessel. Note When entering this data, you need to multiply the wind pressure at each elevation by the shape factor you wish to use. If you do not do this, your wind loads will be higher (conservative) than they really are. The first Elevation field should not be zero. If it is zero the program will not compute the wind loads on the following elements. The input should follow the convention below.


6-30

General Vessel Data

Mexican Wind Code 1993 Percent Wind for Hydrotest Enter the fraction of the wind load (not wind speed) that will be applied during the hydrotest. This is typically as low as one-third the design wind load, since it can be assumed that the vessel will not be hydrotested during a hurricane or severe storm.

Design Wind Speed Enter the design value of the wind speed. These will vary according to geographical location and according to company or vendor standards. Typical wind speeds range from 85 to 120 miles per hour. Enter the lowest value reasonably allowed by the standards you are following, since the wind design pressure (and thus force) increases as the square of the speed.


Párrafo 4.6.1 Tabla 1.1 CATEGORIA DEL TERRENO SECUN SU RUGOSOIDAD Cat.

Descripción

Ejemplos

Limitaciones



6-31

Cat.

Descripción

Ejemplos

Limitaciones

1

Terreno abierto, prácticamente piano y sin obstrucciones

Franjas costeras planas, zonas de pentanos, Campos aéreos, pastizales y tierras de cultivo sin setos o bardas alrededor. Superficies nevadas planas

La longitud mínima de este tipo de terreno en la dirección del viento debe ser de 2000 m 0 10 veces la altura de las construcción por diseñar, la que sea mayor.

Terreno plano u ondulado con pocas obstrucciones

Campos de cultivo o gran jas con pocas obstrucciones tales como setos o bardas alrededor, árboles y construcciones dispersas

Las obstrucciones tienen Alturas de 1.5 a 10 m, en una longitud mínima d 1500 m.

Terreno cubierto por numerosas obstrucciones estrechamente espaciadas

Áreas urbanas, suburbanas y de bosques, o cualquier terreno con numerosas obstrucciones estrechamente espaciadas. El tamaño de las construcciones corresponde al de las casas y viviendas.

Las obstrucciones presentan Alturas de 3 a 5 m. La longitud mínima de este tipo de terreno en la dirección del viento debe ser de 500 m o 10 veces la altura de la construcción, la que sea mayor.

Terreno con numerosas obstrucciones largas, allas y estrechamente espaciadas

Centros de grandes ciudades y complejos industriales bien desarrollados.

Por lo menos el 50% de los edificios tiene una altura mayor que 20 m. Las obstrucciones miden de 10 a 30 m de altura. La longitud mínima de este tipo de terreno en la dirección del viento debe se la mayor entre 400 m y 10 veces la altura de la construcción.

2

3

4

Párrafo 4.6.2 MAPAS DE ISOTACAS VELOCIDAD REGIONAL, VR La velocidad regional del viento, VR, es la máxima velocidad media probable de presentarse con un cierto periodo de recurrencia en una zona o región determinada del país. En los mapas de isotacas que se incluyen en este inciso con diferentes periodos de retorno, dicha velocidad se refiere a condiciones homogéneas que corresponden a una altura de 10 metros sobre la superficie del suelo en terreno piano (Categoría 2 según la tabla I.1); es decir, no considera alas características de rugosidad locales del terreno ni la topografía especifica del sitio. Asimismo, dicha velocidad se asocial con ráfagas de 3 segundos y toma en cuenta lo posibilidad de que se presenten vientos debidos a huracanes en las zonas coteras. La velocidad regional, VR, se determina tomando en consideración tanto la localización geográfica del sitio de desplante de la estructura como su destino. En las figures I.1 a I.4 se muestran los mapas de isotacas regionales correspondientes a periodos de recurrencia de 200, 50 y 10 anos, respectivamente. La importancia de las estructuras (vease el inciso 4.3) dictamina los periodos de recurrencia que deberán considerarse para el diseño por viento; de esta manera, los Grupos A, B y C se asocian con los periodos de retorno de 200, 50 y 10 anos, respectivamente. El sitio de desplante se localizara en el mapa con el periodo de recurrencia que corresponde al grupo al que pertenece la estructura a fin de obtener la velocidad regional. En el Tomo III de Ayudas de diseño se presenta un tabla con las principales ciudades del país y sus correspondientes velocidades regionales para diferentes periodos de retorno.


6-32

General Vessel Data

Párrafo 4.6.3 FACTOR DE EXPOSICION, FR El coeficiente Fg refleja la variación de la velocidad del viento con respecto a la altura Z. Asismo, considera el tamaño de la construcción o de los elementos de recubrimiento y las características de exposición o de los elementos de recubrimiento y las característica de exposición. El factor de exposición se calcula con siguiente expresión: F" = FC FRZ en donde: FC=

se el factor que determina la influencia del tamaño de la construcción, adimensional, y

FRZ=

el factor que establece la variación de la velocidad del viento con la altura Z en función de la rugosidad del terreno de los alrededores, adimensional.

Los coeficientes FC y FRZ se definen en los incisos 4.6.3.1 y 4.6.3.2, respectivamente.

Párrafo 4.6.3.1 to 3 Factor de tamaño, FC R T U El factor de tamaño, FC, es el que toma en cuenta el tiempo el que la ráfaga del viento actúa de manera efectiva sobre una construcción de dimensiones dadas. Considerando la clasificación de las estructuras según su tamaño (vease la tabla I.2), este factor puede determinarse de acuerdo con la tabla I.3. Clase de estructura

FC

A

1.0

B

0.95

C

0.90

Tabla I.4 VALORES DE R T U N

Categoría de terreno

Clase de estructura A

B

C

P



6-33

1

0.099

0.101

0.105

245

2

0.128

0.131

0.138

315

3

0.156

0.160

0.171

390

4

0.170

0.177

0.193

455

hi - es la altura, media a partir del nivel del terreno de desplante, por encima de la cual la variación de la velocidad del viento no es importante y se puede suponer constante; a esta altura se le conoce como altura gradiente; h y Z están dadas en metros, y giel exponente que determina la forma del la variación de la velocidad del viento con la altura y es adimensional. g - Los coeficientes g j h están en función de la rugosidad terreno (tabla I.1) [see above please]. En la tabla I.4 se consignan los valores que se aconsejan para estos coeficientes. En la figura III.1 del tomo de Ayudas de diseño se muestra la variación del factor Fg con la altura, con la categoría del terreno y con la clase de estructura.

Párrafo 4.5.4 FACTOR DE TOPGRAFIA, FT Este factor toma en cuenta el efecto topográfico local del sitio en donde se desplantara la estructura. Así, por ejemplo, si la construcción se localiza en las laderas o cima de colina o montanas de altura importante con respecto al nivel general del terreno de los alrededores, es muy probable que se generen aceleraciones del flujo del viento y, por consiguiente, deberá incrementarse la velocidad regional.

Tabla I.5 FACTOR DE TOPOGRAFIA LOCAL FT Sitios

Topografía

FT

Base de promontorios y faldas de serranías del lado de sotavento.

0.8

Valles cerrados.

0.9

Terreno prácticamente plano, campo abierto, ausencia de cambios topográficos importantes, con pendientes menores que 5%.

1.0

Terrenos inclinados con pendientes entre 5 y 10%, valles abiertos y litorales planos.

1.1

Cimas de promontorios, Colinas o montanas, terrenos con pendientes mayores que 10%, cañadas cerradas y valles que formen un embudo o canon, islas.

1.2

Protegidos

Normales

Expuestos

Expertos en la material deberán justificar y validar ampliamente los resultados de cualquiera de estos procedimientos.


6-34

General Vessel Data

Párrafo 4.6.5 W LA RELACION ENTRE LOS VALORES DE LA ALTITUD hm Altitud (msnm)

Presión barométrica (mm de Hg)

0

760

500

720

1000

675

1500

635

2000

600

2500

565

3000

530

3500

495

Nota: Puede Interpolarse para valores intermedios de la altitud, hm.



6-35

Párrafo 4.8.2.12 COEFICIENTE DE ARRASTRE Ca PARA CHIMENEAS Y TORRES

COEFICIENTE DE ARRASTRE Ca Sección transversal

Tipo de superficie

Circular (bVd l 6 m2/s)

Relación H/b 1

7

25

R40

Lisa o poco rugosa (d’/b k 0.0)

0.5

0.6

0.7

0.7

Rugosa

(d’/b k 0.02)

0.7

0.8

0.9

1.2

(d’/b k 0.08)

0.8

1.0

1.2

1.2

Muy rugosa Circular (bVd < 6 m2/s)

Cualquiera

0.7

0.8

1.2

1.2

Hexagonal u octagonal

Cualquiera

1.0

1.2

1.4

1.4

Cuadrada (viento normal a una cara)

Cualquiera

1.3

1.4

2.0

2.2

Cuadrada (viento sobre una esquina)

Cualquiera

1.0

1.1

1.5

1.6

1

b es el diámetro o la dimensión horizontal de la estructura, incluyendo la rugosidad de lo pared; para determinar el producto bVD, este diámetro será el que se localiza a dos tercios de la altura total, a partir del nivel del terreno, en m.

2

d’ es la dimensión que sobresale de las rugosidades, tales como costillas o “spoilers”, en m.

3

VD es la velocidad del viento de diseño (inciso 4.8), convertida a m/s, y valuada para los dos tercios de la altura total.

4

Para valores intermedios de H/b y d’/b se permite la interpolación lineal.

Párrafo 4.9.3.2 LAS VARIABLES o’ p h:

Tabla I.29 FACTORES Y’ [ Categoría

1

2

3

4

o’

1.224

1.288

1.369

1.457

p

-.032

-.054

-.096

-0.151

h

245

315

390

455

Las variables o’ p h, adimensionales, dependen de la rugosidad del sitio de desplante, y h es la altura gradiente en m. Estas variables se definen en la tabla I.29. Las variables kr q


6-36

General Vessel Data

kr es un factor relacionado con la rugosidad del terreno: Para terrenos con gatería

1 = 0.06,

Para terrenos con gatería

2 = 0.10,


3 = 0.06, y


4 = 0.06

5

6es el coeficiente de amortiguamiento critico:

Para construcciones formadas por marcos de acero = 0.01, y para aquellas formadas por marcos de concreto = 0.02.

VALORES DE R’ kR Categoría de terreno

a'

kR

1

0.13

0.06

2

0.18

0.08

3

0.245

0.10

4

0.31

0.14

VALORES DE \ Nota:

\

Para construcciones formadas por marcos de acero

0.01

Para aquellas formadas por marcos de concreto

0.02



6-37

British Wind Code BS-6399 British Wind Code BS-6399-97 BS 6399-97 - The British Wind Code - Loadings for buildings - Part 2: Code of practice for wind loads. The year of issuance of this code is 1997 and it replaces CP3.

Design Wind Speed - Vb Design wind speeds vary according to geographical location and to company or vendor standards. Wind speed units are calculated in miles per hour and/or meters per seconds and are only relevant to the United Kingdom. Typical wind speeds display in Figure 6 of BS 6399. The wind speeds vary from 20 m/sec to 31 m/sec (44.7 mph to 69.3 mph). Users should enter the lowest value reasonably allowed by the standards you are following, since the wind design pressure (and thus force) increases as the square of the speed.

Site Elevation - Delta s If the site altitude is above mean sea level (paragraph 2.2.2.2 of the code), then this value plus the Base Elevation is used to calculate the height of each point in the vessel above mean seal level. For example, if the vessel is installed on a site that is 100 m (328 ft) above seal level, it is exposed to a higher wind pressure (P) than if installed on the beach (at mean sea level).

Upwind Building Height (Obstruction Height) - Ho For buildings in town terrain, enter the average height of the building upwind of the vessel (as they tend to shield the vessel from the wind). To be conservative, this value can be zero, so the vessel takes the full force of the wind. Ho is used to modify the effective vessel wind height (He) for any vessel element. For more information see paragraph 1.7.3.3 of BS-6399.

Upwind Building Spacing - X For buildings in town terrain, enter the average spacing of the buildings upwind of the vessel (as they tend to shield the vessel from the wind). If the buildings are closer together, they provide greater protection from the wind. For more information see paragraph 1.7.3.3 of BS-6399.

Base Elevation Enter the elevation at the base of the vessel. This value plus the Site Elevation is used to calculate the height of each point in the vessel above mean sea level.

Vessel Location Enter the location where the vessel is installed. Table 4 of BS-6399 factors modify the wind velocity. The final wind pressure acting on any element of the vessel is determined by the distance from the coast, whether located in the country or a town, and the effective height (He). This table derives Sb, which is calculated by PVElite internally.


6-38

General Vessel Data

Distance to Coast Line Enter the distance the vessel is located from the coast in kilometers. This distance affects the corrected wind speed (Ve). Table 4 of BS-6399 factors modify the wind velocity. The final wind pressure acting on any element of the vessel is determined by the distance from the coast, whether located in the country or a town, and the effective height (He). This table derives Sb, which is calculated by PVElite internally.

External Wind Coefficient - cpe Enter the external wind coefficient. This value is taken from Table 7 of BS-6399. Typical values usually range from 0.60 to 0.80 depending on the H / D ratio of the vessel. Because of the complexity of the vessel configurations, (platforms, piping added equipment etc.), users must use discernment or consult an authority on this subject.

Factor Kb from Table 1 - Kb This is the 'Building-type factor Kb' taken from Table 1 of BS-6399. PVElite automatically defaults to 2, but other values may be selected. Please note the following limitations of Kb based on the vessel height:

Kb

Maximum Vessel Total Height

8

23 m (75.4 ft)

4

75m (246 ft)

2

240m (787 ft)

1

300m (984 ft)

0.5

300m (984 ft)

Of course designing towers over 75 meters in height is not likely, and many other things would need to be considered.



6-39

BS 6399 Table 1 Building-Type Factor Kb Kb

Building Type

8

Welded Steel unclad frames

4

Bolted steel and reinforced concrete unclad frames

2

Portal sheds and similar light structures with few internal walls

1

Framed buildings with structural walls around lifts and stairs only (e.g. office buildings of open plan or with partitioning)

0.5

Framed buildings with structural walls around lifts and stairs with additional masonry subdivision walls (e.g. apartment buildings), building of masonry construction and timber-framed housing

Annual Probability Factor - Q The default value is Q = 0.02. This value is used to calculate the final probability factor (Sp) associated with the likelihood of high velocity gusts occurring over a designated time period. The code sets 0.02 as a 'standard value' for a mean recurrence value of 50 years. For more information refer to Annex D of BS6399.

Q

Explanation

0.632

NOTE 1: The annual mode, corresponding to the most likely annual maximum value. (Sp = 0.749)

0.227

NOTE 2: For the serviceability limit, assuming the partial factor for loads for the ultimate limit is f = 1.4 and for the serviceability limit is f = 1.0, giving Sp = Sqrt(1 / 1.4) = 0.845. (Sp = 0.845)

0.02

NOTE 3: The standard design value, corresponding to a mean recurrence interval of 50 years. (Sp = 1.000)

0.0083

NOTE 4: The design risk for bridges, corresponding to a mean recurrence interval of 50 years. (Sp = 1.048)

0.00574

NOTE 5: The annual risk corresponding to the standard partial factor for loads, corresponding to a mean recurrence interval 1754 years. Back-calculated assuming the partial factor load for the ultimate limit is f = 1.4 and all risk is ascribed to the recurrence of wind. (Sp = Sqrt(1.4))

0.001

NOTE 6: The design risk for nuclear installations, corresponding to a mean recurrence interval of 10000 (yes that is ten thousand) years. (Sp = 1.263)

Seasonal Factor - Ss BS6399 in paragraph 2.2.2.4 states: ' ..For permanent buildings and buildings exposed for continuous periods of more than 6 months a value of 1.0 should be used for Ss..' PVElite uses 1.0 as the default value for this reason. Using a value of less than 1.0 is not recommended, or should only be used with a solid researched.


6-40

General Vessel Data

Directional Factor - Sd This value is taken from Table 3 of BS-6399. Because a tower is symmetrical about its central axis, the default value has been taken as 1.0. It is recommended that this value not be reduced other than for exceptional circumstances. For more information consult Table 3. The values in that table range between 0.73 and 1.00.



6-41

Seismic Data Seismic Design Code Select the design code to use for seismic calculations: ASCE-88

American Society of Civil Engineers Standard 7 (formerly ANSI A58.1) released in 1988.

ASCE-93

American Society of Civil Engineers Standard 7 (formerly ANSI A58.1) released in 1993. The new ASCE 7 earthquake standards released in 1993 are significantly more involved than the previous standards, and are also more strictly limited to buildings, and thus not as easily applied to vessels. Temporarily the program does not implement the complete dynamic analysis according to this standard. However the program does address the computation of the element mass multiplier as outlined on page 62 of the standard. In effect, the factors Av, Cc, P, and ac are multiplied together and then by the weight of the element to obtain the lateral force on the element. The program then computes the moments on the tower based on these results. One should have a good understanding of this code before using it.

UBC

Uniform Building Code. The program implements the 1991 edition.

NBC

National Building Code of Canada. The program implements the 1990 edition.

IS-1893 RSM

India's seismic design code based on the response spectrum method.

IS-1893 SCM

India's seismic design code based on the seismic coefficient method.

ASCE-95

American Society of Civil Engineers 1995 edition. The methodology of this calculation is very similar to other earthquake codes. Essentially the base shear is computed based on paragraph 9.2.3.4 and the paragraphs, which precede it. The base shear is then distributed to the elements according to the equation 9.2.3.4-2 on page 70 of the standard.

UBC97

Uniform Building Code. The 1997 version of this code is implemented.

G Loading

Acceleration of the vessel based on a fraction of gravity.

ASCE 7-98/02

American Society of Civil Engineers Standard 7 (formerly ANSI A58.1) released in 1998.

IBC-2000

International Building Code released in 2000.

Mexico Sismo

Seismic Design per Mexico's Manual De Diseno Por Sismo

Response Spectrum

The response spectrum analysis allows the use of modal time history analysis. The general design guidelines for this analysis are taken from the ASCE 7-98 or IBC 2000 Codes. Other predefined spectra are built into the program, such as the 1940 Earthquake El Centro and various spectra from the United States National Regulatory Commission Guide 1.60. If the spectrum analysis type is user- defined, the table of points that define the response spectra must be entered in the table, in the appropriate units. For tall structures, this analysis gives a much more accurate calculation than the typical static equivalent method. Usually the computed loads are lower in magnitude than those computed using the conventional Building Code techniques.


6-42

General Vessel Data

ASCE 7-88 Seismic Data Importance Factor Enter the value of ASCE 7-88 Importance Factor. Please note the program will use this value directly without modification. This value is taken from Table 22, Occupancy Importance Factor, I (Earthquake Loads) of the ASCE standard. Building categories are defined in Table1 of the standard.

Entry

Definition

1.00

Category I: Buildings not listed below

1.25

Category II: High occupancy buildings

1.50

Category III: Essential facilities

0.00

Category IV: Low hazard buildings

Note that most petrochemical structures are Importance I.

Soil Type Enter an integer indicating the Soil Profile Coefficient, S found in Table 24 of the standard. Soil Profiles are identified in Section 9.4.2 of the standard. Note that where soil properties are not known, soil profiles S2 or S3 shall be used, whichever produces the larger value of CS. (C is defined in Eq. 8 of the standard.) Entry

Definition

1

Soil Profile S1: Rock or stiff soil conditions (S Factor = 1.0)

2

Soil Profile S2: Deep cohesion less deposits or stiff clay conditions (S Factor = 1.2)

3

Soil Profile S3: Soft- to medium-stiff clays and sands (S Factor = 1.5)

Horizontal Force Factor Enter the seismic force factor per ANSI A58.1 Table 24. Typical values for this factor are as follows: Entry

Definition

1.33

Buildings with bearing walls

1.00

Buildings with frame systems

2.50

Elevated tanks

2.00

Other structures

Note that the value most often used is 2.0, though 2.5 is sometimes chosen for tanks supported by structural steel or legs.



6-43

Percent Seismic for Hydrotest Enter the percent of the total seismic horizontal force, which is to be applied during hydrotest. Although you can not predict an earthquake, as you can high winds, some designers use a reduced seismic load for hydrotest on the theory that the odds of an earthquake during the test are very low, and the hazards of a water release small.

Seismic Zone Select the zone for seismic calculations. See ASCE 7-88 Figures 14 & 15 to select the appropriate zone. Values for Seismic Coefficient, Z are found in Table 21 of the standard.

Zone

Definition

0

Zone 0: Gulf coast and prairies. (Z = 1/8)

1

Zone 1: Rockies and Appalachian areas. (Z = 3/16)

2

Zone 2: New England, Carolinas, Ozarks, valley area west of the Rockies and the Pacific Northwest. (Z = 3/8)

3

Zone 3: Sierras. (Z = 3/4)

4

Zone 4:California fault areas. (Z = 1)

Note that 0 indicates the least chance of a major earthquake, while 4 indicates the greatest chance of an earthquake.


6-44

General Vessel Data

ASCE7-93 Seismic Data Seismic Coefficient Av Enter Av, the seismic coefficient representing the effective peak velocity-related acceleration from Section 9.1.4.1 of the code. This value may be obtained from the map on pages 36 and 37 of the standard. In general this value ranges from 0.05 (low incidence of earthquake) to 0.4 (high incidence of earthquake).

Seismic Coefficient Cc Enter Cc, the system seismic coefficient for mechanical and electrical components from Table 9.8-2 on page 63 of the code. For tanks, vessels and heat exchangers this value is normally taken as 2.0.

Performance Criteria Factor P Enter P, the performance criteria factor from Table 9.8-2 on page 63 of the code. This factor depends on the Seismic Hazard Exposure Group, which is defined in Section 9.1.4.2 of the standard.

Entry

Definition

1.5

Seismic Hazard Exposure Group III: Essential facilities required for post-earthquake recovery

1.0

Seismic Hazard Exposure Group II: Buildings that have a substantial public hazard due to occupancy or use

0.5

Seismic Hazard Exposure Group I: All other buildings


Amplification Factor ac Enter ac, the attachment amplification factor determined in accordance with ASCE 7-93 Table 9.8-3. Values for this entry may be 1.0 or 2.0 depending on the relationship between the fundamental period of the vessel and the fundamental period of its supporting structure.



6-45

UBC Seismic Data Importance Factor Enter the value of the UBC Importance Factor. Please note the program will use this value directly without modification. This value is taken from Table 23-L of the UBC standard:

Entry

Definition

1.25

Category I: Essential facilities

1.25

Category II: Hazardous facilities

1.00

Category III: Special occupancy structures

1.00

Category IV: Standard occupancy structures

Note that most petrochemical structures have an Importance Factor of 1.0.

Soil Type Select the soil type (S1 to S4) defined in Table 23-J of the code. Note that where soil properties are not known, soil profile S3 shall be used. Soil

Definition

1

Soil Profile S1:Rock (S Factor = 1.0)

2

Soil Profile S2:Dense or stiff soil (S Factor = 1.2)

3

Soil Profile S3:Not more than 40 ft. of soft clay (S Factor = 1.5)

4

Soil Profile S4:More than 40 ft. of soft clay (S Factor = 12.0)

Horizontal Force Factor Enter an integer corresponding to the factor RW found in UBC Table 23-Q. RW is used in determining the seismic force factor for non-building structures. As per UBC: tanks, vessels or pressurized spheres on braced or unbraced legs have RW = 3 and distributed mass cantilever structures such as stacks, chimneys, silos, and skirt-supported vertical vessels have RW = 4.



6-46

General Vessel Data

Seismic Zone Select the zone for seismic calculations. See UBC-91 Figure No. 23-2 to select the appropriate zone. The zone establishes the Seismic Zone Factor, Z, found in Table No. 23-I. Zone

Definition

0

Zone 0:Gulf coast and prairies. (Z = 0.00)

1

Zone 1:Rockies and Appalachian areas. (Z = 0.075)

2

Zone 2a:New England, Carolinas, and Ozarks. (Z = 0.15)

3

Zone 2b:Valley area west of the Rockies and the Pacific Northwest (Z = 0.20)

4

Zone 3:Sierras. (Z = 0.30)

5

Zone 4:California fault areas. (Z = 0.40)




6-47

NBC Seismic Data Importance Factor Enter the value of the NBC Importance Factor found in Sentence 4.1.9.1 (10). Please note the program will use this value directly without modification.

Entry

Definition

1.5

Post-disaster buildings

1.3

Schools

1.0

All other buildings

Note that most petrochemical structures have an Importance Factor of 1.0.

Soil Type Select the soil factor (From Table 4.1.9C) for the site:

Soil

Definition

1

Category 1:From rock to stiff fine-grained soils up to 15 m deep

2

Category 2:From compact coarse-grained soils to soft fine-grained soils up to 15 m deep

3

Category 3:Very loose and loose coarse-grained soils with depth greater than 15 m

4

Category 4:Very soft and soft fine-grained soils with depth greater than 15 m

Force Modification Factor Enter an integer to indicate the type of lateral load resisting system. This value will be used to set the Force Modification Factor (R) per Table 4.1.9.B and sentences 4.1.9.1 (8) and 4.1.9.3 (3)

Entry

Definition

1

Case 18 - Elevated tanks (such as equipment on legs). (R = 1.0)

2

Case 6 - Ductile structures (such as towers on skirts). (R = 1.5)

Note

Elevated tank analysis also includes the special provisions of sentence 4.1.9.3 (3).



6-48

General Vessel Data

Acceleration Zone Select the acceleration-related seismic zone. For locations in Canada, the velocity and acceleration seismic zones are found in the city list, Chapter 1 of the supplement to NBC. Here are some examples of each zone: Entry

Acceleration-Related Zone

0

Calgary, Alberta

1

Toronto, Ontario

2

Saint John, New Brunswick

3

Varennes, Quebec

4

Vancouver, British Columbia

5

Duncan, British Columbia

6

Port Hardy, British Columbia


Velocity Zone Select the zone indicating the velocity-related seismic zone. For locations in Canada, the velocity and acceleration seismic zones are found in the city list, Chapter 1 of the supplement to NBC. Here are some examples of each zone:

Zone

Velocity-Related Zone

0

Steinbach, Manitoba

1

Calgary, Alberta

2

Montreal, Quebec

3

Quebec City, Quebec

4

Dawson, Yukon

5

Victoria, British Columbia

6

Destruction Bay, Yukon




6-49

India's Earthquake Standard IS-1893 RSM and SCM Percent Seismic for Hydrotest Enter the percent of the total seismic horizontal force, which is to be applied during hydrotest. Although you can not predict an earthquake, as you can high winds, some designers use a reduced seismic load for hydrotest on the theory that the odds of an earthquake during the test are very low, and the hazards of a water release small.

Importance Factor The importance factor is taken from table 4 in the IS-1893 standard. This value ranges from a maximum of 6.0 to 1.0. Factor

Description

6.0

A value typically used in nuclear applications.

2.0

Dams of all types and lethal service applications

1.5

Used in the design of important structures such as hospitals, tanks, water towers, and large assembly structures.

1.0

All others

Soil Factor The soil factor (Beta) is taken from Table 3 of the IS-1893 seismic design code. This value ranges between 1 and 1.5. Type I soils and hard rock should have a value of 1. Type II soils should also use a value of 1 except for well foundations or isolated RCC footings without tiebeams or un-reinforced strip foundations, which receive a value of 2.0. Type III soils can receive a value between 1.0 and 1.5.

Zone Number The zone number ranges between 1 and 5 and depends on where the vessel will operate in India. You can determine the zone from a colored map of which is Figure 1 in IS 1893.

Period of Vibration This field is optional. PVElite computes the natural frequency of the vessel and can thus compute the period of vibration. If this field is not 0 the program will use the entered value. This value is used in conjunction with Beta in order to determine Sa/g.

Damping Factor This value which is used with the period of vibration to determine Sa/g. Values of damping in the IS 1893 standard are 2, 5, 10 and 20 percent. The program will interpolate for intermediate values in between 2, 5, 10 and 20 percent. Extreme values will be used if a damping factor is entered which is outside the range above.


6-50

General Vessel Data

ASCE - 95 Seismic Data Percent Seismic for Hydrotest Enter the percent of the total seismic horizontal force, which is to be applied during hydrotest. Although you can not predict an earthquake, as you can high winds, some designers use a reduced seismic load for hydrotest on the theory that the odds of an earthquake during the test are very low, and the hazards of a water release small.

Importance Factor ASCE-95 does not address an importance factor. However, this value is multiplied times the other values to compute the base shear. Thusly, this entry can be used as a scale factor for the base shear. If you do not wish to use this value simply enter a value of 1.0.

Force Factor ( R ) This value is taken from table 9.2.7.5. For vertical vessels, towers, stacks etc. this value is 2.0.

Seismic Coefficient Ca This value is derived from table 9.1.4.2.4A on page 55 of ASCE7-95. This factor is a function of the soil profile type and the value of Aa. Typically this will be a given value. However, if given the soil type and the value Aa, you will need to pick Ca from the table.

Seismic Coefficient Cv This value is derived from table 9.1.4.2.4B on page 55 of ASCE7-95. This factor is a function of the soil profile type and the value of Aa. Typically, this will be a given value. However, if given the soil type and the value Aa, you will need to pick Ca from the table. The help facility in PVElite contains the above referenced tables.



6-51

Seismic Load Input in G's Enter the value of G's that your vessel will be subjected to in the specified direction. For vertical vessels, the horizontal component used will be the maximum of the Gx and Gz values. The horizontal force computed will be equal to the element's weight times this maximum G factor. This force times its distance to the support will be computed and summed with all of the others. The Y component is also considered. This value is usually 2/3 of the Gx or Gz value, but note however any of these values can be zero. For horizontal vessels, the lateral (Gz) and longitudinal (Gx) directions are considered independently. The vertical load component (Gy) acting on the saddle supports is also computed. Typical values of G loads are from 0 to 0.4.


6-52

General Vessel Data

UBC 1997 Earthquake Data Percent Seismic for Hydrotest Enter the percent of the total seismic horizontal force, which is to be applied during hydrotest. Although you can not predict an earthquake, as you can high winds, some designers use a reduced seismic load for hydrotest on the theory that the odds of an earthquake during the test are very low, and the hazards of a water release small.

UBC Earthquake Importance Factor Enter the value of the UBC Importance Factor. Please note the program will use this value directly without modification. This value is taken from Table 16-K of the UBC 1997 standard. The following is the context of Table 16-K. Category

Value

1

Essential facilities 1.25

2

Hazardous facilities 1.25

3

Special occupancy structures 1.0

4

Standard occupancy structures 1.0

UBC Seismic Coefficient CA Enter the value of CA per the project specifications and table 16-Q of UBC 1997 edition. This value is a function of the seismic zone Z, and the soil profile type. This coefficient ranges from 0.44 to 0.06. In zone 4 this value is also a function of Na.

UBC Seismic Coefficient CV Enter the value of CV per the project specifications and table 16-R of UBC 1997 edition. This value is a function of the seismic zone Z, and the soil profile type. This coefficient ranges from 0.96 to 0.06. In zone 4 this value is also a function of Nv.

UBC Near Source Factor This factor is only used in UBC Seismic Zone 4. This value ranges from 1 to 2 and is a function of the distance relative to the seismic source.

UBC Seismic Zone See UBC-91 Figure No. 23-2 to select the appropriate zone. The zone establishes the Seismic Zone Factor, Z, found in Table No. 23-I.



Zone 0

Gulf and prairies (Z=0.00)

Zone 1

Rockies and Appalachian areas (Z=0.075)

Zone 2a

New England, Carolinas, and Ozarks (Z=0.15)

Zone 2b

Valley area west of the Rockies and the Pacific Northwest (Z=0.20)

Zone 3

Sierras (Z=0.30)

Zone 4

California fault areas (Z=0.40)

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Note that Zone 0 indicates the least chance of a major earthquake, while Zone 4 indicates the greatest chance of an earthquake.

UBC Horizontal Force Factor Enter the seismic force factor R per UBC Table 16-P 1997 edition: 2.2

Tanks on braced or unbraced legs

2.9

Distributed mass cantilever structures such as stacks, chimneys, silos, and skirt supported vertical vessels.

*R is defined as the numerical coefficient representative of the inherent overstrength and global ductility of lateral force resisting systems.


6-54

General Vessel Data

IBC-2000 Earthquake Parameters Selection of this option performs a seismic analysis according to the requirements of the International Building Code 2000 (which happens to mirror those of ASCE 7).

EarthQuake Parameters Ss and Sl The values for Ss and Sl are taken from the ASCE 7-98 / IBC 2000 publication. These factors are for short and long periods (0.2 and 1.0). These tables are found on pages: 100 - 117 (ASCE 98), page 351 (IBC) publication.

Response Modification Factor R Enter the value from table 9.5.2.2 (ASCE) 1617.6 (IBC) as required. R is usually equal to 2.5 for inverted pendulum systems and cantilevered column systems. For elevated tanks use a value of 4. For horizontal vessels, leg supported vessels and others use a value of 3.0.

Importance Factor This is the occupancy importance factor as given in 9.1.4 (ASCE) 1604.5 (IBC). The importance factor accounts for loss of life and property. This value typically ranges between 1.0 and 1.5.

Moment Reduction Factor Tau This value is used to reduce the moment at each level. A value greater than one will scale the moments up, while a value that is less than one will lower the moments. We suggest a value of 1.0. This value should not be less than 0.8.

Seismic Design Category Select an appropriate category from the pulldown. The choices are A through F. The program uses these values only to check the minimum value of Cs per equation 9.5.3.2.1-4 (ASCE), 1615.1.1 (IBC). This additional check is only performed if the Seismic Design Category is E or F.

EarthQuake Parameters Fa and Fv Enter the coefficient from table 9.4.1.2.4A or 9.4.1.2.4B (ASCE), 1615.1.2(1) or 1615.1.2(2) (IBC) as required.



6-55

Table—9.4.1.2.4.A Values of Fa as a Function of Site Class and Mapped Short-Period Maximum Considered Earthquake Spectral Acceleration Site Class

Ss<+0.25

Ss=0.5

Ss=0.75

Ss=1.0

Ss>1.25b

A

0.8

0.8

0.8

0.8

0.8

B

1.0

1.0

1.0

1.0

1.0

C

1.2

1.2

1.1

1.0

1.0

D

1.6

1.4

1.2

1.1

1.0

E

2.5

1.7

1.2

0.9

a

F

a

a

a

a

Table—9.4.1.2.B (ASCE) 1615.2(2) (IBC), Values of Fv as a function of Site Class and Mapped 1-Second Period Maximum Considered Earthquake Spectral Acceleration Site Class

Sl<+0.1

Sl=0.2

Sl=0.3

Sl=0.4

Sl>0.5b

A

0.8

0.8

0.8

0.8

0.8

B

1.0

1.0

1.0

1.0

1.0

C

1.7

1.6

1.5

1.4

1.3

D

2.4

2.0

1.8

1.6

1.5

E

3.5

3.2

2.8

2.4

a

F

a

a

a

a

a

Note: For intermediate values, the higher value of the straight line interpolation shall be used to determine the value of Ss or Sl. a

Site specific geo-technical information and dynamic site response analyses shall be performed.

Site specific studies required per Section 9.4.1.2.4 may result in higher values of than included on hazard maps, as may the provisions of Section 9.13. b


6-56

General Vessel Data

Response Spectrum Selecting this method performs a dynamic analysis of the vessel, applying loading based upon the selected seismic Response Spectrum. Initially, the vessel is modeled as a 2-dimensional structure (note that for asymmetric leg arrangements, the horizontal direction of interest is taken as that corresponding to the weakest axis of the arrangement). Next an Eigensolution is performed on the vessel, which determines system mode shapes and modal natural frequencies (all modes with natural frequencies up through 100 Hz are calculated). The seismic response of each mode is then extracted from the Response Spectrum according to the natural frequency of each mode, and then adjusted according to the mode's "participation factor". The system response is then determined by combining all of the modal responses. For tall structures, this analysis gives a much more accurate calculation than the typical static equivalent method. Usually, the computed loads are lower in magnitude than those computed using conventional building Code techniques.

Percent Seismic for Hydrotest Enter the percent of the total seismic horizontal force, which is to be applied during hydrotest. Although you cannot predict an earthquake, as you can high winds, some designers use a reduced seismic load for hydrotest on the theory that the odds of an earthquake during the test are very low, and the hazards of a water release small.



6-57

Response Spectrum Name The following seismic response spectra are available:

User Defined This option allows the user to enter a custom seismic response spectrum of type Frequency or Period vs. Displacement, Velocity, or Acceleration (see instructions below). The same spectrum will be applied in both the horizontal and vertical directions.

El Centro This response spectrum is based on the May 18, 1940 El Centro, California earthquake, North-South component, 510% damping as described in Introduction to Structural Dynamics by John Biggs. This spectrum will be applied in both the horizontal and vertical directions.

ASCE Selection of this option performs a seismic analysis according to the requirements of the modal analysis procedure of ASCE Standard 7-98. The horizontal spectrum is a built according to the ASCE-7 Section 9.4.1.2.6, while the vertical spectrum provides a flat acceleration of 0.2S

IBC Selection of this option performs a seismic analysis according to the requirements of the modal analysis procedure of the International Building Code 2000 (which happen to mirror those of ASCE-7). The horizontal spectrum is built according to IBC-2000 Section 1615.1, while the vertical spectrum provides a flat acceleration of 0.2 (as per IBC2000 Section 1617. 1).

1.60D.5 Selection of this option applies (in the X- and Y-directions respectively) the horizontal and vertical spectra specified in the United States Nuclear Regulatory Commission's Regulatory Guide 1.60, for systems with 0.5% of critical damping. Note that this spectrum is normalized, so it must be scaled the site's Zero Period Acceleration (see below).

1.60D2 Selection of this option applies (in the X- and Y-directions respectively) the horizontal and vertical spectra specified in the United States Nuclear Regulatory Commission's Regulatory Guide 1.60, for systems with 2 % of critical damping. Note that this spectrum is normalized, so it must be scaled the site's Zero Period Acceleration (see below).

1.60D5 Selection of this option applies (in the X- and Y-directions respectively) the horizontal and vertical spectra specified in the United States Nuclear Regulatory Commission's Regulatory Guide 1.60, for systems with 0.5% of critical damping. Note that this spectrum is normalized, so it must be scaled the site's Zero Period Acceleration (see below).


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General Vessel Data

1.60D7 Selection of this option applies (in the X- and Y-directions respectively) the horizontal and vertical spectra specified in the United States Nuclear Regulatory Commission's Regulatory Guide 1.60, for systems with 7% of critical damping. Note that this spectrum is normalized, so it must be scaled the site's Zero Period Acceleration (see below).

1.60D10 Selection of this option applies (in the X- and Y-directions respectively) the horizontal and vertical spectra specified in the United States Nuclear Regulatory Commission's Regulatory Guide 1.60, for systems with 10% of critical damping. Note that this spectrum is normalized, so it must be scaled the site's Zero Period Acceleration (see below).

Importance Factor This is used for the ASCE and IBC options. For ASCE, this is the I, the occupancy importance factor determined from ASCE-7 Section 9.14. For IBC, this is the Ie, the occupancy importance factor in accordance with IBC 1616.2.

Shock Scale X|Y dir This is used for User defined, El Centro, and the 1.60Dxx spectra; and is used to scale the horizontal and vertical spectra respectively. For example, many seismic specifications require that the vertical spectrum be identical to, but with 2/3 of the magnitude, of the horizontal spectrum. This corresponds to an X scale of 1.0 and a Y scale of 0.6667. Traditionally in the analysis of vertical vessels, the component in the vertical direction is typically ignored. If you wish to do so, enter a value of 0 in the Y direction field.

Zero Period Acceleration This is used to scale the normalized 1.60 Dxx spectra. The Zero Period Acceleration corresponds to the acceleration of the rigid (high frequency) portion of the spectrum, which usually corresponds to the maximum ground acceleration expected at the site.

Combination Method Modal responses must be combined in a way that most accurately captures the statistical correlation of the responses to each other. The available options are: SRSS: This method performs a Square Root of the Sum of the Squares combination of the modal results. This simulates a response where all modal results are assumed to be uncorrelated with, or totally unrelated to, each other. If the ASCE or IBC method has been chosen, modal combinations will automatically be performed using this method. This is usually non-conservative, especially if there are any modes with very close frequencies, since those modes will probably experience their maximum DLF at approximately the same time during the load profile.



6-59

Group: This method performs a group combination method as described in the United States National Regulatory Commission's Regulatory Guide 1.92 - responses of modes with natural frequencies within 10% of each other are combined using the Absolute Value method, while those sums are combined with each other and with m0ore far-flung modes, using the SRSS method. This simulates a response where the results of similar modes are assumed to be correlated, while those of all dissimilar modes are assumed to be uncorrelated. Absolute: This method performs an Absolute Value combination of the modal results. This simulates a response where all modal results are assumed to be correlated with each other. This method gives the most conservative result, since it assumes that the all maximum modal responses occur at exactly the same time during the course of the applied load. This is usually overly-conservative, since modes with different natural frequencies will probably experience their maximum DLF at different times during the load profile.

Acc. Based Factor Fa: This factor is required for ASCE-7 and IBC, and is used to construct the horizontal response spectrum. For ASCE-7 it is determine from Table 9.4.1.2.4a, while for IBC- 2000 it is determined from Table 1615.1.2(1). Typical values are 0.8 through 2.5 and above. For more information on the values of Fa refer to IBC 2000 Earthquake Parameters in this chapter.

Acc. Based Factor Fv: This factor is required for ASCE - 7 and IBC, and is used to construct the horizontal response spectrum. For ASCE-7 it is determine from Table 9.4.1.2.4a, while for IBC- 2000 it is determined from Table 1615.1.2(2). Typical values are 0.8 through 3.5 and above. For more information on the values of Fv refer to IBC 2000 Earthquake Parameters in this chapter.

Max. Mapped Res. Acc. Ss: This factor, the "mapped maximum considered earthquake spectral response acceleration at short periods" is required for ASCE-7 and IBC, is used to construct the horizontal response spectrum. For ASCE-7 it is determined in accordance with Section 9.4.1, while for IBC-2000 it is determined from Section 1615.1. Typical values are 0.0 through 2.0g.

Max. Mapped Res. Acc. Sl: This factor, the mapped maximum considered earthquake spectral response acceleration at a period of 1 second", is required for ASCE-7 and IBC, is used to construct the horizontal response spectrum. For ASCE-7 it is determined in accordance with Section 9.4.1, while for IBC-2000 it is determined from Section 1615.1. Typical values are 0.0 through 1.5g.

Response Modification R: This factor is required for ASDCE-7 and IBC, and is used to reduce the spectrum response. For ASCE-7 it is determined from Table 9.5.2.2, while for IBC-2000 it is determined from Table 1617.6 Typical values are 1.25 through 8.0. For elevated tanks use a value of 4. For horizontal vessels, leg supported vessels and others use a value of 3.0.


6-60

General Vessel Data

Coefficient Cd: This factor, the "deflection amplification factor", is used to scale up the calculated seismic displacements. For ASCE-7 it is determined from Table 9.5.2.2, while for IBC-2000 it is determined from Table 1617.6. Typical values are 1.25 through 6.5.

Range Type: User Defined spectra may be entered with a range X-axis representing either Frequency or Period. In either case, the data points should be entered with ascending range values. Note: A zero entry for either Frequency or Period is invalid. Interpolation will be made linearly for intermediate range values. Data points defining the spectrum can be entered by clicking EDIT/REVIEW SPECTRUM POINTS.

Ordinate Type: User Defined spectra may be entered with an ordinate Y-axis representing Displacement, Velocity, or Acceleration entered in units of Diameter, Diameter /second, of G's respectively. Interpolation will be made linearly for intermediate Ordinate values. Data points defining the spectrum can be entered by clicking EDIT/REVIEW SPECTRUM POINTS.

Include Missing Mass Components: Since only a limited number of modes of vibration i.e., only those with natural frequencies up to 100 Hz or so are used in the analysis, the entire mass of the structure doesn't get considered in the seismic analysis. Clicking this box causes PVElite to estimate the contribution of the neglected modes of vibration and add that to the dynamically calculated response. Note:

Selecting this option should always lead to a more conservative result.


CH AP TER

7

Chapter 7 PVElite Analysis In This Chapter Introduction ................................................................................ 7-2 Calculating and Displaying Vessel-Analysis Results ................. 7-3 Optional Steps............................................................................. 7-9 Component Analysis................................................................... 7-11


7-2

PVElite Analysis

Introduction Once all the data for the vessel model and analysis have been entered and corrected, the model is ready for analysis. The pull-down menu under Analyze shows two options: Analyze Error Check Only

Analyze Menu

Error Check Only will review all the data and produce an output report listing any errors that are found. These messages can be examined through the Output - Review option. If Analyze is selected, PVElite will also run through the error checker but then continue on (if no errors are found) through the complete analysis. The analysis program is the heart of the PVElite system. The analysis program uses all the data entered into the model to evaluate or design the pressure vessel. In any given analysis there will be between 16 and 20 analysis steps. As the program completes each calculation, important information from the step is displayed on the screen. The screen display at the completion of the internal pressure calculations, for example, lists both the given element thickness and the required thickness for each element in the vessel. The program waits for a user response before clearing the screen and moving on to the next analysis step. The user may respond by continuing on to the next step, continue non-stop through the remainder of all analysis steps, or quit the analysis. The results of the analysis are stored in two separate files on the hard disk. The text results of the job are held in a file with the extension .TAB (e.g. the jobname VES01 will have an input file named VES01.PVI and a text results file of VES01.TAB). The output processor replaces this .TAB file with a .T80 file (VES01.T80). The .T80 file contains a complete report for each analysis step for inspection and printing through the Review processor. The analysis also creates a .PVR file (e.g.. VES01.PVR); this file is used by the Output Review processor for component analysis. The program transfers to the Review processor at the completion of the analysis. PVElite not only analyzes vessels, it also designs vessel walls for pressures and loads. In addition to increasing the vessel wall thickness, the program can instead introduce stiffener rings to accommodate external pressures. The program directives for these design modifications are set in each job in the Design Data section of Global Data. In increasing the wall thickness to meet the required values, PVElite can either set the thickness to the exact requirement, or, round up to the next nominal value (1/16 inch in English units or 1 mm in metric units). This switch, too, is a setting in the Configuration option under Utility. If PVElite's design process changes any of the original input, the program will automatically erase the current output report and return to the beginning of the analysis and restart the run. All results will reflect the design changes, from the input echo to the added deadweight. The user's original input, however, will not be changed. If a design flag is turned on and the required thickness is less than the entered thickness, PVElite will increase the thickness as needed and continue.


Chapter 7 PVElite Analysis

7-3

Calculating and Displaying Vessel-Analysis Results Each of these steps calculates and displays specific results of a vessel analysis. A brief description of the key analysis steps is defined below:

Step 0: Error Checking The input program will have already caught most of the errors that are easily made. However, there are some errors, which can only be discovered after the analysis begins. There are also some warnings that may be of help to the user. This first routine check creates a report in the output. If any of the input errors would prevent the program from running, execution stops here. Check the output to determine the exact error discovered by the program.

Step 1: Input Echo PVElite provides a complete listing of your input. This includes the geometry and materials for each element (head, shell, cone, flange, skirt, etc.) and the information for any details attached to that element.

Step 2: XY Coordinate Calculations The program calculates the X and Y locations of the first end of every element.

Step 3: Internal Pressure Calculations The geometry, material, and loading data from your model are used to calculate the required thickness and maximum allowable working pressure for each element (except skirts and flanges). The calculations are done using the ASME Code, Section VIII, Division 1 rules, or the British Standard PD:5500 rules. The internal design pressure at any point is taken to be the given design pressures for that element, plus the pressure due to liquid head, if any. If you checked the Increase Thickness For Internal Pressure design flag and any element is too thin for the given pressure, the program will automatically (or under interactive control) increase the thickness of the element. There is a computation control (under Utilities on the Main Menu) that allows you to increase the element thickness to exactly that required, or to round the thickness up to the next nominal size. If the program has increased the thickness, it will recalculate all the required thicknesses and maximum allowable working pressures for the vessel, and create a new table showing these results. After the internal pressure calculation is complete, PVElite prints the formulas and substitutions, as well the minimum design metal temperatures for the elements.

Step 4: Hydrotest Calculations The user specifies what kind of hydrotest (and/or the hydrotest pressure) on the global input screens. The program uses this information to calculate the maximum allowed hydrotest pressure and required thickness at the given pressure for each element.


7-4

PVElite Analysis

Step 5: External Pressure Calculations The user explicitly defines two of the three key variables for external pressure calculations: diameter and thickness. The program calculates the third variable, length of section, for the given geometry. Thus if the vessel has two heads and some number of cylindrical elements with no stiffening rings, the program will calculate the design length for each cylinder using the full length of the vessel plus 1/3 the depth of the heads. If there are stiffening rings, the program will calculate an appropriately shorter value. The program displays the formulas and substitutions for the external pressure calculations on each element. Then the same results are displayed in tabular form. If the element is not thick enough for the external pressure (and you checked the design boxes in the input) the program will allow you to increase the thickness and/or add stiffening rings (which are created automatically and added to your model). If the thickness is increased the program has to go back to step 3. For rings it repeats this step with the new lengths.

British Standard PD:5500 When performing the PD:5500 external pressure calculations, the program first computes the length of section for the given geometry. The length of section is either the distance between stiffeners, or, if there are no stiffeners, it is the full length of the vessel plus 0.4 times the depth of the heads. Using the length of section computed, the program first tests to see whether the thickness of the unsupported cylinder (or distance between supports) is satisfactory for the given pressure. A value of Pmax is determined. If there are stiffeners, then the program performs the calculations described in section 3.6.2.3. The program first performs the computations described in Method A, and then performs the more rigorous calculations described in Method B. For each of these methods (and each value of n), a value of Pn and Fn are obtained. Pn is the elastic instability pressure of the stiffened cylinder or cone. The value of Pn must not be less than 1.8*Pext in the case of fabricated or hot formed stiffeners and 2.0*Pext in the case of cold formed stiffeners. Fn is the maximum stress in the stiffener flange divided by the yield stress of the stiffener. A value for Fn is computed for both fabricated or hot formed stiffeners and cold formed stiffeners. These values must be between 0.0 and 1.0.

Step 6: Weight of Elements Element weights are calculated in both the corroded and uncorroded conditions. Note that for heads the distance given in the input program is taken as the length of the straight flange on the head. This step also calculates the volume of the element.

Step 7: Weight of Details Each detail has a separate weight calculation. Of note is the fact that partial volumes of liquid in both the heads and the cylinders and in both the horizontal and vertical directions are correctly calculated.



7-5

Step 8: ANSI Flange MAWP If you entered nozzles, you specified the material and class of the attached flanges. PVElite has the full ANSI flange tables built in, and tells you the rating of the flanges at the operating temperature.

Steps 9 and 10: Total Weight And Detail Moment Several weight cases are calculated including: empty, operating, and hydrotest. The various detail weights/loads are included in the following cases:

Detail

Empty

Operating

Hydrotest

Saddle

#

#

#

Platform

#

#

#

Packing

#

Liquid

#

Insulation

#

#

#

Lining

#

#

#

Rings

#

#

#

Nozzles

#

#

#

Saddles

#

#

#

Trays

#

Legs

#

#

#

Lugs

#

#

#

Weights

#

#

#

Forces/Moments

#

This step also calculates the moment due to individual details, which may not be on the centerline of the vessel. These are usually small. Finally, this step calculates the forces at the support. The vertical force and bending moment (due to detail weights only) are calculated for the 'one support' case (skirts, legs, lugs) and the vertical force at each support is calculated when there is two saddle supports. Note: In addition to computing the above weights PVElite also computes the fabricated weight, shop test weight, shipping weight, erected weight, empty weight and field test weight. The computed weights may or may not include removable or field installed items such as packing and other details. You can specify where these details are to be installed (either shop or field) in the Global Input. Switch to the global input screen and click the Installation Miscellaneous Options button located at the top of the screen. By default the program assumes that all details will be installed in the shop and calculate these various weights based on that assumption. The cumulative weight on the vessel will look drastically different for horizontal vessels on saddle supports than for vertical vessels on skirts, legs, and lugs:


7-6

PVElite Analysis

Horizontal cases: Expect the highest weight forces near the saddles, with almost no weight force at the ends or in the middle. Vertical cases: Expect the weight forces to increase from zero at the top to a maximum at the support. If there are elements below the support, expect the weight force to be negative. The cumulative moment includes only the moment due to eccentric details, and is usually quite small (except in the case of a large applied moment).

Step 11: Natural Frequency Calculation PVElite uses two classical solution methods to determine the first order natural frequencies of vessels. For vertical vessels, the program uses the Freese method, which is commonly used in industry. For horizontal vessels a similar method attributed to Rayleigh and Ritz is used. Each method works by calculating the static deflection of the vessel (for vertical, the vessel as a horizontal cantilever beam). The natural frequency is proportional to the square root of the deflection. As of version 4.3 PVElite uses the matrix solution methods (Eigen Solution) to determine the modes of vibration. Horizontal vessels are assumed to be rigid and as such are assigned a frequency of 33 hertz, which is coincident of a ZPA for a rigid structure.

Step 12: Wind Load Calculation PVElite uses the rules of ASCE-7, NBC, UBC, and IS-875 to calculate wind loads. Each of these codes uses a basic wind pressure, a function of the velocity squared, along with several surface and site factors to determine the final wind pressure.

Step 13: Earthquake Load Calculation The five codes used by PVElite - ASCE-7, UBC, NBC, IS-1893 RSM and IS-1893 SCM each use a static equivalent load to model the earthquake load. Simple site data and loading data are used to determine an expected static equivalent horizontal load on the vessel.

Step 14: Shear and Bending Moments due to Wind and Earthquake These loadings generate horizontal loads, which are usually fine on a horizontal vessel, but can cause high overturning moments on a vertical vessel. The program calculates the cumulative shear and bending moment on the vessel, for use in later stress calculations.

Step 15: Wind Deflection PVElite calculates the deflection at every point in either horizontal or vertical vessels.

Step 16: Longitudinal Stress Constants As the program prepares to do structural calculations on the vessel, it first calculates the cross sectional area and section modulus of each element in both the corroded and uncorroded condition.



7-7

Step 17: Longitudinal Allowable Stresses There are four allowable stresses in the longitudinal direction for each element: (1) Longitudinal tension based on the basic allowable stress, often multiplied times 1.2 (as specified on the global input), (2) Hydrotest longitudinal tension - 1.5 times the allowable stress new & cold. (3) Longitudinal compression - based on paragraph UG-23 of the Code, and the material's external pressure chart. (4) Hydrotest allowable compression - the basic allowable compression new & cold, multiplied by 1.5.

Step 18: Longitudinal Stresses Due to . . . Each load (wind, earthquake, weight, pressure) generates a stress. These are calculated individually and displayed by this routine. Note that bending stresses, though only displayed once, are actually positive on one side of the vessel and negative on the other.

Step 19: Stress Due to Combined Loads In this step the various load cases combinations defined by the user are evaluated. If there are applied forces and moments in the model, then other identifiers such as BS, BN and so forth may appear in the load case definition. There can be as many as twenty cases, combining pressure loads, weight loads, and moments in various ways. A fairly complete set of load cases is included as a default:


7-8

PVElite Analysis

Load Case

Definition

1 NP+EW+WI+FW

No pressure + empty weight + wind

2 NP+EW+EQ+FS

No pressure + empty weight + earthquake

3 NP+OW+WI+FW

No pressure + operating weight + wind

4 NP+OW+EQ+FS

No pressure + operating weight + earthquake

5 NP+HW+HI

No pressure + hydrotest weight + hydro wind

6 NP+HW+HE

No pressure + hydrotest weight + hydro earthquake

7 IP+OW+WI+FW

Internal pressure + operating weight + wind

8 IP+OW+EQ+FS

Internal pressure + operating weight + earthquake

9 EP+OW+WI+FW

External pressure + operating weight + wind

10 EP+OW+EQ+FS

External pressure + operating weight + earthquake

11 HP+HW+HI

Hydrotest pressure + hydrotest weight + hydro wind

12 HP+HW+HE

Hydrotest pressure + hydrotest wind + hydro earthquake

13 IP+WE+EW

Internal pressure + wind empty + empty weight

14 IP+WF+CW

Internal pressure + wind filled + empty weight no ca

15 IP+VO+OW

Internal pressure + vortex shedding (OPE) + operating weight

16 IP+VE+OW

Internal pressure + vortex shedding (EMP) + operating weight

17 IP+VF+CW

Internal pressure+ vortex shedding (Filled) + empty weight no ca

The difference between wind loads and hydrotest wind loads is simply a ratio (percentage) defined by the user. This percentage is specified in the Wind Data definition of Global Data - usually about 33% (thus setting the hydrotest wind load at 33% of the operating wind load). Likewise, the hydrotest earthquake load is a percentage of the earthquake load; this percentage is defined in the Seismic Data definition of Global Data. Some steps that are not applicable for horizontal vessels, such as natural frequency, will not be printed. Also, if a vessel has no supports, then there will be no calculations that involve wind or seismic loads.



7-9

Optional Steps PVElite includes the following analyses that are performed under specific circumstances: 1

Cone Evaluation - cones are evaluated for internal and external pressure at the large and small ends, and any stiffening rings near the cones are included and evaluated.

2

Zick Stresses - stresses due to saddle supports are evaluated and compared to allowable stresses using the method of L.P. Zick. Note that the stresses are calculated for each saddle, since in PVElite each saddle can have different loading. Note also that the stresses are not evaluated at the mid span, since the program automatically does that for all the various load case combinations.

3

AISC Leg Check: After the program has computed all of the weights, forces and moments, it can then determine the overall state of stress by using the AISC unity check method. The program typically looks at the worst loads on the legs due to wind or seismic in the operating condition and then applies the AISC method of checking the legs. The unity check must be less than or equal to 1.0. Most typical designs fall in the 0.7 - 0.8 range, which is a good check both in terms of economy and safety.

4

Lug Support Check: In a similar manner to the leg check the program gathers the worst loads on the support lugs and then evaluates them according to a set of acceptable standards. In this case, gussets are checked by the AISC method and the lug plates are checked by common industry standard methods. These methods are outlined in common pressure design handbooks.

5

Baserings: With known forces and moments at the base and the geometry of the basering, PVElite will analyze or design the basering and gusset geometry.

6

Flanges: For main body flanges, the program will compute the required thickness of the flange, all relevant stresses, and MAWP for the given geometry. The results seen in the output are based on the input thickness. The program additionally computes the required thickness of the flange. Please note that the program does not include the forces and moments to determine an equivalent design pressure. There are separate fields in the input that can be entered in if these effects are to be considered. In order to do this two runs would have to made. After run 1 was made the forces and moments on the flange could be entered in as needed.

7

Nozzle Analysis: Complete nozzle evaluation is incorporated into the program based on the rules in the ASME code. Design cases are made for Internal Pressure, External Pressure and MAPnc. The internal pressure can be based on the MAWP of the entire vessel or the exact pressure at the nozzle location. These options are located in the Global Input section of the input. In addition to perpendicular nozzles, hillside geometries are also considered. Nozzles at any angle can be entered in by using the ANG=xx.x command in the nozzle description field. The nozzle analysis also computes MDMT, weld size and strength calculations along with provisions for large nozzles as outlined in appendix 1-7 of the ASME Code. Another description option is for small nozzles. If there is a small nozzle that must have area calculations performed, enter the text "#SN" as part of the nozzle description. By default PVElite will not calculate small openings for Division 1 vessels per UG-36. If local loads have been defined on the nozzle, the nozzle report will display the results from WRC 107 or PD 5500 Annex G, whichever one was selected.

8

Fatigue Analysis: The fatigue analysis is activated when the number of pressure cycles is specified on the Design/Analysis Constraints screen. Click the Perform Fatigue Analysis button to bring up the dialog. Change the number of pressure cycles. This value must be between 1 and 20. This cumulative damage analysis is in accordance with PD:5500 2000 Annex C. In order for this analysis to activate, at least one nozzle must be specified. In the nozzle dialog, there is a check box and a pull down selection menu describing the class of the weld attachment per Annex C. Once all of the data is specified, PVElite will produce the Fatigue Analysis Report.


7-10

9

PVElite Analysis

Tubesheet Analysis: When the vessel design Code is ASME VIII or PD 5500, tubesheets are allowed to be defined. They can be attached to flange or cylinder parent elements. PVElite will compute tubesheet required thickness, shell and tube stresses per the rules of TEMA, ASME Part UHX or PD 5500.

10 Skirt Hole Opening Analysis: For vertical skirt supported vessels, PVElite can compute bending and axial stresses due to missing material in skirt openings typically for pipe openings, vents and access openings. 11 ASME App. EE Analysis: If you have specified a helical half pipe jacket, this analysis will be performed per ASME Appendix EE. 12 ASME App. 14 large Central Opening Analysis: For Welded flat heads, the analysis of large central opening can be performed per Appendix 14.



7-11

Component Analysis Once the program has completed the above calculations, the results may be reviewed in the output processor. These results (such as required wall thickness vs. finished wall thickness) may also be used for the evaluation of other components of the vessel. Rather than automatically analyzing all the possible vessel element details, the output processor provides component analysis for only those details selected by the user. Other details that are not part of the current vessel may also be analyzed here. This processor is described in the next chapter.



CH AP TER

8

Chapter 8 Output/Review In This Chapter Generating Output ...................................................................... 8-2 The Review Screen ..................................................................... 8-3 Using Review ............................................................................. 8-4 Component Analysis................................................................... 8-5


8-2

Output/Review

Generating Output Output may be reviewed or generated for any job that has some input. Results of any previous analysis, of course, are only available if the analysis has been run. To access the output, first bring up the proper job through the File item on the Main Menu. Then, clicking on Output on the Main Menu will produce a pull-down menu that controls the program's output. The pull-down menu provides three options:

Output Menu

Review Report

Enters the Review processor where results of the analysis may be inspected on the screen, printed, or copied to a file.

Review the DXF File

Invokes a compatible DXF processor on the machine if one exists.

Review the Access Database

If a database has been created, it can be reviewed directly using Microsoft Access.

The remainder of this chapter will focus on the many capabilities of the Review processor.


Chapter 8 Output/Review

8-3

The Review Screen The body of the Review screen shows all the reports available for the current job or file. These reports follow the analysis steps described in the previous chapter. To select one or more reports, simply use the mouse and (CTRL) key to select one or more reports.

The first report selected will immediately be displayed in the main window. Use the mouse to view other reports or if multiple reports are selected, press the blue right and left arrow buttons on the toolbar to cycle through the viewing of the reports.


8-4

Output/Review

Using Review To use the Review or Output processor, simply click on the report of interest that is in right hand column of the screen. That report will then show up in the main panel. Multiple reports can be selected by holding the control (CTRL) key down while clicking the reports with the mouse. You can then use the blue arrows on the toolbar to navigate backwards and forwards through the selected reports. You can then print the reports or create a Microsoft Word document by pressing on the appropriate toolbar button at the top of the window.



Component Analysis Analysis of vessel details is initiated from the Input Menu.


8-5

8-6

Output/Review

The units for the component analysis are extracted from the current vessel input. In the example here, Half Pipes Jacket was selected.



The initial screen is shown below.

To produce a report, click the Analyze Current Item icon.


8-7

8-8


Output/Review

CH AP TER

9

Chapter 9 HEAT EXCHANGERS In This Chapter Introduction ................................................................................ 9-2 Purpose, Scope and Technical Basis........................................... 9-3 Analyzing Heat Exchangers........................................................ 9-4


9-2

HEAT EXCHANGERS

Introduction The HEAT EXCHANGER program performs the analysis of heat exchangers in accordance with the following Codes: ASME Section VIII Division 1 TEMA 1998 PD 5500: 2003 The ASME tubesheet (heat exchanger) analysis rules were formerly found in Appendix AA, but in 2003, were rewritten and moved to the main body of the code, Part UHX. At the time of this writing, the heat exchanger committee is refining some details, which will be included in the program as time progresses. The TEMA and PD 5500 methods of analysis have undergone little change since the last edition of PVElite. Formerly, tubesheets could only be analyzed in the Component Analysis module of PVElite, although this facility is still available for more information see The Tubesheet Program (see "TUBESHEETS" on page 17-1), this new feature has a number of advantages not formerly available. Among these advantages are: 1

Tubesheets can be integrated into a model, including cylindrical shells (main shell and channels), heads, and nozzles in the same model.

2

The total weight of the heat exchanger can be computed including all of its component parts

3

Supports, such as saddles, can be analyzed directly from the integrated model, ensuring that all weights and applied loads are addressed.

4

The tubesheet reports are part of the overall analysis.

5

The tubesheet design code can be changed between TEMA and ASME with little modification to the input.


Chapter 9 HEAT EXCHANGERS

9-3

Purpose, Scope and Technical Basis The HEAT EXCHANGER program performs the analysis of shell and tube type heat exchangers. The program computes the stresses generated in the shell, channel, tubesheets, and tubes for heat exchanger configuration entered by the user. The program allows the user to enter multiple pressure / temperature combinations to provide a complete analysis. Users have the choice of the following Codes (Reference Documents): ASME Section VIII Division 1 - 2004 Addenda 2005 PD 5500: 2003 TEMA - Tubular Exchanger Manufacturers Association: 1998 Because the heat exchanger is built by the user as a complete model, including the support structure, nozzles, and external loads etc., the exchanger will be analyzed to include all of these conditions. The program considers the following types of construction: Fixed and Floating Tubesheets with various packing seals Plain Shells, and Shell with Expansion joints or Bellows U-Tube exchangers Tubesheets that are subject to bolting moments from mating flanges Tubesheets that are closed by floating heads


9-4

HEAT EXCHANGERS

Analyzing Heat Exchangers Heat Exchanger analysis is initiated from the Heat Exchanger Data Input Screen. When you first load PVElite, it is not active.

button, which is located near the top of the

Note: We use English (Imperial) units throughout this exercise. We strongly recommend you use these units for this sample exercise.

To Analyze a Heat Exchanger: 1

Launch PVElite and ensure the Input Screen is showing. Select an ellipsoidal head by clicking the Ellipse Head icon. To build the heat exchanger in the horizontal orientation, click

2

.

Enter the information exactly as shown below for the head. The screen should then look exactly like this. Check your input before you move on. Remember, click on the text in the left column and then start typing. The cursor will automatically move to the right column. When you are finished, press Enter twice.



3

9-5

Click the Cylinder icon to add a cylinder to the head. Ensure the input for the new cylinder has exactly this appearance:


9-6

HEAT EXCHANGERS

4

Click the Body Flange icon to add a body flange to the right hand end of the channel shell. After adding the flange enter all the values exactly as shown below.

5

Click the Perform Flange Calculation box, and the Flange dialog will display.

We need to correctly dimension the flange. To do this, change the flange as it appears to a 24 inch Class 150 flange, which will fit into our heat exchanger.



9-7

6

Click the Perform Flange Calculations box and the Flange dialog automatically displays. At the bottom of the new Flange dialog you will see a section that resembles this:

7

Select 150 as the Class, 24 for the Nom then click ANSI Dim Lookup. The flange screen is now set up for the 24 inch Class 150 dimensions and bolting. Verify your screen resembles this:

Up to this point, we have been using the normal vessel building techniques that PVElite uses for building non-heat exchanger pressure vessels. We are now ready to start the construction (build the model) of the heat exchanger main elements, the tubesheets, tubes and main shell that enclose the tube bundle. 8

Look at the Heat Exchanger button you will see that it is no longer disabled, as there is now a component to which to attach the first tubesheet.


9-8

9

HEAT EXCHANGERS

Click the Heat Exchanger button the Heat Exchanger Tubesheet Input dialog displays. We will now construct an ASME Section UHX exchanger, which requires a large amount of input data.

10 From the Exchanger Type box, click the arrow, and select Fixed. Your screen should now resemble this:

11 Click the Tubesheet Properties tab and enter the following information exactly as it displays below. Note the type of tubesheet we have chosen: b Fixed Tubesheet, shell integral, extended as flange. Note also that we enabled the Tubesheet Extended as Flange? box.



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12 Click the Tube Data tab and enter the information as it displays below.

We need to enter the pressures and temperatures for our heat exchanger to complete the tubesheet and tubes data. 13 Click the Load Cases tab and enter the information shown below.

PVElite enables users to enter multiple combinations of pressures and temperatures for heat exchangers. 14 From the bottom of the dialog screen, click OK and the Data Input screen will display. Look at the 3D model on your screen, and it should resemble this figure.

Notice that there is no cylindrical shell between the two tubesheets. PVElite cannot perform tubesheet analysis unless the shell is present, because the thermal load from the shell is needed to complete this analysis. So, we must add the shell between the tubesheets. Before we do this, recall that we stated in the Heat Exchanger dialog that the tubes were 60 inches long. This is the distance between the tubesheets. So for a good match, the outer shell must also be 60 inches long. Also note that there are only two rows of tubes displayed. Because of the intensive nature of 3D graphics it is impractical to show hundreds of tubes. Doing so would render the 3D model useless.


9-10

HEAT EXCHANGERS

15 Click the Cylindrical Shell icon, to add a cylindrical shell to our model. This shell is 60 inches or 5 feet long as discussed above. Verify your entries match those below:

All that remains is for us to add the body flange to the right end of our heat exchanger, then another channel shell and the final right channel head. Before doing so, your model should look like this.



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You should be able to do this by yourself. Do so, and we can then proceed to the final step. You are able free to add saddle supports, nozzles, and any other loads that apply.

Building Heat Exchangers Tubesheet Type and Design Code This section discusses the meanings and requirements relating to all the fields or screens presented to the user. Once you have built the left hand side of your heat exchanger up to the point where you have a place to attach your first tubesheet, click the

Heat Exchanger button. The Heat Exchanger Tubesheet Input screen appears.

Across the top of this dialog six tabs display:

Each tab displays a different data area which where users can enter heat exchanger information. We are going to discuss each tab and its data area in turn. This section of the manual is concerned with the Tubesheet Type and Design Code tab. The Tubesheet Analysis Method


9-12

HEAT EXCHANGERS

From the list box, choose the code you wish to use for the analysis. Available choices are: ASME UHX - which is ASME Section VIII Division 1, Section UHX PD 5500 - The British Pressure Vessel Code, Section 3.9 - Flat Heat Exchanger Tubesheets TEMA - Tubular Exchanger Manufacturers Association Note: In the case of PD 5500 if you previously selected PD:5500 on the Constraints dialog, then PD 5500 is the only choice available in this drop down box. Exchanger Type

From the list box, choose the type of tubesheet configuration you wish to analyze. The choices are U-Tube - This is where there is only one tubesheet, and each tube is in the form of a U shape so that both ends of the tube are in the same single tubesheet. Fixed - Fixed tubesheets are fixed to either end of the exchanger and are subject to thermal loads imposed by expansion. Floating - The right hand tubesheet is free and as the tubes expand or contract from thermal effects, the tubesheet is free to move with the tube bundle. These sketches illustrate the three basic types of exchangers:

ASME Specific Information The frames look like this:



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Depending on the code and type of exchanger you have chosen, the relevant fields will be come available for you to enter the respective information. Let us consider first the ASME frame: Floating Exchanger Type (ASME Specific) If you have chosen the ASME Floating Head Type Exchanger, the following frame becomes active. From the list box, select the type of floating head as illustrated just below:

The various types of exchanger as shown in the ASME code have the following floating head configurations.

The U-Tube Tubesheet Stress Reduction Option If your design is a 'U-Tube' type exchanger, the following frame is active. From the list box choose stress reduction option:


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HEAT EXCHANGERS

Tell PVElite what it must do in the event the model must be changed because of over stress. Available choices are: Increase the Tubesheet Thickness Increase the Integral Cylinder Thickness Increase Both the Cylinder and Tubesheet Perform Elastic-Plastic Calculation Enter the method you wish PVElite to use to reduce any over stress condition. TEMA Specific Information If you had chosen TEMA as the design code, the TEMA frame would have become active like this:

Before discussing the three drop down list boxes labeled: TEMA Exchanger Notation, consider the nomenclature used by the TEMA code. TEMA divides a typical heat exchanger into three sections, namely: the Front Channel, the Shell and the Rear Channel respectively. The different types are assigned letters. The following table which has been taken from the TEMA code gives shows the letters, and the corresponding designs for these three sections of the heat exchanger: For more details, please refer to the TEMA code.



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From the list boxes, enter your chosen configuration. The following example shows a common heat exchanger configuration:

From the TEMA Exchanger Class list box select the appropriate class. Available choices are: Class R Class C Class B


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HEAT EXCHANGERS

Each Class has certain design constraints imposed from the TEMA Code, such as tube pitch, baffle spacing, number of tie rods etc. The computations for each Class is identical, but the limitations are different.

Tubesheet Properties This section is concerned with the Tubesheet Properties as shown on the second tab of the main exchanger input screen. Clicking the Tubesheet Properties tab, you will get the following dialog screen:

Description Enter the description you wish to include on your report for the tubesheet analysis section. In the above example, we have set the Description to: 'MY EXCHANGER'. Element From Node This is the element to which the tubesheet is attached. Suppose for example, you want to attach the tubesheet to Node 50 (as illustrated below), and the wrong Node Number is shown in the text box (shown as 30 above), you must enable this field, to do this press F8. You will now be able to enter the number 50 in this field. Distance from Node

Be careful here. The distance from node is the distance from the left hand end of the component to which the first tubesheet is attached. We illustrate this distance as follows:



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Tubesheet Type

Enter the type of tubesheet you are to design or analyze. From the drop down list box choose the tubesheet type from this list: If you had earlier (see above) chosen to compute a Fixed Tubesheet type exchanger, you would be presented with these choices: Fixed Tubesheets, integral both sides Fixed Tubesheets, shell integral, extended as flange Fixed Tubesheets, shell integral, not extended as flange Fixed Tubesheets, gasketed both sides If you had earlier (see above) chosen to compute a U-Tube type exchanger, you would be presented with these choices: U-tubesheet, integral both sides U-tubesheet, integral with shell U-tubesheet, gasketed on both sides U-tubesheet, integral with channel If you had earlier (see above) chosen to compute a Floating Head type exchanger, you would be presented with these choices: Stationary tubesheets, integral with both sides Stationary tubesheets, integral with shell


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HEAT EXCHANGERS Stationary tubesheets, gasketed on both sides Stationary tubesheets, integral with channel

From the list above, the following illustrations explain the meanings of the some of the terms used above:

In the top left picture above, the tubesheet is shown integral with the shell. However if the tubes were to point to the left instead of the right, then the tubesheet would be integral with the channel. Outside Diameter, Tubesheet Thickness and Corrosion Allowance Shell side / Channel side

Enter the outside diameter of the tubesheet. If the tubesheet extends beyond the shell (or channel) then enter that diameter. However, if the shell is integral with either the shell, or the channel, then enter the inside diameter of the shell or channel as applies. Enter the balance of the information for the tubesheet new thickness, and the corrosion on the shell and channel sides. When PVElite calculates the stresses, it will deduct both of these corrosion allowances. These entries are straight forward. Depth of Groove in Tubesheet (in any)

If there is a groove across the tubesheet for a pass partition, then enter the depth of this groove. The depth of this groove is deducted from the thickness of the tubesheet during the calculation process. This is an illustration of a pass partition located into the tubesheet. At the bottom of the groove, there is usually a gasket which PVElite refers to as the Pass Partition Gasket (see elsewhere in this manual where flanges are discussed):



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Weld Leg at Back of Tubesheet (if any)

Enter the fillet leg size of the weld between the shell and the tubesheet, or the channel and the tubesheet as the case may be if there is such a weld. This is the type of weld meant here:

Tubesheet Extended as Flange? / Thickness of Extended Portion / Bolt Load Transferred to Tubesheet?

If the tubesheet extends beyond the outside shell / channel diameter, and this extension is attached to a body flange, then check the Tubesheet Extended as Flange box. The thickness of the part of the tubesheet that is extended as a flange may be the same or a different thickness from the rest of the flange. Enter the thickness of the tubesheet extension. If the tubesheet is bolted to a flange (either on the channel side or shell side), and the bolts produce a moment on the edge of the tubesheet, then check the Bolt Load Transferred to Tubesheet box. Here we illustrate a tubesheet extended as a flange. In this illustration the tubesheet is subject to the bolt force, and is therefore experiences the bolt load, which is transferred from the flange.


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HEAT EXCHANGERS

Backing Ring

If there is a backing ring at the back of the tubesheet, we need the details. Here is an illustration of a tubesheet with a backing ring:

Enter the thickness of the backing ring, Enter the Outside and Inside Diameters of the Backing Ring, and the effective diameter of the gasket(s) - G. To accurately determine the effective diameter of the gasket 'G', you are referred to ASME VIII Division 1 - Appendix 2 Table 2-5.2. For a flat gasket, a typical procedure for finding the value of G is as follows: N = (O/Dia of gasket - I/Dia of gasket) / 2 bo = N / 2 If bo > 1/4 in. then b = Sqrt( bo ) / 2 and G = O/Dia of Gasket - 2.b If bo <= 1/4 in. then b = (O/Dia of gasket + I/Dia of gasket) / 2 However, the user is urged to check the formula that applies to the type of gasket chosen.



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Shell Bands - ASME Part UHX Specific

If you have selected the analysis to be performed in accordance with ASME Section UHX, and you have a fixed tubesheet heat exchanger, you will then be asked if there are shell bands. Here is what shell bands look like:

If there is a shell band (see above illustration), then check the Is there a Shell Band box. Then, enter the shell dimensions in the appropriate fields as indicated in the above illustration. Thicker shell bands are used in areas where the shell would be too highly stressed, and the thicker sections will reduce the stresses in the region of the tubesheets. PD 5500 Specific

If you chose PD:5500 as your code on the Constraint screen, the frame shown above becomes active. From the list box, choose the combination of the way the tubesheet is restrained in the heat exchanger. The following choices are available: Stationary Simply / Floating Simply Stationary Simply / Floating Clamped Stationary Clamped / Floating Simply Stationary Clamped / Floating Clamped PD:5500 uses the following diagram to explain the meaning of tubesheets that are Simply Supported, and tubesheets that are Clamped. PVElite uses this information to determine which PD:5500 graphs to use to obtain certain values required in the computation of the tubesheet analysis.


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HEAT EXCHANGERS

Tube Input Data Information Specific to the Tubes Click the tab: Tube Data (shown below): We need information about the tubes that comprise the tube bundle. This is the third tab in the heat exchanger input screen.



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Basic Tube Data

Number of Holes Enter the number of tubes in the tube bundle (the number of holes in one tubesheet). Pattern From the list box, choose the arrangement of the tubes in the tube bundle. Here are the two arrangements:

Wall Thickness Enter the wall thickness of the tube. If you have finned tubes, it is usual to enter the thickness of the tubes ignoring the fins (usually referred to as the root thickness of the tube). Corrosion Allowance If the tubes are subject to a corrosion allowance, then enter the corrosion allowance of the tubes. PVElite will as one of its load cases check the stresses in the corroded conditions (see Load Cases below). Outside Diameter Enter the Outside Diameter of the tubes. Tube Pitch Enter the center to center distance between the tubes. See the diagram above. Length of Expanded Portion of Tube Enter the distance the tube is expanded into the tubesheet. This is illustrated below:

Radius to Outermost Tube Hole Center Enter the Distance from the Center of the Tubesheet to the Centerline of the furthest tube. This is the distance from the center of the tubesheet to the center of the furthest tube.


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HEAT EXCHANGERS

Distance Between Innermost Tube Centers Between passes there are often open lanes to provide space for partitions in the channels that control the flow of the fluid in the tubes. This distance is often greater than the pitch in the main areas of the tube bundle. Enter this distance, even if it is the same as the general tube pitch (see above). If there are no pass partitions then this value must be 0. This distance is illustrated thus:

PD 5500 or TEMA / ASME Fixed Tubesheet Input If you chose a fixed tubesheet type design, then following frame will be activated for entry of required information. We cover the fields in order:

Max Distance from Tubesheet to 1st Tube Support and Max Distance Between 2 Tube Supports Tube supports are often referred to baffles. Not only do these tube supports or baffles support the tubes, but they also control the path taken by the shell side fluid. If the tubes are subjected to axial compression, they act as struts or slender columns, and are subject to buckling. Tube supports or baffles help to shorten the effective lengths of the tubes, thus providing support from sagging and compression. The distances are illustrated here:



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End Condition k / Max. Unsupported Len SL The end condition controls the effective length of the tube against buckling. TEMA and PD:5500 specify appropriate values for 'k' as follows:

From the above table, enter the appropriate value of 'k'. Length SL Enter the distance between the points of support as indicated in the left most column of the above table associated with the chosen value 'k'. Tube-Tubesheet Weld (TEMA / ASME)

This section of the input screen is concerned with the strength of the joint between the tubesheet and the tube. Tubes can be installed in the tubesheet by being expanded to grip the hole in the tubesheet, or can be fixed by welding. It is also possible to use a combination of expanding and welding, where the weld is merely a seal weld, not a strength weld. PVElite determines the effectiveness (strength) of this joint to investigate if the joint is strong enough to withstand the axial forces to which the tube is subjected during service.


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HEAT EXCHANGERS

Fillet Weld Leg Size (If Any) If there is a weld between the tube and the tubesheet, then enter the fillet leg size. Groove Weld Leg Size (If Any) If the tubesheet is chamfered in order that the attachment weld partially penetrates the tubesheet, then enter the fillet weld size. This is the type to tube to tubesheet weld being considered:

Tube Weld Joint Type PVElite needs to know the degree of support the weld contributes to the tube to tubesheet joint. From the drop down list box choose from the following:

Type

Description

Full Strength

where the weld alone provides the strength to the joint

Partial

where the weld provides support in combination with the fact that the tube is expanded to grip the tube hole

Seal

where the weld only serves to prevent leakage, and does not contribute to the strength of the joint.

Design Strength (Only for U-Tubes) In the case of U-Tube exchangers, where the tubes are welded to the tubesheet with a full strength weld, PVElite will calculate the required weld size to withstand the load entered by the user. In this field, enter a suitable axial load on the tubes from the loadings they expected to experience in service. Allowable Joint Load Method This list box is only active if you are designing an exchanger in accordance with the ASME code. PVElite will compute the Allowable Joint Load either using Appendix A, or according to Section UW-20 of the code. Select from the drop down list box one of the following: ASME Appendix A ASME UW-20



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Is the Tube Tubesheet Joint Tested ASME in its Appendix A provides a procedure for testing the strength of the tube to tubesheet joint. If this test is performed, then the actual strength is known, and this provides for a higher degree of confidence in the integrity of the joint. If the joint configuration has been tested in accordance with the stated procedure, then check this box. In the case of PD 5500 there is also a procedure for testing the tube tubesheet joint. This procedure is to be found in the publication BS 4870-3 obtained from the British Standards Institution. Tube Joint Reliability Factor (table 3-9-2) The Joint Reliability Factor is determined by the type of tube to tubesheet joint, and the code. The ASME and PD 5500 codes have different reliability factors. Here are the reliability factors for the two codes (for TEMA exchangers, choose the ASME values):

Interface Pressure (Pressure on Outside of Tube)

Here, two values are called for, namely: Po and Pt. Po is the pressure that exists between the outside of the tube after the tube is expanded into the tubesheet, and Pt is the pressure that will exist on the outside of the tube once the exchanger is in service. These values are difficult to obtain presently as the ASME code gives little guidance. This is a representation of the pressure on the outside of the tube once it is expanded into the tubesheet:


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HEAT EXCHANGERS

Tube Product Specification

Exchanger tubes are available as either seamless or welded products. If the tubes are of welded construction then check this box.

Expansion Joint Data

If there is an expansion joint in the main shell between the tubesheets (which only applies to tubesheets fixed to each end of the shell), then PVElite needs to know all the details of the expansion joint to compute its flexibility (or spring rate), as the expansion joint plays a role in the axial forces that exist between the shell and the tubes as a result mainly of the thermal growth of the shell and tubes relative to each other. Type of Expansion Joint (If any)

From the above list box choose the type of expansion joint employed in your design. The choices are:

Joint Type

Description

No Joint

If there is no expansion joint present

Thin Bellows

If the expansion joint is a many convolution thin metal bellows per ASME Appendix 26

Thick Joint

if the expansion joint is made up of pressed elements - either per TEMA or ASME Appendix 5

We here illustrate the type of expansion joints. Note the dimension of each type, as you will be required to enter the relevant dimension details for the joint type you choose: This the Thick Joint as prescribed by the TEMA Code:



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Note: TEMA refers to each of the elements shown below as a Shell Element. One convolution comprises 2 shell elements. Please take a note of this, it follows that shell elements exist in pairs and that the number of shell elements required is twice the number of convolutions.

This is a Thick Joint as prescribed by the ASME Code Appendix 5:

This is a Thin Joint as prescribed by the ASME Code Appendix 26:

If you choose the thin joint as shown above, then the axial stiffness will be set to zero by PVElite unless a value is entered (see below), as this type of joint is very flexible.


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HEAT EXCHANGERS

Make a note of the nomenclature and dimensions in the above figures, you will need them for the type of expansion joint you install in your model. You need to gather all the information before you begin entering the data that follows. Number of Flexible Shell Elements (1 Convolution = 2 Fsa)

This field only applies to Thick Joints which comprise shell elements (described just above). An alternative way of looking at this information is to ask yourself how many PAIRS of elements do I need to make up the number of convolutions needed. Remember, the greater the number of convolutions, the greater the flexibility. This flexibility is affected by the dimensions, thickness of the vertical legs of the elements, and the number of elements employed in the expansion joint. Enter the number of shell elements in the expansion joint. Distance From Node

The start of the expansion joint must be located somewhere in the shell to which in which it is installed. The Distance From the Node is shown below:

Design Option

From the list box choose from the list: Existing Analyze If you wish to enter the details of an existing expansion component, then you will be required to enter the spring rate and other information. However, if you required PVElite to compute the flexibility of the expansion joint, then select Analyze from this list box. The command button labeled Set Defaults enable you to toggle between using the actual dimensions of the expansion joint elements (which you will have to enter). In this way, once you have entered the geometric data, you will be able to quickly change from a full analysis to using the flexibility values for an existing joint.



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Dimensions for the Shell Elements:

In the case of thick walled expansion joints, and you want PVElite to compute the axial stiffness (or flexibility) enter the dimensions for one shell element (defined above). You will be able to see the nomenclature related to the shell element from the thumbnail picture on the input screen. Desired Cycle Life

During service, the expansion joint will experience a number (cycles) of expansions and contractions from the changing temperatures and pressures during its lifetime. PVElite computes the maximum number of cycles the expansion joint is able to withstand. A number must be typed into this field. PVElite will compare the computed number of cycles with the user entered value. User Input Spring Rate

These fields only apply if the user has entered 'Existing' in the Design Option field above. Enter the spring rate for both the Corroded and Uncorroded states. The Outer Cylinder

If there is an Outer Cylinder between two shell element pairs like this:


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HEAT EXCHANGERS

From the figure showing the TEMA Thick Joint dimensions above, enter the Material, and outer cylinder dimensions for the diameters and any corrosion allowances.

Load Cases Click the Load Cases tab

During operation, and during its service life a heat exchanger is subject to different combinations of pressure and temperature. PVElite enables the user to set up to 8 combinations known as Load Cases. Some of these load case might include the initial and periodic hydrostatic pressure tests, normal predicted service, and upset or emergency conditions where unusual conditions may apply such as sudden plant shut down, cold start up etc. Performing these calculations could be extremely tedious and time consuming. PVElite not only considers up to 8 load cases, but also considers each of these load cases for both corroded and un-corroded conditions as well as the possibility of a vacuum being encountered for any one of these load cases. This could in an extreme case mean that up to 128 different conditions are being computed.

Entering Individual Load Cases: How Many Load Cases? First determine how many load cases must be considered:

From the Number of cases to process drop down box select a number between 1 and 8. This sets the total number of load cases PVElite will include in its analysis. From the Active Load Case counter click on the arrow to navigate through the load cases, as only one load case at a time will appear on the screen. In the example above, 2 load cases have been specified, but the input screen will only accept information for load case number 1. Let's consider all the information thus ensuring that sufficient information is entered for each load case. Remember, if for example 8 load cases are chosen, then PVElite expects the user has entered all the information for every load case.

In the Case Description field, type a meaningful description of this code case. This will be included in the final report generated by PVElite. Just to the right of the Case Description field is a command button that looks like this:

Click this button to display the Report Print Options dialog.



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It is important to realize that the load cases shown in the left hand column in the illustration above are NOT the load cases entered on the parent screen. Use the table below to identify the meanings of the symbols used in the Report Print Options dialog. Descriptor

Description

Fvs

This is the user defined shell side pressure set to a full vacuum

Fvt

This is the user defined tube side pressure set to a full vacuum

Ps

The user defined shell side design pressure

Pt

The user defined tube side design pressure

Th

Thermal Expansion: +Th means with thermal expansion and -Th means without thermal expansion

For example: Ps + Fvt + Th tells PVElite to use the design pressure in the shell, a vacuum in the tubes, and also to include thermal expansion from temperature differentials.


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HEAT EXCHANGERS Fvs + Fvt - Th tells PVElite to use a vacuum in the shell, a vacuum in the tubes, but to ignore thermal expansion. ASME: In the case of the ASME analysis, PVElite will only run cases 1, 2, 3 and 8 TEMA / PD 5500: In the case of these codes, PVElite will run all cases.

Once you have set up the load cases, click OK to close the dialog. Remember, this combination of load cases is available for each major load case entered on the parent screen. As can be seen, it is possible to have a large number of total combinations, so only enter cases that are absolutely necessary, because the computation time can be long, and the report can generate a lot of output. Let us now return to the parent screen:

Load Case - Pressures, Temperatures and Materials

Across the top of the figure the following headings are located: Shell, Channel, Tubes, Tubesheet and Shell Band. Running down the left hand side are the following labels: Design Pressure, Design Temperature, Material, Metal Temperature along length, Metal Temperature at Tubesheet Rim and Database lookup and Properties. Design Pressure Enter the design pressure for the shell and the channel (tube side). Design Temperature Enter the design temperature for the Shell, Channel, Tubes, Tubesheet and Shell Band. This is the maximum design temperature. PVElite will use this temperature to determine the allowable stresses, coefficient of expansion and Young's Modulus. These temperatures are typically higher than the actual metal temperatures. Material Underneath each component is two command buttons Tubes, and a Right Arrow.

Clicking the Tubes button displays a list of materials from which users can select the appropriate material. Clicking the Arrow button displays the details of the current material for that component. At this point, verify that the information in the detail screen is complete, including the yield stresses, and any other information. PVElite uses this information to determine the mechanical properties of the component. The material definitions are only available for load case 1. So if it is desired to change the material for any component, then select load case 1 from the spin box discussed above.



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Metal Temperature Along the Length This field refers to the Actual Metal temperatures - often called the Mean Metal Temperature for a specific component. These temperatures are used to compute the thermal expansion of the shell and tubes. Users must be as accurate as possible when assigning these values, because thermal expansions can be the major contributor to axial stresses. Not much information is available for determining these temperatures, but TEMA section T-4 supplies a suggestion. However, the determination of these temperatures is complex, and much information is required to attempt their derivation. Modulus of Elasticity

If the User-defined values box is checked, then users may enter user defined values for Young's Modulus. Users are cautioned to ensure that the defined values are realistic. Typically this check box is not enabled in those instances PVElite uses its internal database to find these values. This is usually considered the safer method to use. Coefficient of Thermal Expansion

If the User-defined values box is checked, then users may enter user-defined values for the Coefficient of Thermal Expansion. Users are cautioned that if user-defined values are used, ensure they are realistic. Typically this check box is not enabled in those instances PVElite uses its internal database to find these values. This is usually considered the safer method to use. Differential Design Pressure

In the case of TEMA and PD 5500 only, the codes allow users to have PVElite compute the stresses using only the Differential Design Pressures (difference between Shell and Tube sides as defined) combination only. If this field is left as a zero input, PVElite will ignore the field, and will carry out the computation for all the combinations of pressure. The differential pressure selection assumes that these are the ONLY pressure that will be encountered for this load case. The user is cautioned that typically, this field would be left as zero unless the user is absolutely certain that this case only need be considered. Expansion Joint Material and Differential Pressure Design

If an expansion joint is present, then the material for that joint is required. Clicking the Matl.. button displays a list of materials from which the appropriate material may be selected. The Arrow button is used to view the actual material characteristics. Click this button to verify all the information is available including the yield stress values.


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HEAT EXCHANGERS

PVElite requires this information during the computation of the thermal stress, and all relevant information must be available to the program. PD 5500 Specific Information

Selecting PD 5500 for the exchanger requires other information concerning the materials of construction. From each of the drop down boxes, users must designate the material class. Plain Carbon Steel and Carbon-Manganese Steel C-Si, C-1/2 Mo and Cr-1/2 Mo Steel C-Mn-Si, 1-1/4 Cr - 1/2 Mo and 3Cr - 1Mo Steel Mn - Mo Steel 2-1/2 and 3-1/2 Ni Steel Sea-Cure Steel C-Si, C-1/2 Mo and Cr -1/2 Mo and 3Cr-1Mo Steel C-Mn-Si, 1-1/4Cr-1/2Mo and 3Cr-1Mo 33Cr-31Ni-32Fe-1.5Mo-6Cu-N Steel For more information refer to PD 5500.

Floating Tubesheets Click the Floating Tubesheets tab.

If you have chosen to analyze a Floating Tubesheet, you will be presented with the following input screen:



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Let us consider each field in turn: Description Enter a meaningful description for the floating head that will be included in the final report generated by PVElite. Floating Tubesheet Type

From the list box select one of the following: In the case of TEMA / PD 5500 Exchangers, the list is as follows (P) Floating tubesheet, outside packed (T) Floating Tubesheet, pull through floating head (S) Floating tubesheet, gasketed, not extended, with backing device (W) Floating tubesheet, externally sealed. In the case of ASME Exchangers, the list is as follows: (a) Floating tubesheet, integral (b) Floating tubesheet, gasketed, extended as a flange (c) Floating tubesheet, gasketed, not extended with backing device (d) Floating tubesheet, internally sealed. The floating heads for the TEMA / PD 5500 codes is illustrated below:


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HEAT EXCHANGERS



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The floating heads for the ASME code is illustrated as follows:

Floating Tubesheet Geometry

Outside Diameter Enter the outside diameter of the floating tubesheet. Tubesheet Thickness Enter the Actual Thickness of the Tubesheet. Corrosion Allowance Enter the Corrosion Allowances for both the Shell and Channel sides. This corrosion allowance will be deducted when computing the tubesheet stresses for the corroded condition calculation. Depth of Groove in Tubesheet (if any)

If there is a groove across the tubesheet for a pass partition, then enter the depth of this groove. The depth of this groove is deducted from the thickness of the tubesheet during the calculation process. Below is an illustration of a


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HEAT EXCHANGERS

pass partition located into the tubesheet. At the bottom of the groove, there is usually a gasket, which PVElite refers to as the Pass Partition Gasket (see elsewhere in this manual where flanges are discussed):

Is The Floating Tubesheet Extended as a Flange

If the floating tubesheet is extended as a flange to be bolted to a body flange, then check the box: Tubesheet Extended as Flange. The thickness of the part of the tubesheet that is extended as a flange may be the same or a different thickness from the rest of the flange. Enter the Thickness of Extended Portion.

Integral Channel Properties for ASME Floating Configuration A

If you selected the ASME Floating Tubesheet for Configuration A analysis, then enter the New Channel Thickness tc and the Design Temperature.



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Use the command buttons to choose the appropriate material, and ensure that all the data fields (click the right command button) are entered including the yield strength. PD 5500

If you selected PD:5500 from the Constraint dialog, the PD 5500 frame becomes active. From the list box, choose the combination of the way the tubesheet is restrained in the heat exchanger. The choices available: Stationary Simply / Floating Simply Stationary Simply / Floating Clamped Stationary Clamped / Floating Simply Stationary Clamped / Floating Clamped PD:5500 uses the following diagram to explain the meaning of Tubesheets that are Simply Supported, and Tubesheets that are Clamped. PVElite also uses this information to determine which PD:5500 graphs to use to obtain certain values required in the computation of the tubesheet analysis.


9-42

HEAT EXCHANGERS

Spherical Cover / Backing Device This section covers the data required to analyze the Spherical Cover and Backing Device (if there is one).

Description

Enter an appropriate description that describes the type of bolted cover for reference in the final report generated by PVElite. Type of Floating Head

PVElite will analyze four different type of Floating Heat (Bolted Cover). They are illustrated here:



9-43

Dimensions of the Bolted Cover

From the illustration just above, enter the following information which is specific to the bolted cover (not the mating flange or backing device): Design Temperature of the Bolted Cover The Inside Crown Radius of the spherical cap, or formed dome (see the illustration above) The Head Thickness. This is the thickness of the spherical or domed portion of the cover. Head Internal Corrosion Allowance (this is the tube side). Enter the corrosion allowance. Head External Corrosion Allowance (this is the shell side). Enter the corrosion allowance. Flange Thickness. In the above illustration, this is the thickness of the actual flange part of the bolted cover, not the spherical cap. Once you have selected the type of cover (a, b, c or d), a new screen opens up. This screen is for the flange, gasket and bolting details. A partial view of this input screen is shown thus: For details in completing the data in this screen, please refer to the section titled Bolted Cover Mating Flange.


9-44

HEAT EXCHANGERS

Continuing with the input: The remainder of the required data is thus:

Slotted Flange If the flange is slotted, check this box. This is an illustration of a slotted flange:

Have a care, because slotted flanges are very much weaker than conventional flanges. Perform Soehren's Calculation A more detailed analysis of bolted dished heads is included, based on Soehren's analysis, "The Design of Floating heads for Heat-Exchangers", ASME 57-A-7-47. The more detailed analysis may be used for the design of floating heads, as specifically mentioned in the ASME Code, Paragraph 1-6 (h). Dimension Q If you have checked the box to perform the Soehren's Calculation, then enter the 'Q' dimension as shown below:



9-45

Head and Flange Materials Use the left hand command button in each case to select the material from the drop down list box, and use the right hand command button to view the properties. Verify all the properties are included, including the yield value, which you may have to enter yourself for a non-ASME material. Compute 'F' Even if the Pressure is Zero In ASME Division 1, Appendix 1 for the type 'd' head, the thickness of the head is computed using a derived 'F' value. 'F' is a function of the pressure, therefore, for the initial bolt-up condition 'F' would become zero. Some are of the opinion that the 'F' value should never be zero, but that the value of 'F' computed for the operating condition should be used. If you wish to have PVElite use a non-zero value of 'F', then check this box. Dimension hr

In the illustration of a type 'd' head (see illustration above), the distance 'hr' can be entered in two different ways. If the distance 'hr' is known, then enter this value in the upper box. However, if you know the distance from the top of the flange to where the top of the spherical cap (Head) intersects the inside diameter of the flange, then enter this dimension, and when the Compute button is clicked, PVElite will compute the value of 'hr'. Backing Ring Data

If there is a backing ring (or backing device) behind the tubesheet, then check the Is There a Backing Ring box. Backing Ring Material Select the backing ring material and check all the data is complete as discussed above for other components. Backing Ring Inside Diameter / Outside Diameter Enter the Inside Diameter and the Outside Diameter of the Backing Ring.


9-46

HEAT EXCHANGERS

Backing Ring Thickness Enter the thickness of the backing ring. Number of Splits in Backing Ring Sometimes backing rings are split diametrically to facilitate assembly. More than one split ring may be employed in the construction of the backing ring for added strength. Illustrated below are two rings each of which is split diametrically, the splits being located at 90 degrees to each other. Enter the number of rings that are split. For the diagram below the number of splits would be two. If the backing ring is not split then enter zero from the list box.

In the above illustration, there are two backing rings, each of which is split. In this case, The number of splits in Backing Ring would be entered as '2'.



9-47

Bolted Cover Mating Flange Flange and Gasket Information The bolted cover attached to the floating tubesheet produces a moment on this tubesheet. In order that PVElite can compute this moment, we need all the flange and bolting information. The following input screen Flange and Gasket Information will now be discussed:

A typical tubesheet extended as a flange subject to the bolting moment has the following appearance and dimensions:

Flanged Portion ID / OD Enter the Inside Diameter of the Cover Flange, and the Outside Diameter of the Cover Flange


9-48

HEAT EXCHANGERS

Flange Face ID / OD Enter the Inside Diameter of the Flange Raised Face, and the Outside Diameter of the Flange Raised Face. Gasket ID / OD Enter the Inside Diameter of the Gasket, and the Outside Diameter of the Gasket. Gasket m / y From ASME VIII Division 1 - Appendix 2, Table 2-5.1, enter the gasket seating factor 'm' factor, and the gasket seating stress 'y'. In the case of a PD:5500 exchanger, refer to Table 3-8.4 Flange Face Sketch / Column From ASME Table 2-5.1 or PD:5500 Table 3-8.4, select facing sketch and column number from the drop down list boxes. Gasket Thickness Enter the thickness of the gasket. This value is not used in the tubesheet computation, but is included in the final report. Nubbin Width Referring to the above illustration, the Nubbin Width is the tongue defined by the inside and outside diameters of the raised face. Partition Gasket Details If the channel has a partition plate (see the manual section 'Tubesheet Properties' for a sketch of this arrangement), or gasket then enter the length and width of the partition plate or gasket. In this way, PVElite with include the extra forces to compress the gasket at the location of the partition plate. Partition Gasket m / y As in the case of the main gasket, enter the values of m and y specific to the partition gasket. Typically, these vales would be the same as the m and y values for the main gasket as discussed above. Number of Bolts Enter the number of bolts that connect the cover to the tubesheet. Bolt Circle Diameter / Nominal Bolt Diameter Enter the diameter of the circle where the bolts are located around the flange, and the nominal diameter of each bolt. Thread Series From the drop down list box select: TEMA UNC User Specified Root Area of a Single Bolt



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British Standard South African Standard The purpose of this box is to determine the root area of the thread in the determination of the bolt load applied to the flanged joint. Bolt Design Temperature Enter the Design Temperature of the bolts. This temperature should not be less than the Design Temperature of the flange or tubesheet, whichever is the larger. Bolt Material As discussed in other areas of this manual, select the Bolt Material from the list box ensuring that all fields contain correct information, especially the value of the yield value in the case of non-ASME materials. Alternate Bolt Loads (used if greater than calculated values) If you wish to enter the Wm1, Wm2 and W to over-ride the values computed by PVElite, then enter these values. They will only be used if they exceed the valued computed by PVElite.

Precautionary Note Tubesheets Integral with Shell Only When a tubesheet is defined by the user as being Integral with the Shell and Channel, PVElite expects the design to look like this:

Notice this important point: PVElite expects the tubesheet to be welded to both the Channel, and the Shell. The reason for this as follows: The program computes the pressure and loads on the channel side using the dimensions of the channel The program computes the pressure and loads on the shell side using the dimensions of the shell. The shell and channel sides can have different thicknesses and different corrosion allowances. If for example, the Channel side were of thin Austenitic steel with no corrosion allowance, and the Shell side were of thick Carbon steel with a large corrosion allowance, then the corroded diameters of the shell and channel sides would be different when PVElite computes the stresses in the corroded condition.


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HEAT EXCHANGERS

Provided the user constructs the heat exchanger as shown above, this will not create a problem, because PVElite knows the dimensions of both the shell and channel sides. However: Suppose the user constructed the exchanger like this:

there would be a problem. Looking carefully at this type of construction, the tubesheet is inserted fully into the main shell, and does NOT connect to the channel. With this type of construction, PVElite will use the dimension of the Channel for the channel side, and the dimension of the Shell for the shell side. This would give incorrect results, because both the shell and channel sides should be computed using only the shell dimensions. How can we solve this problem? The best way of solving the problem is for the user to include a dummy piece of channel as an extra component into the design (both ends of the exchanger in the case of a fixed tubesheet exchanger). This is how the dummy channel can be introduced by the user to correct the problem:

By introducing this Dummy Channel, which has the identical dimensions, corrosion allowance and material specification as the main shell between the two tubesheets, PVElite will now correctly compute the stresses based upon the correct components.


CH AP TER

1 0

Chapter 10 Component Analysis Tutorial In This Chapter Purpose of this Chapter............................................................... 10-2 Starting CodeCalc from PVElite................................................. 10-3 Main Menu ................................................................................. 10-4 Performing an Analysis .............................................................. 10-24 Reviewing the Results - The Output Option............................... 10-30 Summary - Seeing Results for a Whole Vessel .......................... 10-32 Tutorial Problem Printout ........................................................... 10-33


10-2


Purpose of this Chapter This purpose of this chapter is to explain the basics of the PVElite component analysis operation by guiding you through one application of it. Each of the main menu choices used to control the program is described and illustrated. Use of PVElite assumes that the software has been installed per the instructions detailed in Chapter 2.


Chapter 10 Component Analysis Tutorial

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Starting CodeCalc from PVElite The COMPONENT ANALYSIS DATA processor (CodeCalc) may be started by selecting COMPONENT ANALYSIS DATA ... from the Input option on the Main Menu. At this point the COMPONENT ANALYSIS DATA processor is loaded.


10-4


Main Menu CodeCalc starts with the Data Input screen. Across the top of this screen is a line of items, which comprise the Main Menu. The Main Menu controls the major functions of the program. This chapter will review the functions available in each of these menu items. The items in the Main Menu - File, Edit, Analysis, Output, Tools, Diagnostics, View, ESL and Help - may be selected with a mouse click or by pressing the underlined character while pressing the Alt key. For example, the Output processor may be selected by pressing the Alt and O keys simultaneously. First, we will begin by going over each of the Main Menu options.



10-5

File Menu The FILE MENU controls the general operations of CodeCalc files. Options that are displayed in the menu with an ellipsis (…) cause a file manage window to appear when selected.

File Menu

The FILE MENU may be used to: New - Starts or opens a new or existing file.

A blank screen appears.


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Component Analysis Tutorial Open - Opens a previously created file.

This gives you access to files that have previously been created by CodeCalc. Simply double click on the file name, or enter the file name into the File Name field, and the file will be loaded, and you will be able to make any changes to the components it contains. When OPEN is selected the user is prompted to select an existing job file. Files of type *.cci will be displayed for selection. Save - Saves the current file in its present condition. However, if the file is being saved for the first time, you will need to give the file a name. For saving the first time, you will get the Save As menu. Save As - Saves a file that has not been previously named or saves the current file under another name.

Print - Sends the current vessel graphic image directly to a postscript or laser jet printer. Print Preview - Displays the page that will be sent to the printer (see above). Print Setup - Displays the standard Windows printer setup screen. Exit - Exits CodeCalc. A message window will appear to give the user a last opportunity to save any modifications to the current job. The File Menu also lists the last four vessel input files. Any of these files can be opened with a mouse click.



10-7

Edit Menu Once a file is selected, the EDIT MENU indicates the options available for editing.

Edit Menu

Title Page - Allows the user to enter report titles for this group of reports. Project Data - Allows the user to enter up to 3 title lines, which appear at the top of each page of the printed reports. Add New Item - Allows the user to enter a new item Insert New Item - Inserts a new element after the current element. Delete Current Item - Deletes the current element. Select All - Selects all of the items in the browse window. Deselect All - Clears all of the items in the browse window.


10-8


Analysis Menu The ANALYSIS options cause the program to quit the input process and enter the analysis process. CodeCalc will first save the current job to the input file with the same filename, and then process the analysis.

Analysis Menu

The following options are available: Analyze Current Item - Performs the analysis of the current component. Analyze Selected Items - This option will perform calculations for selected analysis types. The calculations will be saved in a binary file and will be ready for display or printing. Summary - This option will look through all the data in the current analysis file and prepare a brief summary of each analysis. Choose Analysis Type - Use this option to select the type of component you wish to work on. The various analysis types are shown in the figure above. The analysis types chosen from this menu can also be selected from the Analysis toolbar by clicking the icon.



Output Menu

Output Menu

Review - Allows the user to review the analysis results of the current job, if those results are available.


10-9

10-10


Tools Menu The TOOLS MENU controls the utility processors and drawing options.

Tools Menu

The following options are available: Configuration

Enables users to set some specific program computation control parameters.

Computation Control Tab



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Compute Increased Nozzle Thickness? In many cases pressure vessels are designed and built long before the piping system is attached to them. This means that the nozzle loadings are unknown. If this field is checked, then your minimum nozzle thickness (trn) will be the maximum of: trn = (.134, trn for internal pressure) less than or equal NPS 18 trn = (OD/150, trn for internal pressure) greater than NPS 18 By using such a requirement in addition to UG-45, the piping designers will have some additional metal to work with to satisfy thermal bending stresses in systems these vessels are designed for. Note carefully, that these formulae are not in the ASME Code. They are used in industry. You can also specify the minimum wall thickness of the nozzle (Trn) in the Nozzle input. If you do so, that will override this calculation.

Calculate F in Flohead if the Pressure is Zero? In the design of the Floating head, a factor F is computed. The factor F is a direct function of the internal pressure. If the internal pressure is 0, then F is equal to 0. However, some interpret the Code to mean that F should always be computed regardless of which case we are analyzing. Typically, the case in question is the flange bolt up case. When bolting up the unit there is no internal pressure. That is why the default is not checked. If you wish F to always be considered in the thickness calculations, then check this box. This is conservative.

Use P instead of MAWP for UG-99B? The Code paragraph UG-99(b) discusses the subject of hydrostatic test pressure on vessels. The equation that would normally be used is as follows: Test Pressure = 1.5 * MAWP * Stest/Sdesign (for A-98 Addenda) or Test Pressure = 1.3 * MAWP * Stest/Sdesign (for post 2001 edition of ASME VIII Division 1) The code in note 32 states that the MAWP may be assumed to be the same as the design pressure when calculations are not made to determine the MAWP. This will allow for lower test pressures. This directive should be used with caution.

Print Water Volume in Gallons/Liters? Normally the volumes computed by the program are in diameter units. If for example the diameter were entered in feet, then the volume will be output as cubic feet, however, if the diameter is entered in mm, then the output will be output as cubic mm.


10-12


If you want to use US Gallons instead of cubic diameter units check this directive. The program will use cubic units if the default value is not checked. For all other units, the volume prints in liters if this box is checked. A note of caution: A US gallon is smaller than an Imperial gallon as defined in Europe. The difference is that a US gallon is 3.7854 liters, and an Imperial gallon is 4.5461 liters. This is mentioned as the program considers only the US gallon.

Use Calculated Value of M for Torispherical Heads in UG-45 b1? The Code in paragraph UG-45 requires a calculation of the required head thickness at the location of the nozzle. This may lead one to believe that the thickness may be computed per paragraph UG-37. However the code interpretation, VIII-1-95-133 states that the thickness should be computed by the rules of paragraph UG-32 or by the rules in Appendix 1. Thus this directive should always be checked. Below is the interpretation VIII-1-95-133 issued December 1996 Question: Does the definition of the required thickness tr for a formed head given in the nomenclature of UG-37(a) in section VIII, Division 1 apply when determining the minimum nozzle neck thickness in UG-45(b)(1)? Reply: No, see UG-32

Use Pre-99 Addenda? In the 1999 addendum to ASME Section VIII, Division 1, the allowable design stresses (S) were increased. However, it is recognized that it may be necessary to re-rate vessels constructed before this directive came into effect. Check this box to use the material database that precedes the 1999 Addendum. This is only relevant to Division 1 of ASME VIII.

Use Code Case 2260? CodeCase 2260 Approval Date: May 20, 1998. This Code Case is entitled "Alternate Design Rules for Ellipsoidal and Torispherical Formed Heads". It applies for Section VIII Division 1. If this flag is checked then CodeCalc will use the modified equations in the Code Case to compute the required thickness of Elliptical/Torispherical heads. The typical net result is that by using these modified rules, a thinner head will designed.

Material Database Year

Users can choose from several different material years. Each material year contains a complete database listing of materials, their allowable design stresses and other relevant properties.



10-13

Select the year required. If a different material database is selected from the one used for the current set of components update the materials by re-selecting them from the material database before performing the computations.

Miscellaneous Tab

The MISCELLANEOUS OPTIONS of the CONFIGURATION MENU lets the user select some miscellaneous directives. These directives control some printout style options and others. Following is a description of the options:

Report Content This directive allows the user to change the length of the printed reports. When the summary option is checked, the formulas and substitutions will not be printed out. Thus, this option will generate less paper and more compact reports. When the detailed option is checked, the reports will be the normal length.


10-14


External Printout in Rows? There are 2 choices for the style of printing external pressure results rows and columns. Printing the values row wise tend to reduce the length of the printouts. This is the default. If you wish to use the column wise printout, do not check this directive.

Reload Last File at Startup? If this box is checked, CodeCalc will load the last file worked on by the user the next time the program is started.

Syntax Highlighting In Output Reports When CodeCalc sends the results to the output processor, the style of the reports is affected by this check box. If the box is checked, warnings will be printed in blue or red type, and errors or fatal problems will be printed in red type. This feature can be switched on by checking this box, or turning it off by un-checking this box. When this box is checked, output might be generated a little slower, and will also affect the time it takes to send the output to MSWord©.

Do not Print Extended ASCII Characters in Output Reports The extended ASCII characters such as superscript 2 are not displayed properly on some versions of Windows such as the Chinese, Korean or Japanese. If you are having difficulty with extended ASCII characters, then check this box. When this box is checked the program uses ASCII characters.

Default Units File

Select the units you wish to use when starting a new file. The selected file will be used both for the input and the computed results. Note: This feature cannot be used for changing the units for a currently opened input file. To change units for a currently opened file use the Set Units option discussed later in this section.

HOOPS' Display Driver



10-15

Hoops is the third party software used by CodeCalc and PVElite for generating the images on the screen of either the individual components or the 3D model generated in PVElite for the vessel as it is constructed. If your computer does not generate the image correctly on the screen, then switch the choice from the currently set driver.

Nozzle Pro Path

If you have purchased Nozzle Pro from the Paulin Research Group www.paulin.com http://www., this feature enables you to access Nozzle Pro to perform finite element analysis (FEA) of nozzles. This feature can also be used to perform more accurate and detailed analysis than can be performed using the other local load procedures (WRC107, WRC297 and PD 5500 Annex G).

Default Save Folder Use this option to set the default location for saving input files. Users also have the option to save files in a different location.

Enable Auto Save Check this box to enable automatic saving of the input files. Users can also specify the time interval between saves.

Perform Background Saves Check this box if you want the program to silently save the current input file (if Auto-Save is turned on using the box above). If this box is not checked then the program will prompt you to save after the time interval specified. Set Unit

Displays the Open dialog.


10-16


Double clicking on the unit system of your choice, updates the current file and the output processor to reflect the new units selected. Make Unit

Enables the user to create any set of units by opening the Create a New Units File dialog.



10-17

CodeCalc (and indeed all of COADE's products) internally use conventional American units. You can also choose some of the unit files supplied with the program. Additionally, you can also make your own unit files using this menu. The conversion factor from CodeCalc to the chosen unit must be known in order that CodeCalc can provide the conversion for the output and on-screen units for the various entry fields. Calculator

Use the calculator to compute a number and transfer that number into CodeCalc by using EDIT/COPY. From the desired field, right click and choose the PASTE option. Before pasting, ensure the fields' content is selected.

Units Conversion View

Allows users to quickly convert a value in one set of units to a value in another set of units


10-18

.Edit / Add Materials


Enables users to create and edit user-defined material in the CodeCalc material database. Clicking this menu option displays the Material Database Editor:

Material Database Editor Dialog



To use the processor, click the areas sections. Click the

10-19

button. Next enter the material properties under the General and the Stresses button to add another material if desired. When all of the materials have been entered,

click the button to add these materials to the end of the materials supplied in the CodeCalc material database. The material list from the main database can also be imported into this processor. A material from this list can be button to accomplish this task. In addition to adding imported into the user's material database. Use the materials to the ASME Databases, it is also possible to add materials to the PD:5500 database. When the option to edit this database is selected, the Material Database Editor window appears:

To use this processor, click the button. Next enter the Material Name, Yield Strength and other information. Next fill in the table of stress versus temperature sections. This processor creates a user material database that is stored in the CodeCalc\System subdirectory. Once the database has been saved after the initial use, those materials will be available for editing.


10-20


Diagnostic Menu The DIAGNOSTICS MENU helps to troubleshoot problem installations.

Diagnostics Menu

The following options are available: CRC Check - This option performs a cyclic redundancy check on each of the supplied PVElite files. Build Version Check - This option checks the revision level of the PVElite executable files. DLL Version Check - This option checks to make sure the PVElite.dll files are current. Please note that if the dll's are not current the program could behave in an unusual manner or may not run at all. Error Review - This option allows the user to review errors that may have been generated at startup or during program execution. Register Servers - Register the dynamic link libraries that PVElite uses during its operation.



View Menu The VIEW MENU allows the user to display the input, drawing and quick analysis and browse views.

View Menu


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10-22


ESL Menu The ESL MENU provides access to utilities, which interact with the external software lock.

ESL Menu

The options are as follows: Show Data - Displays the data stored on the ESL. Generate Access Codes - Allows you to generate access codes to update the ESL. These access codes should be sent to COADE to obtain the authorization codes. Enter re-Authorization Codes - Allows you to enter the remote authorization codes received from COADE. Each set of four codes will make one change to the data stored on your ESL. Check ESL Driver Status - Checks the version of the installed ESL drivers. Install ESL Device Driver - Installs the ESL device drivers.



10-23

Help Menu The HELP MENU displays on-line help and information on how to obtain technical support for CodeCalc.

Help Menu

The options available are as follows: Tip of the Day - Provides tips for running CodeCalc. Help Topics - Starts the help facility. View Documentation - Displays the online documentation in PDF format. CodeCalc Quick Start - Displays the CodeCalc Quick Start documentation. This section is primarily for first time users to enable them to get up and running quickly. New Features in this Version - Describes the new features added in the most recent version of the program. On-Line registration - Allows users to electronically register this program with COADE. Once registered users receive email notifications about program updates. Desktop (On-line Help) - Displays the on-line help. About This Program - Provides the user with the latest build information and operating system information. It also contains information on the ways to contact COADE personnel for technical support, and provides some helpful links on COADE's Web Site.


10-24


Performing an Analysis The remainder of this chapter assists you in performing an analysis using the Shell program.

icon on the desktop or selecting the item from Programs. If you are running Start CodeCalc by clicking the the program through PVElite use the Input option and select COMPONENT ANALYSIS DATA. From the Main Menu click FILE, NEW or click the New icon. This will allow you to specify the current analysis type. From the Analysis Toolbar, select Shells and Heads and then click the displays.

icon. A blank input screen

Shell analysis can be defined on the Design tab of this screen. You can use the Tab or Enter keys to move the cursor up and down the column of data. Notice also that many of the fields display default values. The first field on the input screen is the Item Number. A value must be entered in this field or the program cannot perform the analysis. We suggest that you number the different calculations sequentially. Type 1 in this field and press Tab. The next field to analyze is the Description. The information entered can be the part number or a short description of the part. This field is an optional input. For this tutorial, type Spherical Head. The next four fields govern the pressure and temperature. Move to the Design Internal Pressure field and type 100 (assuming you are using English units). Now tab to the Design Temperature for Internal Pressure and type 700. When you press Tab, the program pauses momentarily to check whether the material specified has an allowable stress greater than zero at the temperature entered. Click the button to view the allowable stress. Note that the allowable stress for SA516-70 material is 18,100 psi at this temperature. This is precisely the value that PVElite extracted from the material database. The Design External pressure for this problem is 15. The Design Temperature for External pressure should be 650. Now you are ready to enter the material. Let's say this vessel is constructed of SA-516-70. As you might expect, one way to enter that material is just to type it in the field. When you do so, the program will check the database, and then update the allowable stresses. This material happens to be the program default, but type the name anyway just to see what the program does.

Another way to select a material is from the list of materials in the database. To see this list, click the A screen will display showing the materials list.


button.


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Material Selection Screen

You can move the scroll bar up and down the screen to view the properties for all of the materials in the database. Note that each major material classification is divided into columns. You can view the parameters for a specific material by clicking the material name.

Material Parameters Screen


10-26


These parameters may be viewed and modified through the Material Edit window. To see this window, click the Material Edit

button and the Material Properties Dialog displays.

Material Properties Dialog

Click Yield Stress to display the Yield Stress Record dialog. The Yield Stress Record dialog enables PVElite to scan the yield stress database for an exact material match and fill in the appropriate yield stress at operating temperature. For many applications, this value is not needed.

Yield Stress Record Dialog

On the Joint Efficiency Longitudinal Seams dialog, enter the value of E, the longitudinal joint efficiencies to be used in the calculator. For full radiography, enter a value of 1.



10-27

The next question asks if you would like to include Hydrostatic Head Components to our vessel design. Click the box to activate the Hydrostatic Head dialog.

Hydrostatic Head Dialog

This dialog will prompt you for the operating liquid density enter a value of 38 lb/cu.ft. The next two fields request the height of liquid column in the operating and hydrotest position of the vessel. This particular vessel is a horizontal drum that will be operating in a partially filled position. When the shop hydrotests the vessel it will be filled and in the horizontal position. Enter values of 54 and 72 in. for these two fields. Click OK to return to the Data Input screen. Now click the Geometry tab of the input screen. The first field is the shell or head type. Six options are shown on the pull-down, for more details on this field press [F1] for help. We will analyze a hemispherical head, a cylinder and an elliptical head. These are all components of the horizontal vessel we are analyzing. First enter the Diameter Basis (OD) for an Outside Diameter measurement (and calculation). Next, tab to the Diameter of Shell/Head field and enter the diameter, 72 inches. Now, enter the Minimum Thickness of Pipe or Plate, .5 inches, and the Nominal or Average Thickness of Pipe or Plate, .5 inches. Enter 0.0625 inches for the Corrosion Allowance. Since the input fields have calculator capability, you can also enter the Corrosion Allowance as '1/16'. For this example there is no reinforcing ring required for internal pressure, so select None for the ring type. You have now completed the hemispherical head input. Your screen should look like this:


10-28


Completed Hemispherical Head Input Screen

Note: You may view the drawing of the current item at any time by clicking the Cactus Picture icon. This horizontal tank has two additional sections, the shell and the elliptical head on the other end. To add the new section, click . Clicking this button returns you to the Design tab of the input screen and prompts you to enter the second item. Type 2 in the Item Number field and Cylinder in the Description field. Click the Geometry tab to enter the shell type. Since this is a cylinder type, from the pull down, select CYLINDRICAL SHELL. A window will display prompting for the Design Length of Section and the Design Length for Cylinder Volume Calculations; enter 180 inches for both. Click OK to resume. Next, we will enter elliptical head data. Click the Add New Item icon. Type 3 in the Item Number field and Elliptical Head in the Description field. The data from the previous element is carried forward, so you will only have to modify the shell/head type. Click the Geometry tab of the Input screen. From the TYPE OF SHELL pull-down, select Elliptical Head. The Elliptical Head dialog appears and prompts for the head ratio. Enter 2 for a 2:1 elliptical head. Click OK to continue. Tip: When entering new components be sure to type appropriate descriptions in the Description field. This will help make your finished reports more clear and easier to follow. You are now ready to analyze these three components for internal pressure and hydrostatic head considerations. Save the file and click

on the Analysis toolbar. Your screen will resemble this:



Analysis Output

Click

to review the results.


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Reviewing the Results - The Output Option You can quickly review the results of this analysis using the OUTPUT option. From the Main Menu select OUTPUT/REVIEW. If you have analyzed the components from the input, PVElite will automatically display the output for you. You will see the following screen:

Output Reports Screen

At the moment there are 3 analyses in the output file. However, if you were to do additional runs of the Shell program, or analyze nozzles, flanges, tubesheets, or anything else those analyses would also appear on this list. Thus you can review (and print) all of the calculations you have done for a given vessel or job at one time. The individual report can be viewed by selecting one of the items in the report area. You can scroll up and down in the text to see all of the input and results. Note especially the Summary of Internal Pressure Results, where you can clearly see that the required thickness is less than the actual thickness for this job, while the Maximum allowable working pressure is greater than the design pressure. Therefore, the shell thickness you selected is acceptable.



10-31

You may also select more than one analysis at a time by holding down the Ctrl key while selecting the items to view. You can also select all reports by selecting EDIT/SELECT ALL from the menu. When viewing the reports, click the Next Report button to move the next component.

Printing or Saving Reports to a File Printing the Graphics To print the graphics created by your input, click FILE/PRINT PREVIEW.

and then click

. To view the graphic on the screen, click

Printing the Reports The PVElite output results can be sent directly to a printer. To print a hard copy of the reports, first select the report font by clicking the Select Font icon from the Available Reports Menu toolbar. You may then select a new font for your reports by clicking the Select Font icon. You can also enter a new starting page number by clicking the Page Number icon on the toolbar. Now, click

.


10-32


Summary - Seeing Results for a Whole Vessel This section of the tutorial discusses the summary program in PVElite. . Selected portions of the output generated by PVElite are stored in the input file. The summary program will pull selected information from within the input file and summarize it. The summary is automatically generated when all of the items in the file are executed.

Output Screen Tutorial



10-33

Tutorial Problem Printout PVElite Licensee: Coade Local White Lock FileName : Tutorial -------------------------------------- Page 2 Shell Analysis : Spherical Head Item: 1 4:39p Dec 12,2002 Input Echo, Component

1,

Description: Spherical Head

Design Internal Pressure P Temperature for Internal Pressure User Entered Minimum Design Metal Temperature Design External Pressure PEXT Temperature for External Pressure External Pressure Chart Name

100.00 700.00 -20.00 15.00 650.00 CS-2

Include Hydrostatic Head Components Operating Liquid Density Height of Liquid Column ( Operating ) Height of Liquid Column ( Hydrotest )

YES 38.000 54.00 72.00

Material Specification (Not Normalized) Material UNS Number Allowable Stress At Temperature Allowable Stress At Ambient Curve Name for Chart UCS 66 Joint efficiency for Head Joint Outside Diameter of Hemispherical Head Minimum Thickness of Pipe or Plate Nominal Thickness of Pipe or Plate Corrosion Allowance

lb./ft³ in. in.

psi psi

E

SA-516 70 K02700 18100.00 20000.00 B 1.00

D

72.0000

in.

T T CA

0.5000 0.5000 0.0625

in. in. in.

S SA

Skip UG-16(b) Min. thickness calculation Type of Element:

psig F F psig F

NO


INTERNAL PRESSURE RESULTS, SHELL NUMBER 1, Desc.: Spherical Head ASME Code, Section VIII, Division 1, Ed-2001, A-02 Thickness Due to Internal Pressure (TR): = (P*D/2)/(2*S*E+0.8*P) per Appendix 1-1(a)(2) = (101.19*72.0000/2)/(2*18100.00*1.00+0.8*101.19) = 0.1004 in. Max. All. Working Pressure at Given Thickness (MAWP): Less Operating Hydrostatic Head Pressure of 1.19 psig = (2*S*E*(T-CA))/((D/2-0.8*(T-CA)) per Appendix 1-1 (a)(2) = (2*18100.00*1.00*(0.4375))/(72.0000/2-0.8*(0.4375)) = 444.25 - 1.19 = 443.06 psig


10-34


Maximum Allowable Pressure, New and Cold (MAPNC): = (2*SA*E*T)/((D/2-0.8*T) Appendix 1-1 (a)(2) = (2*20000.00*1.00*0.5000)/(72.0000/2-0.8*0.5000) = 561.80 psig Actual stress at given pressure and thickness (Sact): = (P*(D/2-0.8*(T-CA)))/(2*E*(T-CA)) = (101.19*(72.0000/2-0.8*(0.4375)))/(2*1.00*(0.4375)) = 4122.67 psi SUMMARY OF INTERNAL PRESSURE RESULTS: Required Thickness plus Corrosion Allowance, Trca Actual Thickness as Given in Input Maximum Allowable Working Pressure MAWP Design Pressure as Given in Input P HYDROSTATIC TEST PRESSURES ( Hydrotest per UG-99(b); 1.3 Hydrotest per UG-99(c); 1.3 Pneumatic per UG-100 ; 1.1

0.1629 0.5000 443.062 100.000

in. in. psig psig

Measured at High Point ): * MAWP * Sa/S 636.44 * MAPNC - Head (Hydro) 727.74 * MAWP * Sa/S 539.97

psig psig psig

Percent Elongation per UCS-79 ( 75t/Rf * (1-Rf/Ro) Min. Metal Temp. w/o impact per Fig. UCS-66 Min. Metal Temp. at Req'd thk. (per UCS 66.1)

)

1.049 -6 F -146 F

%

WEIGHT Volume Weight Inside Weight

and VOLUME RESULTS, ORIGINAL THICKNESS: of Shell Component VOLMET of Shell Component WMET Volume of Component VOLID of Water in Component WWAT

4015.2 1136.3 93700.9 3383.6

in.**3 lb. in.**3 lb.


AND VOLUME RESULTS, CORRODED THICKNESS: of Shell Component, Corroded VOLMETCA of Shell Component, Corroded WMETCA Volume of Component, Corroded VOLIDCA of Water in Component, Corroded WWATCA

3519.4 996.0 94196.7 3401.5

in.**3 lb. in.**3 lb.

EXTERNAL PRESSURE RESULTS, SHELL NUMBER 1, Desc.: Spherical Head ASME Code, Section VIII, Division 1, Ed-2001, A-02 External Pressure Chart CS-2 Elastic Modulus for Material

at

650.00 25125000.00

Results for Max. Allowable External Pressure (Emawp): Corroded Thickness of Shell TCA 0.4375 Outside Diameter of Shell OD 72.0000 Diameter / Thickness Ratio (D/T) 164.5714 Geometry Factor, A f(DT,LD) A 0.0015191 Materials Factor, B, f(A, Chart) B 9327.4229 Maximum Allowable Working Pressure 113.35 EMAWP = B/((D/T)/2) = 9327.4229/( 164.5714 / 2 ) = 113.3541 Results for Reqd Thickness for Ext. Pressure (Tca): Corroded Thickness of Shell TCA Outside Diameter of Shell OD

0.1113 72.0000

F psi in. in. psi psig

in. in.



10-35

Diameter / Thickness Ratio (D/T) 647.0902 Geometry Factor, A f(DT,LD) A 0.0003863 Materials Factor, B, f(A, Chart) B 4853.4580 Maximum Allowable Working Pressure 15.00 EMAWP = B/((D/T)/2) = 4853.4580/( 647.0902 / 2 ) = 15.0009 SUMMARY of EXTERNAL PRESSURE RESULTS: Allowable Pressure at Corroded thickness Required Pressure as entered by User Required Thickness including Corrosion all. Actual Thickness as entered by User

113.35 15.00 0.1738 0.5000

psi psig

psig psig in. in.

PVElite by COADE Engineering Software


10-36


PVElite Licensee: Coade Local White Lock FileName : Tutorial -------------------------------------- Page 5 Shell Analysis : Cylinder Item: 2 4:39p Dec 12,2002 Input Echo, Component

2,

Description: Cylinder


100.00 700.00 -20.00 15.00 650.00 CS-2


YES 38.000 54.00 72.00

Material Specification (Not Normalized) Material UNS Number Allowable Stress At Temperature Allowable Stress At Ambient Curve Name for Chart UCS 66 Joint efficiency for Shell Joint Design Length of Section Length of Cylinder for Volume Calcs. Outside Diameter of Cylindrical Shell

lb./ft³ in. in.

psi psi

E

SA-516 70 K02700 18100.00 20000.00 B 1.00

L CYLLEN D

180.0000 180.0000 72.0000

in. in. in.

T T CA

0.5000 0.5000 0.0625

in. in. in.

S SA

Minimum Thickness of Pipe or Plate Nominal Thickness of Pipe or Plate Corrosion Allowance Skip UG-16(b) Min. thickness calculation Type of Element:

psig F F psig F

NO Cylindrical Shell

INTERNAL PRESSURE RESULTS, SHELL NUMBER 2, Desc.: Cylinder ASME Code, Section VIII, Division 1, Ed-2001, A-02 Thickness Due to Internal Pressure (TR): = (P*D/2)/(S*E+0.4*P) per Appendix 1-1 (a)(1) = (101.19*72.0000/2)/(18100.00*1.00+0.4*101.19) = 0.2008 in. Max. All. Working Pressure at Given Thickness (MAWP): Less Operating Hydrostatic Head Pressure of 1.19 psig = (S*E*(T-CA))/(D/2-0.4*(T-CA)) per Appendix 1-1 (a)(1) = (18100.00*1.00*(0.4375))/(72.0000/2-0.4*0.4375) = 221.04 - 1.19 = 219.85 psig Maximum Allowable Pressure, New and Cold (MAPNC): = (SA*E*T)/(D/2-0.4*T) per Appendix 1-1 (a)(1)



10-37

= (20000.00*1.00*0.5000)/(72.0000/2-0.4*0.5000) = 279.33 psig Actual stress at given pressure and thickness (Sact): = (P*(D/2-0.4*(T-CA)))/(E*(T-CA)) = (101.19*((72.0000/2-0.4*(0.4375)))/(1.00*(0.4375)) = 8285.81 psi SUMMARY OF INTERNAL PRESSURE RESULTS: Required Thickness plus Corrosion Allowance, Trca Actual Thickness as Given in Input Maximum Allowable Working Pressure MAWP Design Pressure as Given in Input P HYDROSTATIC TEST PRESSURES ( Hydrotest per UG-99(b); 1.3 Hydrotest per UG-99(c); 1.3 Pneumatic per UG-100 ; 1.1

0.2633 0.5000 219.852 100.000

in. in. psig psig


psig psig psig


)

0.699 -6 F -55 F

%


and VOLUME RESULTS, ORIGINAL THICKNESS: of Shell Component VOLMET of Shell Component WMET Volume of Component VOLID of Water in Component WWAT

20216.1 5721.2 712654.6 25734.8

in.**3 lb. in.**3 lb.


AND VOLUME RESULTS, CORRODED THICKNESS: of Shell Component, Corroded VOLMETCA of Shell Component, Corroded WMETCA Volume of Component, Corroded VOLIDCA of Water in Component, Corroded WWATCA

17704.6 5010.4 715166.2 25825.4

in.**3 lb. in.**3 lb.

EXTERNAL PRESSURE RESULTS, SHELL NUMBER 2, Desc.: Cylinder ASME Code, Section VIII, Division 1, Ed-2001, A-02 External Pressure Chart CS-2 Elastic Modulus for Material

at

650.00 25125000.00

F psi

Results for Max. Allowable External Pressure (Emawp): Corroded Thickness of Shell TCA 0.4375 in. Outside Diameter of Shell OD 72.0000 in. Design Length of Cylinder or Cone SLEN 180.0000 in. Diameter / Thickness Ratio (D/T) 164.5714 Length / Diameter Ratio LD 2.5000 Geometry Factor, A f(DT,LD) A 0.0002498 Materials Factor, B, f(A, Chart) B 3138.2285 psi Maximum Allowable Working Pressure 25.43 psig EMAWP = (4*B)/(3*(D/T)) = ( 4 * 3138.2285 )/( 3 * 164.5714 ) = 25.4255 Results for Reqd Thickness for Ext. Pressure (Tca): Corroded Thickness of Shell TCA Outside Diameter of Shell OD

0.3545 72.0000

in. in.


10-38


Design Length of Cylinder or Cone SLEN 180.0000 in. Diameter / Thickness Ratio (D/T) 203.1269 Length / Diameter Ratio LD 2.5000 Geometry Factor, A f(DT,LD) A 0.0001819 Materials Factor, B, f(A, Chart) B 2285.3257 psi Maximum Allowable Working Pressure 15.00 psig EMAWP = (4*B)/(3*(D/T)) = ( 4 * 2285.3257 )/( 3 * 203.1269 ) = 15.0010 Results for Maximum Length Between Stiffeners (Slen): Corroded Thickness of Shell TCA 0.4375 in. Outside Diameter of Shell OD 72.0000 in. Design Length of Cylinder or Cone SLEN 303.3275 in. Diameter / Thickness Ratio (D/T) 164.5714 Length / Diameter Ratio LD 4.2129 Geometry Factor, A f(DT,LD) A 0.0001474 Materials Factor, B, f(A, Chart) B 1851.5686 psi Maximum Allowable Working Pressure 15.00 psig EMAWP = (4*B)/(3*(D/T)) = ( 4 * 1851.5686 )/( 3 * 164.5714 ) = 15.0011 SUMMARY of EXTERNAL PRESSURE RESULTS: Allowable Pressure at Corroded thickness Required Pressure as entered by User Required Thickness including Corrosion all. Actual Thickness as entered by User Maximum Length for Thickness and Pressure Actual Length as entered by User

25.43 15.00 0.4170 0.5000 303.327 180.00

psig psig in. in. in. in.




10-39

PVElite Licensee: Coade Local White Lock FileName : Tutorial -------------------------------------- Page 8 Shell Analysis : Ellipse Item: 3 4:39p Dec 12,2002 Input Echo, Component

3,

Description: Ellipse


100.00 700.00 -20.00 15.00 650.00 CS-2


YES 38.000 54.00 72.00

Material Specification (Not Normalized) Material UNS Number Allowable Stress At Temperature Allowable Stress At Ambient Curve Name for Chart UCS 66 Joint efficiency for Head Joint

psi psi

E D

72.0000

in.

T T CA

0.5000 0.5000 0.0625

in. in. in.

AR STRTFLG

2.0000 2.0000

in.

Minimum Thickness of Pipe or Plate Nominal Thickness of Pipe or Plate Corrosion Allowance

Skip UG-16(b) Min. thickness calculation Type of Element:

lb./ft³ in. in.

SA-516 70 K02700 18100.00 20000.00 B 1.00

Outside Diameter of Elliptical Head

Aspect Ratio Length of Straight Flange

psig F F psig F

S SA

NO Elliptical Head

INTERNAL PRESSURE RESULTS, SHELL NUMBER 3, Desc.: Ellipse ASME Code, Section VIII, Division 1, Ed-2001, A-02 Thickness Due to Internal Pressure (TR): = (P*D*K)/(2*S*E+2*P*(K-0.1)) per Appendix 1-4 (c) = (101.19*72.0000*1.00)/(2*18100.00*1.00+2*101.19*(1.00-0.1)) = 0.2002 in. Max. All. Working Pressure at Given Thickness (MAWP): Less Operating Hydrostatic Head Pressure of 1.19 psig = (2*S*E*(T-CA))/(K*D-2*(T-CA)*(K-0.1)) per Appendix 1-4 (c) = (2*18100.00*1.00*(0.4375))/(1.00*72.0000-2*(0.4375)*(1.00-0.1)) = 222.40 - 1.19 = 221.21 psig


10-40


Maximum Allowable Pressure, New and Cold (MAPNC): = (2*SA*E*T)/(K*D-2*T*(K-0.1)) per Appendix 1-4 (c) = (2*20000.00*1.00*0.5000)/(1.00*72.0000-2*0.5000*(1.00-0.1)) = 281.29 psig Actual stress at given pressure and thickness (Sact): = (P*(K*D-2*(T-CA)*(K-0.1)))/(2*E*(T-CA)) = (101.19*(1.00*72.0000-2*(0.4375)*(1.00-0.1)))/(2*1.00*(0.4375)) = 8235.22 psi SUMMARY OF INTERNAL PRESSURE RESULTS: Required Thickness plus Corrosion Allowance, Trca Actual Thickness as Given in Input Maximum Allowable Working Pressure MAWP Design Pressure as Given in Input P HYDROSTATIC TEST PRESSURES ( Hydrotest per UG-99(b); 1.3 Hydrotest per UG-99(c); 1.3 Pneumatic per UG-100 ; 1.1

0.2627 0.5000 221.210 100.000

in. in. psig psig


psig psig psig


)

3.085 -6 F -55 F

%

WEIGHT and VOLUME RESULTS, ORIGINAL THICKNESS: Volume of Shell Component VOLMET Weight of Shell Component WMET Inside Volume of Component VOLID Weight of Water in Component WWAT Inside Vol. of 2.00 in. Straight VOLSCA Total Volume for Head + Straight VOLTOT

3283.9 929.4 46850.4 1691.8 7918.4 54768.8

in.**3 lb. in.**3 lb. in.**3 in.**3

WEIGHT AND VOLUME RESULTS, CORRODED THICKNESS: Volume of Shell Component, Corroded VOLMETCA Weight of Shell Component, Corroded WMETCA Inside Volume of Component, Corroded VOLIDCA Weight of Water in Component, Corroded WWATCA Inside Vol. of 2.00 in. Straight, Corr. VOLSCA Total Volume for Head + Straight Corroded VOLTCA

2873.4 813.2 47098.3 1700.8 7946.3 55044.6

in.**3 lb. in.**3 lb. in.**3 in.**3

EXTERNAL PRESSURE RESULTS, SHELL NUMBER 3, Desc.: Ellipse ASME Code, Section VIII, Division 1, Ed-2001, A-02 External Pressure Chart CS-2 Elastic Modulus for Material

at

650.00 25125000.00

F psi

Results for Max. Allowable External Pressure (Emawp): Corroded Thickness of Shell TCA 0.4375 in. Outside Diameter of Shell OD 72.0000 in. Diameter / Thickness Ratio (D/T) 164.5714 Geometry Factor, A f(DT,LD) A 0.0008439 Materials Factor, B, f(A, Chart) B 8167.3354 psi Maximum Allowable Working Pressure 55.14 psig EMAWP = B/(K0*(D/T)) = 8167.3354/( 0.9000 * 164.5714 ) = 55.1421 Results for Reqd Thickness for Ext. Pressure (Tca):



10-41

Corroded Thickness of Shell TCA 0.2003 in. Outside Diameter of Shell OD 72.0000 in. Diameter / Thickness Ratio (D/T) 359.4879 Geometry Factor, A f(DT,LD) A 0.0003864 Materials Factor, B, f(A, Chart) B 4853.5474 psi Maximum Allowable Working Pressure 15.00 psig EMAWP = B/(K0*(D/T)) = 4853.5474/( 0.9000 * 359.4879 ) = 15.0014 SUMMARY of EXTERNAL PRESSURE RESULTS: Allowable Pressure at Corroded thickness Required Pressure as entered by User Required Thickness including Corrosion all. Actual Thickness as entered by User

55.14 15.00 0.2628 0.5000

psig psig in. in.




CH AP TER

1 1

Chapter 11 SHELLS In This Chapter Introduction ................................................................................ 11-2 Purpose, Scope and Technical Basis........................................... 11-3 Discussion of Input Data............................................................. 11-5 Results ........................................................................................ 11-12 API 579 Introduction .................................................................. 11-14 Purpose, Scope, and Technical Basis.......................................... 11-15 Discussion of Input Data............................................................. 11-18 Discussion of Results.................................................................. 11-27 Example ...................................................................................... 11-28 Jacket .......................................................................................... 11-29


11-2

SHELLS

Introduction SHELLS performs internal and external pressure design of vessel and exchanger components using the rules in the ASME Code, Section VIII, Division 1, Edition 2004 A-05. This program considers static liquid head in the pressure design, performs stiffening ring calculations, sizes stiffening rings, and computes weld shear flows on stiffening ring welds. Jackets can be attached to the vessel and are analyzed per Appendix 9 of ASME Sec. VIII Div. 1 code. This module also contains information for performing fitness for service evaluation per API-579.


Chapter 11 SHELLS

11-3

Purpose, Scope and Technical Basis The SHELL program calculates the required thickness and Maximum Allowable Working Pressure for cylindrical shells and heads under internal or external pressure. The program is based on the ASME Boiler and Pressure Vessel Code, Section VIII, Division 1, 2001 Edition 2004 A-05. Under internal pressure, the program analyzes six types of heads or shells, using applicable code formulae as follows:

Shell or Head Type

ID Basis

OD Basis

Cylinder

UG-27 (c) (1)

App 1-1 (a) (1)

Elliptical

App 1-4 (c) (1), App 1-4 (f)

App 1-4 (c) (2), App 1-4 (f)

Torispherical

App 1-4 (d) (3), App 1-4 (f)

App 1-4 (d) (4), App 1-4 (f)


UG-27 (d) (3)

App 1-1 (a) (2)

Conical Head or Shell

UG-32 (g)

App 1-4 (e) (1)

Flat Head

UG-34 (1)and (3)

Elliptical heads with aspect ratios between 1.0 and 3.0 (typically 2.0) may be analyzed. Torispherical heads with knuckle radii between 6% and 100% of the crown radius may be analyzed. The thin, large diameter elliptical or torispherical head is also checked using App. 1-4 (f) in the SHELL program. Conical heads and sections with half apex angles up to 30 degrees may be analyzed. Reinforcement at the large and small ends of the cone should be analyzed in the CONICAL program. Welded flat heads, circular or non-circular, are analyzed in this program. Bolted flat heads are analyzed in the FLANGE program. Bolted dished heads under internal or external pressure are analyzed in the FLOHEAD program. Under external pressure program analyzes five types of heads or shells, using applicable code formulae as follows:

Shell or Head Type

Code Paragraph

Cylinder

UG-28 (c)

Elliptical

UG-33 (d)

Torispherical

UG-33 (e)


UG-33 (c) and UG-28 (d)

Conical Shell or Head

UG-33 (f)

All of these shell or head types are analyzed for diameter to thickness ratios greater than 10. Elliptical heads with aspect ratios between 1.0 and 3.0 may be analyzed Torispherical heads with any crown radius may be analyzed. Reinforcement at the large and small end of conical heads or sections is analyzed in the CONICAL program. The SHELL program takes full account of corrosion allowance. You enter actual thickness and corrosion allowance, and the program adjusts thicknesses and diameters when making calculations for the corroded condition. Figure A shows the geometry for the SHELL program. In addition, the SHELL program also accounts for static liquid head for shell components. For carbon steel vessels, normalized material can be used for UCS-66 calculations.


11-4

SHELLS

Figure A - SHELL Program Geometry

Figure B - Head Geometry


Chapter 11 SHELLS

11-5

Discussion of Input Data Main Input Fields Analysis Type Please select the following analysis type: ASME Sec VII Div. 1 API 579 - Fitness for Service

Design Internal Pressure Enter the internal design pressure. You must define either the design pressure or the minimum metal thickness, preferably both. Design pressure is used to determine the required thickness and minimum metal thickness is used to determine the Maximum Allowable Working Pressure.

Design Temperature for Internal Pressure Enter the temperature associated with the internal design pressure. PVElite will automatically update materials properties for BUILT-IN materials when you change the design temperature. If you entered the allowable stresses by hand, you are responsible to update them for the given temperature.

Design External Pressure Enter the design pressure for external pressure analysis. This should be a positive value, i.e. 14.7 psig. If you enter a zero in this field the program will not perform external pressure calculations.

Design Temperature for External Pressure Enter the temperature associated with the external design pressure. The design external pressure at this temperature is a completely different design case than the internal pressure case. Therefore this temperature may be different than the temperature for internal pressure. Many external pressure charts have both lower and upper limits on temperature. If your design temperature is below the lower limit, use the lower limit as your entry to the program. If your temperature is above the upper limit the component may not be designed for vacuum conditions.

Include Hydrostatic Head Component If your shell or head design needs to account for hydrostatic liquid head, click this box. PVElite will add the hydrostatic pressure head to the internal design pressure for the required thickness calculation.

Shell Section Material Name Click the Material Database button to search for a material in the material database. Also, you can type the material name in this cell, and the system will retrieve the first material it finds with a matching name. Click the Material Edit Properties button to change the properties of the selected material. You can also create new materials by selecting the TOOLS/EDIT/ADD MATERIALS option on the MAIN MENU.


11-6

SHELLS

Shell Allowable Stress at Design Temperature The program automatically fills in this entry by entering a material specification. When you change the internal design temperature, or the thickness of the shell, the program will automatically update this field, but only for BUILT-IN materials. If you enter the allowable stress by hand, be sure to verify your entry to ensure conformance with the latest edition of the ASME Pressure Vessel Code Section VIII Division 1 at the ambient temperature.

Shell Allowable Stress at Ambient Temperature The program automatically fills in this entry by entering a material specification. If you enter the allowable stress by hand, be sure to verify your entry to assure conformance with the latest edition of the ASME Pressure Vessel Code Section VIII Division 1 at the ambient temperature.

Joint Efficiency for Longitudinal Seams Enter the efficiency of the welded joint for shell sections with welded seams. This will be the efficiency of the longitudinal seam in a cylindrical shell or any seam in a spherical shell. Elliptical and torispherical heads are typically seamless but may require a stress reduction, which may be entered as a joint efficiency. Please be sure to refer to Section VIII, Div. 1, Table UW-12 for help in determining this value. The Joint Efficiency in this (and all other) ASME Code formulas is a measure of the inspection quality on the weld seam. In general, weld seams that receive full radiography have a joint efficiency of 1.0. Weld seams that receive spot radiography have a joint efficiency of 0.85. Weld seams that receive no radiography have a joint efficiency of 0.7. Seamless components have a joint efficiency of 1.0. In addition to the basic rules described above, the Code requires that no two seams in the same vessel differ in joint efficiency by more than one category of radiography. For example, if circumferential seams receive no radiography (E=0.7) then longitudinal seams have a maximum E of 0.85, even if they receive full radiography. The practical outworking of this is that circumferential seams, which are usually less highly stressed, may be spot radiographed (E=0.85) while longitudinal seams are fully radiographed. This provides the same metal thickness at some savings in inspection costs.

Is the Shell/Head Material Normalized If your vessel material has been produced to a fine grain structure, click this box. PVElite will use the normalized material curve for the UCS 66 calculations.

Type of Shell or Head Enter the type of shell for this shell section. Choose one of the following shell types: Shell or Head Type Cylindrical Shell Elliptical Head Torispherical Head Hemispherical Head or Spherical Shell Conical Shell Welded Flat Head


Chapter 11 SHELLS

11-7

Diameter Basis If the vessel dimensions are specified on inside basis, pull down the ID selection. If the dimensions are based on the vessels outside diameter select the OD selection. For flat heads, this value is ignored. Always enter the outside diameter of the flat head.

Diameter of Shell or Head Enter the diameter of the shell or head. For torispherical heads, enter the crown radius. For flat heads, enter the outside diameter of the head. For cones, enter the largest diameter of the cone. The program allows you to use either an inside diameter or an outside diameter.

Minimum Thickness of Pipe or Plate Enter the minimum thickness of the actual plate or pipe used to build the vessel, or the minimum thickness measured for an existing vessel. Many pipe materials have a minimum specified wall thickness, which is 87.5% of the nominal wall thickness. You should enter the minimum thickness.

Nominal or Average Thickness of Pipe or Plate (OPTIONAL) Enter the NOMINAL or AVERAGE thickness of the actual plate or pipe used to construct the vessel. This thickness is used to calculate the volume and weight of the metal ONLY if it is between 1 and 1.5 times the minimum thickness. If this value is left blank or 0 the program will use the minimum thickness to compute the weight and volume of this shell element.

Corrosion Allowance Enter the corrosion allowance. The program adjusts both the actual thickness and the inside diameter for the corrosion allowance you enter.

Type of Reinforcing Ring Enter the index for the type of reinforcing ring on the cylindrical or conical section. Three options are available: Reinforcing Ring Type No Reinforcing Ring Simple Bar Reinforcing Ring (You must enter the width and thickness of the bar.) General Beam Section (You must enter the moment of inertia, cross sectional area, and the distance from the shell to the centroid of the beam). In all cases PVElite includes the shell in the calculation of the moment of inertia for the stiffening ring. You can only perform this calculation for external pressure calculations. Also, the detailed analysis for the required moment of inertia and cross section area for cones is contained in the separate CONICAL program.

Minimum Design Metal Temperature If this component is a carbon or low alloy steel shell or head, the program will compute its Minimum Design Metal Temperature (MDMT). The value to be entered in this field is the user defined MDMT. This value is for reference only and will not be used by the program.


11-8

SHELLS

If this material is not a carbon steel then enter a 0 in this field. If a value of zero is entered, the program will not echo this value out during runtime.

Skip UG-16(b) Minimum Thickness Calculation Click this box to skip the UG-16(b) calculation. Section UG-16(b) states the minimum thickness for pressure retaining components as 0.0625 in. (1.6 mm). There are certain exemptions from this requirement such as in the case of heat exchanger tubes. Refer to the ASME Section VIII, Division -1, UG-16(b) for more details.

Is Jacket Present Check this box if a jacket is present. The program will analyze jackets per Appendix-9 of the ASME Sec. VIII Div. 1. For more information refer to the discussion about the jackets (see "Jacket" on page 11-29).

Pop-up Input Fields Operating Liquid Density Enter the density of the operating fluid here. This value will be multiplied by the height of the liquid column in order to compute the static head pressure.

Height of Liquid Column Operating Enter the distance from the bottom of this shell or head element to the surface of the liquid. The head pressure is determined by multiplying the liquid density by the height of the fluid to the point of interest.

Height of Liquid Column Hydrotest Enter the distance from the bottom of this shell or head element to the surface of the liquid when the vessel is being hydrotested. If this is shop hydrotest, and the vessel is laying on its side, then the height of the liquid column should be equal to the inside diameter of the vessel. In the case of a vertical hydrotest this liquid height can be greater than the vessel diameter.

Design Length of Section Enter the design length of the section, typically the length of the vessel plus one-third the depth of the heads or, alternately, the distance between stiffening rings. For a vessel with 2 elliptical heads and no intermediate stiffeners, the design length is the tangent length plus the diameter/6. For a vessel with 2 spherical heads and no intermediate stiffeners, the design length is the tangent length plus the diameter/3. For a vessel with 2 flanged and dished heads and no intermediate stiffeners, the design length is the tangent length plus the diameter/9. When analyzing a head, enter zero for the length.

Design Length for Cylinder Volume Calculations Enter the distance that you want PVElite to use for the liquid volume computation.

Aspect Ratio for Elliptical Heads


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11-9

Enter the aspect ratio for the elliptical head. The aspect ratio is the ratio of the major axis to the minor axis for the ellipse. For a standard 2:1 elliptical head the aspect ratio is 2.0.

Crown Radius for Torispherical Heads Enter the crown radius for torispherical heads. The crown radius for a torispherical head is referred to as the dimension "L", in the ASME VIII Div. 1 Code.

Knuckle Radius for Torispherical Heads Enter the knuckle radius for torispherical heads. This dimension is "r", in the ASME VIII Div. 1 Code.

Half Apex Angle for Conical Sections Enter the half-apex angle for cones or conical sections. The maximum value of the half apex angle for cones under internal pressure and without toriconical transitions or discontinuity stress check is 30 degrees. The largest angle for cones under internal pressure and with toriconical sections or discontinuity stress check is 60 degrees. Typically the largest angle for cones under external pressure is 60 degrees. If you exceed these values the program will run, but with a warning. In that case the user is encouraged to use the CONICAL module for a more detailed analysis.

Large Diameter for Non-circular Welded Flat Heads If you have a non-circular welded flat head, enter the large dimension in this field, and enter the small dimension as the component diameter on the GEOMETRY tab.

Attachment Factor for Flat Head Enter the flat head attachment factor, calculated or selected from ASME Code, Section VIII, Division 1, Paragraph UG-34, Figure UG-34. Some typical attachment factors display below, however consult Paragraph UG-34 before using these values: 0.17 (b-1)

Head welded to vessel with generous radius

0.20 (b-2)

Head welded to vessel with small radius

0.20 (c)

Lap welded or brazed construction

0.13 (d)

Integral flat circular heads

0.20 (e f g)

Plate welded inside vessel (check 0.33*m)

0.33 (h)

Plate welded to end of shell

0.20 (I)

Plate welded to end of shell (check 0.33*m)

0.30 (j k)

Bolted flat heads (include bending moment)

0.30 (m n o)

Plate held in place by screwed ring

0.25 (p)

Bolted flat head with full face gasket

0.75 (q)

Plate screwed into small diameter vessel

0.33 (r s)

Plate held in place by beveled edge

Width of Reinforcing Ring


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SHELLS

Enter the width of the reinforcing ring. For a reinforcing ring that is a simple bar, this is the dimension that is perpendicular to the surface of the shell. See the figure on the next page.

Thickness of Reinforcing Ring Enter the thickness of the reinforcing ring. For a reinforcing ring that is a simple bar, this is the dimension that is parallel to the surface of the shell. See the figure below.

Figure C - Reinforcing Ring

Size of Fillet Weld Leg Connecting Ring to Shell Enter the dimension of the weld leg, which connects the stiffening ring to the shell section. This value will be used in the weld shear flow calculations if a simple bar stiffener has been selected as the type of reinforcing ring.

Ring Type to Satisfy Inertia and Area Requirements Entering a structural ring type here will cause PVElite to search the structural database for a suitable member that will meet the inertia requirements for the ring. The valid types of structural shapes to enter here are: EQUAL ANGLE

Equal Leg Angles

UNEQUAL ANGLE

Unequal Angle

DBL LARGE ANGLE

Double Angles Large Legs back to back

DBL SMALL ANGLE

Double Angles Small Legs back to back

CHANNEL

Channel Sections

I-BEAM

Wide Flange Sections

WT SECTION

Wide Flange Sections ( T type )

MT SECTION

Miscellaneous Tee

ST SECTION

Structural Tee

MC SECTION

Miscellaneous Channel

Ring Weld Attachment Style (Intermittent, Continuous, Both) Enter the style of the weld that attaches the stiffening ring to the shell section. Per UG-29 of the Code there are 3 "styles": INTERMITTENT CONTINUOUS BOTH


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This input in conjunction with the shell thickness and corrosion allowance will allow for the computation of the maximum spacing between weld segments.

Location of Ring (Internal or External) There are two possibilities for the location of the stiffening ring. INTERNAL

Attached to the inside of the Shell

EXTERNAL

On the outer surface of the Shell

Moment of Reinforcing Ring Enter the moment of inertia for the beam section, which is being used as a reinforcing ring, in the direction parallel to the surface of the shell.

Cross Sectional Area of Reinforcing Ring Enter the cross sectional area for the beam section which is being used as a reinforcing ring.

Distance from Ring Centroid to Shell Surface Enter the distance from the surface of the shell to the centroid of the reinforcing ring. This distance should be measured normal to the shell surface.

Is the Ring Angle Rolled the Hard Way If you have selected an angle type ring to satisfy the inertia requirements above, this box is meaningful, otherwise it is ignored. When this option is used PVElite computes the distance from the shell surface to the ring centroid based on information in the AISC Steel handbook.


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SHELLS

Results Thickness Due to Internal Pressure The appropriate formula from ASME Section VIII is referenced, and the formula and substitutions are shown. The diameter or crown radius is adjusted to take into account the corrosion allowance. If your shell design includes hydrostatic head components, the additional pressure due to the height of the liquid column and the operating liquid density will be included with the basic design pressure. The hydrostatic head will be subtracted in order to properly determine the MAWP for the vessel part that is being analyzed. Remember, when pressures are being read from the pressure gauge, the gauge is usually at the high point of the vessel. The pressure registered by the gauge would be different if were at the bottom of the liquid filled vessel. For elliptical heads, the K factor is (2 + Ar * Ar) / 6, per App. 1-4 (c). For torispherical heads the factor M is (1/4) * (3 + SQRT (L / R)), where "L" (the crown radius) and "R" (the knuckle radius) were entered by the user. PVElite does not replace the given thickness with this calculated minimum. If you are choosing the thickness for a component, compare the values shown under "Summary of Internal Pressure Results" (required vs. actual) and adjust the actual thickness up or down accordingly.

Maximum Allowable Working Pressure at Given Thickness This value is calculated as described above, using the given thickness minus corrosion allowance and the operating allowable stress. The hydrostatic head component is subtracted from this value. The pressure gauge is assumed to be at the top of the vessel.

Maximum Allowable Working Pressure, New & Cold This value is calculated as described above, using the uncorroded thickness and the ambient allowable stress.

Actual Stress at Given Pressure and Thickness Note that the joint efficiency is included in this value, so this can be considered as the stress at the welded joint rather than in the base metal.

Summary of Internal Pressure Results Either of two conditions can indicate a problem in your design. First, if the required thickness plus corrosion allowance is greater than the given thickness, then you must increase the given thickness. Second, if the MAWP is less than the design pressure then you must either decrease the design pressure or increase the given thickness to achieve an acceptable design. The hydrotest pressure is calculated as the maximum allowable working pressure times 1.5 or 1.3 (depending the material database selection) times the ratio of the allowable stress at ambient temperature to the allowable stress at design temperature. The hydrotest pressure may not be appropriate for the entire vessel for three reasons. First, some other component may have a lower maximum allowable working pressure, which may govern the hydrotest pressure. Second, you may choose to base hydrotest pressure on design pressure rather than maximum allowable working pressure. Third, if the vessel is tested in the vertical position you may have to adjust the hydrotest pressure for the head of water in the vessel.


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11-13

For the UG99-C hydrotest, the liquid head is subtracted from the basic result.

Minimum Metal Temperatures For carbon steels, these temperatures represent the minimum design metal temperature for the given thickness and, in the second case, the given pressure. The first temperature is interpolated directly from chart UCS-66. The second temperature is reduced if the actual stress is lower than the allowable stress, using figure UCS-66.1. The program also checks for materials, which qualify for the -20 minimum design temperature per UG-20 and prints it in the output. See the input notes above to enter normalized or non-normalized materials.

Weight & Volume Results, No Corrosion Allowance PVElite computes the volume and weight of the shell component. Additionally, the inside volume for a 2.00 inch straight flange is computed and used in the computation of the total volume for the head and the flange. The dimensions used in the volume and weight calculations are non-corroded dimensions.

Results for Max. Allowable External Pressure For the given diameter, thickness, and length, the maximum allowable external pressure is computed per UG--28.

Results for Required Thickness for External Pressure Required thickness results are computed using the rules of UG-28 iteratively. Such items as the length and outside diameter are held constant, and the program calculates the required thickness based on the user entered external pressure.

Summary of External Pressure Results Summary listing displaying external pressure results for both the user entered thickness and the computed required thickness.


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SHELLS

API 579 Introduction Fitness For Service (FFS) assessments using API Recommended Practice 579 (API RP 579) are performed to assess the operation safety and reliability of process plant equipment, such as pressure vessels, piping, and/or tanks - for some desired future period. The assessment procedure will provide an estimate of the remaining strength of the equipment in its current state, which may become degraded while in-use from its original condition. Typical FFS assessments entail: Identifying the flaw type and damage mechanism. Considering the applicability and limitations of the specific flaw type procedure. Reviewing data requirement and gathering the data. Applying the assessment techniques and comparing the result to the acceptance criteria. Estimating the remaining life for the inspection interval. Applying remediation as appropriate. Applying in-service monitoring as appropriate. Documenting the results. Common degradation mechanisms include general corrosion, localized corrosion, pitting corrosion, blister, mechanical distortion, etc. The procedures on how to assess these common degradations or flaws are discussed in the sections described in the Table of Contents for API RP 579 and listed below: Section 1 – Introduction Section 2 – Fitness-For-Service Engineering Assessment Procedure Section 3 – Assessment of Equipment for Brittle Fracture Section 4 – Assessment of General Metal Loss Section 5 – Assessment of Local Metal Loss Section 6 – Assessment of Pitting Corrosion Section 7 – Assessment of Blisters and Laminations Section 8 – Assessment of Weld Misalignment and Shell Distortions Section 9 – Assessment of Crack-Like Flaws Section 10 – Assessment of Component Operating in the Creep Regimes Section 11 – Assessment of Fire Damage


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11-15

Purpose, Scope, and Technical Basis CodeCalc supports the following flaw assessments for cylindrical shells, simple cones, and formed heads: Section 4, General Metal Loss. Section 5, Local Metal Loss. Section 6, Pitting Corrosion. Note: Future software releases will include flaw assessments of other types. There are three levels of assessments available for each flaw type. Level 1 - Typically involves a simplified method using charts, simple formulae, and conservative assumptions. Level 2 - Generally requires a more detailed evaluation and produce more accurate results Level 3 - Allows flaw assessments using a more sophisticated method such as FEA. CodeCalc provides only Level 1 and Level 2 assessments. In each assessment level, the respective remaining life or the de-rate value of MAWP is calculated depending on passing or failing acceptance criteria. Section 4 covers flaw assessment procedures for components subject to general metal loss resulting from corrosion and/or erosion. Meanwhile Section 5 covers the analysis of local metal loss or Local Thin Areas (LTAs), which include groove-like flaws or gouges. In general, flaw assessments using Section 4 criteria produce more conservative results. The differences between Section 4 and 5 when applied to LTAs are as follows: Section 4 - Rules for all Level 1 and 2 assessments are based on the Average Thickness Averaging approach, which is combined with the ASME code rules to determine the acceptability for continued operation. Section 5 - Rules for all Level 1 and Level 2 assessments are based on establishing a Remaining Strength Factor (RSF), which is used to determine the acceptability for continued operation. The Assessment of General Metal Loss described in Section 4 can be performed using either point thickness (random type readings) or profile thickness (grid type readings) measurement data. API RP 579 requires a minimum of 15 data measurement points be used for the analysis. The localized metal loss assessment (described in Section 5), can only be performed using profile thickness data according to a grid setup as shown in Figure 10.3. Two data entry types are provided in the Profile Type selection list; Grid and Critical Thickness Profile (CTP). The number of rows and columns are set by entering the number of points in both the circumferential and longitudinal directions. The total number of data inputs provided are 256 for both point and profile thickness data measurements.


11-16

SHELLS

Figure D - Profile Thickness Inspection Planes

For most evaluations, it is recommended to first perform the assessment using Section 4, then perform Section 5 if necessary. The rules in Section 4 have been structured to provide consistent results with Section 5. However, it is the responsibility of the user to review the Assessment Applicability and Limitation whenever the assessment changes. API 579 Section 4 limitations for Level 1 and Level 2 assessments are as follows: The original design is in accordance with a recognized code or standard. The component is not operating in the creep range. The region of metal loss has relatively smooth contours without notches. The component is not in cyclic service (less than 150 total cycles). The component under evaluation does not contain crack-like flaws. The component under evaluation has a design equation, which specifically relates pressure and/or other loads, as applicable, to a required wall thickness. With some exception, the following specific components do not have equations relating pressure and/or other loads to a required wall thickness may be evaluated using Level 2 assessments: Pressure vessel nozzles and piping branch connections. Cylinder to flat head junctions. Integral tubesheet connections Flanges Piping systems. Note: Currently CodeCalc does not support API 579 analysis on nozzle, flange, tubesheet, flathead, and piping system components. The following limitations on applied loads are satisfied


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11-17

Level 1 assessment - Components are subject to internal and/or external pressure (negligible supplemental loads). Level 2 assessment - Components are subject to internal and/or external pressure and/or supplemental loads such as weight, wind and earthquake. Limitations for API 579 Section 5 Level 1 and Level 2 assessments are similar to the limitations for Section 4 with the following additions: The components cannot be subjected to external pressure, or if the flaw is located in the knuckle region of elliptical head (outside of the 0.8D region), torispherical/toriconical head, or conical transition. The material component is considered to have sufficient material toughness. Special provisions are provided for groove-like flaws such as: Groove (no mechanical cold work). Gouge (mechanical cold work). For more details, refer to Section 4 and Section 5 in the API Recommended Practice 579. Section 6 covers flaw assessment procedures for components that are subjected to pitting damages as described below: Widespread Pitting. Localized Pitting. Region of Local Metal Loss Located in an Area of Widespread Pitting. Pitting Confined within a Region of Localized Metal Loss. Pitting damage can occur on the inside, outside, or both sides of the component surfaces. For components with pittings on both surfaces, be sure to indicate the location of each pit-couple in the data entry table. Pitting damage is described using pit-couples, each is composed of two pits that are separated by a solid ligament. The procedure for determining pit-couples is described in the API 579 paragraph 6.3.3.3. A representative number of pit couples measurements in the damage area should be used. If the pit flaw is uniform then a minimum of 10 pit-couple measurements should be used. For non-uniform pit flaw, additional pit-couple measurements are required. CodeCalc can analyze up to 36 pit-couples measurements. The limitations for API 579 Section 6 Level 1 and Level 2 assessments are similar to the limitations for Section 5 Level 1 and Level 2 assessments. For more details refer to API RP 579 Section 6 .


11-18

SHELLS

Discussion of Input Data In addition to the variable inputs describe in the Main and Pop-up Input Fields, the following inputs are required for the API 579 FFS analysis.

Flaw Type Assessment of General Metal Loss

Option to assess the flaw using API 579 Section 4 analysis

Assessment of Local Metal Loss


Assessment of Pitting Corrosion


Note: It is the responsibility of the user to review the Assessment Applicability and Limitations whenever the assessment is changed.

Flaw Location Select the location of the flaw: Inside

Located on the ID surface

Outside

Located on the OD surface

Inside and Outside

Located on both ID and OD surfaces (used in Section 6 for Multiple Layer Analysis)

Near Axisymmetric Structural Discontinuity Select the available option if the flaw is near an axisymmetric structural discontinuity such as a seam weld, a stiffening ring, or the knuckle area of the head. The available options are listed below for each element type: Cylinder

None User specified Near a stiffening ring Skirt weld seam Cone weld seam

Formed Heads

None User specified Beyond the spherical portion

Cone

None User specified Near the large end or the small end junction

For more details refer to Figure E.


Chapter 11 SHELLS

11-19

Figure E - Zone for Thickness Averaging - Axisymmetric Discontinuity

Distance of Head Tangent from Skirt Weld Seam Enter the distance of head tangent from the skirt weld seam. For more details refer to dimension b in Figure E.

Distance of the First Data Point to the Discontinuity Enter the nearest distance of the first data point along the longitudinal or meridional direction to the axisymmetric structural discontinuity. This value will be used to determine the location of each thickness profile data in reference to the axisymmetric structural discontinuity location. For more details refer to dimension a in Figure E.

User Specified, Lv Enter the user specified zone thickness averaging length, Lv. The entered value will override the calculated value described in API 579. A blank in the input box is interpreted as a zero value. For more details refer to Figure E.

Pitting Type Select the type of pitting damage: Widespread Pitting - Pitting occurs over a significant region of the component Localized Pitting - Pitting occurs over a localized region of the component LTA Region Located in Widespread Pitting Area - A region of LTA is located in an area of widespread pitting Pitting Confined in Region of Localized Metal Loss - Pitting which confined within LTA


11-20

SHELLS

LTA Dimensions Enter the s and c dimensions. These dimensions are required for the following pitting damage types: Localized pitting Region of LTA located in an area of widespread pitting Pitting confined within a region of localized metal loss For more details refer to Figure F.

Figure F - LTA Dimensions in Pitting Damage

Uniform Metal Loss Enter the metal loss prior to the assessment.

LMSD Enter the shortest distance from the edge of the local metal loss region under investigation to the nearest major structural discontinuity such as a weld seam and/or a stiffening ring. This parameter will be used to check the limiting flaw size in the Section 5 analysis.

Point Check this box if the Point Thickness measurement method is used.

Profile Check this box if the Profile Thickness measurement method is used.

Groove Check this box if a groove is present.

Pitting Check this box for analyzing pitting flaw.


Chapter 11 SHELLS

Groove Radius (gr) Groove radius. For more details refer to Figure G for more information on the Groove Description.

Figure G - Groove Description

Groove Length (gl) Enter the groove length. For more details refer to Figure G - Groove Description.

Groove Depth (gd) Enter the groove depth. For more details refer to Figure G - Groove Description.

Groove Width (gw) Enter the groove width. For more details refer to Figure G - Groove Description.

Beta Enter the groove orientation in degrees. For more details refer to Figure G - Groove Description.

Critical Exposure Temperature (CET) The lowest metal temperature derived from either the operating or atmospheric conditions.

P_k Enter the pit-couple spacing in pit-couple k. For more details refer to Figure H.

Theta_k Enter the pit-couple orientation in degree. For more details refer to Figure H.


11-21

11-22

SHELLS

d_i,k Enter the diameter of the pit i in pit-couple k. For more details refer to Figure H.

d_j,k Enter the diameter of the pit j in pit-couple k. For more details refer to Figure H.

w_i,k Enter the depth of the pit i in pit-couple k. For more details refer to Figure H.

w_j,k Enter the depth of the pit j in pit-couple k. For more details refer to Figure H.

Pitting Location Enter the pit-couple location on the element. This pit-couple location is required when the pit damage located on both sides of the component. Enter 1 for pit-couple is located on the ID surface Enter 2 for pit-couple is located on the OD surface

Figure H - Pitting Description


Chapter 11 SHELLS

11-23

Profile Type Select the profile thickness measurement data type, CTP (Critical Thickness Profile) or Grid type (raw data). The selection will set the data entry table accordingly.

Number of Points (Data Size Inputs) Enter the total number of measurement points for Point Thickness measurement method.

Circumferential Direction (Data Size Inputs) Enter the total number of measurement points along the Circumferential Direction for Profile Thickness measurement method.

Longitudinal/Meridional Direction (Data Size Inputs) Enter the total number of measurement points along the Longitudinal/Meridional Direction for Profile Thickness measurement method.

Number of Pit-Couples (Data Size Inputs) Enter the total number of pit couples for pitting flaw.

Circumferential Direction (Grid Size Inputs) Enter the grid size of the thickness profile in the circumferential direction.

Longitudinal/Meridional Direction (Grid Size Inputs) Enter the grid size of the thickness profile in the longitudinal or meridional direction.

Maximum Allowable Working Pressure (MAWP) Enter the design MAWP. If this value is provided, the calculated MAWP based on the input nominal thickness will be overridden and used to compute the de-rated MAWP in Section 5 and 6 analysis. The de-rating of the vessel element will be computed automatically when the results indicate failure for continuing operation. However when the results meet the passing criteria, a remaining life of the equipment will be presented.

Remaining Strength Factor Allowable (RSFA) It is defined as RSF = LDC / LUC Where LDC = Limit or plastic collapse load of the damaged component LUC = Limit of plastic collapse load of the undamaged component. The default value currently set in API Recommended Practice 579 is 0.9.


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SHELLS

Supplemental Loads Enable this check box for supplemental loads inputs

Axial Force, F Enter the net-section axial force from supplemental loads excluding the pressure trust for the Sustained and Expansion Cases if any. For more details refer to Figure I below for the directional convention.

Figure I - Supplemental Load

Shear Force, V Enter the net-section shear force from the supplemental loads for the Sustained and Expansion Cases. For more details refer to Figure I.

Bending Moment, Mx Enter the component of the net-section bending moment from the supplemental loads in the X direction for the Sustained and Expansion Cases. For more details refer to Figure I.

Bending Moment, My Enter the component of net-section bending moment from the supplemental loads in the Y direction for the Sustained and Expansion Cases. For more details refer to Figure I.

Bending Moment, Mz Enter the net-section bending moment from the supplemental loads in the Z direction for the Sustained and Expansion Cases. For more details refer to Figure I.

Joint Efficiency, Circumferential Seam Enter the joint efficiency in the circumferential direction.


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11-25

Shell Orientation Select the orientation of the installed vessel. This input will be used to get the horizontal input data for the thickness calculation due to supplemental loads.

Depth of Head Enter the head depth of the horizontal vessel. For more details refer to Figure J.

Figure J - Horizontal Vessel Parameters

Saddle Contact Angle Enter the contact angle of the saddle with the shell. For more details refer to Figure J.

Distance from Saddle to Vessel Enter the length from the tangent line of the horizontal vessel to the centerline of a saddle support. For more details refer to Figure J.

Maximum Saddle Reaction Force Enter the saddle reaction force resulting from the weight of the vessel and vessel content. For more details refer to Figure J.

Flaw Location Along Vessel Select from the option the nearest point where the flaw located. For more details refer to Figure J.

Compute Remaining Life Check this check box to enable the remaining life calculation when the assessments have met the passing the criteria.


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SHELLS

Corrosion Rate per Year (Section 4 and 5 inputs) Enter the corrosion rate per year in both directions, circumferential and longitudinal directions. These corrosion rates are also required for the Localized Pitting in which is analyzed using Section 5.

Pit Size (Section 6 inputs) Enable this check box to activate the pit grow in "Increasing In Pit Size" mode. This mode will simulate the increase of the pit size, diameter and depth. This check box will enable the Diameter and Depth Pit Propagation Rate (PPR) input boxes

Region Size (Section 6 inputs) Enable this check box to activate the pit grow in "Increasing In Pit Region Size" mode. This mode will simulate the increase of the LTA size. This check box will enable the C dim and S dim PPR input boxes

Density (Section 6 inputs) Enable this check box to activate the pit grow in "Increasing In Pit Density" mode. This mode will simulate the increase the pit density by decreasing the pit spacing. This check box will enable the Couple Spacing PPR input boxes

Diameter (Section 6 inputs) Enter the Diameter PPR.

Depth (Section 6 inputs) Enter the Depth PPR.

S dim (Section 6 inputs) Enter the S dimension (longitudinal direction) PPR. For more details refer to Figure F.

C dim (Section 6 inputs) Enter the C dimension (circumferential direction) PPR. For more details refer to Figure F.

Couple Spacing Input (Section 6 inputs) Enter the Pit Couple Spacing PPR.

RLife Computation Approach Select the method for calculating the RLife: Thickness approach. MAWP approach.


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11-27

Discussion of Results An effort has been made to use the same variable names and reporting formats as are used in the API Recommended Practice 579 book. A summary at the end of the analysis of each level will be written. Depending on the pass or fail criteria, either the remaining life using the thickness (or MAWP) approach will be computed or a de-rating MAWP will be printed. As suggested in the API Recommended Practice 579 book, the following, or combinations thereof can be considered when the component does not meet the Level 2 Assessment requirements: Re-rate, repair and retire the component. Adjust the FCA by applying remediation techniques Adjust the weld joint efficiency factor, E, by conducting additional examinations and repeat the assessment Conduct a Level 3 assessment.


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SHELLS

Example The example problems illustrating these principles are located in the program installation directory/Examples directory.


Chapter 11 SHELLS

11-29

Jacket PVElite will compute the required thickness of the jacket, closure bar and the internal chamber (cylindrical / conical shell, or head covered by the jacket). The code gives weld sizes, which must be adhered to, as they are designed to ensure full integrity of the jacket attachment to the vessel. ASME VIII Div 1 Appendix 9 sets out 5 basic jacket configurations. For more information refer in the code to Figure 9-2.

Figure K - Jackets Types Available in the Program.

In a type 3 jacket arrangement, there is no closure bar, however the welding is critical, and the notes set out in the code must be adhered to. Typically, the jacket is attached by means of a closure bar as shown here:

Figure L - Inner Vessel with Jacket and Closure Bar

The closure bar can be a simple rectangular section ring as displayed above, or it can be more elaborate as displayed in Appendix 9 of the code.


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SHELLS

Note: Verify the inner shell/head for external pressure using (any) vacuum plus the Jacket Pressure and consider the Design Length of the Jacket section L.

Jacket Type From the list box select the Jacket Type you are analyzing. For more information refer to the types above. If you cannot decide what type most suits your model, then enter Type 2. If this is not appropriate, then the program will give you a warning message.

Closure Bar Type From the list box select the closure bar type most resembling your design. For more information use the pictures below.


Chapter 11 SHELLS


11-31

11-32


SHELLS

Chapter 11 SHELLS


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SHELLS

Figure M - Closure Bar Jacket Types

Jacket Welded Joint Efficiency E Enter the jacket and jacket head welded joint efficiencies. This is obtained from table UW-12 in ASME Section VIII Division 1. In the case of a type 1 weld (Welded from both sides, or with removable backing strip), the joint efficiencies are as follows:

Value

Result

1.00

Full Radiography

0.85

Spot Radiography

0.70

No Radiography


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11-35

Jacket Head Type From the drop down box, select the jacket head type: Ellipsoidal Head Torispherical Head Hemispherical Head

Corrosion Allowances Enter the following corrosion allowances. The program will perform all the calculations in the corroded condition. 1

Inner shell corrosion allowance outside

cso

2

Jacket corrosion allowance inside

cji

3

Jacket head corrosion allowance inside

ci

Note that the input for the inner shell corrosion allowance inside is available on the 'Geometry' tab of the main input screen.

Jacket Design Temperature Enter the Design Temperature of the Jacket.

Jacket Material Select the jacket material.

Jacket Pressure Pj Enter the pressure in the jacket space. This is the pressure shown in the figure L.

Inside Diameter of the Jacket Dj Enter the inside diameter of the jacket as shown in figure L.

Jacket Thickness tj Enter the thickness of the jacket as shown in figure L.

Jacket Half Apex Angle Enter the half apex angle for the (c), (b-2), (k) and (l) closure bar types as shown in the following figure.


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SHELLS

Jacket Length Ltot Enter the total length of the jacket, which can be used for computing the volume and weight of the jacket. The following fields refer to the dimensions required for the jacket head:

Jacket Head Thickness New th Enter the new thickness of the jacket head.

Jacket Head Aspect ratio The aspect ratio is the ratio of the major axis to the minor axis for the ellipse. For a standard 2:1 elliptical head the aspect ratio is 2.0.

Jacket Head Crown Radius L Enter the crown radius in the case of a torispherical jacket head.

Jacket - Jacket Knuckle Radius r Enter the knuckle radius in the case of a torispherical jacket head.

Closure Bar Material Select the closure bar material from the button on the screen.

Closure Bar Thickness tc Enter the thickness of the closure bar.

Closure Bar Corrosion Allowance cc Enter the corrosion allowance of the closure bar. if the closure is subject to corrosion both outside and inside, then enter the combined corrosion allowance.


CH AP TER

1 2

Chapter 12 NOZZLES In This Chapter Introduction ................................................................................ 12-2 Purpose, Scope, and Technical Basis.......................................... 12-3 Discussion of Input Data............................................................. 12-4 Discussion of Results.................................................................. 12-14 Example ...................................................................................... 12-17


12-2

NOZZLES

Introduction NOZZLES calculates required reinforcement under internal pressure and performs failure path calculations for nozzles in shells and heads, using the ASME Code, Section VIII, Division 1 rules. The program also enables the user to orientate the nozzle in various directions such as hillside, lateral and radial.


Chapter 12 NOZZLES

12-3

Purpose, Scope, and Technical Basis NOZZLE calculates the required wall thickness and area of reinforcement for a nozzle in a pressure vessel shell or head, and compares this area to the area available in the shell, nozzle and optional reinforcing pad. The program also calculates the strength of failure paths for a nozzle. NOZZLE is based on the ASME Code, Section VIII, Division 1, Paragraph UG-37 through UG-45, Edition 2004 A-05. The calculation procedure is based on figure UG-37.1. The program calculates the required thickness (for reinforcement conditions) based on inside or outside diameter for the following vessel components:

Component

Paragraph

Limitations Per UW-37

Cylinder

UG-27 (c) (1)

None

Elliptical Head

UG-32 (d) (1)

Nozzle concentric within 0.8D

Torispherical Head

UG-32 (e) (1)

Nozzle in spherical portion


UG-27 (d) (3)

None

Conical

UG-27 (g)

None

The program evaluates nozzles at any reasonable angle from the perpendicular, allowing evaluation of off angle, hillside or tangential nozzles. NOZZLE takes full account of the internal corrosion allowance. You enter actual thickness and corrosion allowance, and the program adjusts thicknesses and diameters when making calculations for the corroded condition. NOZZLE also performs UCS-66 MDMT calculations for nozzles.

Figure A - Nozzle Program Geometry


12-4

NOZZLES

Discussion of Input Data Main Input Fields Description Enter a maximum 15 character alpha-numeric description for this item. This entry is optional.

Design Internal Pressure Enter the internal design pressure. This is a non-zero positive value and is usually obtained from the design drawings or vessel design specification. Required information such as the required thickness of the shell (TR) and the nozzle (trn) are determined from the design internal pressure.

Design External Pressure Enter the external design pressure. PVElite will automatically compute the required thickness of the given geometry for the external pressure entered. If you are designing for a full vacuum you would enter a value of 15.00 psig. If you are entering an external pressure there are some prompts such as shell design length, which will appear. PVElite will automatically compute the required thickness for both external and internal pressure. It will then choose the greatest tr and proceed with the calculations.

Maximum Allowable Pressure New & Cold The normal entry in this field will be the hydrostatic test pressure on the nozzle. When the program computes the areas for this case it will automatically use ambient allowable stresses and 0 corrosion allowance. If this is the case that governs the area analysis, the corrosion allowance used in the remainder of the calculations will be set to 0.0

Shell, Nozzle or Pad Material Name Click the Material Database button to search for a material in the material database. Also, you can type the material name in this cell, and the system will retrieve the first material it finds with a matching name. Click the Material Edit Properties button to change the properties of the selected material. You can also create new materials by selecting the TOOLS/EDIT/ADD MATERIALS option on the MAIN MENU.

Allowable Stress at Design Temperature The program automatically fills in entry by entering a material specification. When you change the internal design temperature, or the thickness of the shell, the program will automatically update this field, but only for BUILT-IN materials. If you enter the allowable stress by hand, be sure to verify your entry to assure conformance with the latest edition of the ASME Pressure Vessel Code Section II Part D at the design temperature. If using a module where PD:5500 is selected as design code, then the program will use the PD:5500 Material Database.

Allowable Stress at Ambient Temperature The program automatically fills in entry by entering a material specification. When you change the internal design temperature, the program will automatically update this field, but only for BUILT-IN materials. If you enter the


Chapter 12 NOZZLES

12-5

allowable stress by hand, be sure to verify your entry to assure conformance with the latest edition of the ASME Pressure Vessel Code Section II Part D. If using a module where PD:5500 is selected as design code, then the program will use the PD:5500 Material Database.

Include Hydrostatic Head Component If you enter the allowable stress by hand, be sure to verify your entry to assure conformance with the latest edition of the ASME Pressure Vessel Code Section II Part D at ambient temperature.

Operating Liquid Density Enter the density of the operating fluid here. This value will be multiplied by the height of the liquid column in order to compute the static head pressure. You can enter a number of specific gravity units and PVElite will convert the number entered to the current set of units. To do this, enter a number followed by the letters "sg".

Height of Liquid Column, Operating Enter the distance from this nozzle to the surface of the liquid. The head pressure is determined by multiplying the liquid density by the height of the fluid to the point of interest.

Shell or Head Type Enter the type of shell for this shell section. Choose one of the following shell types: Cylindrical Shell Elliptical Head Torispherical Head Hemispherical Head or Spherical Shell Conical Head or Shell Welded Flat Head

Shell Diameter Basis (ID or OD) Select ID for shell sections based on the inside diameter. Select OD for shell sections based on the outside diameter. Normally, for a flanged & dished torispherical head, the inside crown or radius is equal to the vessel outside diameter. For flat heads, this value is ignored. Always enter the diameter of the flat head that is exposed to the pressure.

Shell Diameter Enter the diameter of the shell or head. For flat heads, enter the outside diameter of the head. For cones, enter the diameter of the cone at the point where the nozzle intersects the shell.


12-6

NOZZLES

Actual Thickness of Shell Enter the minimum thickness of the actual plate or pipe used to build the shell, or the minimum thickness measured for an existing vessel. Many pipe materials have a minimum specified wall thickness, which is 87.5% of the nominal wall thickness. You should enter the minimum thickness.

Enter Required Thickness The only time the required thickness must be entered is if the component being analyzed is a bolted flat head. Otherwise the program will compute the required thickness of the shell/head. For hillside nozzles, as of Version 4.50, several changes have been made relating to the use of the required thickness. They are as follows: If you wish to enter an offset and allow PVElite to compute the nozzle angle, then leave the required thickness blank. If you wish to enter an angle less than 90, or enter a computed value via the entered offset values, and you would like to take credit for the Code 0.5 F-correction factor, then enter the value obtained by multiplying the required thickness times the F-correction factor. If you wish to enter an angle less than 90 and you do not which to take credit for the Code 0.5 F-correction factor, then enter the required thickness.

Shell Corrosion Allowance Enter the corrosion allowance. The program adjusts both the actual thickness and the inside diameter for the corrosion allowance you enter.

Is The Nozzle Outside the 80% Diameter Limit If the nozzle is outside of the spherical portion of the elliptical or torispherical head, check this field. Doing so will cause PVElite to use the standard internal pressure equation from UG-27 instead of the equation from UG-37. In the case where a nozzle is within the 80 % diameter limit then, the required thickness of the head is equal to that of a seamless sphere of radius K1*D, where D is the shell diameter and K1 is given by Table UG-37.

Modification of Reinforcement Limit Check this box as necessary. You may enter any physical limitation, which exists, on the thickness available for reinforcement or the diameter available for reinforcement. An example of a thickness limitation would be a studding pad or nozzle stub, which would not extend normal to the vessel wall as far as the thickness limit of the nozzle calculation. An example of a diameter limitation would be two nozzles close together, or a vessel seam for which you did not want to take an available area reduction.

Is This a Manway or Access/Inspection Opening UG 45 states that if the opening is a Manway or access opening the minimum thickness requirement per UG-45 is not required. Checking this box will cause the program to bypass the UG-45 minimum nozzle neck thickness requirement.


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12-7

Perform Area Calculations for Small Nozzles he Code paragraph UG-36 discusses the requirement of performing area replacement calculations when small nozzles are involved. The Code States : Openings in vessels not subject to rapid fluctuations in pressure do not require reinforcement other than that inherent in the construction under the following conditions : 3.5" finished opening in a shell or head with minimum required thk. of .375 inches or less 2.375" finished opening in a shell or head greater than minimum required thk. of .375 inches

If your geometry meets this criteria and this check box is NOT checked, then no area of reinforcement calculations will be performed on this nozzle item.

Set Area 1 or Area 2 Equal To 0 In some vessel design specifications it is mandated that no credit be taken for the area contributed by the shell or nozzle. You can click this box and select one of the following options: "A1"

To set area1 (the shell) to zero

"A2"

To set area2 (the nozzle) to zero

"A1 A2"

To set both area1 and area2 to zero.

Rating of attached flange If you check this prompt the program will ask you the class and grade of the attached flange. The program will use these two items along with the temperature to rate the flange using the tables in ANSI B16.5.

Nozzle Diameter Basis Select inside diameter or outside diameter basis as necessary.

Actual or Nominal Diameter of Nozzle Enter the diameter of the nozzle. If you specify nominal or minimum for the nozzle size and thickness basis, then you must enter the nominal diameter of the nozzle in this field. Valid nominal diameters are: 0.125

0.25

0.375

0.5

0.75

1

1.25

1.5

2

2.5

3

3.5

4

5

6

8

10

12

14

16

18

20

24

30

Note that if you are using Metric or non-English units, then the diameter when converted must end up as a value in the table above. For example if the size were 10 inch nominal, this would correspond to 254 mm. In the nozzle dialog, press the button next to the pipe size to select it from the list. In the list, both the ANSI nominal and Metric Nominal are shown.

Nozzle Size and Thickness Basis Enter Actual, Nominal, or Minimum, representing the basis for nozzle diameter and thickness.


12-8

NOZZLES Actual: The program uses the actual diameter entered in the field above and the actual thickness entered in the field below. Nominal: The program looks up the actual diameter based on the nominal diameter entered in the field above, and looks up the nominal thickness based on the schedule entered in the second field below. Minimum: The program looks up the actual diameter based on the nominal diameter entered in the field above, and looks up the nominal thickness based on the schedule entered in the second field below. It then multiplies the nominal thickness by a factor of 0.875.

Actual Schedule of Nozzle Enter the minimum actual thickness of the nozzle wall. Enter a value in this field only if you selected ACTUAL for the nozzle diameter and thickness basis. Otherwise enter a schedule in the field below.

Nominal Thickness of Nozzle Select the schedule for the nozzle wall. Enter a value in this field only if you selected NOMINAL or MINIMUM for the nozzle diameter and thickness basis. Otherwise enter a thickness in the field above. Type the schedule for the nozzle, i.e. SCH 40. Available nozzle schedules are: SCH 10

SCH 80

SCH STD

SCH 10S

SCH 80S

SCH X-STG

SCH 20

SCH 100

SCH XX-STG

SCH 30

SCH 120

SCH 40

SCH 140

SCH 40S

SCH 160

SCH 60

Required Thickness of Nozzle The program normally calculates the required thickness of the nozzle but under the following circumstances you must enter the required thickness when: Your job specification requires you to exclude the area from the nozzle. Enter the actual thickness minus the corrosion allowance. The nozzle is non-circular.

Nozzle Corrosion Allowance Enter the corrosion allowance. The program adjusts both the actual thickness and the inside diameter for the corrosion allowance you enter.

Efficiency of Shell Seam Through Which Nozzle Passes Enter the seam efficiency. The seam efficiency is used in the 'area available' calculations to reduce the area available in the shell. Note that for shell and nozzle wall thickness calculations, the seam efficiency is always 1.0.

Insert Nozzle or Abutting Nozzle The nozzle type and depth of groove welds are used to determine the required weld thicknesses and failure paths for the nozzle. If the nozzle is welded to the outside of the vessel wall, it is abutting the vessel wall. If the hole in the


Chapter 12 NOZZLES

12-9

vessel is bigger than the nozzle OD and the nozzle is welded into the hole, it is inserted. Figure UW-16.1 shows typical insert and abutting nozzles.

Reinforcing Pad If there is a reinforcing pad on the nozzle, or if you wish to specify the geometry for a reinforcing pad, check this field. NOTE CAREFULLY that though PVElite will design and recommend a reinforcing pad if one is needed, the analysis of areas is based only on what you have entered. If PVElite recommends a pad or a larger pad than the one you enter, you must go back into input and enter a pad of the correct size in order for the final configuration to be reflected in the final analysis.

Nozzle Angle Geometry Non-radial nozzles can be specified by entering the angle between the vessel and nozzle centerlines, and the offset from vessel centerline. This vessel-nozzle centerline angle can vary from 0 to a limiting value depending upon specific geometry. Figure B below illustrates these dimensions. To specify a radial nozzle on a head or shell just click the Is Lateral .. check box. In this case the input for the offset dimension and vessel-nozzle centerline angle are optional, only required for the graphic and not for the analysis.

Figure B - Nozzle Angle Description

Hillside nozzles and some angular nozzles are subject to calculations to meet area requirements in both planes of reinforcement. In these cases PVElite automatically checks the area requirements in both the planes, using the corresponding lengths of the nozzle opening. For integral construction, the Code F correction factor of 0.5 will automatically be applied in the hillside direction. If the connection is pad reinforced, a value of 1.0 will be used. The F factor is used to account for the fact that the longitudinal stress is one half of the hoop stress. The use of the F factor is limited to nozzles located on cylindrical and conical sections. One hill-side nozzle example based on ASME VIII Div 1 Appendix L-7.7 is illustrated in the file checks under the PVElite examples directory – Nozzles item #10 and 11. Some examples are shown in Figure C.


12-10

NOZZLES

Figure C - Hillside Nozzle Configuration Example

Y-angle or lateral nozzles can be specified in case of conical and cylindrical sections, by clicking on the Is Lateral .. check box. In this case only the vessel-nozzle centerline angle needs to be specified. The following Figure D and Figure E show examples of typical Y-angle nozzles.

Figure D - Y-Angle Nozzle on a Cylinder

Figure E - Y-Angle Nozzle on a Cone

Pop-Up Input Fields Enter the Shell Design Length for External Pressure Enter the design length of the section, typically the length of the vessel plus one-third the depth of the heads or, alternatively, the distance between stiffening rings. For a vessel with 2 elliptical heads and no intermediate stiffeners, the design length is the tangent-to-tangent length plus the shell diameter /6. For a vessel with 2 spherical heads and no intermediate stiffeners, the design length is the tangent length plus the diameter /3. For a vessel with 2 flanged and dished heads and no intermediate stiffeners, the design length is the tangent length plus the diameter /9.


Chapter 12 NOZZLES

12-11

When analyzing a conical head enter the axial length of the cone. If you are analyzing any other head types, enter a 0 here. You must also enter the required thickness of the component in the appropriate field.

Print Intermediate Calcs for External Pressure If you check this field PVElite prints the parameters used for external pressure design. If you do not check this field PVElite will not print the intermediate computations.

Enter the Aspect Ratio for Elliptical Heads The aspect ratio is the ratio of the major axis to the minor axis for the ellipse. For a standard 2:1 elliptical head the aspect ratio is 2.0.

Inside Crown Radius (L) of the Torispherical Head Enter the inside crown radius of torispherical head.

Inside Knuckle Radius of Torispherical Head Enter the inside knuckle radius of the torispherical head. This value is typically 0.17 * the head inside diameter.

Half Apex Angle for Conical Sections Enter the half-apex angle for cones or conical sections. The maximum value of the half apex angle for cones under the internal pressure and without toriconical transitions is 30 degrees. The largest angle for cones under internal pressure and with toriconical sections is 60 degrees. The largest angle for cones under external pressure is 60 degrees. If you exceed these values the program will run, but with a warning.

Enter The Attachment Factor For Welded Flat Heads Enter the attachment factors for the welded flat head. You can find these factors in Section VIII, Division 1, Figure UG-34. The typical value for an attachment factor is 0.3.

Enter the Large Diameter for Non-circular Flat Heads If you have a non-circular welded flat head, enter the large dimension in this field, and enter the small dimension as the component diameter.

Class for Attached B16.5 Flange Select the class of the attached flange from the following list:


12-12

NOZZLES

CL 150 CL 300 CL 400 CL 600 CL 900 CL 1500 CL 2500

Grade for Attached B16.5 Flange Select the grade of the attached flange from the following list: GR 1.1

Med C Steel

GR 1.14

9Cr-1Mo

GR 1.2

Med C Steel

GR 2.1

Type 304

GR 1.4

Low C Steel

GR 2.2

Type 316

GR 1.5

C-1/2Mo

GR 2.3

Type 304L, 316L

GR 1.7

1/2Cr-1/2Mo, Ni-Cr-Mo

GR 2.4

Type 321

GR 1.9

1-1/4Cr-1/2Mo

GR 2.5

Type 347, 348

GR 1.10

2-1/4Cr-1Mo

GR 2.6

Type 309

GR 1.13

5Cr-1/2Mo

GR 2.7

Type 310

Physical Maximum for Nozzle Diameter Limit Enter the maximum diameter for material contributing to nozzle reinforcement. An example of a diameter limitation would be two nozzles close together, or a vessel seam for which you do not want to take an available area reduction.

Physical Maximum for Nozzle Thickness Limit Enter the maximum thickness for material contributing to nozzle reinforcement. An example of a thickness limitation would be a studding pad or nozzle stub which would not extend normal to the vessel wall as far as the thickness limit of the nozzle calculation.

Nozzle Outside Projection Enter the distance the nozzle projects outward from the surface of the vessel. This distance is usually to the attached flange or cover. Use this length for weight calculations and for external pressure calculations.

Weld Leg Size Between Inward Nozzle and Inside Shell Enter the size of one leg of the fillet weld between the inward nozzle and the inside shell.

Depth of Groove Weld Between Nozzle and Vessel Enter the total depth of the groove weld. Most groove welds between the nozzle and the vessel are full penetration welds. Thus the depth of the weld would be the same as the depth of the component, that is the thickness of the


Chapter 12 NOZZLES

12-13

nozzle. If the nozzle is attached with a partial penetration weld, or just a fillet weld, enter the depth of the partial penetration or a zero, respectively, in this field.

Nozzle Inside Projection Enter the projection of the nozzle into the vessel. The program uses the least of the inside projection and the thickness limit with no pad to calculate the area available in the inward nozzle. Therefore, you may safely enter a large number such as six or twelve inches if the nozzle continues into the vessel a long distance.

Weld Leg Size for Fillet Between Nozzle and Shell or Pad Enter the size of one leg of the fillet weld between the nozzle and the pad or shell.

Pad Outside Diameter Along Vessel Surface Enter the outside diameter of the pad. You must enter the diameter of the pad as the length along the vessel shell not the projected diameter around the nozzle, although these two values are equal when the nozzle is at 90 degrees.

Pad Thickness Enter the thickness of the pad. Any allowances for external corrosion should be taken into account for the pad thickness.

Pad Weld Leg Size at Outside Diameter Enter the size of one leg of the fillet weld between the pad OD and the shell. Note that if any part of this weld falls outside the diameter limit, the weld will not be included in the available area.

Depth of Groove Weld Between Pad and Nozzle Neck Enter the total depth of the groove weld. Most groove welds between the pad and the nozzle are full penetration welds. Thus the depth of the weld would be the same as the depth of the component, that is the thickness of the pad. If the pad is attached with a partial penetration weld, or just a fillet weld, enter the depth of the partial penetration or a zero, respectively, in this field.


12-14

NOZZLES

Discussion of Results Actual Nozzle Diameter Thickness If you specified an 'actual' basis for nozzle diameter and thickness, the diameter and thickness shown will be the same as those which you entered. If you specified 'Nominal', these values will be the nominal diameter and thickness found in the programs pipe size tables. If you entered minimum the program will have looked up the diameter and thickness in the pipe size tables and then multiplied the thickness by 0.875.

Required Thickness of Shell and Nozzle The program calculates the required thickness for the shell and nozzle as follows: Cylindrical (and the nozzle wall)

-

Calculated per UG-27 or as given by the user.

Hemisphere

-


Torispherical

-


Elliptical

-


Conical

-


Flat

-


The joint efficiency used in this calculation is always 1.0. In 1989 we submitted a request for interpretation to the ASME Code in order to show that the use of 1.0 under all circumstances was justified. The reply was published in the A-90 addenda as Interpretation VIII-1-89-171. The question and reply were as follows: Question: In reinforcement calculations, is the joint efficiency used in calculating the required thickness of the vessel wall tr and the required thickness of the wall trn 1.0 regardless of the joint efficiency determined for the vessel wall and nozzle wall from the rules in UW-12, provided the nozzle does not pass through a weld? Reply: Yes. Note also that the program takes into account the case where the nozzle passes through a weld by asking the joint efficiency of the weld, if any.

UG-45 Minimum Nozzle Neck Thickness The program uses the design rules from paragraph UG-45 for minimum nozzle neck thickness. If the thickness used by PVElite for your nozzle calculation is less than required by UG-45, your Code Vessel is in violation of this paragraph.

Required and Available Areas The area required is calculated per UG-37(c). For external pressure and flat heads, this value is multiplied by 0.5. The required areas are calculated per Fig. UG-37.1. Note that the program uses dl-d, (Diameter limit minus inside hole radius) in the calculations for the area available in the shell. This is because the Code incorrectly assumes that the dl-d is always equal to d, which is only true when the natural diameter limit is used. Since we allow you to enter a reduced diameter limit, we could not use the pure Code equation.


Chapter 12 NOZZLES

12-15

Selection of Reinforcing Pad The program gives up to three possible reinforcing pad selections. The first is a pad thickness based on the given pad diameter. The second is a pad diameter based on the given pad thickness. Finally, the program selects a thickness based on the thinner of the shell and nozzle walls, and calculates a required diameter. If this exceeds the diameter limit, it selects a thickness based on a pad at the diameter limit. All thickness results are rounded up to the nearest sixteenth, while all diameter results are rounded up to the nearest eighth.

Large Diameter Nozzle Calculations For large diameter nozzles, the rules of Appendix 1-7 require that two-thirds of the reinforcement be within 0.75 of the natural diameter limit for the nozzle. If the calculated value of the percent within this limit is greater than 66%, the nozzle is adequately reinforced for the large diameter rules. For a large nozzle geometry to meet Code requirements both sets of area calculations must meet their respective area requirements.

Effective Material Diameter and Thickness Limits The diameter limit is the maximum distance from the centerline of the nozzle along the vessel wall, which can be taken credit for when calculating available areas in the shell or a pad. If your pad has a greater diameter than the diameter limit, only the area inside the limit is credited. If you entered a DMAX value for the analysis, that value is used only if it is the least of all the diameter limit candidates. The thickness limit is the distance from the vessel surface along the nozzle axis, which can be taken credit for when calculating the areas available in the nozzle wall and the pad. If your inward nozzle projection or outward pad projection are greater than the diameter limit, only the area inside the limit is credited. If you entered a TMAX value for the analysis, that value is used only if it the least of all the thickness limit candidates.

Effective Material Diameter and Thickness Limits The MAWP for reinforcement is an estimate, usually accurate to within 1 or 2 psi. Enter the given MAWP as the design pressure to check its accuracy. The MAP for the flange is based on ANSI B16.5 tables for the given grade and class of flange.

Minimum Design Metal Temperature The minimum design metal temperature is computed for the nozzle. The program considers UG-20(f), UCS-66 and UCS-66.1 when performing these calculations.

Weld Size Calculations Nozzle weld thicknesses are based on Figure UW-16.1. The outward nozzle weld is compared to the cover weld required by the Code. Note that the minimum dimension of a weld is 0.7 times its leg dimension. Note also that for cover welds the maximum weld the Code requires is 0.25 inches. The pad weld requirement is typically at least one half of the element thickness. In addition to the cover welds, the total groove weld plus cover weld for inserted nozzles must be at least 1.25 times the minimum element thickness.


12-16

NOZZLES

Weld Strength Calculations The strength of connection elements is their cross sectional area times the allowable unit stress for the element. The last two terms in the equations shown give the stress factor and basic allowable stress for the element in the direction considered.

Failure Path Calculations The failure paths differ based on whether there is a reinforcing pad, whether the nozzle is inserted or abutting, and whether there is an inward projection. Note that the strength of each path must exceed either the W value or the W## associated with that path. Note also that UW-15(b) indicates that no strength calculations for nozzle attachment welds are required for figure UW-16.1, sketches (a), (b), (c), (d), (e), (f-1), (f-2), (f-3), (f-4), (g), (x-1), (y-1), and (z1). But, for types I, J, K, L, X-2, Y-2, Z-2 weld, PVElite will perform the additional weld size calculations per UW16(d)(1).

Iterative Results Per Pressure, Area , And UG-45 Assuming the same corrosion allowance for the shell and nozzle, the maximum (failure) corrosion allowance, the minimum (discard) nozzle thickness and the minimum (failure) shell thickness are computed. The user can project the nozzle service lifetime based on the rate of corrosion and the above results.


Chapter 12 NOZZLES

12-17




CH AP TER

1 3

Chapter 13 FLANGES In This Chapter Introduction ................................................................................ 13-2 Purpose, Scope, and Technical Basis.......................................... 13-3 Discussion of Input Data............................................................. 13-5 Discussion of Results.................................................................. 13-18 Example ...................................................................................... 13-22


13-2

FLANGES

Introduction FLANGE calculates actual and allowable stresses for all types of flanges designed and fabricated to the ASME Code, Section VIII, Division 1. The program uses the Code rules found in Appendix 2 of the Edition 2004 A-05.


Chapter 13 FLANGES

13-3

Purpose, Scope, and Technical Basis The flange design rules incorporated in the Code were based on a paper written in 1937 by Waters, Westrom, Rossheim, and Williams. These rules were subsequently published by Taylor Forge in 1937, and were incorporated into the Code in 1942. For all practical purposes they have been unchanged since that time. The Taylor Forge bulletin, frequently republished, is also still available, and is one of the most useful tools for flange analysis. The input and results for the FLANGE program are roughly modeled on the Taylor Forge flange design sheets. The flange analysis model assumes that the flange can be modeled as stiff elements (the flange and hub) and springs (the bolts and gaskets). The initial bolt loads compresses the gasket. This load needs to be high enough to seat (deform) the gasket, and needs to be high enough to seal even when pressure is applied. The pressure load adds to the bolt load and unloads the gasket. Analysis of a typical flange includes the following steps: 1

Identify operating conditions and materials. Determine the allowable stresses for the flange material and the bolting at both ambient and operating temperatures, from the Code tables of allowable stress.

2

Identify the gasket material and the flange facing type. Determine the effective width, the effective diameter of the gasket and the gasket factors from the Code charts (Tables 2-5.1 and 2-5.2).

3

Calculate the required area of the bolts, from the design pressure and the gasket information. Calculate the actual area of the bolts, and make sure it is greater than the required area. Based on the bolt areas and the allowable stresses, calculate the flange design bolt loads.

4

Calculate the bending moments on the flange. In each case the bending moment is the product of a load (pressure, gasket load, etc.) and the distance from the bolt circle to the point of application of the load. The final result is one bending moment for operating conditions and a second for gasket seating conditions.

The stresses on a given flange are determined entirely by the bending moment on the flange. All the loads on the flange produce bending in the same direction (i.e., counterclockwise) and this bending is resisted by the ring behavior of the flange, and in integral flanges by the reaction of the pipe. 5

Calculate the hub factors and other geometry factors for the flange based on the flange type (Code Figure 2-4). The factors are found in Code figures 2-7.1, 2-7.2, 2-7.3, 2-7.4, 2-7.5, and 2-7.6. Formulae are also given in the Code so that computer programs can consistently arrive at the answers that are normally selected from charts in the appendix. These formulae are implemented in the flange program.

6

Calculate the stress formula factors based on the geometry factors and the flange thickness.

7

Calculate the flange stresses using the stress formula factors and the bending moments. Compare these stresses to the allowable stresses for the flange material.

The form of the stress equations is: S = k(geometry) * M / t2 That is, a constant dependant on the flange geometry times the bending moment, divided by some thickness squared, either the thickness of the flange or the thickness of the hub. The calculation procedures and format of results in this program are similar to those given in "Modern Flange Design", Bulletin 503, Edition VII, published by Taylor Forge.


13-4

FLANGES

The FLANGE program includes the capability to analyze a given flange under the bolting loads imposed by a mating flange. The program also takes full account of corrosion allowance. You enter uncorroded thicknesses and diameters, which the program adjusts before performing the calculations. The program can treat corrosion in a special manner based on the input of a Yes/No question in the input. The program can also be used for two levels of flange design. The PARTIAL option forces the program to calculate the minimum flange thickness for a given geometry. The DESIGN option forces the program to select all of the relevant flange geometry including bolt circle, number of bolts, outside diameter, thickness, and hub geometry.

Figure A - Flange Program Geometry


Chapter 13 FLANGES

13-5

Discussion of Input Data Main Input Fields Flange Number Enter the flange ID number. It is recommended that the flange numbers start at 1 and increase sequentially. If this field is left blank PVElite will assume there is no data here to be analyzed. The only exception to this is the first element, if an analysis is attempted and the item number is blank, PVElite will assign a value of 1 to the item number.

Flange Designation Enter an alphanumeric tag for this flange. When performing a partial analysis, PVElite iterates for the required thickness of the flange. The final set of results you see is made using the final required thickness. If you would like to see the results using the input thickness, then enter a colon ":" as any character in the description. In both cases, PVElite will determine the required thickness. This entry is optional.

Flange Type Enter the flange type number for this flange. Flange types are: Integral Weld Neck Integral Slip On Integral Ring Loose Slip On Loose Ring Lap Joint Blind Reverse There are essentially only two categories of flanges for the purposes of analysis. These are integral type flanges, where the flange and the vessel to which it is attached behave as a unit, and loose types, where the flange and the vessel do not behave as a unit. Within these categories, however, there are several additional subdivisions.


13-6

FLANGES

Weld Neck Flanges - These have a hub that is butt welded to the vessel. Slip-on Flanges - These have hubs, and are normally analyzed as loose type flanges. To qualify as integral type flanges they require a penetration weld between the flange and the vessel. Ring Flanges - These do no have a hub, though they frequently have a weld at the back of the flange. They are normally analyzed as loose, but may be analyzed as integral if a penetration weld is used between the flange and the vessel. Lap Joint Flanges - These flanges may or may not have a hub, but they are completely disconnected from the vessel, bearing only on a vessel 'lap'. They are always analyzed as loose. Reverse Geometry Flange - Here the gasket seat is on the inside of the shell diameter. These use integral flange rules, which are suitably modified for the reversal of the bending moments. See Appendix 2-13. Loose Type Flanges - Especially lap joints, may be split. A split is used when it is required to have the flange completely removable from the vessel. If the flange is split into two pieces by a single split, the design moment for the flange is multiplied by 2.0. If the flange consists of two separate split rings, each ring shall be designed as if it were a solid flange (without splits) using 0.75 times the design moment. The pair of rings shall be assembled so that the splits in one ring shall be 90 deg. from the splits in the other. Flat Face Flanges with Full Face Gaskets - A special type of gasket geometry, which is not included in the Code sketches, or in the Code design rules, is the flange with a flat face and a gasket that extends from the ID of the flange to the OD, beyond the bolt circle. The gaskets used with this type of flange are usually quite soft. These flanges can be analyzed using the Taylor Forge calculation sheets.

Analysis Type Enter the analysis type for the computations to be performed on this flange. Analyze - For this analysis type, users must give the complete flange definition. The program will compute the resulting stresses. Partial - For this analysis type, all information except for the flange thickness must be specified. The program will select a flange thickness such that the resulting flange stress equals the allowable stress. Design - For this analysis type, only the flange diameter and thickness, gasket and flange face geometry, and gasket properties are specified. The program computes all other flange dimensions and stresses.

Print Final Results for the Given Thickness If the partial design option is chosen and this box is checked, the program will display the results using the given thickness. If this box is unchecked the results will be displayed using the calculated required thickness.

Design Pressure Enter the internal design pressure. If the value entered in this field is negative, it will be treated as external pressure.

Design Temperature Enter the design temperature for the flange. This temperature will be used to interpolate the material allowable tables and external pressure curves.

Flange/Bolt Material Specification Click the Material Database button to search for a material in the material database. Also, you can type the material name in this cell, and the system will retrieve the first material it finds with a matching name. Click the


Chapter 13 FLANGES

13-7

Material Edit Properties button to change the properties of the selected material. You can also create new materials by selecting the TOOLS/EDIT/ADD MATERIALS option on the MAIN MENU.

Allowable Stress at Design Temperature The program automatically fills in entry by entering a material specification.

CAUTION: You should verify your entry to assure conformance with the latest edition of the ASME Pressure Vessel Code Section II Part D.

Allowable Stress at Ambient Temperature The program automatically fills in entry by entering a material specification.

CAUTION: You should verify your entry to assure conformance with the latest edition of the ASME Pressure Vessel Code Section II Part D.

Flange Thickness Enter the flange thickness. The corrosion allowance will be subtracted from this value.

Corrosion Allowance Enter the corrosion allowance for this flange. The value entered here will be subtracted from the flange and hub thicknesses to obtain the thicknesses actually used in the computations.

Include Corrosion in Flange Thickness Calculations The flange thickness is used in several places throughout Appendix 2. The Code states that every dimension used should be corroded. In the flange stress calculations the flange thickness is used. However, some feel that the corrosion should not be taken off of the thickness for the stress calculations.

Flange ID Enter the inner diameter of the flange. For integral type flanges, this value will also be the inner pipe diameter. This value is refereed to as "B" in the ASME code. The corrosion allowance will be used to adjust this value - two times the corrosion allowance will be added to the uncorroded ID given by the user. For a blind flange this entry should be 0.

Flange OD Enter the outer diameter of the flange. This value is refereed to as "A" in the ASME code.

Enter Shell Material Select the shell material name. This is used for computing the longitudinal hub allowable stress for optional type flanges, which are analyzed as integral.


13-8

FLANGES

Flange Face Outer Diameter Enter the outer diameter of the flange face. The program uses the minimum of the flange face outer diameter and the gasket outer diameter to calculate the outside flange contact point, but uses the maximum in design when selecting the bolt circle. This is done so that the bolts do not interfere with the gasket. The program uses the maximum of the flange face ID and the gasket ID to calculate the inside contact point of the gasket.

Flange Face Inner Diameter Enter the inner diameter of the flange face. The program uses the maximum of the Flange Face ID and the Gasket ID to calculate the inner contact point of the gasket.

Gasket Outer Diameter Enter the outer diameter of the gasket. The program uses the minimum of the flange face outer diameter and the gasket outer diameter to calculate the outside flange contact point, but uses the maximum in design when selecting the bolt circle. This is done so that the bolts do not interfere with the gasket. The program uses the maximum of the flange face ID and the gasket ID to calculate the inside contact point of the gasket.

Gasket Inner Diameter Enter the inner diameter of the gasket. The program uses the maximum of the Flange Face ID and the Gasket ID to calculate the inner contact point of the gasket.

Hub Thickness, Small End Enter the thickness of the small end of the hub. This value is referred to as "g0" in the ASME code. The corrosion allowance will be subtracted from this value. For weld neck flange types, this is the thickness of the shell at the end of the flange. For slip on flange geometries, this is the thickness of the hub at the small end. For flange geometries without hubs, such as a blind flange, this thickness may be entered as zero.

Hub Thickness, Large End Enter the thickness of the large end of the hub. This value is referred to as "g1" in the ASME code. The corrosion allowance will be subtracted from this value. It is permissible for the hub thickness at the large end to equal the hub thickness at the small end. For flange geometries without hubs, such as a blind flange, this thickness may be entered as zero.

Hub Length Enter the hub length. This value is refereed to as "h" in the ASME code. For flange geometries without hubs, this length may be entered as zero. When analyzing an optional type flange that is welded at the hub end, the hub length should be the leg of the weld, and the thickness at the large end should include the thickness of the weld. When you analyze a flange with no hub, i.e. a ring flange, a lap joint flange, etc., you should enter zero for the hub length, the small end of the hub, and the large end of the hub. However, when you design as a loose flange a ring flange that has a fillet weld at the back, enter the size of a leg of the fillet weld as the large end of the hub. This will insure that the program designs the bolt circle far enough away from the back of the flange to get a wrench around the nuts.

Diameter of Bolt Circle Enter the diameter of the bolt circle of the flange.


Chapter 13 FLANGES

13-9

Nominal Bolt Diameter Enter the nominal bolt diameter. The tables of bolt diameter included in the program range from 0.5 to 4.0 inches. If you have bolts that are larger or smaller than this value, enter the nominal size in this field, and also enter the root area of one bolt in the Thread Series cell.

Thread Series The following bolt thread series tables are available: TEMA Bolt Table UNC Bolt Table User specified root area of a single bolt TEMA Metric Bolt Table British, BS 3643 Metric Bolt Table Irrespective of the table used, the values will be converted back to the user selected units. TEMA threads are National Coarse series below 1 inch and 8 pitch thread series for 1 inch and above bolt nominal diameter. The UNC threads available are the standard threads.

Number of Bolts Enter the number of bolts to be used in the flange analysis.

Compute Full Flange Design Bolt Load (S*Ab) ? If this box is un-checked then flange design bolt load for the gasket seating condition is computed as: W = Sa * ( Am + Ab ) / 2 otherwise it is computed as follows per note 2 of App. 2-5 of the ASME code: W = Sa * Ab this equation can be used when additional safety against abuse is desired. Where, Sa = bolt ambient allowable stress Am = total required bolt area Ab = total available bolt area


13-10

FLANGES

Table 2-5.1 - Gasket Materials and Contact Facings Gasket Material

Gasket Factor m

Self energizing Types, including metallic and elastomer O 0.00 ring

Seating Stress y

Facing Column

0

II

Flat Elastomers Below 75A Shore Durometer

0.50

0

II

75A Shore Durometer or higher

1.00

200

II

1/8 inch thick

2.00

1600

II

1/16 inch thick

2.75

3700

II

1/32 inch thick

3.50

6500

II

Elastomer with cotton fabric insert

1.25

400

II

3 ply

2.25

2200

II

2 ply

2.50

2900

II

1 ply

2.75

3700

II

Vegetable Fiber

1.75

1100

II

Carbon Steel

2.50

10000

II

Stainless Steel or Monel

3.00

10000

II

Soft aluminum

2.50

2900

II

Soft copper or brass

2.75

3700

II

Iron or soft steel

3.00

4500

II

Monel or 4-6% Chrome

3.25

5500

II

Stainless Steel

3.50

6500

II

Flat asbestos with suitable binder

Elastomer with asbestos fabric insert

Spiral-wound metal, asbestos filled

Corrugated metal, asbestos filled or Corrugated metal jacketed, asbestos filled


Chapter 13 FLANGES

Gasket Material

13-11

Gasket Factor m

Seating Stress y

Facing Column

Soft aluminum

2.75

3700

II


3.00

4500

II

Iron or soft steel

3.25

5500

II


3.50

6500

II

Stainless Steel

3.75

7600

II

Soft aluminum

3.25

5500

II


3.50

6500

II

Iron or soft steel

3.75

7600

II

Monel

3.50

8000

II

4-6% Chrome

3.75

9000

II

Stainless Steel

3.75

9000

II

Soft aluminum

3.25

5500

II


3.50

6500

II

Iron or soft steel

3.75

7600

II


3.75

9000

II

Stainless Steel

4.25

10100

II

Soft aluminum

4.00

8800

I


4.75

13000

I

Iron or soft steel

5.50

18000

I


6.00

21800

I

Stainless Steel

6.50

26000

I

Corrugated metal, not filled

Flat metal jacketed, asbestos filled

Grooved metal

Solid flat metal

Ring Joint


13-12

FLANGES

Gasket Material

Gasket Factor m

Seating Stress y

Facing Column

Iron or soft steel

5.50

18000

I


6.00

21800

I

Stainless Steel

6.50

26000

I

Flange Face Facing Sketch Using Table 2-5.2 of the ASME code, select the facing sketch number according to the following correlations:

Table 2-5.2 Facing Sketch Descriptions FACING SKETCH

DESCRIPTION

1a

flat finish faces

1b

serrated finish faces

1c

raised nubbin-flat finish

1d

raised nubbin-serrated finish

2

1/64 inch nubbin

3

1/64 inch nubbin both sides

4

large serrations, one side

5

large serrations, both sides

6

metallic O-ring type gasket

Gasket Thickness Enter the gasket thickness. This value is only required for facing sketches 1c and 1d (PVElite equivalents 3 and 4).

Nubbin Width If applicable, enter the nubbin width. This value is only required for facing sketches 1c, 1d, 2 and 6 (PVElite equivalents 3, 4, 5, and 9). Note that for sketch 9 this is not a nubbin width, but the contact width of the metallic ring.

Full Face Gasket Options ASME Sec. VIII Div. 1 does not cover the design of flanges for which the gasket extends beyond the bolt circle diameter. A typically used method for the design of these types of flanges is found in the Taylor Forge Flange Design Bulletin. This method is implemented in the program. Gaskets for Full Face Flanges are usually of soft materials such as rubber or an elastomer, so that the bolt stresses do not go too high during gasket seating. The program adjusts the flange analysis and the design formulae to account for the full face gasket. There are 3 Full Face Gasket Flange options:


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13-13

Program Selects: Instructs the program to automatically make the determination if this is a full face gasket flange, depending upon the input. If the gasket ID and OD matches with Flange ID and OD dimensions respectively (except for a blind flange) then it is determined to be a full face flange. See the figure below.

Full Face Gasket: Indicates to the program that this is a full face gasket flange. Use this option when the gasket ID or OD does not match the flange ID/OD dimensions, but the gasket extends beyond the bolt circle diameter. See the figure below:

Not a Full Face: Indicates to the program that this is not a full face gasket flange.

Is There a Partition Gasket? If your exchanger geometry has a pass partition gasket, check this entry. PVElite will then prompt for the overall length and width of the gasket.

Specify External Loads In order for leakage computations to be performed, the external loads acting on the flange must be specified. By checking this field, an input form displays that allows entry of the loading data. Loading data of this nature would typically come from a pipe stress analysis program, such as CAESAR II. Flanges are frequently subject to external forces and moments, in addition to internal pressure. The program calculates a roughly equivalent pressure for flanges loaded axially and/or in bending using the following formula:


13-14

FLANGES

Peq = Pdes + 4 * F / 3.14 G2 + 16 * M / 3.14 * G3 Where: Peq = Equivalent pressure, psi Pdes = Design pressure, psi F = Axial force, lbs M = Bending moment, in-lbs G = Diameter of gasket load reaction, in. The program then uses the equivalent pressure as the design pressure.

Mating Flange Loads If loads from the mating flange are to be considered, check this field. A pop-up spreadsheet will appear for additional data entry. This auxiliary bolt loading will only be used if it is greater then the standard bolt loads computed using the ASME formulas.

WARNING: The use of mating flange values for bolt design calculations will result in incorrect MAWP calculations. You probably don't want to calculate MAWP based on the mating flange values, but rather based on the values developed by this flange at a given pressure. Also you definitely don't want to do "design" when you have a mating flange, since the program selects a different bolt circle, etc. than the one chosen for the other flange. You can however, do a partial thickness design.

Compute Thickness Based on Flange Rigidity? Appendix 2 contains equations that attempt to determine whether or not a given flange geometry will leak. If the computed rigidity factor is > 1.0, then leakage is predicted. Note: Appendix 2 calculations are mandatory as of Addenda-2005 and flange designs must satisfy these calculations. These rigidity factor calculations are not mandatory for Pre-1999 addenda users By enabling this box, users can instruct the program to compute thickness, such that the corresponding rigidity index is 1.0.

Pop-Up Input Fields Number of Splits in the Ring Enter the number of splits in the ring, if any, for loose type flanges. This value must be either 0, 1, or 2. Typically split flanges are ring-type flanges. A split is used when it is required to have the flange completely removable from the vessel. If the flange is split into two pieces by a single split, the design moment for the flange is multiplied by 2.0. If the flange consists of two separate split rings, each ring shall be designed as if it were a solid flange - without splits) using 0.75 times the design moment. The pair of rings shall be assembled so that the splits in one ring shall be 90º deg. from the splits in the other.


Chapter 13 FLANGES

13-15

Weld Leg at Back of Ring Enter the length of the weld leg at the back of the ring. This value is added to the inside diameter during the design of ring type flanges to determine the minimum bolt circle when the design option is turned on. If you are performing a partial or regular analysis, PVElite will check to see if there is interference between the wrench and the weld. PVElite will print a brief message letting you know there is a potential problem.

Lap Joint Contact ID Enter the inner diameter of the flange/joint contact surface. For more information see Figure B.

Lap Joint Contact OD Enter the outer diameter of the flange/joint contact surface. For more information see Figure B.

Figure B - Lap Joint Flange Geometry

TEMA Channel Cover This cell indicates whether or not the current flange is a TEMA channel cover. A separate thickness and MAWP are computed for channel covers, as well as the deflection.

Diameter of the Load Reaction (Long Span) Enter the distance to the center of the gasket on the long side of the flange. This diameter is used to calculate the non- circular flange correction factor for ASME blind flanges. This factor is discussed in paragraph UG-34 of the ASME code.

Diameter of the Load Reaction (Short Span) Enter the distance to the center of the gasket on the short side of the flange. This diameter is used to calculate the non- circular flange correction factor for ASME blind flanges. This factor is discussed in paragraph UG-34 of the ASME code.


13-16

FLANGES

Allowed Channel Cover Deflection For TEMA channel covers, enter the magnitude of the allowed deflection at the center of the cover. This value will be used in computing the channel cover thickness and MAWP, even if it is larger than the allowed deflection. However, a warning message will be printed stating this problem exists.

Perimeter Along the Center of the Bolt Holes (L) Enter the perimeter of the bolted head measured along the centerline of the bolts. This value (L) is needed for both non-circular and circular geometries. For a circular head, enter the value of (3.14159 * bolt circular diameter). For non-circular heads this value will have to be computed and entered in.

Length of Partition Gasket This is the cumulative length of all the heat exchanger pass partition gaskets associated with this flange.

Width of the Pass Partition Gasket Enter the width of the pass partition gasket. Using the partition gasket properties entered, and the known width, PVElite will compute the effective seating width and compute the gasket loads contributed by the partition gasket.

Partition Gasket Factor M Enter the partition gasket factor M.

Partition Gasket Design Seating Stress Y: Enter the partition gasket design seating stress Y.

Partition Gasket Flange Facing Sketch: Enter the partition gasket flange face facing sketch.

Partition Gasket Column for Gasket Seating Enter the partition gasket column for gasket seating.

Partition Gasket Thickness Enter the thickness of the partition gasket. This value is only required for facing sketches 1c and 1d.

Partition Gasket Nubbin Width If applicable, enter the nubbin width for the pass partition gasket. This value is only required for facing sketches 1c, 1d, 2 and 6. Note that for sketch 9 this is not a nubbin width, but the contact width of the metallic ring.

Node Number (Optional) Enter the node number of this flange. This entry represents the node point in a stress analysis model from which the loads are obtained.


Chapter 13 FLANGES

Axial Force Enter the magnitude of the external axial force, which acts, on this flange.

Bending Moment Enter the magnitude of the external bending moment, which acts, on this flange.

Mating Flange Bolt Load, Operating Enter the bolt load from the mating flange in the operating case.

Mating Flange Bolt Load, Seating Enter the bolt load from the mating flange for seating conditions.

Mating Flange Design Bolt Load Enter the design bolt load for the mating flange.


13-17

13-18

FLANGES

Discussion of Results Flanges with Different Bending Moments: The flange design moments differ from the norm for external pressure, reverse flanges, and flat flanges. Under external pressure only the end load and flange pressure are included in the design, and their sense is reversed. For reverse flanges all the moments are present, but the moment arm hd is negative, making MD negative. The load HT is negative, and the moment arm ht may be either positive or negative. The absolute value of the moment is used in the calculations. For flat faced flanges an alternate value of hg (h''g) is used to calculate a reverse moment at the bolt circle. No calculations for seating conditions for full faced flanges are required.

Blind Flanges and Channel Covers: The ASME Code formula for a circular blind flange is: t = d * SQRT( C * P / S * E + 1.9 * W * Hg / S * E * d3 ) The first term in this formula is the bending of a flat plate under pressure. The second term is the bending of the plate due to an edge moment. The stress is limited to 1.5 times the allowable stress, but the 1.5 factor is already built into the equation. For seating conditions the first term is zero - the thickness of the flange depends only on the edge bending. For non-circular blind flanges the term Z is added to the first term in the square root. Once again, Z is a simple function of the ratio of the large dimension to the small dimension of the flange. It is interesting to note that the Code covers non-circular blind flanges, but no other type of non-circular flange (not even in the rectangular vessel appendix). Channel covers designed to TEMA must meet at least the minimum thickness requirements of the Code. In addition, if there is a pass partition groove, the cover deflection is limited. The formula for flange deflection limitation is found in paragraph 9.21 of TEMA. The deflection is, of course, a function of t3 and G3. Thus, a very small increase in flange thickness will decrease the deflection significantly. The Seventh Edition of TEMA also gives recommended deflections as a function of flange size. The previous editions hid the actual deflection you were working toward in a thickness equation.


Chapter 13 FLANGES

13-19

Allowable Flange Stresses: Allowable flange stresses are based on the ASME Code Allowable Stress for the flange material at the Ambient and Operating design temperatures. In the case of bending stresses, these allowable are multiplied by 1.5. This takes into account the higher maximum strain required to yield a section in bending versus pure tension. The stresses calculated and the allowable stresses are as follows: Operating

Ambient

Longitudinal Hub Stress (bending)

1.5 x Sfo

1.5 x Sfa

Radial Flange Stress

1.0 x Sfo

1.0 x Sfa

Tangential Flange Stress

1.0 x Sfo

1.0 x Sfa

Maximum Average Stress

1.0 x Sfo

1.0 x Sfa

Stress in Bolts

1.0 x Sbo

1.0 x Sba

Stress in Reverse Flanges

1.0 x Sfo

1.0 x Sfa

Stress in Full Faced Gasket Flanges

1.0 x Sfo

1.0 x Sfa

Where:

Sfo

=

ASME Code Allowable Stress for flange material at operating temperature.

Sfa

=

ASME Code Allowable Stress for flange material at ambient temperature.

Sbo

=

ASME Code Allowable Stress for flange material at ambient temperature.

Sba

=

ASME Code Allowable Stress for bolt material at ambient temperature.


13-20

FLANGES

Maximum Allowable Working Pressure: The following graph shows conceptually how the program extrapolates for the Maximum Allowable Working Pressure:

1. For Operating Pressure MAWP The program calculates the stresses at the pressure given by the user. The program calculates the slope between the stress at zero pressure and the stress at the given pressure The program extrapolates the slope out to the point where the stress is equal to the allowable stress. The pressure at this point is the maximum allowable working pressure. 2. For Gasket Seating MAWP Note that at low pressures the stress due to gasket seating is not a function of the design pressure. At higher pressures the stress is a function of pressure, and the MAWP can be calculated as described above, except that the extrapolation is from the point where pressure comes into the calculation of the seating stress. The program calculates the Gasket Seating MAWP and Operating MAWP based on the input geometry and pressure. In theory both MAWPs should be independent of the input pressure. However, because of the extrapolation algorithm, the estimate of the MAWP may depend on the pressure slightly (when the pressure is very small). Please note that in Partial or Design mode, the program will calculate MAWP based on the required flange thickness.

Flange Rigidity Calculations Appendix 2 also contains equations that attempt to determine whether or not a given flange geometry will leak. The cases considered are ambient and operating. If the computed rigidity factor is > 1.0, then leakage is predicted.


Chapter 13 FLANGES

13-21

Note: Appendix 2 calculations are mandatory as of Addenda-2005.

Flange Design The geometry defined by the user is the basis for the design performed by the program. Specifically, the inside diameter, materials, pressure, gasket geometry and gasket properties remain fixed throughout the design. Beginning from this point, the program uses the following approach to design the rest of the flange: 1

For slip-on type flanges, calculate the small end of the hub equal to roughly the thickness required for the design pressure

2

For weld neck, slip-on, and reverse flanges, calculate the large end of the hub as the small end of the hub plus 1/16th (for small end thickness less than one inch) or 1/8th (for small end thickness greater than one inch). Then calculate a hub length equal to the small end thickness plus the minimum slope (3:1) for the hub. The effect of these choices is to design a small hub when compared with standardized flanges. This has the additional effect of keeping the moment arms and diameters (of the bolt circle and flange OD) small, and keeping the flange light. Finally, the selection of a small hub keeps the amount of machining required for the flange to a minimum.

3

Select a preliminary number of bolts. This is a multiple of four based on the diameter of the flange. The algorithm chosen tends to select more and smaller bolts than would be found on standard flanges. This also has the effect of minimizing the flange outside diameter and the weight of the flange.

4

Select a bolt size that will give the required bolt area for this number of bolts.

5

Using this bolt size, calculate a final number of bolts based on:

The area required divided by the area available per bolt -ORThe maximum allowed spacing between bolts of this size. 6

Using this number of bolts, calculate the bolt circle based on:

The OD of the hub plus the minimum ID spacing of the bolt -ORThe OD of the gasket face plus the actual size of the bolt -ORThe minimum spacing distance between the bolts -ORFor reverse flanges, the vessel OD plus the bolt ID spacing. 7

Calculate the outside diameter of the flange based on the bolt circle plus the minimum edge spacing for the bolt size chosen.

8

For flanges with full face gaskets, adjust the gasket and face outside diameter for the values chosen, and recalculate the moment arms for the flange.

9

Finally (and this step also applies to partial design of the flange), select a thickness for the flange and calculate the stresses. If the stress is not equal to the allowable, adjust the thickness based on the difference between the actual and allowable stresses, and then repeat the stress calculation. This process continues until the actual stress for one of the stress components is equal to the allowable stress.


13-22

FLANGES



CH AP TER

1 4

Chapter 14 CONICAL SECTIONS In This Chapter Introduction ................................................................................ 14-2 Purpose, Scope and Technical Basis........................................... 14-3 Discussion of Input Data............................................................. 14-4 Discussion of Results.................................................................. 14-10 Example ...................................................................................... 14-12


14-2

CONICAL SECTIONS

Introduction CONICAL SECTIONS performs internal and external pressure design of conical sections and stiffening rings using the ASME Code, Section VIII, Division 1 rules, Edition 2004 A-05.


Chapter 14 CONICAL SECTIONS

14-3

Purpose, Scope and Technical Basis CONICAL SECTIONS calculates the required thickness and Maximum Allowable Working Pressure for conical shells and sections under either internal or external pressure. The program is based on the ASME Boiler and Pressure Vessel Code, Section VIII, Division 1, 2001, A-2003. Specifically, the program is based on the rules in paragraphs UG-32, UG-33, and Appendix 1, Sections 1-5, and 1-7. The program calculates required thickness for the cone under both internal and external pressure. Also calculated is the required thickness of the attached cylinders under either internal or external pressure. Calculations for the required thickness of a transition knuckle are included. The required area of reinforcement and actual reinforcement available are calculated for both internal and external pressures. Reinforcement is limited to the area available in the shell sections plus simple stiffening rings. CONICAL SECTIONS takes full account of corrosion allowance. You enter actual thickness and corrosion allowance, and the program adjusts thicknesses and diameters when making calculations for the corroded condition.

Figure A - Conical Section Geometry


14-4

CONICAL SECTIONS

Discussion of Input Data Main Input Fields Cone Number Enter an ID number for the cone. This may be the item number on the drawing, or numbers that start at 1 and increase sequentially.

Cone Description Enter an alphanumeric description for this item. This entry is optional.

Internal Design Pressure You may analyze both internal and external pressure at the same time, since the two cases are analyzed and reported separately. Enter zero for internal pressure if you only wish to analyze the external pressure case.

Internal Design Temperature Enter the temperature associated with the internal design pressure. PVElite will automatically update materials properties for BUILT-IN materials when you change the design temperature. If you entered the allowable stresses by hand, you are responsible to update them for the given temperature.

External Design Pressure Enter the design pressure for external pressure analysis. This should be a positive value, i.e. 14.7 psia. If you enter a zero in this field the program will not perform external pressure calculations.

External Design Temperature Enter the temperature associated with the external design pressure. PVElite will automatically update materials properties for external pressure calculations when you change the design temperature. The design external pressure at this temperature is a completely different design case than the internal pressure case. Therefore this temperature may be different than the temperature for internal pressure. Many external pressure charts have both lower and upper limits on temperature. If your design temperature is below the lower limit, use the lower limit as your entry to the program. If your temperature is above the upper limit the component may not be designed for vacuum conditions.

Cone\Cylinder\Ring\Knuckle Material Name Enter the ASME code material specification as it appears in the ASME material allowable tables. Alternatively, you can select the material from the Material Database by pressing the Database button while the cursor is in this field. If a material is not contained in the database, you can select its specification and properties can be entered manually by selecting TOOLS/EDIT/ADD MATERIALS, from the Main Menu.

Material Allowable Stress, Design Temperature The program automatically fills in entry by entering a material specification. When you change the internal design temperature, or the thickness of the shell, the program will automatically update this field, but only for BUILT-IN



14-5

materials. If you enter the allowable stress by hand, be sure to verify your entry to assure conformance with the latest edition of the ASME Pressure Vessel Code Section II Part D at the design temperature.

Material Allowable Stress, Ambient Temperature The program automatically fills in entry by entering a material specification. When you change the internal design temperature, or the thickness of the shell, the program will automatically update this field, but only for BUILT-IN materials. If you enter the allowable stress by hand, be sure to verify your entry to assure conformance with the latest edition of the ASME Pressure Vessel Code Section II Part D at the ambient temperature.

Cone Joint Efficiency Enter the efficiency of the welded joint for shell sections with welded seams. This will be the efficiency of the longitudinal seam in a cylindrical shell or any seam in a spherical shell. Elliptical and torispherical heads are typically seamless but may require a stress reduction, which may be entered as a joint efficiency. Please be sure to refer to Section VIII, Div. 1, Table UW-12 for help in determining this value.

Cone Actual Thickness Enter the minimum thickness of the actual plate or pipe used to build the vessel, or the minimum thickness measured for an existing vessel. Many pipe materials have a minimum specified wall thickness, which is 87.5% of the nominal wall thickness. You should enter the minimum thickness.

Cone Corrosion Allowance Enter the corrosion allowance. The program adjusts both the actual thickness and the inside diameter for the corrosion allowance you enter.

Cone Diameter Basis (ID, OD) Select the diameter basis, ID for the inside diameter and OD for the outside diameter. Note that this diameter basis is also used for the cylinder at the small end of the cone, and the cylinder at the large end of the cone.

Cone Diameter at Small End Enter the diameter of the cone at the small end. This diameter is also used for the cylinder at the small end of the cone. Note that this should not be the diameter at the point where a knuckle or flare intersects the conical section, but at the point where the knuckle or flare intersects the cylindrical section. The program will calculate the other diameter.

Cone Diameter at Large End Enter the diameter of the cone at the large end. This diameter is also used for the cylinder at the large end of the cone. Note that this should not be the diameter at the point where a knuckle or flare intersects the conical section, but at the point where the knuckle or flare intersects the cylindrical section. The program will calculate the other diameter.


14-6

CONICAL SECTIONS

Cone Half Apex Angle For internal pressure calculations the half apex angle should not be greater than 30 degrees, though the program will give results for up to 60 degrees. For external pressure calculations it must not be greater than 60 degrees. If you enter a zero for the angle, PVElite will calculate an angle based on the cone diameters and length.

Cone Axial Length Enter the length of the cone along the axis of the vessel. The program will calculate the effective length of the cone for internal and external pressure calculations.

Are There Axial Forces on the Cone? If there are axial forces on the cone, check this field. Examples of axial forces would include weight loads, from external attachments, and possibly thermal loads. The axial force due to internal or external pressure are already taken into account by the program. Note that in general loads causing compression are significant for the external pressure case, while loads causing tension are significant for the internal pressure case.

Small Cylinder Joint Efficiency Enter the efficiency of the welded joint for shell sections with welded seams. This will be the efficiency of the longitudinal seam in a cylindrical shell or any seam in a spherical shell. Elliptical and torispherical heads are typically seamless but may require a stress reduction, which may be entered as a joint efficiency. Please be sure to refer to Section VIII, Div. 1, Table UW-12 for help in determining this value.

Small Cylinder Actual Thickness Enter the minimum thickness of the actual plate or pipe used to build the vessel, or the minimum thickness measured for an existing vessel. Many pipe materials have a minimum specified wall thickness, which is 87.5% of the nominal wall thickness. You should enter the minimum thickness.

Small Cylinder Corrosion Allowance Enter the corrosion allowance. The program adjusts both the actual thickness and the inside diameter for the corrosion allowance you enter.

Small Cylinder Axial Length Enter the length of the cylinder along the axis of the vessel. This value is not used in internal pressure calculations, but is required for external pressure calculations.

Small End Reinforcing (None, Bar, Section, Knuckle, Knuckle-Bar, Knuckle-Section) Select the type of reinforcing bar for the small end:



NONE

= no reinforcement at the small end and no knuckle.

BAR

= reinforcing bar at small end (width and thickness).

SECTION

= reinforcing beam section at small end (inertia, area, and depth of beam).

KNUCKLE

= toroidal knuckle at small end ( radius and thickness ).

KNUCKLE and BAR RING

= toroidal knuckle and a reinforcing bar at small end.

KNUCKLE and SECTION

= toroidal knuckle and a reinforcing beam section at small end.

14-7

Note that whichever option is chosen you will be prompted to enter a reinforcing material. If there is no reinforcing material, enter the small end shell material. The values for the elasticity and allowable stress values will be needed for the area and inertia calculations depending on the value of Delta.

Large Cylinder Joint Efficiency Enter the efficiency of the welded joint for shell sections with welded seams. This will be the efficiency of the longitudinal seam in a cylindrical shell or any seam in a spherical shell. Elliptical and torispherical heads are typically seamless but may require a stress reduction, which may be entered as a joint efficiency. Please be sure to refer to Section VIII, Div. 1, Table UW-12 for help in determining this value.

Large Cylinder Actual Thickness Enter the minimum thickness of the actual plate or pipe used to build the vessel, or the minimum thickness measured for an existing vessel. Many pipe materials have a minimum specified wall thickness, which is 87.5% of the nominal wall thickness. You should enter the minimum thickness.

Large Cylinder Corrosion Allowance Enter the corrosion allowance. The program adjusts both the actual thickness and the inside diameter for the corrosion allowance you enter.

Large Cylinder Axial Length Enter the length of the cylinder along the axis of the vessel. This value is not used in internal pressure calculations, but is required for external pressure calculations.

Large End Reinforcing (None, Bar, Section, Knuckle, Knuckle-Bar, Knuckle-Section) Select the type of reinforcing bar for the large end:


14-8

CONICAL SECTIONS

NONE

=

no reinforcement at the large end and no knuckle.

BAR

=

reinforcing bar at large end (width and thickness).

SECTION

=

reinforcing beam section at large end (inertia, area, and depth of beam).

KNUCKLE

=

toroidal knuckle at large end ( radius and thickness ).

KNUCKLE and BAR RING

=

toroidal knuckle and a reinforcing bar at large end.

KNUCKLE and SECTION

=

toroidal knuckle and a reinforcing beam section at large end.

Note that whichever option is chosen you will be prompted to enter a reinforcing material. If there is no reinforcing material, enter the large end shell material. The values for the elasticity and allowable stress values will be needed for the area and inertia calculations depending on the value of Delta.

Pop-Up Input Fields Take Cone as Lines of Support for External Pressure? The ASME Code allows you to take the intersections of the cone and the two cylinders as lines of support for external pressure, provided that the moment of inertia and area of reinforcement requirements of Appendix 1-8 are satisfied. Normally it is preferable to take the cone as lines of support, since the equivalent length of the large cylinder/ cone/small cylinder combination may easily result in low allowable external pressures. However, the moment of inertia is very easy to be less than the required for knuckle-to-cylinder junction — because the shell/knuckle/cone is usually so close to the resulting neutral axis. Starting from CODECALC version 5.6, the moment of inertia with the knuckle is calculated, following the procedure of code example L-3.3.

Total Axial Force on Large End for Internal Pressure Case Enter the axial force, not the force per unit circumferences as used by the Code (f1, f2). The program calculates the force per unit circumference before performing the calculation. Note that we have formulated the calculations so that a positive (tensile) axial force adds to the tension due to internal pressure, while a negative (compressive) axial force subtracts from the tension due to internal pressure.

Total Axial Force on Large End for External Pressure Case Enter the axial force, not the force per unit circumferences as used by the Code (f1, f2). The program calculates the force per unit circumference before performing the calculation. Note that we have formulated the calculations so that a negative (compressive) axial force adds to the compression due to external pressure, while a positive (tensile) axial force subtracts from the compression due to external pressure.

Total Axial Force on Small End for Internal Pressure Case Enter the axial force, not the force per unit circumferences as used by the Code (f1, f2). The program calculates the force per unit circumference before performing the calculation. Note that we have formulated the calculations so that a positive (tensile) axial force adds to the tension due to internal pressure, while a negative (compressive) axial force subtracts from the tension due to internal pressure.

Total Axial Force on Small End for External Pressure Case Enter the axial force, not the force per unit circumferences as used by the Code (f1, f2). The program calculates the force per unit circumference before performing the calculation. Note that we have formulated the calculations so that a negative (compressive) axial force adds to the compression due to external pressure, while a positive (tensile) axial force subtracts from the compression due to external pressure.



14-9

Location of Reinforcing Ring (Shell, Cone) Enter the location of the reinforcing bar: SHELL

=

welded to the shell (cylinder).

CONE

=

welded to the cone

Radial Width of Reinforcing Ring Enter the width of the reinforcing bar. You can also think of this as the projection of the bar out from the vessel OD. For example, a donut shaped plate 10 inches by 1 inch has a radial width of 10.

Axial Thickness of Reinforcing Ring Enter the thickness of the reinforcing bar. For example, a donut shaped plate 10 inches by 1 inch has an axial thickness of 1.

Moment of Inertia of Reinforcing Section Enter the moment of inertia of the beam section (I, T, etc.) used to reinforce the cone/cylinder junction. This can usually be found in the 'Manual of Steel Construction' for common beam sections.

Cross Sectional Area of Reinforcing Section Enter the cross sectional area of the beam section (I, T, etc.) used to reinforce the cone/cylinder junction. This can usually be found in the 'Manual of Steel Construction' for common beam sections.

Distance to Centroid of Reinforcing Section Enter the distance to the centroid of the beam section ( I, T, etc) used to reinforce the cone/cylinder junction. This can usually be found in the 'Manual of Steel Construction' for common beam sections.

Knuckle Bend Radius, Large End Enter the bend radius of the toroidal knuckle at the large end. Note that the Code requires this radius to be no less than 6% of the outside diameter of the head, or less than three times the knuckle thickness (UG-31, (h)).

Knuckle Thickness, Large End Enter the minimum thickness after forming of the toroidal knuckle at the large end.

Knuckle Bend Radius, Small End Enter the bend radius of the toroidal knuckle at the large end. Note that the Code requires this radius to be no less than 6% of the outside diameter of the head, or less than three times the knuckle thickness (UG-31, (h)).

Knuckle Thickness, Small End Enter the minimum thickness after forming of the toroidal knuckle at the large end.


14-10

CONICAL SECTIONS

Discussion of Results Internal Pressure Results The first section of results shows the required thicknesses and Maximum Allowable Working Pressures for the cone and for the upper and lower cylinders under internal pressure. Note that this section is shown even when the internal design pressure is zero: the required thicknesses will be zero, but the Maximum Allowable Working Pressures will be meaningful. Next the program summarizes these internal pressure results, adding the corrosion allowances as necessary.

External Pressure Results The External Pressure module calculates materials properties and required thicknesses under external pressure. Because the program uses Young's modulus values in both the internal and external reinforcement calculation, this module is called even when the external design pressure is zero. However, in this case the required thickness and Maximum Allowable Working Pressure calculations for external pressure are skipped. The required thickness under external pressure is calculated using the interactive method outlined in Paragraph UG33 of the ASME Code. The effective length for toriconical sections is adjusted to include a fraction of the knuckle in the design length.

Reinforcement Calculations Under Internal Pressure The program calculates the required reinforcement for the cone/cylinder junctions at both the large and the small ends. This calculation is performed whenever the internal pressure is greater than zero, and the reinforcing material is defined. If a knuckle is specified instead of a reinforcing ring, the knuckle calculation will be performed and the required area calculation will not. When a knuckle calculation is performed, the program calculates both the required thickness and the maximum allowable working pressure for the toroidal portion of the knuckle, using the rules in Appendix 1-4(d). When there is no knuckle, the program calculates the required area of reinforcement at the intersection of the cylinder and the two cones. Cones are required to have reinforcement at the large and small ends under internal pressure (Appendix 1-5) because of the tendency of the cone/cylinder junction to buckle under the radial load developed in the cone. The Code calculates the maximum angle below which buckling will not occur as a function of the design pressure and allowable stress. This ratio is used because it is a pretty good indication of the diameter thickness ratio for the cylinder, and takes into account the strength of the material. This approach has the odd effect that when you increase the allowable stress you decrease the allowable cone angle. However, you will normally find that for a given thickness this effect is offset by the increase of area available in the cone for reinforcement. Given that reinforcement is required, the area required is a function of the pressure and the square of the radius. Area available in the shell within one decay length may be included in the area available for stiffening.



14-11

PVElite will set the area required in the reinforcing ring to zero if either the allowed apex angle is higher than the actual apex angle or the area available in the shell is greater than the area required.

Reinforcement Calculations Under External Pressure The program calculates the required reinforcement and moment of inertia for the cone/cylinder junctions at both the large and the small ends. This calculation is performed whenever the external pressure is greater than zero, the cone is taken as a line of support and the reinforcing material is defined. If a knuckle is specified instead of a reinforcing ring, the knuckle calculation will be performed and the area of reinforcement calculation will not. If the user specifies that the cone/cylinder junctions are not to be taken as a line of support, then the area of reinforcement and moment of inertia calculations will not be performed. Cones are required to have reinforcement at the large and small ends under external pressure (Appendix 1-7) because of the tendency to buckle under axial external loads. At both the large and small ends there are requirements for the area of reinforcement and moment of inertia of the reinforcement. The area of reinforcement is based on considerations similar to those described for internal pressure. The required moment of inertia of the reinforcement is a function of the strain in the ring at the cone/shell junction, which is in turn calculated using the Code materials chart from the stress in the ring. See the comments on stiffening rings in the external pressure section for further insight. The maximum apex angle is taken from Tables 1-8.1 in Appendix 1 of the ASME Code. The program calculates the ratio P/SE. Note that this angle applies only to the large end of the cone - the small end always requires at least a little reinforcement. The area required in the reinforcing ring will be set to zero if either the cone angle is less than the maximum angle (large end only), or the area of reinforcement available in the shell is greater than the area required.


14-12

CONICAL SECTIONS



CH AP TER

1 5

Chapter 15 FLOATING HEADS In This Chapter Introduction ................................................................................ 15-2 Purpose, Scope and Technical Basis........................................... 15-3 Discussion of Input Data............................................................. 15-4 Discussion of Results.................................................................. 15-14 Example ...................................................................................... 15-16


15-2

FLOATING HEADS

Introduction FLOATING HEADS performs internal and external pressure design of spherically dished covers (bolted heads) using ASME Code, Section VIII, Division 1 rules Edition 2004 A-05.


Chapter 15 FLOATING HEADS

15-3

Purpose, Scope and Technical Basis The FLOATING HEAD program calculates the required thickness of spherically dished covers (bolted heads) according to the ASME Code, Section VIII, Division 1 analysis rules found in Appendix 1, Paragraph 1-6. A more detailed analysis of bolted dished heads is included, based on Soehren's analysis, "The Design of Floating heads for Heat-Exchangers", ASME 57-A-7-47. The more detailed analysis may be used for the design of floating heads, as specifically mentioned in the ASME Code, Paragraph 1-6 (h). The program calculates required thickness for the dished part of the head under both internal and external pressure. Also calculated are the required thickness of the flange and the backing ring. Three types of heads as defined in the Code and shown in Figure A are included. Soehren's analysis applies only to the most common type of head, type d.

Figure A - Floating Head Program Geometry


15-4

FLOATING HEADS

Discussion of Input Data Main Input Fields Floating Head Identification Number Enter the floating head ID number. It is recommended that the floating head numbers start at 1 and increase sequentially, but you may also enter some other meaningful number. This field is required, since the program uses this field to determine if a floating head has been defined.

Floating Head Description Enter an alphanumeric tag for this floating head. This entry is optional.

Floating Head Type (b, c, d) Enter the type of floating head or spherically dished cover, which you are analyzing. Refer to Figure A. b

=

solid thick head, spherically dished.

c

=

thin dished head, continuous across flange face.

d

=

spherical cap welded to flange ID.

Type d is the most common type of head used for heat exchanger floating heads.

Tube Side (Internal) Design Pressure Enter the internal pressure, which is the pressure on the concave side of the head, and is also the tubeside pressure for heat exchanger floating heads. Normally you may enter both the shellside and the tubeside pressures and evaluate the entire head in a single analysis. However, when analyzing a type 'd' head, the interaction between shellside and tubeside pressure may result in a lower thickness than if each pressure is entered separately. Therefore you may want to run the program twice, with first the internal and then the external pressures set to zero.

Shell Side (External) Design Pressure Enter the external pressure, which is the pressure on the convex side of the head, and is also the shellside pressure for heat exchanger floating heads. Normally you may enter both the shellside and the tubeside pressures and evaluate the entire head in a single analysis. However, when analyzing a type 'd' head, the interaction between shellside and tubeside pressure may result in a lower thickness than if each pressure is entered separately. Therefore you may want to run the program twice, with first internal and then external pressures set to zero.

Design Temperature Enter the design temperature for each head. This temperature will be used to interpolate the material allowable tables and external pressure curves.

Material Specification Enter the ASME code material specification as it appears in the ASME material allowable tables. Alternatively, you can select the material from the Material Database by clicking the Database button. If a material is not contained in



15-5

the database, you can enter its specification and properties manually by selecting TOOLS,/EDIT/ADD MATERIALS, from the Main Menu.


Allowable Stress at Ambient Temperature The program automatically fills in entry by entering a material specification. When you change the internal design temperature, the program will automatically update this field, but only for BUILT-IN materials. If you enter the allowable stress by hand, be sure to verify your entry to assure conformance with the latest edition of the ASME Pressure Vessel Code Section II Part D. If using a module where PD:5500 is selected as design code, then the program will use the PD:5500 Material Database.

Inside Crown Radius of Head Enter the inside crown radius of the head. This value may be any dimension greater than the inside radius of the flange. However, values roughly equal to the flange ID are more typical.

Actual Thickness of Head Enter the minimum thickness of the actual plate used to build the floating head or spherical cap, or the minimum thickness measured for an existing floating head or spherical cap.

Tube Side (Internal) Corrosion Allowance Enter the corrosion allowance on the concave side of the head. The shellside and tubeside corrosion allowances are fully implemented in this version of FLOHEAD. Thicknesses and diameters are adjusted by the program for the evaluation of allowable pressure. They are also added to the required thicknesses.

Shell Side (External) Corrosion Allowance Enter the corrosion allowance on the convex side of the head. The shellside and tubeside corrosion allowances are fully implemented in this version of FLOHEAD. Thicknesses and diameters are adjusted by the program for the evaluation of allowable pressure. They are also added to the required thicknesses.

Outside Diameter of Flanged Portion Enter the outer diameter of the flange. This value is referred to as "A" in the ASME code.


15-6

FLOATING HEADS

Inside Diameter of Flange Enter the inner diameter of the flange. For integral type flanges, this value will also be the inner pipe diameter. This value is referred to as "B" in the ASME code. The corrosion allowance will be used to adjust this value (two times the corrosion allowance will be added to the uncorroded ID given by the user).

Actual Thickness of Flange Enter the through thickness of the flange. For type c spherical caps this includes the thickness of the head.


Thread Series The following bolt thread series tables are available: TEMA Bolt Table UNC Bolt Table User specified root area of a single bolt TEMA Metric Bolt Table British, BS 3643 Metric Bolt Table Note: Irrespective of the table used, the values will be converted back to user selected units. TEMA threads are National Coarse series below 1 inch and 8 pitch thread series for 1 inch and above bolt nominal diameter. The UNC threads available are the standard threads.

Number of Bolts Enter the number of bolts to be used in the flange analysis. Note that the number of bolts is almost always a multiple of 4.

Full Face Gasket Options ASME Sec. VIII Div. 1 does not cover the design of flanges for which the gasket extends beyond the bolt circle diameter. A typically used method for the design of these types of flanges is from the Taylor Forge Flange Design Bulletin. This method is implemented in the program. Gaskets for Full Face Flanges are usually of soft materials such as rubber or an elastomer, so that the bolt stresses do not go too high during gasket seating. The program adjusts the flange analysis and the design formulae to account for the full face gasket. There are 3 Full Face Gasket Flange options:



15-7

Program Selects: Instructs the program to automatically make the determination if this is a full face gasket flange, depending upon the input. If the gasket ID and OD matches with Flange ID and OD dimensions respectively (except for a blind flange) then it is determined to be a full face flange. For more information refer to Figure B.

Figure B - Full Face Gasket Flange

Full Face Gasket: Indicates to the program that this is a full face gasket flange. Use this option when the gasket ID or OD does not match the flange ID/OD dimensions, but the gasket extends beyond the bolt circle diameter. For more information refer to Figure C.

Figure C - Other Full-Face Gasket Flanges That Require Users Indicate Full-Face Flange.

Not a Full Face: Indicates to the program that this is not a full face gasket flange

Flange Face Outer Diameter Enter the outer diameter of the flange face. The program uses the minimum of the flange face outer diameter and the gasket outer diameter to calculate the outside flange contact point, but uses the maximum in design when selecting the bolt circle. The program uses the maximum of the flange face ID and the gasket ID to calculate the inside contact point of the gasket.


15-8

FLOATING HEADS

Flange Face Inner Diameter Enter the inner diameter of the flange face. The program uses the maximum of the flange face ID and the gasket ID to calculate the inner contact point of the gasket.





15-9

Table 10.1 - Gasket Materials and Contact Facings Gasket Material

Gasket Factor m


Seating Stress y

Facing Column

0

II


0.50

0

II


1.00

200

II

1/8 inch thick

2.00

1600

II

1/16 inch thick

2.75

3700

II

1/32 inch thick

3.50

6500

II


1.25

400

II

3 ply

2.25

2200

II

2 ply

2.50

2900

II

1 ply

2.75

3700

II

Vegetable Fiber

1.75

1100

II

Carbon Steel

2.50

10000

II


3.00

10000

II

Soft aluminum

2.50

2900

II


2.75

3700

II

Iron or soft steel

3.00

4500

II


3.25

5500

II

Stainless Steel

3.50

6500

II






15-10

Gasket Material

FLOATING HEADS

Gasket Factor m

Seating Stress y

Facing Column

Soft aluminum

2.75

3700

II


3.00

4500

II

Iron or soft steel

3.25

5500

II


3.50

6500

II

Stainless Steel

3.75

7600

II

Soft aluminum

3.25

5500

II


3.50

6500

II

Iron or soft steel

3.75

7600

II

Monel

3.50

8000

II

4-6% Chrome

3.75

9000

II

Stainless Steel

3.75

9000

II

Soft aluminum

3.25

5500

II


3.50

6500

II

Iron or soft steel

3.75

7600

II


3.75

9000

II

Stainless Steel

4.25

10100

II

Soft aluminum

4.00

8800

I


4.75

13000

I

Iron or soft steel

5.50

18000

I


6.00

21800

I

Stainless Steel

6.50

26000

I

5.50

18000

I



Grooved metal

Solid flat metal

Ring Joint Iron or soft steel



15-11

Gasket Material

Gasket Factor m

Seating Stress y

Facing Column


6.00

21800

I

Stainless Steel

6.50

26000

I


Table 2-5.2 Facing Sketch and Description FACING SKETCH

DESCRIPTION

1a

flat finish faces

1b


1c


1d


2

1/64 inch nubbin

3


4


5


6


Gasket Thickness Enter the gasket thickness. This value is only required for facing sketches 1c and 1d.

Nubbin Width If applicable, enter the nubbin width. This value is only required for facing sketches 1c, 1d, 2 and 6. Note that for sketch 9 this is not a nubbin width, but the contact width of the metallic ring.


Width of Partition Gasket Enter the width of the pass partition gasket. Using the properties such as such as the facing sketch, column, M and Y and the known width, PVElite will compute the effective seating width and the gasket loads contributed by the partition gasket.

Partition Gasket Factor M Enter the partition gasket factor m.


15-12

FLOATING HEADS

Partition Gasket Design Seating Stress Y: Enter the partition gasket design seating stress Y.

Partition Gasket Column for Gasket Seating: Enter the partition gasket column for gasket seating.



Distance From the Flange Centroid to Head Centerline HR is the distance from the flange centroid to the intersection of the head centerline and the flange. HR is positive if it is above the flange centroid, and negative if it is below the flange centroid. HR is used in the Code calculation, but not in Soehren's calculation.

Is the Flange Slotted Check this box if the flange has slotted bolt holes for quick opening. A slotted flange has bolt holes, which extend radially to the outer edge of the flange. The program automatically adjusts for this condition - you do not have to change the flange outside diameter.

Also Perform Soehren's Calculation? Check this box if you wish to perform Soehren's Calculation. Soehren's calculation is a more detailed analysis of the interaction between the spherical cap and the flange. Frequently the stresses calculated using this method will be acceptable for heads or flanges that are slightly less thick than required by the normal code rules. Note that this analysis can only be done for type d heads. Note also that the Code (Par. 1-6(h)) allows this type of analysis.

Is There A Backing Ring? Check this box if there is a backing ring. A backing ring is a second flange used to sandwich the tubesheet of a floating head heat exchanger. The backing ring may be a split ring. If the ring has one split, then it has been split along a diameter, into two pieces. The bending moment on the ring is multiplied by 2.0 for this case. A ring with two splits has been sliced in half like a bagel, and then each half has been split along a diameter. The ring is assembled with the diametral splits offset by 90 degrees. For this case, enter the thickness of one half of the original ring, since each half is required to support 75 percent of the original design moment.

Mating Flange Loads? If loads from the mating flange are to be considered, check this field. A pop-up spreadsheet will appear for additional data entry. This auxiliary bolt loading will only be used if it is greater then the standard bolt loads computed using the ASME formulas.



15-13

Pop-Up Input Fields Bolt Root Area For nonstandard bolts, enter the root cross sectional area of the bolt.

Inside Depth of Flange From Flange Face to Attached Head Q is the distance from the bolting face of the flange to the intersection of the head inside diameter and the flange. Q is used in Soehren's calculation, while HR is used in the Code calculation.

Backing Ring Inside Diameter Enter the inside diameter of the backing ring. This value is usually a little larger than the inside diameter of the flange.

Back Ring Actual Thickness Enter the actual through thickness of the backing ring. Note that for doubly split rings, this is the thickness of each piece.

Number of Splits in Backing Ring (0, 1, OR 2) The backing ring may be a split ring. If the ring has one split, then it has been split along a diameter, into two pieces. The bending moment on the ring is multiplied by 2.0 for this case. A ring with two splits has been sliced in half like a bagel, and then each half has been split along a diameter. The ring is assembled with the diametral splits offset by 90 degrees. For this case, enter the thickness of one half of the original ring, since each half is required to support 75 percent of the original design moment.

Mating Flange Operating Load (WM1) Specify the alternate operating bolt load such as from the mating flange. This value will be used if it is greater than the operating bolt load computed by the program.

Mating Flange Seating Load (WM2) Specify the alternate seating flange bolt load such as from the mating flange. This value will be used if it is greater than the seating bolt load computed by the program.

Mating Flange Design Bolt Load (W) Specify the alternate flange design bolt load such as from the mating flange. This value will be used if it is greater than the flange design bolt load computed by the program.


15-14

FLOATING HEADS

Discussion of Results Internal Pressure Results for the Head: The ASME Code provides a simple formula for calculating the required thickness of the head under internal pressure. This formula is the same for type b, c, and d heads: t=5PL/6S The program solves this formula for required thickness, maximum allowable working pressure, and actual stress, and displays the results. Note that these results are also displayed in the thickness summary at the end of the printout.

External Pressure Results for Heads: The required thickness and maximum allowable working pressure for each head type is based on the external pressure requirements for an equivalent sphere.

Intermediate Calculations for Flanged Portion of Head: Three separate bending moments are calculated for each head. These are the bolt up moment, the moment due to external pressure, and the moment due to internal pressure. In each case the moment is calculated per the ASME Code, Section VIII, Division 1, Appendix 2. However, in the case of the type d head the moment is further modified to take into account the force imposed on the flange by the pressure on the head. This force is shown in the printout as MH. The sign of this force will be negative if the head is attached above the centroid of the flange, and positive if the head is attached below the centroid.

Required Thickness Calculations: The required thickness formulae for each flange type and loading condition are printed by the program. These formulae are taken from Appendix 1-6, paragraphs (e)(2) and (3), (f)(2) through (5) and (g)(2). The required thickness calculations for the backing ring are also shown. The backing ring is taken as a ring flange and calculated per Appendix 2. The analysis is corrected for the number of splits in the backing ring, and shows the required thickness for each piece of the split ring. The thickness calculations for the main flange and backing ring involve the factor F that is directly proportional to the design pressure. Thus when the pressure is 0, for the bolt-up condition, the factor F is theoretically equal to 0. Some however interpret the Code to mean that F should be computed using the design pressure even for the bolt-up cases. There is a setup file directive that allows you to toggle this to work one way or the other. To keep the program results consistent with older versions, this setup file parameter is set to compute F with 0 pressure for the bolt-up conditions. After the required thicknesses are calculated, a summary table is printed.

Soehren's Calculations: The ASME Code, Section VIII, Division 1, Appendix 1-6, paragraph (h) states:



15-15

These formulas are approximate in that they do not take into account continuity between the flange ring and the dished head. A more exact method of analysis, which takes this into account may be used if it meets the requirements of U-2. The analysis referred to in this paragraph is Soehren's calculation, based on the paper "The Design of Floating heads for Heat-Exchangers", ASME 57-A-7-47. Intermediate results and calculated stresses are shown in the printout. Equation numbers are included from the original paper. Allowable stresses are not shown in the printout, but bending stresses should be limited to 1.5 times the basic Code allowable stress, while membrane stresses should be limited to 1.0 times the basic Code allowable.


15-16

FLOATING HEADS



CH AP TER

1 6

Chapter 16 HORIZONTAL VESSELS In This Chapter Introduction ................................................................................ 16-2 Discussion of Input ..................................................................... 16-3 Discussion of Results.................................................................. 16-16 Saddle Wear Plate Design........................................................... 16-17 Example ...................................................................................... 16-20


16-2

HORIZONTAL VESSELS

Introduction This chapter discusses the HORIZONTAL VESSEL module of PVElite. To use the HORIZONTAL VESSEL module from the Main Menu click ANALYSIS/CHOOSE ANALYSIS TYPE/HORIZONTAL VESSELS. This module computes stresses in horizontal pressure vessels created by the combination of internal pressure and the weight of the vessel, its contained liquid and stiffener rings. If included in the analysis, additional loads due to wind per ASCE98/02,95 93, UBC-97/94, IBC 2003 and earthquake will be included. The program is based on "Stresses in Large Horizontal Cylindrical Pressure Vessels on Two Saddle Supports", The Welding Research Supplement, 1951 and subsequent interpretations of that work. This is also termed Zick's Analysis.


Chapter 16 HORIZONTAL VESSELS

16-3

Discussion of Input Main Input Fields Item Number Enter the vessel number for this analysis. This number can be up to 15 digits in length.

Vessel Description Any combination up to 15 letters and numbers can be used to briefly identify the vessel that is being analyzed. This description is reflected in the output reports and is used in error checking.

Vessel Design Pressure Enter the pressure under which the horizontal vessel is operating. A positive entry here indicates internal pressure while a negative number indicates external pressure. Please note that no external pressure check for adequate wall thickness will be performed. Use the Shell program and analyze the geometry before using the HORIZONTAL VESSEL module.

Vessel Design Temperature Enter the maximum temperature the horizontal vessel will be operating at. The temperature will be used in determining the allowable stress of the material chosen. If the temperature is changed, note that the allowable stress of the material at operating temperature will be updated accordingly.

Corrosion Allowance Enter the allowance given for corrosion in this field. The corrosion allowance cannot be greater than the vessel wall thickness. In addition, it must not be less than 0 .

Material Specification Enter the material specification for the shell section of the horizontal vessel. An example of a material type is SA516 70. Define the material by typing in the name. Alternatively, you can select the material from the Material Database by clicking the Database button. If a material is not contained in the database, its specification and properties can be entered manually by selecting TOOLS, EDIT/ADD MATERIALS, from the Main Menu.

Allowable Stress At Operating Temperature The program automatically fills in entry by entering a material specification. When you change the internal design temperature, or the thickness of the shell, the program will automatically update this field, but only for BUILT-IN materials. If you enter the allowable stress by hand, be sure to verify your entry to assure conformance with the latest edition of the ASME Pressure Vessel Code Section VIII Division 1 at the ambient temperature.


16-4

HORIZONTAL VESSELS

Allowable Stress At Ambient Temperature The program automatically fills in entry by entering a material specification. If you enter the allowable stress by hand, be sure to verify your entry to assure conformance with the latest edition of the ASME Pressure Vessel Code Section VIII Division 1 at the ambient temperature.

Density Of Stored Liquid Enter the density of the fluid in the horizontal vessel. If you have more than 1 fluid consideration ( i.e. test (water) and or (operating) you may have to have more than 1 item with the appropriate fluid densities defined. You can enter a number of specific gravity units and PVElite will convert the number entered to the current set of units. To do this, enter a number followed by the letters "sg".

Liquid Height From Bottom Of Tank Enter the height of the liquid in the tank. Normally, a Zick analysis is run with the vessel full of water, however, it may be necessary to run a partially filled tank for wind or seismic analysis for an operating type load case.

Extra Weight Enter any additional weight present on the vessel. Additional weight may come from insulation, steel structures or piping loads. There is no on screen range checking for this entry since it may be positive or negative. However, if negative, this entry should not be greater than the total weight of the vessel.

Saddle Reaction Force Factor Enter the factor for computing the saddle reaction force due to the Wind (or Earthquake) transverse load. The recommended value is 3, The value of 6, is conservative in that it assumes that the maximum edge load is uniform across the entire base. When in reality it occurs only at the edge. A more accurate method may be to convert this triangular loading into a more realistic uniform load, this leads to a value of 3. The following figure illustrates the loading.

Figure A - End view of a horizontal vessel with a transverse load, simulating Wind/Seismic loading.



16-5

The saddle reaction load Fst (or Fwt for wind) due to the transverse load Ft is: Fst (or Fwt) = ftr * Ft * B / E

Distance From Vessel Centerline To Saddle Base Enter the distance from the center of the vessel to the bottom of the saddle support. This distance must be greater than the vessel outside radius.

Check Saddle Webs, & Base Plate If you wish PVElite to perform computations on the structure, which supports the vessel check this field. PVElite will compute the inertia's, moments and forces on the members necessary to perform an AISC unity check.

Apply Wind Loads to Vessel If wind loads are to be considered, check this field. If checked, other information such as basic wind speed and input prompts will have to be answered.

Apply Seismic Loads to Vessel If seismic loads are a design consideration check this field. Both seismic and wind loads will increase the saddle load reaction forces, and thus higher vessel stresses will result.

Apply Longitudinal Loads to Vessel Check this box to enter longitudinal forces such as due to saddle friction or tube-bundle pull out force (for a heatexchanger) acting on the vessel.

Stiffening Ring Present If the vessel is equipped with stiffening rings check this field. Stiffening rings are used to reduce stresses in the vicinity of the saddle supports and are also used to meet external pressure requirements. When equipped with rings the assumption is that there are either 1 or 2 rings located directly over the saddle. The rings are assumed to span (360 - saddle bearing angle) degrees around the vessel. This is mainly used for the calculation of the ring weight.

Shell and Head Diameter Basis Select the diameter basis for the shell and Head, following options are available. ID

Inside Diameter basis

OD

Outside Diameter basis

Merge Shell Click on this button to import the Shell information from this CodeCalc file.


16-6

HORIZONTAL VESSELS

Shell Diameter Enter the shell diameter with respect to the shell and head diameter basis. The diameter must be greater than 0 and greater than 2.0 times the wall thickness.

Shell Length Tangent toTangent Enter the length of the cylindrical shell from tangent to tangent.

Shell Thickness Enter the uncorroded thickness of the shell in this cell. PVElite will automatically corrode the wall thickness as necessary.

Shell Joint Efficiency Enter the seam efficiency of the shell. This value is greater than 0 and less than or equal to 1.0. This entry is used to compute the required thickness of the shell.

Head Type Select the type of head that is used on the vessel ends. If a flat head is selected then it is assumed to be round and the same diameter as the shell. Following types are available. Elliptical Torispherical Hemispherical Flat

Head Thickness Enter the uncorroded thickness of the head. The value must be greater than 0.0. Effects of corrosion are handled automatically.

Head Joint Efficiency Enter the seam efficiency of the head. This value is greater than 0 and less than or equal to 1.0. This entry is used to compute the required thickness of the head.

Distance From Saddle to Vessel Tangent Enter the length from the vessel tangent to the saddle support. This distance must be positive and less than 1/2 of the vessel tangent to tangent length.

Saddle Width Enter the width of the surface on the saddle support that will contact the vessel.

Saddle Bearing Angle Enter the number of degrees that the saddle bears on the shell surface. Valid entries range from 120 to 180 degrees.



16-7

Wear Pad Thickness If there is a wear pad on the vessel, enter that thickness here. If the distance from the vessel tangent to the saddle location is less than or equal to 0.5 times the shell radius and the wear pad extension above the horn of the saddle is greater than the shell radius divided by 10.0 then the thickness of the wear pad will be included. If this is not the case then the shell thickness - CA will be used.

Wear Pad Extension Above Horn of Saddle If the vessel has a wear pad and it extends above the horn of the saddle enter that extension distance here. For more information on wear pads, see the help text for wear pad thickness.

Wear Pad Width If the vessel has a wear pad enter the width here. The width of the wear pad is measured along the long axis of the vessel.

Pop-Up Input Fields Base Plate Length Enter the length of the base plate. This is typically referred to as dimension "A". This value is usually close to the diameter of the vessel.

Base Plate Thickness Enter the thickness of the base plate. If you wish to consider any external corrosion or erosion enter the corroded thickness value, not the uncorroded value. The baseplate thickness will be computed using a beam bending type equation found in pressure vessel texts. The baseplate thickness is not a function of the number of ribs.

Base Plate Width Enter the width of the base plate. This is the short dimension.

Number of Ribs Enter the number of ribs in your design. This number should include the outside ribs.

Thickness of Ribs Enter the thickness of the ribs. The ribs run in a direction that is parallel to the long axis of the vessel. Any external corrosion allowance should be taken into account when this value is entered.

Thickness of Web Enter the thickness of the Webs. The webs run in a direction perpendicular to the long axis of the vessel. Any external corrosion should be taken into account when this value is entered.


16-8

HORIZONTAL VESSELS

Web Location Center or Side Select the web location. Center webs run through the middle of the middle of the base plate. Side webs will run along the edge of the base plate.

Height of Center Web The height of the center web extends from the bottom of the base to the shell ID.

Additional Area The user may wish to consider the additional area exposed to the wind from piping, platforms, insulation etc. PVElite will automatically compute an effective diameter with the input diameter known.

User Defined Wind Pressure On Vessel If your vessel specification calls for a constant wind pressure design, and you know what that pressure is, enter it here. Most Wind Design codes have minimum wind pressure requirements, so check those carefully. The wind pressure will be multiplied by the area calculated by the program to get a shear load and a bending moment. If you enter a positive number here, CodeCalc will use this number regardless of the information in the following cells.

Wind Design Standard Enables users to choose the wind design standard.The list below displays the options available: ASCE 7-93 ASCE 7-95 ASCE 7-98/02 / IBC 2003 UBC 94/97 To use wind codes not listed above users must compute and enter the design wind pressure and the program will multiply the wind pressure by the area to compute the wind load.

Force Coefficient (Cf) Enter the force coefficient (also known as shape factor) for the vessel here. This factor takes into account the shape of the structure. This factor is known as pressure coefficient, Cq in the UBC wind code. The acceptable range of input is between 0.5 and 1.2. This can be seen as, For ANSI A58.1 refer to Table 12 For ASCE 7-93 refer to tables 11-14, p21-22 For ASCE 7-95, refer to tables 6-6 to 6-10, p32-33 For ASCE 7-98, refer to tables 6-9 to 6-13 For ASCE 7-2002, refer to tables 6-18 to 6-22, p68-72 For UBC-1997 code, refer to table 16-H.



16-9

Importance Factor ( I ) Enter the value of the importance factor that you wish the program to use. The importance factor accounts for the degree of hazard to life and property. Please note the program will use this value directly without modification. Values of typical importance factors are listed below for ASCE 7-93, ASCE 7-95/98/02 and UBC 1997 standards. ASCE7-93: Following values are used for ASCE 7-93. In general this value ranges from .95 to 1.11.: Category

100 mi from Hurricane Oceanline

At Oceanline

I

1.00

1.05

II

1.07

1.11

III

1.07

1.11

IV

0.95

1.00

Category Classification: I

buildings and structures not listed below

II

buildings and structures where more than 300 people congregate in one area

III

buildings designed as essential facilities, hospitals etc.

IV

buildings and structures that represent a low hazard in the event of a failure

Note that most petrochemical structures are 1, Importance I. ASCE-7-95/98/02: In general this value ranges from .77 to 1.15. It is taken from table 6-2 of the ASCE 95 standard or table 6-1 from the 98 standard.

Category

Importance Factor (I)

I

0.87

II

1.00

III

1.15

IV

1.15

In the 98 standard for Wind Speeds > 100 mph for category I, the importance factor can be 0.77. Category Classification: I

buildings and other structures that represent a low hazard to human life in the event of failure

II

buildings and structures except those listed in categories I, III and IV

III

buildings and structures that represent a substantial hazard in the event of a failure

IV


Note that most petrochemical structures are 1, Importance I.


16-10

HORIZONTAL VESSELS

UBC: For UBC 1997 code these values are listed as follows:

Category


I, Essential facilities

1.15

II, Hazardous facilities

1.15

III, Special occupancy structures

1.00

IV, Standard occupancy structures

1.0

Basic Wind Speed Enter the design value of the wind speed. The wind speeds will vary according to geographical location and/or to company/vendor standards. A few typical wind speeds in miles per hour display below: 85.0 miles per hour 100.0 miles per hour 110.0 miles per hour 120.0 miles per hour Note: Users should enter the lowest value reasonably allowed by the standards you are following, since the wind design pressure and thus force increases as the square of the speed.

Wind Exposure This category reflects the characteristics of ground surface irregularities for the site at which the structure is to be constructed. Use the table below to determine the appropriate exposure category For ASCE codes, the exposure categories are as follows

Exposure Category

Description

A

Large city centers with at least 50% of the buildings having a height in excess of 70 feet.

B

Urban and suburban areas, wooded areas, or other terrain with numerous closely spaced obstructions having the size of single family dwellings.

C

Open terrain with scattered obstructions having heights generally less than 30 feet. This category includes flat, open country and grasslands.

D

Flat, unobstructed coastal areas directly exposed to wind flowing over large bodies of water.

Note that most petrochemical sites use a value of 3 (exposure C).



16-11

UBC Exposure Factor UBC Exposure Factor as defined in UBC-91 Section 2312: Exposure Category

Description

B

Terrain with building, forest or surface irregularities 20 feet or more in height covering at least 20 percent or the area extending one mile or more from the site.

C

Terrain which is flat and generally open, extending one-half mile or more from the site in any full quadrant.

D

The most severe exposure with basic wind speeds of 80 mph or more. Terrain which is flat and unobstructed facing large bodies of water over one mile or more in width relative to any quadrant of the building site. This exposure extends inland from the shoreline 1/4 mile or 0 times the building (vessel) height, whichever is greater.


Height of Vessel Above Grade Enter the height of the vessel above the surface of the earth (grade).

Types of Hill Enter the type of hill. See ASCE 7-95 Fig. 6-2 for details. None 2-D Ridge 2-D Escarpment 3-D Axisymmetric Hill

Height of Hill or Escarpment (H) Enter height of hill or escarpment relative to the upwind terrain. See ASCE 7-95 Fig. 6-2 for details.

Distance to Site (x) Enter distance (upwind or downwind) from the crest to the building site. See ASCE 7-95 Fig. 6-2 for details.

Distance to Crest (Lh) Enter distance upwind of crest to where the difference in ground elevation is half the height of hill or escarpment. See ASCE 7-95 Fig. 6-2 for details.

Seismic Zone Select the seismic zone in which your vessel is operating. The seismic zones are pictured in ASCE #7 and reproduced below. A value of 0 will not increase the saddle reaction force. An Identifier of 5( zone 4) will produce the highest saddle load reactions. These values are derived from UBC. The basic equation for lateral G force is :


16-12

HORIZONTAL VESSELS

Cs = Z I C / Rw : Rw = 3, C = 2.75, I = 1.0

Seismic Zone

Cs

0

0.0

1

0.069

2a

0.138

2b

0.184

3

0.275

4

0.367

Figure B - Seismic risk map of United States from the ASCE code

User Entered Seismic Zone Factor CS When you enter a valid seismic zone and leave this field blank or 0, CodeCalc will look the seismic zone factor up from the table shown below. This number is then used in conjunction with the operating weight of the vessel to compute the forces, which act on the saddle supports. If for any reason the table value of Cs is unacceptable, entry of a non-zero value will cause this to be used in lieu of the table value. This might occur if the building code in your project specifications is different from the one used by CodeCalc.



Zone

Cs

0

0.0

1

0.069

2a

0.138

2b

0.184

3

0.275

4

0.367

16-13

Friction Coefficient Between the Saddle and the Foundation, mu Enter the friction coefficient between the saddle and the foundation. The frictional force is caused by expansion and contraction of the vessel shell if the operating system varies from the atmospheric temperature. The table below displays some coefficient of friction values, taken from the Pressure Vessel Design Manual by Dennis R. Moss 2nd edition, page 156. Surfaces

Friction Factor mu

Lubricated Steel-to-Concrete

0.45

Steel-to-Steel

0.40

Lubrite-to-Steel Temperature over 500º F

0.15

Temperature 500º F or less

0.10

Bearing pressure less than 500 psi

0.15

Teflon-to-Teflon Bearing pressure 800 psi or more

0.06

Bearing pressure 300 psi or less

0.1

User Defined Longitudinal Force Enter any additional longitudinal force acting on the horizontal vessel. The largest of the longitudinal forces: userdefined, Wind/Seismic and due to friction, is used for designing the horizontal vessel. Examples could be pier deflection or tube bundle pullout load for a heat exchanger.


16-14

HORIZONTAL VESSELS

Stiffening Ring Location If the stiffening rings are located on the outside of the vessel select OD. If the rings are located inside the vessel select ID.

Stiffening Ring Material Properties Enter the material specification for the stiffening ring. An example of a material type is SA-516 70. Define the material by typing in the name. Alternatively, you can select the material from the Material Database by clicking the Database button. If a material is not contained in the database, its specification and properties can be entered manually by selecting TOOLS, EDIT/ADD MATERIALS, from the Main Menu. The program will use the shell design temperature to obtain the stiffening ring material properties at design condition.

Stiffening Ring Properties

Figure C - Stiffening Ring Geometry

Moment of Inertia of Stiffening Ring If the stiffening ring properties cannot be defined in the fields above then use these fields. The entry in this cell is for the moment of inertia of the ring about its neutral axis. For typical cross-sections this property can be calculated or "looked up" in a handbook that lists properties of steel shapes. An example of such a book would be the AISC steels handbook.

Cross Sectional Area of Stiffening Ring For the user defined ring enter the cross-sectional area of the ring in this field. This number can be calculated or "looked up" in a steels handbook.

Distance to Centroid of Reinforcing Section Enter the distance to the centroid of the beam section ( I, T, etc) used to reinforce the cone/cylinder junction. This can usually be found in the 'Manual of Steel Construction' for common beam sections.



16-15

Height of Stiffener from Shell Surface If the stiffening ring is on the outside of the vessel then enter the distance from the outside shell surface to the top most part of the ring. If the ring is on the inside of the vessel then enter the distance from the inner surface of the shell to the top of the ring.

Aspect Ratio (D/2H) for Elliptical Heads Enter the aspect ratio for elliptical heads here. A very typical aspect ratio for an elliptical head is 2:1. This would mean entering a 2 in this field.

Knuckle Ratio for Torispherical Heads The knuckle ratio for a torispherical head is defined as the crown radius of the head divided by the knuckle radius. This ratio is typically 16.6667:1 which means that a value of 16.667 would be entered here. Note since this is a ratio, this value is unitless.

Crown Radius for Torispherical Heads Enter the crown radius of the torispherical head in this cell.


16-16

HORIZONTAL VESSELS

Discussion of Results PVElite will determine the volume of the vessel as well as the empty and full weights. These weights are computed with the vessel in the corroded condition. Knowing the weights may be useful for cost estimating and for design of supporting attachments, such as lifting lugs. The longitudinal stresses displayed in the output include the stresses due to internal pressure. Since these are normal stresses they are added together. The tension allowable is the basic operating allowable times the joint efficiency. The compressive allowable is the factor B taken from UG-23 using the materials chart for the given material. The tangential shear in the shell varies depending on whether the shell is stiffened or the head acts as a stiffener, or neither of these cases. Tangential stress in the head only exists if the head is close enough to the saddle to be used as a stiffener. The allowable stress in shear is 80% of the allowable tensile stress for the head or shell. The stress at the horn of the saddle depends on the location of the saddle and the equivalent thickness of the saddle and wear pad. It is zero if rings stiffen the shell. This stress is always compressive and the allowable stress is a negative of the minimum of 1.5 times the allowable tensile stress and 0.9 times the yield stress. Use of the head as a stiffener creates additional tension stress in the head. The allowable additional stress in the vessel head is limited to 0.25 times the allowable tension stress in the head. If pressure is added, the resulting stress must be less than 1.25 times the allowable tensile stress. If the tip of the stiffening ring is in compression its allowable will be -0.5 times the yield stress. If a tensile condition exists the basic material allowable will be used.



16-17

Saddle Wear Plate Design The horizontal vessels considered by CodeCalc are assumed to have saddle supports. One of the problems with this type of support is the high localized stress, which exists in the vessel in the region of saddles. Typically, the highest stress is the outside circumferential stress at the saddle horn. The ASME code does not address the details of saddle support design, nor does it offer guidance in the computation of the resulting vessel stresses. Instead, the code directs designers to other references for these methods. To date, the design of saddle supports and their associated stresses are based on past practice and experience, without theoretical analysis. A recent paper published in the Journal of Pressure Vessel Technology addresses the issue of local vessel stresses due to saddle supports. This paper (Effectiveness of Wear Plate at the Saddle Support, Ong Lin Seng, Transactions of the ASME, Journal of Pressure Vessel Technology, Vol 114, February 1992) provides a method for the estimation of the wear plate thickness, extension above the saddle horn, and the amount of stress reduction. (It is interesting to note that this paper suggests some of Zick's recommendations are non-conservative.) This optimum thickness of the wear plate is a function of the mean radius of vessel, the thickness of vessel, and the width of wear plate. The optimum wear plate thicknesses is determined for both welded and non-welded conditions, with wear plate angular extensions of 5, 10, and 15 degrees. Restrictions of this method: a) The saddle angle must be greater than 120 degrees. Saddle angles of 120 degrees with an appropriate wear plate can result in a 15 to 40 percent stress reduction at horn of the saddle. Larger saddle angles cause a greater stress reduction for the same wear plate ratios. b) The value of ( (r/b) * sqrt(r/t) ) must be between 10 and 60, when this term is not within this range, no thickness will be selected. (r = mean radius of the vessel, b = width of the wear plate, t = thickness of the vessel) The conclusions drawn in this paper are:


16-18

HORIZONTAL VESSELS

a) The peak stress in the vessel at the saddle horn can be reduce from 15 to 40 percent when a wear plate is used if the wear plate has the same thickness as the vessel and extends at least 5 degrees above the saddle horn. b) The peak stress in the vessel remains at the saddle horn when using a thin wear plate. c) The stress reduction does not vary greatly with a variation in saddle support angle. d) A welded wear plate reduces stresses better than a non-welded wear plate.

Figure D - Horizontal Vessel Program Geometry



Figure E - Wear Plate and Saddle Detail for a Typical Horizontal Tank


16-19

16-20

HORIZONTAL VESSELS



CH AP TER

1 7

Chapter 17 TUBESHEETS In This Chapter Introduction ................................................................................ 17-2 Purpose, Scope, and Technical Basis.......................................... 17-3 Discussion of Input Data............................................................. 17-6 Discussion of Results.................................................................. 17-31 Example ...................................................................................... 17-36


17-2

TUBESHEETS

Introduction TUBESHEETS performs tubesheet thickness analysis for all tubesheet types, including fixed tubesheet exchangers, based on the Standards of the Tubular Exchanger Manufacturer's Association, 8th Edition, 1999 or PD 5500, 2004 (British standard). Flanged and flued (thick) expansion joint for a fixed tubesheet is also analyzed per TEMA and ASME Sec. VIII Div. 1 Appendix 5.


Chapter 17 TUBESHEETS

17-3

Purpose, Scope, and Technical Basis TUBESHEETS calculates required thickness and Maximum Allowable Working Pressure of tubesheets for all of the exchanger types described in the 8th Edition of the Standards of the Tubular Exchanger Manufacturers Association (TEMA) and PD 5500. It also calculates thermal stresses and forces in the shell and tubes of fixed tubesheet exchangers. Load on the Tube-Tubesheet joint is also checked per the method provided in the ASME and PD 5500 codes respectively. This program will analyze the following tubesheet types: Stationary tubesheets, gasketed between the shell and the channel. Stationary tubesheets, integral with the shell and the channel. Stationary tubesheets, integral with the shell only. Stationary tubesheets, integral with the channel only. U-tube exchangers, tubesheet gasketed between shell and channel U-tube exchangers, tubesheet integral with channel only. U-tube exchangers, tubesheet integral with shell only. U-tube exchangers, tubesheet integral with both shell and channel. Floating tubesheets, outside packed floating head (P). Floating tubesheets, floating head with backing device (S). Floating tubesheets, pull through floating head (T). Floating tubesheets, externally sealed floating head (W). Floating tubesheets, divided floating head. Fixed tubesheets, stationary tubesheet at both ends. The program does the required calculations for the thickness of a tubesheet that has been extended as a flange. It also calculates the required thickness of the extension. You must enter the geometry of the flange extension, including the gasket and bolting for the flange. TUBESHEETS takes into account the following additional loadings for fixed tubesheet exchangers: Expansion joints - thin walled, thick walled, or none. Tubesheets - integral, gasketed, or extended as flanges. Pressure and thermal loads - on shell, tubesheet, tubes and tube-to-tubesheet joints. Differential pressure designs. It is possible to analyze multiple load cases (startup, shut-down etc) for fixed tubesheets, in both the corroded and uncorroded condition. Program can also analyze a thick expansion joint attached to a fixed tubesheet. The expansion joint spring rate and stresses are computed per TEMA standard. The actual stresses are then compared with the allowables provided in ASME Sec. VIII Div. 1, Appendix 5 to check the joint's adequacy.


17-4

Figure A - TEMA Tubesheet Module Geometry

Figure B - Fixed Tubesheet Exchanger With Expansion Joint


TUBESHEETS


Figure C - Tubesheet Extended as a Flange Geometry


17-5

17-6

TUBESHEETS

Discussion of Input Data Main Input Fields Item Number Enter the item ID number. This may be the item number on the drawing, or numbers that start at 1 and increase sequentially.

Description Enter a maximum 15 character alpha-numeric description for this item. This entry is optional.

Tubesheet Design Code Select the design code to be used for designing the tubesheets. There are two options available: TEMA - Tubular Exchanger Manufacturers Association, Inc. PD:5500 - British Standard (formerly known as BS 5500) Note: ASME tubesheet can also be designed in the ASME Tubesheet module.

Shell Design Pressure Enter the design pressure for the shell side of the exchanger. If the shell side has external pressure, enter a negative pressure. The program will correctly combine this pressure with the positive pressure on the other side. Note that if you specify a differential pressure in the differential pressure input field, the values on the shellside and tubeside will usually be ignored. The exception to this is fixed tubesheet exchangers, where the differential pressure field only serves as a flag to indicate to the program that the appropriate calculations for differential pressure should be performed.

Shell\Channel Tube\Tubesheet\ Bolt Material Specification Type the ASME or PD:5500 code material specification. The program will display all the materials matching the name and occurrence number. Alternatively, click the Material Database button to search a material name from the Material Database. Click the Material Edit Properties button to change the properties of the selected material. If a material is not contained in the database, you can enter its specification and properties manually by selecting TOOLS, EDIT/ADD MATERIALS, from the Main Menu. The Material Database, for both TEMA and PD:5500, is available based on the design code selected.

Allowable Stress at Ambient Temperature The program automatically fills in entry by entering a material specification. When you change the internal design temperature, the program will automatically update this field, but only for BUILT-IN materials. If you enter the allowable stress by hand, be sure to verify your entry to assure conformance with the latest edition of the ASME Pressure Vessel Code Section II Part D. If using a module where PD:5500 is selected as design code, then the program will use the PD:5500 Material Database.



17-7


Shell Metal Design Temperature Enter the design metal temperature for the shell side components. This is the design temperature for determining the allowable stresses only. This temperature is not assumed to be the metal temperature for thermal expansion. There is a separate input field for the actual metal temperature.

Shell Wall Thickness Enter the minimum wall thickness for the shell of the exchanger. This value is used by the program to calculate the characteristic diameter for all tubesheets, and especially in calculating longitudinal shell stresses for fixed tubesheet exchangers.

Shell Corrosion Allowance Enter the shell side corrosion allowance for the exchanger. This value is used to calculate the corroded thickness of the shell.

Shell Inside Diameter Enter the inside diameter for the shell of the exchanger. This value is used by the program to calculate the characteristic diameter for all tubesheets, and especially in calculating longitudinal shell stresses for fixed tubesheet exchangers.

Shell Mean Metal Temperature Enter the actual metal temperature for the shell under realistic operating conditions. It is important, especially when evaluating fixed tubesheets without expansion joints, that you enter accurate values for the metal temperatures for each operating condition. You may have to run the analysis more than once to check several metal temperature cases. Frequently the metal temperatures will be less severe than the design temperatures, due to thermal resistances. For example, if the shellside fluid has a good heat transfer coefficient and the tubeside fluid has a relatively poor heat transfer coefficient, then the tube temperature will be quite close to the shell temperature. Don't forget to evaluate the condition of shellside or tubeside loss of fluid. Especially for shellside loss of fluid, this design condition may govern the exchanger design. Refer to TEMA standard, section T-4 (8th Ed.) for guidance to compute the Mean Metal Temperatures.

Channel Design Pressure Enter the design pressure for the tube side of the exchanger. If the tube side has a vacuum design condition, enter a negative pressure. The program will correctly combine this pressure with the positive pressure on the other side.


17-8

TUBESHEETS

Note that if you specify a differential pressure in the Differential Pressure Input field, the values on the shellside and tubeside will usually be ignored. The exception to this is for fixed tubesheet exchangers, where the Differential Pressure Input field only serves as a flag to indicate to the program that the appropriate calculations for differential pressure should be performed.

Channel Metal Design Temperature Enter the design metal temperature for the tube side components. This is the design temperature for determining allowable stresses only. This temperature is not assumed to be the metal temperature for thermal expansion. There is a separate input field for the actual metal temperature.

Channel Wall Thickness Enter the minimum wall thickness for the channel of the exchanger. This value is used by the program to calculate the characteristic diameter for all tubesheet types.

Channel Corrosion Allowance Enter the tube side corrosion allowance for the exchanger. This value is used to calculate the corroded thickness of the channel.

Channel Inside Diameter Enter the inside diameter for the channel of the exchanger. This value is used by the program to calculate the characteristic diameter for all tubesheets.

Tube Mean Metal Temperature Enter the actual metal temperature for the tubes under realistic operating condition. This value is only required for British tubesheets or TEMA fixed tubesheets. It is important, especially when evaluating fixed tubesheets without expansion joints, that you enter accurate values for the metal temperatures for each operating condition. You may have to run the analysis more than once to check several metal temperature cases. Frequently the metal temperatures will be less severe than the design temperatures, due to thermal resistances. For example, if the shellside fluid has a good heat transfer coefficient and the tubeside fluid has a relatively poor heat transfer coefficient, then the tube temperature will be quite close to the shell temperature. Don't forget to evaluate the condition of shell side or tube side loss of fluid. Especially for shellside loss of fluid, this design condition may govern the exchanger design. For a fixed tubesheet, you can instruct the program, to evaluate multiple load cases. Refer to TEMA standard, section T-4 (8th Ed.) for guidance to compute the Mean Metal Temperatures.

Tube Design Temperature Enter the design temperature of the tubes. This value will be used to look up the allowable stress values for the tube material from the material tables.



17-9

Tube Wall Thickness Enter the wall thickness of the tubes. This value is used to determine the total tube area and stiffness. The following table displays thickness for some common tube gauges.

B.W.G. Gauge

Thickness (Inches)

B.W.G. Gauge

Thickness (Inches)

7

.180

17

.058

8

.165

18

.049

10

.143

19

.042

11

.120

20

.035

12

.109

22

.028

13

.095

24

.022

14

.083

26

.018

15

.072

27

.016

16

.065

Tube Corrosion Allowance Enter the tube corrosion allowance.

Number of Tube Holes Enter the number of tube holes in the tubesheet. This value is used to determine the total tube area and stiffness

Tube Pattern (Triangular, Square) Enter the pattern of the tube layout. The tube diameter, pitch, and pattern are used to calculate the term 'eta' in the tubesheet thickness equation. These rules are the same for triangular, square, rotated triangular and rotated square layouts.

Tube Outside Diameter Enter the outside diameter of the tubes. This is usually an exact fraction, such as .5, .75, .875, 1.0, or 1.25 (inches). The tube diameter, pitch, and pattern are used to calculate the term 'eta' in the tubesheet thickness equation. These rules are the same for triangular, square, rotated triangular and rotated square layouts.

Tube Pitch Enter the tube pitch, the distance between the tube centers. The tube diameter, pitch, and pattern are used to calculate the term 'eta' in the tubesheet thickness equation. These rules are the same for triangular, square, rotated triangular and rotated square layouts.

Enter Tube-Tubesheet Joint Information Check this box to enter information about the Tube-Tubesheet joint (weld, classification).


17-10

TUBESHEETS

Differential Design Pressure (Used if > 0.0) Enter the differential design pressure if you want the program to use the differential design rules. The differential pressure is used as the design pressure on both the tube side and the shell side, except for fixed tubesheet exchangers. In this case any number greater than zero serves as a flag to tell the program to turn on the special differential design pressure rules for fixed tubesheets. You must enter the shell side and tube side design pressures for fixed tubesheet exchangers.

Straight Length of Tubes Enter the length of the tubes. For U-tubesheet exchangers this is the straight length of the tube. For fixed tubesheet exchanger this is the overall length from the inside face of one tubesheet to the inside face of the other tubesheet. This value is used to determine the thermal expansion of the tubes. This input is only needed for British tubesheets and TEMA fixed tubesheets.

Enter Unsupported Tube Span SL For Max (k*SL) For computing the allowable tube compression, the values of k and SL are required. Where, SL = Unsupported Span of the tube k = Tube end condition corresponding to the span SL. The table below lists the values of k. Unsupported Spans

k for TEMA

k for PD:5500

Between two tubesheets

0.60

0.50

Between tubesheet and baffle

0.80

0.707

Between two baffles

1.00

1.00

For the worst case scenario enter the values of k and SL that give the maximum combination of k * SL. SL for example, could be the distance between the tubesheet and the first baffle or the tube span between two support baffles.

Length of Expanded Portion of Tube The expanded portion of a tube is that part which is radially expanded outward. When the tube is expanded it is also pressed into the tubesheet. Simply enter this expanded length. Some tubes are welded into place and this value may be 0. The maximum this value can be is the thickness of the tubesheet. This input is only needed for British tubesheets and TEMA fixed tubesheets.

Perimeter Of Tube Layout (if Needed) Enter the length of a path around the outside edge of the tube layout. This can be calculated by counting the number of tubes on the outside of the layout and multiplying that number by the tube pitch. When a tubesheet may be controlled by shear stress, the program requires the perimeter and area of the tubesheet for the shear calculation. An error message displays when these values are required but not given. The result will be conservative if you overestimate the area and underestimate the perimeter. This input is only needed for TEMA tubesheets.



17-11

Area Of Tube Layout Enter the area enclosed by a path around the outside edge of the tube layout. When a tubesheet may be controlled by shear stress, the program requires the perimeter and area of the tubesheet for the shear calculation. An error message displays when these values are required but not given. The result will be conservative if you overestimate the area and underestimate the perimeter. This input is only needed for TEMA tubesheets.

Diameter of Outer Tube Limit Circle Enter the diameter of outer tube limit circle, denoted as Do in PD:5500. This input is only needed for British tubesheets (PD:5500).

Tube Hole Diameter Enter the diameter of the tube hole, denoted as dh in PD:5500 code. This input is only needed for British tubesheets (PD 5500).

Number of Grooves Enter number of grooves in the tube hole.

Tube Sheet Type


17-12

TUBESHEETS

The program analyzes the following tubesheet types. When one tubesheet is stationary and the other tubesheet is a floating type, then analyze the stationary tubesheet as one of the stationary types (listed below) and analyze the floating tubesheet as one of the tubesheet types (listed below). Examples include: AEP, AKT, AJW, NET, etc. If both tubesheets (front and rear) are stationary, then select the fixed tubesheet type. This can include any of the stationary tubesheet types as the front or rear tubesheet type. Choosing this geometry assures the differential thermal expansion (between the shell and the tubes) is properly accounted. Examples of some fixed configurations are BEM, NGN, AEL, etc. Use the table below to determine the correct tubesheet type. Stationary tubesheet, gasketed on both sides (A)

Stationary tubesheets, integral with the shell (B)

Stationary tubesheets, integral with the channel (C)

Stationary tubesheets, integral on both sides (N)

U-tube tubesheets gasketed on both sides (U)



17-13

U-tube tubesheets integral with the channel (V)

U-tube tubesheets integral with the shell

Floating tubesheets, outside packed floating head (P)

See TEMA figure N-1.2

Floating tubesheets, head with backing device (S)


Floating tubesheets, pull through floating head (T)


Floating head, externally sealed floating tubesheet (W)


Divided floating tubesheet (D)

See TEMA 7.132 type k

Fixed tubesheet exchanger - two stationary tubesheets (F)

The figure below displays a NEN fixed tubesheet exchanger. A fixed tubesheet configuration can be comprised of any combination of stationary tubesheets.

Note: Each end can be any type of fixation i.e. integral, gasketed, etc.

Tubesheet Metal Design Temperature Enter the design metal temperature for the tubesheet. This is the design temperature for determining allowable stresses only. This temperature is not assumed to be the metal temperature for thermal expansion. There is a separate input field for the actual metal temperature.


17-14

TUBESHEETS

Flange Merge Use this option to bring in data from the Flange module. Select the flange mating to the tubesheet flange, and press enter, all the appropriate data for that flange will be copied in automatically. You will have to specify the thickness of the flanged extension.

Tubesheet Extended as Flange? Check this field if the tubesheet is extended and used as a bolted flange. If the tubesheet is extended but does not experience the bending moments of the bolts, then checking the box Is Bolt Load Transferred to Tubesheet, allows input echo of the tubesheet extension information and does not transfer the bolt load to the tubesheet. For example when the tubesheet is bolted between a pair of identical flanges, it will not experience a bending moment. It is only when the tubesheet replaces one of the flanges that a moment develops.

Tubesheet Gasket (None, Shell, Channel, Both) Enter the kind of gasketing associated with this tubesheet. If the tubesheet has a circular gasket, even if the gasket is not extended as a flange, you must enter the details of the gasket, so that the program can correctly evaluate the mean diameter of the gasket load reaction (G).

Depth of Groove in Tubesheet If the tubesheet has a groove such as for pass-partition, enter its depth here. This value is used as a candidate when finalizing the required thickness of the tubesheet. The maximum of this value or the channel corrosion allowance plus the shellside corrosion allowance will be added to the computed required tubesheet thickness. If your tubesheet is not grooved, enter a 0 in this field.

Tubesheet Thickness Enter the thickness of the tubesheet, or a reasonable guess at the thickness if the actual thickness is unknown. This thickness should include any allowances for corrosion on the shell side or the tube side. The tubesheet thickness for fixed tubesheet exchangers is also used in the equivalent thermal pressure calculation. When you have finished your design you should come back and put the actual thickness into this field and make sure the required thickness doesn't change.

Tubesheet Corrosion Allowance Shell Side Enter the tubesheet corrosion allowance for the shell side. This value is combined with the tubesheet corrosion allowance channel side to calculate the corroded thickness of the tubesheet.

Tubesheet Corrosion Allowance Channel Side Enter the tubesheet corrosion allowance for the channel side. This value is combined with the tubesheet corrosion allowance shell side to calculate the corroded thickness of the tubesheet.

User Defined G for Floating Tubesheet Enter the G dimension of Stationary Tubesheet to be used for the some floating tubesheet types. If this input is left blank, then the program will compute the G from the specified gasket input. TEMA standard states that for all the floating tubesheet (except divided), the G shall be the G used for the stationary tubesheet.



17-15

The T type floating tubesheet should also be checked with actual gasket G of the floating tubesheet.

TEMA Classification Enter the TEMA classification of the Heat Exchanger from the following categories: B-

Chemical process service. This information is used in computing the minimum required tubesheet thickness.

C-

Moderate requirements of Commercial and general processes.

R-

Severe requirements of Petrochemical and related processing applications.

This information is used in computing the minimum required tubesheet thickness.

Tubesheet Clamped Select the tubesheet edge condition. This determines how the tubesheet is supported at the edge by the shell or channel. This option is used for the PD:5500 code. Fig. 3.9-6 in PD:5500 2003, illustrates the edge support conditions. The available options are listed in the table below: Stationary Simply/ Floating Simply

Select this option if both the stationary and the floating tubesheet are simply supported.

Stationary Simply/ Floating Clamped

Select this option if the stationary tubesheet is simply supported and the floating tubesheet is clamped.

Stationary Clamped/ Floating Simply

Select this option if the stationary tubesheet is clamped and the floating tubesheet is simply supported.

Stationary Clamped/ Floating Clamped

Select this option if both the stationary and the floating tubesheet are clamped.

Expansion Joint Type The following options are available. None

Select this option when there is no expansion joint in the heat exchanger.

Thin Expansion Joint

Select this option if the expansion joint is a bellows type expansion joint. The figure below shows a unreinforced bellows type expansion joint. In this case you should use the Thin Joint module to design the bellows type expansion joints (both reinforced and unreinforced). Then specify the computed spring rate.

Figure D - Thin Expansion Joint


17-16

TUBESHEETS

Thick Expansion Joint

Select this option if the expansion joint is:

flanged and flue flanged only no flanged or no flue. You can specify 2 of the design options:

Existing - specify the spring rate for the expansion joint Analyze - specify the expansion joint. geometry and let the program compute spring rate and stresses. For more information see Figure E - Thick Expansion Joint.

Expansion Joint Design Option The following options are available: Existing

Select this option if you already know the spring rate of the flanged/flued expansion joint.

Analyze

Select this option if you want the program to compute the spring rate of the expansion joint and stresses induced in the expansion joint

Corroded Expansion Joint Spring Rate If there is no expansion joint, enter a zero (0.0). If there is a thin walled expansion joint, then either enter a one (1.0) or enter the actual spring rate. If there is a thick walled expansion joint, either enter the actual spring constant for the joint or let the Tubesheet module compute it using the rules per the TEMA standard RCB-8.

Uncorroded Expansion Joint Spring Rate If there is no expansion joint, enter a zero (0.0). If there is a thin walled expansion joint, then either enter a one (1.0) or enter the actual spring rate. If there is a thick walled expansion joint, either enter the actual spring constant for the joint or let the Tubesheet module compute it using the rules per the TEMA standard RCB-8. Different inputs for the uncorroded and corroded spring rates are required for running the multiple load cases in both the conditions.

Expansion Joint Inside Diameter Enter the inside diameter of the expansion joint, shown as "ID" in the figure above. This value is used by the program to calculate the force on the cylinder, and the equivalent pressure of thermal expansion.



17-17

Figure E - Thick Expansion Joint

Expansion Joint Outside Diameter (OD) Enter the outside diameter of the expansion joint, shown as "OD" in the figure above.

Expansion Joint Flange (minimum) Wall Thickness (te) Enter the minimum thickness of the flange or web of the expansion joint, after forming. This is usually thinner than the unformed metal. This value is shown as te, in the above figure.

Expansion Joint Corrosion Allowance Enter the corrosion allowance for the expansion joint. This value will be subtracted from the minimum thickness of the flange or web for the joint. Some common corrosion allowances are listed below: 0.0625 inches (2 mm)

1/16"

0.125 inches (3 mm)

1/8"

0.25 inches (6 mm)

1/4"

Expansion Joint Knuckle Enter the distance from the shell cylinder to the beginning of the knuckle for an expansion joint with an inside knuckle.

Expansion Joint Outside Knuckle Offset (fb) Enter the distance from the outer cylinder to the beginning of the knuckle for an expansion joint with an outside knuckle. Enter the distance from the outer cylinder to the intersection of the expansion joint web and the outer diameter for joints with a square outside corner. Note that in both cases this distance is frequently zero, and that for an expansion joint with a outside radius but no outside cylinder, this distance is the distance from the end of the knuckle to the symmetrical centerline of the joint.

Expansion Joint Inside Knuckle Radius (ra) Enter the knuckle radius for an expansion joint with an inside knuckle. Enter zero for an expansion joint with a sharp inside corner.


17-18

TUBESHEETS

Expansion Joint Outside Knuckle Radius (rb) Enter the knuckle radius for an expansion joint with an outside knuckle. Enter zero for an expansion joint with a sharp outside corner. (Flanged Only)

Number of Flexible Shell Elements Enter the number of flexible shell elements in the flanged/flued expansion joint. Two flexible shell elements constitute 1 convolution of the Expansion Joint.

Shell Cylinder Length (Li) Enter the length of the shell cylinder to the nearest body flange or head. TEMA Paragraph RCB 8-21 includes the following note: lo and li are the lengths of the cylinders welded to the flexible shell elements except, where two flexible shell elements are joined with a cylinder between them, lo or li as applicable shall be taken as half the cylinder length. If no cylinder is used, lo and li shall be taken as zero. Entering a very long length for this value will not disturb the results, since the TEMA procedure automatically takes into account the decay length for shell stresses and uses this length if it is less than the cylinder length.

Outer Cylinder on the Thick Expansion Joint Check this field if there is a cylindrical section attached to the expansion joint at the OD. This will always be true when you have an expansion joint with only a half convolution (1 FSE). It may also be true when there is a relatively long cylindrical portion between two half convolutions, as in the case of certain inlet nozzle geometries for heat exchangers.

Number of Desired Cycles Enter the number of desired pressure cycles for this exchanger. This will be compared with the actual computed cycle life of the expansion joint.

Pop-Up Input Fields Fillet or Groove Weld Length If the tubes on your exchanger are welded to the tubesheet, then enter the fillet weld or groove weld leg length. Some designs incorporate either only a groove or fillet weld, sometimes both are used. These values are used to determine the weld strengths. PVElite will determine the minimum required weld sizes afm and agm. Refer to section UW-20 in the ASME Code for more details. This input is not active for the PD:5500 code.

Weld Type Following options are available for the connecting tube/tubesheet welds:



Full Strength

A full strength tube-to-tubesheet weld is one in which the joint strength is equal to or greater than the maximum allowable axial tube strength.

Partial Strength

A partial strength weld can be designed based on the actual tube-tubesheet axial load.

Seal Weld/No Weld

No calculations are performed in this case.

17-19

Design Strength This term is Fd as defined in the Code paragraph UW-20. The design strength should not be greater than Ft (tube strength), which is t(do - t)Sa. This value is used to determine the minimum acceptable fillet/groove weld size that connects the tube to the tubesheet. This value is required for U-tube tubesheet exchanger. But, is optional for fixed and floating tubesheet exchangers. For partial strength tube-to-tubesheet joints on fixed/floating tubesheet exchangers, the higher of the actual tube-totubesheet load and the user entered design strength will be used to size welds. For full strength tube-to-tubesheet welds on fixed/floating tubesheet exchangers, tube strength (Ft) is used to size welds.

Is Tube-Tubesheet Joint Tested Check this box if the Tube-Tubesheet joint is tested. In that case the program will use the higher value of factor fr from the table A-2 in ASME code, Sec VIII, Div 1. This input is not active for the PD:5500 code.

Tube Joint Reliability Factor On selecting the appropriate Tube joint type, the program automatically fills in the value of factor Fr. If TEMA is selected, then use the table below to determine the joint type. This table is found in the ASME Code, Section VIII, Division 1, Table A-2, and is used to calculate the allowable tube-to-tubesheet joint loads. A typical value for tubes rolled into two grooves is 0.70.

Table A-2, Efficiencies and Joint Types


17-20

TUBESHEETS

Type

Joint

Description

Fr.(test)

Fr.(no test)

1

a

welded only, a >= 1.4t

1.00

.80

2

b

welded only, t <= a < 1.4 t

.70

.55

3

b-1

Welded only, a < t

.70

...

4

c

brazed, examined

1.00

.80

5

d

brazed, not fully examined

0.50

.40

6

e

welded, a>=1.4t, exp.

1.00

.80

7

f

welded, a<1.4t, exp, with 2 or more grooves

.95

.75

8

g

welded, a<1.4t, exp, enhanced with 1 groove

.85

.65

9

h

welded a 1.4t, exp, not enhanced, 0 grooves

.70

.50

10

i

expanded, enhanced, 2 or more grooves

.90

.70

11

j

expanded, enhanced, single groove

.80

.65

12

k

expanded, not enhanced no grooves

.60

.50

If PD:5500 is selected then use the table below to determine the efficiency and joint type. Table 3.9-2, Efficiencies and Joint Types Type

Joint

Description

Fr.(1)

1

a

welded with min throat thk. >= tube thk.

.80

2

b

welded with min throat thk. < tube thk.

.55

3

c

expanded and welded with min throat thk. >= tube thk.

.80

4

d

expanded and welded with min throat thk. < tube thk.

.55

5

e

expanded only

.50

6

f

explosion expanded/welded

.80

Interface Pressure, Po and Pt Enter the Interface pressures, Po and Pt, between the tube and the tubesheet hole Po

Interface Pressure that remains after expanding the tube at fabrication.

Pt

Interface Pressure due to differential thermal growth.

These pressures are usually established analytically or experimentally. But, must consider the effect of change in material strength at operating temperature. This input is required only for the tube joint types i, j and k, as defined in table A-2 in ASME Sec VIII, Div-1 App. A.



17-21

Is Welded Material Specified (not Seamless) Check this box if the tube has a longitudinal weld seam or in other words it (not seamless) and the material allowables are for welded product. For computing allowable Tube-Tubesheet Joints loads, the allowable stress of a seamless tube is needed. If the user selected a welded tube and clicks on this check box, then the tube allowable stress is divided by 0.85 to an equivalent allowable of a seamless tube. This is per note in ASME Sec. VIII Div. 1 UW-20.3 and App. A.

Actual Tubesheet Metal Temperature Enter the actual metal temperature for the tubesheet under a realistic operating condition. This value does not affect the thermal expansion design, but it is used to determine the elastic modulus of the tubesheet. Refer to TEMA standard, section T-4 (8th Ed.) for guidance to compute the Mean Metal Temperatures.

Is This a Kettle Type Heat Exchanger Check here if the shell is shaped like a kettle. Kettle-type configuration is illustrated in Figure N-1.2 and Figure N-2 in TEMA standard Eighth Edition.

Length of Kettle Port Cylinder (LP) Enter the length of the kettle port cylinder. This dimension is needed if the shell is shaped like a kettle. The Kettletype configuration is illustrated in Figures N-1.2 and N-2 in the TEMA Standard (Eighth Edition).

Thickness of Kettle Port Cylinder (TP) Enter the thickness of the kettle port cylinder. This dimension is needed if the shell is shaped like a kettle. The Kettle-type configuration is illustrated in Figures N-1.2 and N-2 in the TEMA Standard (Eighth Edition).

Mean Diameter of Kettle Port Cylinder (DP) Enter the mean diameter of the Kettle port cylinder. This dimension is needed if the shell is shaped like a kettle. The Kettle-type configuration is illustrated in Figures N-1.2 and N-2 in the TEMA Standard (Eighth Edition).

Length of Kettle Cylinder (LK) Enter the length of the Kettle cylinder. This dimension is needed if the shell is shaped like a kettle. The Kettle-type configuration is illustrated in Figures N-1.2 and N-2 in the TEMA Standard (Eighth Edition).

Thickness of Kettle Cylinder (TK) Enter the thickness of the Kettle cylinder. This dimension is needed if the shell is shaped like a kettle. The Kettletype configuration is illustrated in Figures N-1.2 and N-2 in the TEMA Standard (Eighth Edition).


17-22

TUBESHEETS

Mean Diameter of Kettle Cylinder (DK) Enter the mean diameter of the Kettle cylinder. This dimension is needed if the shell is shaped like a kettle. The Kettle-type configuration is illustrated in Figures N-1.2 and N-2 in the TEMA Standard (Eighth Edition).

Axial Length of Kettle Cone (LC) Enter the axial length of the Kettle cone. This dimension is needed if the shell is shaped like a kettle. The Kettle-type configuration is illustrated in Figures N-1.2 and N-2 in the TEMA Standard (Eighth Edition).

Thickness of Kettle Cone (TC) Enter the thickness of the Kettle cone. This dimension is needed if the shell is shaped like a kettle. The Kettle-type configuration is illustrated in Figures N-1.2 and N-2 in the TEMA Standard (Eighth Edition).

Select Load Cases for Detailed Printout When analyzing the design with the multiple load cases, the program will generate summarized results for all the load cases in tabular form. To see the detailed equations and intermediate calculations for one or more load cases, select those load cases. The available load cases are: Load Case Description Load Case No.

Corroded

Uncorroded

1

Fvs + Pt - Th + Ca

Fvs + Pt - Th - Ca

2

Ps + Fvt - Th + Ca

Ps + Fvt - Th - Ca

3

Ps + Pt - Th + Ca

Ps + Pt - Th - Ca

4

Fvs + Fvt + Th + Ca

Fvs + Fvt + Th - Ca

5

Fvs + Pt + Th + Ca

Fvs + Pt + Th - Ca

6

Ps + Fvt + Th + Ca

Ps + Fvt + Th - Ca

7

Ps + Pt + Th + Ca

Ps + Pt + Th - Ca

8

Fvs + Fvt - Th + Ca

Fvs + Fvt - Th - C

Note: Fvt, Fvs - User-defined Shell-side and Tube-side vacuum pressures or 0.0. Ps, Pt - Shell-side and Tube-side Design Pressures. Th - With or Without Thermal Expansion. Ca - With or Without Corrosion Allowance.

Enter Shell/Channelside Vacuum Pressures When analyzing the design with the multiple load cases, the user can specify shell/channel side vacuum pressures. This should be a positive entry. For example for full atmospheric vacuum condition enter a value of 15.0 psig. If no value is specified then 0 psi will be used.

Outside Diameter of Flanged Portion Enter the outer diameter of the flange. This value is referred to as "A" in the ASME code.



17-23


Thickness of Extended Portion of Tubesheet Enter the flange thickness. This thickness will used in the calculation of the required thickness. The final results should, therefore, agree with this thickness to within about five percent.

Nominal Bolt Diameter Enter the nominal bolt diameter. The tables of bolt diameter included in the program range from 0.5 to 4.0 inches. If you have bolts that are larger or smaller than this value, enter the nominal size in this field, and also enter the root area of one bolt in the Thread Series cell. Thread Series The following bolt thread series tables are available: TEMA Bolt Table UNC Bolt Table User specified root area of a single bolt TEMA Metric Bolt Table British, BS 3643 Metric Bolt Table Irrespective of the table used, the values will be converted back to the user selected units. TEMA threads are National Coarse series below 1 inch and 8 pitch thread series for 1 inch and above bolt nominal diameter. The UNC threads available are the standard threads.

Bolt Root Area If you exchanger design has non-standard bolts, enter a 3 in the field above this one and enter the root area of a single bolt in this field.

Number of Bolts Enter the number of bolts to be used in the flange analysis.

Fillet Weld Between Flange and Shell/Channel Enter the fillet weld height between the tubesheet flange and the shell or channel outside surface. PVElite will use this number to calculate g1 (hub thickness at the large end).

Apply Bolt Load to the Tubesheet Check this box if the bolt load is transferred to the tubesheet extended as the flange.


17-24

TUBESHEETS

Operating Bolt Load (Wm1) Specify the alternate operating bolt load on the tubesheet extended as a flange. This value will be used if it is greater than the operating bolt load computed by the program.

Seating Bolt Load (Wm2) Specify the alternate seating bolt load on the tubesheet extended as a flange. This value will be used if it is greater than the seating bolt load computed by the program.

Flange Design Bolt (W) Specify the alternate flange design bolt load on the tubesheet extended as a flange. This value will be used if it is greater than the flange design bolt load computed by the program.

Flange Face Outer Diameter Enter the outer diameter of the flange face. The program uses the minimum of the flange face outer diameter and the gasket outer diameter to calculate the outside flange contact point, but uses the maximum in design when selecting the bolt circle. The program uses the maximum of the flange face ID and the gasket ID to calculate the inside contact point of the gasket.



FACING SKETCH

DESCRIPTION

1a

flat finish faces

1b


1c


1d


2

1/64 inch nubbin

3


4


5


6


Gasket Outer Diameter Enter the outer diameter of the gasket. The program uses the minimum of the flange face outer diameter and the gasket outer diameter to calculate the outside flange contact point, but uses the maximum in design when selecting



17-25

the bolt circle. This is done so that the bolts do not interfere with the gasket. The program uses the maximum of the flange face ID and the gasket ID to calculate the inside contact point of the gasket.



17-26

TUBESHEETS

Gasket Materials and Contact Facings Gasket Material

Gasket Factor m


Seating Stress y

Facing Column

0

II


0.50

0

II


1.00

200

II

1/8 inch thick

2.00

1600

II

1/16 inch thick

2.75

3700

II

1/32 inch thick

3.50

6500

II


1.25

400

II

3 ply

2.25

2200

II

2 ply

2.50

2900

II

1 ply

2.75

3700

II

Vegetable Fiber

1.75

1100

II

Carbon Steel

2.50

10000

II


3.00

10000

II

Soft aluminum

2.50

2900

II


2.75

3700

II

Iron or soft steel

3.00

4500

II


3.25

5500

II

Stainless Steel

3.50

6500

II







Gasket Material

17-27

Gasket Factor m

Seating Stress y

Facing Column

Soft aluminum

2.75

3700

II


3.00

4500

II

Iron or soft steel

3.25

5500

II


3.50

6500

II

Stainless Steel

3.75

7600

II

Soft aluminum

3.25

5500

II


3.50

6500

II

Iron or soft steel

3.75

7600

II

Monel

3.50

8000

II

4-6% Chrome

3.75

9000

II

Stainless Steel

3.75

9000

II

Soft aluminum

3.25

5500

II


3.50

6500

II

Iron or soft steel

3.75

7600

II


3.75

9000

II

Stainless Steel

4.25

10100

II

Soft aluminum

4.00

8800

I


4.75

13000

I

Iron or soft steel

5.50

18000

I


6.00

21800

I

Stainless Steel

6.50

26000

I

5.50

18000

I



Grooved metal

Solid flat metal

Ring Joint Iron or soft steel


17-28

TUBESHEETS

Gasket Material

Gasket Factor m

Seating Stress y

Facing Column


6.00

21800

I

Stainless Steel

6.50

26000

I



Full Face Gasket Options ASME Sec. VIII Div. 1 does not cover the design of flanges for which the gasket extends beyond the bolt circle diameter. A typically used method for the design of these types of flanges is from the Taylor Forge Flange Design Bulletin. This method is implemented in the program. Gaskets for Full face flanges are usually of soft materials such as rubber or an elastomer, so that the bolt stresses do not go too high during gasket seating. The program adjusts the flange analysis and the design formulae to account for the full face gasket. There are 3 Full Face Gasket Flange options: Program Selects: Instructs the program to automatically make the determination if this is a full face gasket flange, depending upon the input. If the gasket ID and OD matches with Flange ID and OD dimensions respectively (except for a blind flange) then it is determined to be a full face flange. See the figure below.



17-29




Width of Partition Gasket Enter the width of the pass partition gasket. Using the gasket properties such as the facing sketch, column, M and Y and the known width, PVElite will compute the effectives seating width and the gasket loads contributed by the partition gasket.

Partition Gasket Factor M Enter the partition gasket factor M.

Partition Gasket Design Seating Stress Y Enter the partition gasket design seating stress Y.

Partition Gasket Flange Face Facing Sketch Enter the partition gasket flange face facing sketch.




17-30

TUBESHEETS


Outer Cylindrical Element Thickness Enter the actual wall thickness of the outer cylindrical element at the point where the expansion joint is attached. This value is shown on Figure E as 'to'.

Outer Cylindrical Element Corrosion Allowance Enter the corrosion allowance for the outer cylindrical element.

Outer Cylindrical Element Length Enter the length of the outer cylinder to the nearest body flange or head, or to the centerline of the convolute. This value is shown on Figure E as 'lo'. TEMA Paragraph RCB 8-21 includes the following note: lo and li are the lengths of the cylinders welded to the flexible shell elements except, where two flexible shell elements are joined with a cylinder between them, lo or li as applicable shall be taken as half the cylinder length. If no cylinder is used, lo and li shall be taken as zero. Entering a very long length for this value will not disturb the results, since the TEMA procedure automatically takes into account the decay length for shell stresses and uses this length if less than the cylinder length.



17-31

Discussion of Results Intermediate Calculations for Tubesheets Extended as Flange: Two major additions to the tubesheet calculations occur when a tubesheet is extended as a flange. First, a moment is added to the pressure moment, which governs the thickness of most tubesheets. Second, a moment exists on the portion of the tubesheet, which serves as the flange, and the effects of this moment must be evaluated. The TEMA standard requires that these conditions be evaluated using the rules in the ASME Code, Appendix 2. Those rules, in turn, require the complete evaluation of bending moments on the flange. It is those bending moment calculations, which are reflected in this section of the output. The flange design rules in PD:5500 are also very similar to the ASME Appendix 2 rules. These calculations represent the basic bolt loading for the flanged portion of the tubesheet, and will be the same for the mating flange. The actual bending moments may change when compared to the mating flange. The flanged extension of the tubesheet is calculated as a ring type flange. Since no stresses are shown, you need to check the adequacy of the bolting by comparing the required bolt area to the actual bolt area. The bolt spacing correction factor is automatically included in the bending moment, such that the moment is the force times the distance times the bolt correction.

Geometric Constants, Pressure and Thickness Calculations: The tube diameter, pitch, and pattern are used to calculate the term 'eta' in the tubesheet thickness equation. These rules are same for triangular, rotated triangular, square, and rotated square layouts. When a tubesheet may be controlled by shear stress, the program requires the perimeter and area of the tubesheet for the shear calculation. You will receive an error message when these values are required but not given. The result will be conservative if you overestimate the area and underestimate the perimeter. The G dimension is calculated based on the exchanger type and either the diameter of the pressure component or the mean diameter of the gasket. TEMA standard states that for all the floating tubesheet (except divided), the G shall be the G used for the stationary tubesheet. The T type floating tubesheet should also be checked with actual gasket G of the floating tubesheet. In these cases, user can enter the G dimension of the stationary tubesheet. Similarly, the F dimension is calculated based on the exchanger type and the type of connection to the shell and channel. These calculations are based on Table RCB-7.132 and Table RCB-7.133.

Differential Expansion Pressure: The program contains tables of Young's modulus and the coefficient of thermal expansion. It selects these values from the tables based on the materials classification you enter on the Material Editing screen of the input spreadsheet. You should verify that the program has selected the right identification number for the material. You should also check the values to ensure that they agree with your expectations. A good place to find this data, and the source of these tables in the program, is the TEMA Standard, tables D-10 and D-11. The following table displays the program identification numbers for the materials in this standard:


17-32

TUBESHEETS

Chart Number

Cross Ref. to Elastic Chart

Chart Name

1

3

TE-1 : Carbon and Low Alloy Steels

2

4

B31.3 : 5Cr - 9Cr

3

6

B31.3 : 18Cr - 8Ni

4

6

TE-1 : 27Cr

5

6

B31.3 : 25Cr20Ni

6

8

B31.3 : 67Ni30Cu

7

1

B31.3 : 3.5Ni

8

10

B31.3 : Aluminum

9

7

B31.3 : Cast Iron

10

13

B31.3 : Bronze

11

12

B31.3 : Brass

12

9

B31.3 : 70 Cu - 30Ni

13

6

B31.3 : Ni - Fe - Cr

14

6

B31.3 : Ni - Cr - Fe

15

7

B31.3 : Ductile Iron

16

14

TEMA : Plain Carbon Stl & C - Mn Stl.

17

14

TEMA : C - Si, C - 1/2Mo & Cr - 1/2Mo

18

14

TEMA : C - Mn - Si, 1-1/4Cr - 1/2Mo & 3Cr - 1Mo

19

14

TEMA : Mn - Mo

20

20

TEMA : 2 - 1/2 & 3 - 1/2Ni

21

17

TEMA : 2 - 1/4Cr - 1Mo

22

18

TEMA : 5Cr - 1/2Mo

23

18

TEMA : 7Cr - 1/2Mo & 9Cr - 1Mo

24

19

TEMA : 12Cr & 13Cr

25

19

TEMA : 15Cr & 17 Cr

26

15

TEMA : TP316 & TP317

27

15

TEMA : TP304

28

15

TEMA : TP321

29

15

TEMA : TP347

30

15

TEMA : 25 Cr-12Ni, 23 Cr-12Ni, 25Cr-20Ni

31

23

TEMA : Aluminum 3003

32

23

TEMA : Aluminum 6061



17-33

Chart Number

Cross Ref. to Elastic Chart

Chart Name

33

32

TEMA : Titanium, Grades 1, 2, 3, 7

34

21

TEMA : Ni-Cu (Alloy 400)

35

24

TEMA : Ni - Cr - Cr - Fe (Alloy 600)

36

25

TEMA : Ni - Fe - Cr (Alloy 800 & 800H)

37

35

TEMA : Ni - Fe - Cr - Mo - Cu (Alloy 825)

38

34

TEMA : Ni - Mo (Alloy B)

39

27

TEMA : Ni - Mo-Cr (Alloy 276)

40

28

TEMA : Nickel (Alloy 200)

41

33

TEMA : 70-30 Cu - Ni

42

22

TEMA : 90 - 10 & 80 - 20 Cu - Ni

43

29

TEMA : Copper

44

30

TEMA : Brass

45

29

TEMA : Aluminum Bronze

46

29

TEMA : Copper - Silicon

47

31

TEMA : Admiralty

48

37

TEMA : Zirconium

49

15

TEMA : Cr - Ni - Fe - Mo - Cu - Cb (Alloy 20Cb)

50

38

TEMA : Ni - Cr -Mo - Cb (Alloy 625)

51

39

TEMA : Tantalum

52

40

TEMA : Tantalum with 2.5% Tungsten

53

43

TEMA : 17 - 19 CR ( TP 439 )

54

44

TEMA : AL-6XN

55

47

TEMA : 2205 (S311803)

56

48

TEMA : 3RE60 (S31500)

57

41

TEMA : 7 MO (S32900)

58

42

TEMA : 7 MO PLUS (S32950)

59

45

TEMA : AL 29-4-2

60

46

TEMA : SEA-CURE

61

16

TEMA : C-Si, C-1/2 Mo & Cr- 1/2Mo

62

16

TEMA : C-Mn-Si, 1-1/4Cr-1/2Mo & 3 CR - 1Mo

63

17

TEMA : C-Mn-Si 1-1/4Cr-1/2Mo & 3 CR - 1Mo


17-34

TUBESHEETS

When PD:5500 is selected, then the material band is mapped to nearest TEMA number, which is then used to look up the Young's modulus and the coefficient of thermal expansion. This is necessary since 5500 does not provide tables of thermal expansion versus temperature. When a fixed tubesheet is analyzed, the program calculates the following information: 1

The minimum tubesheet thickness per RCB-7.131.

2

The values G, F, and ETA per RCB-7.132 and RCB-7.133

3

The equivalent differential expansion pressure per RCB-7.161

4

The equivalent bolting pressure per RCB-7.162

5

The effective shell side design pressure per RCB-7.163

6

The effective tube side design pressure per RCB-7.164

7

The required thickness per RCB-7.132 or RCB-7.133

8

The shell longitudinal stress per RCB-7.22

9

The tube longitudinal stress per RCB-7.23

10 The allowable tube compressive stress per RCB-7.24 11 The tube to tubesheet joint loads per RCB-7.25 If the tube or shell longitudinal stresses are being exceeded, it can be caused by the differential thermal expansion between the tubes and the shell. For example, when a tube is under compressive stress and the shell is under tensile stress, this indicates that the tube is trying to expand more than the shell. In this case an expansion joint can be used to relieve this axial stress. You can either put a thin expansion joint by checking the appropriate box (designed using the Thin Joint module) or a thick expansion joint (which can be designed the Tubesheet module or the Thick Joint module).

Display of Results on Status Bar As the user enters the data, program performs the calculation and displays the important results on the status bar. Any error messages are also displayed. This allows a quick design of the tubesheet and makes it easier to try various configurations to select the best one. Any failures are indicated in red. Here is a sample:



17-35

Designing a Thick Expansion Joint in the Tubesheet Module: After you input the thick expansion joint geometry in the Tubesheet module, the program uses the following process to design the expansion joint: 1

Compute the expansion joint spring rate

2

Use the expansion joint spring rate in the fixed tubesheet calculations

3

Use the results of the tubesheet calculation, along with the prime pressures (P’s, P’t, Pd) to compute the expansion joint stresses.

4

Run a corresponding expansion joint calculation for each tubesheet load case. The program displays the results for the worst case. (detailed results are also available).

Note: The procedure followed when designing PD:5500 tubesheets is similar to the one shown here.


17-36

TUBESHEETS



CH AP TER

1 8

Chapter 18 WRC 107\FEA In This Chapter Introduction ................................................................................ 18-2 Discussion of Input ..................................................................... 18-3 Discussion of Results.................................................................. 18-18 Example ...................................................................................... 18-27


18-2

WRC 107\FEA

Introduction This chapter discusses the WRC 107/FEA Module in PVElite. To begin, make sure that the current analysis type is WRC 107/FEA. This can be determined when viewing the MAIN MENU. There is also an interface for performing finite element analysis (FEA) of nozzle-shell junctions. WRC 107 is a method for determining stresses on the shell of a vessel when a nozzle or some rectangular attachment is being loaded. A typical case is to analyze the vessel stresses on a nozzle due to external piping loads. These loads are obtained from a piping flexibility analysis. This type of stress analysis is based on "Local Stresses in Spherical and Cylindrical Shells due to External Loadings," Welding Research Council Bulletin 107, August 1965, and revision 1979, based on the prior work of P.P. Bijlaard. There is also a stress summation capability. The program computes overall stress intensities on a vessel/nozzle intersection in accordance with ASME Section VIII Division 2. Local vessel stress calculations for sustained, expansion, and occasional loads along with pressure stresses are transformed into code-defined stress components. The output, in the form of Pm, Pl, and Q and their appropriate combinations, can be compared with Section VIII Div. 2 allowable values. There are times when the applicability of the WRC bulletin 107 is in question or a particular design is out of the scope of the bulletin. Examples include large nozzles, hillside nozzles, and lateral nozzles. In these cases and others, FEA is the best way to get accurate results. The FEA interface in PVElite uses an encapsulated finite element program (NozzlePro) available from Paulin Research Group (www.paulin.com). To run the FEA, the user should purchase the NozzlePro program and install it. Then from the TOOLS MENU, choose CONFIGURATION and click on MISCELLANEOUS and set the path to the installation directory of NozzlePro. PVElite will automatically run it and present the results on the PVElite screen.


Chapter 18 WRC 107\FEA

18-3

Discussion of Input Main Input Fields Enter the Attachment Number for this Analysis The attachment number should start out at 1 and continue by ones for each successive attachment to be analyzed. These whole integer numbers will be reflected in the input echo generated by the program. This number can be between up to 5 digits in length.

Enter the Attachment Description for this Analysis The Description ID can be any combination of numbers and letters up to 15 characters. This label is for user reference and should be meaningful for the analysis. In addition, note that the attachment description will be reflected in the output and also in the display of errors (if any exist).

Merge Use this option to bring in data from the Shells and Heads module. Just select the shell you want to model this nozzle with, and all the appropriate data will be brought in from that shell.

Import Nozzle Data Imports nozzle information from a PVElite input file (.pvi).

Choose the Analysis Type Between WRC 107 and FEA To perform a Finite Element Analysis (FEA) on the nozzle-vessel junction, you must purchase Nozzle Pro from the Paulin Research Group (www.paulin.com) and install it on your computer or network. Then enter the Nozzle Pro installation path in CodeCalc, from the TOOLS menu, choose CONFIGURATION and click MISCELLANEOUS. Some additional input will be required before performing the FEA run.

Select the Attachment Type For WRC 107 analysis possible options are: Typical Pipe Nozzle Square Attachment ( lug type ) Rectangular Attachment ( lug type ) If the attachment in question is a pipe nozzle then select ‘Round’. WRC 107 also analyzes other load bearing attachments such as square or rectangle. An example of a rectangular attachment is a vessel support lug. Illustrations of these attachments can be seen in the WRC107 bulletin. At this time FEA can only be performed on round attachments.

Hollow or Solid Attachment This input is only required for performing a WRC 107 analysis.. One may note that round-hollow attachments are converted to round-solid attachments for the cylinder to cylinder case. In addition, rectangular attachments on


18-4

WRC 107\FEA

spherical shells cannot be analyzed using this method. Also, round-hollow attachments are analyzed on spherical vessels.

Enter the Type of Vessel Being Analyzed The Welding Research Council Bulletin #107 recognizes two types of vessels in which the stress intensities can be calculated. These are cylindrical and spherical vessels. If users decide to perform a finite element analysis then the following vessel types are permitted: Cylindrical Spherical Elliptical Torispherical Conical Flat Head

Enter The Diameter Basis For The Vessel If the vessel on which you are analyzing has dimensions specified based on the inside diameter, choose ID. If the diameter basis is outside, choose OD. These are the only acceptable inputs for this cell.

Diameter of Vessel Enter the diameter of the vessel in the units displayed. The diameter basis for the vessel is a user defined value and appears above with the vessel wall thickness, diameter basis and corrosion allowance known, PVElite will automatically determine the mean radius.

Enter The Vessel Wall Thickness Enter the thickness of the vessel wall in this field. If, the vessel in question is pipe and a 12.5 % mill tolerance is wished to be used then enter the actual thickness of the vessel wall times 0.875. PVElite does not make any modification to this value unless a corrosion allowance is specified.

Enter The Corrosion Allowance of The Vessel If a corrosion allowance is to be used then enter it in this field. The vessel wall thickness will be decreased by this amount and the mean radius will be adjusted accordingly.

Material Name Click the Material Database button to look up a material name from the database. Click the Material Edit Properties button to change the properties of the selected material. If you type the name in this input cell, it will retrieve the first material it finds with a matching name. Some typical material names (standard ASME material):



18-5

Plates & Bolting SA-516 55 SA-516 60 SA-516 65 SA-516 70 SA-193 B7 SA-182-F1 SA-182 F1 SA-182 F11 SA-182 F12 SA-182 F22 SA-105 SA-36 SA-106 B Stainless Steels SA-240 304 SA-240 304L SA-240 316 SA-240 316L SA-193 B8 Aluminum SB-209 SB-234 Titanium SB-265 1 Nickel SB-409 SB-424

Enter the Attachment Type that is Being Analyzed If the attachment in question is a pipe nozzle then select round. WRC 107 also analyzes other load bearing attachments such as square or rectangle. An example of a rectangular attachment is a vessel support lug. Illustrations of these attachments can be seen in the WRC107 bulletin.

Input Vessel Fatigue Curve Select the fatigue curve based on the type of material. Fatigue curves are listed in ASME Section VIII, Division 2, Appendix 5. Possible entries are:


18-6

WRC 107\FEA

S. Number

Material

1

Low Carbon Steels, UTS <130 ksi

2

Low Alloy Steels to 700 degree F

3

Martensitic Stainless Steels to 700 degree F

4

Austenitic Stainless Steels to 700 degree F

5

Wrought 70 Copper, 30 Nickel.

6

Nickel-Chromium-Moly-Iron Alloys up to 800 degree F

Input Loads in WRC 107 Convention Check this field if you would like to input the forces and moments in the traditional WRC107 convention. Users can choose between the WRC convention system or the global coordinates system to define the vessel, nozzle and the loads. Both conventions allow you to enter the loads in categories such as sustained, or occasional and will compare the respective stress intensities to their allowables if at least the sustained loadings are entered. Additionally users can use either convention system to enter loads and to perform a finite element analysis. Users should also specify the vessel allowables. For more information refer to the explanation and illustration of this convention later in this chapter.

Input Loads in Global Coordinates and Allowable Stresses Check this field if you would like to input loads in the Global Coordinates system. For more information refer to the detailed explanation and illustration of this convention.

Design Pressure Enter the design pressure of the vessel in this field using the units above. The pressure stress equation is of the following form: Longitudinal Stress = Pressure * ri2 / ( ro2 - ri2 ) Hoop Stress = 2 * Longitudinal Stress. For the spherical case the membrane stress due to internal pressure uses the Lame type equation to compute the stress at both the upper and lower surfaces of the vessel at the edge of the attachment. When performing a finite element analysis, enter the internal pressure as positive and the external pressure as negative. WRC 107 can only analyze internal pressure.

Include Pressure Thrust Force Check this box if you wish to include the pressure thrust force (P*A) as part of the radial load. This value is used only if the user is performing WRC 107 analysis. The Nozzle Pro program, used for FEA, applies the complete pressure thrust load on the nozzle. For more information on pressure thrust see "Modeling of Internal Pressure and Thrust Loads on Nozzles Using WRC-368" in the July 2001 edition of the COADE Mechanical Engineering News (pages 9-13) or via our Website www.coade.com/newsletters/jul01.pdf.



18-7

Internal Pressure (Pvar) design Enter the DIFFERENCE between the peak pressure of the system and the system design pressure. It will always be a positive (or 0) entry. The additional thrust load due to this pressure difference will also be accounted for in the nozzle radial loading UNLESS the box to Include Pressure Thrust is unchecked. This entry will be superimposed onto the system pressure to evaluate the primary membrane stress due to occasional loads. This value is used only if the user is performing WRC 107 analysis.

Forces/Moments (SUS, EXP, OCC) Enter the value of the nozzle loads from the Restraint Summary of the CAESAR II output and/or other calculations. Enter these loads in either in WRC-107 or in global conventions. Three loading sets may be included in these calculations. For WRC 107, enter the loads according to each category shown on the screen, where: SUS

Primary Loads (typically Weight+Pressure+Forces)

EXP

Secondary Loads (Thermal Expansion)

OCC

Occasional Loads (typically Wind, Seismic)

For FEA, enter the loads according to each category shown on the screen, where: SUS

Primary Loads (typically Weight+Pressure+Forces)

OPE

Operating Loads (typically Weight+Disp+Temp+Pressure+Forces)

OCC

Occasional Loads (typically Wind, Seismic)

The Stress Summation will be performed and the stress intensities will be checked based on the different load cases. Examples of Occasional loads are wind/seismic loads or from some occasional conditions such as water hammer.

Radial Load (P) Enter the value for the load, which is trying to push or pull the nozzle in/out of the vessel. Positive loads try to "push" the nozzle while negative loads try to "pull" the nozzle. The program can also account for the effect of pressure thrust if the corresponding box is checked.

Circumferential Shear Load (VC or V2) Enter the circumferential shear load VC from B to A in the units above. If the vessel is spherical then enter the shear load V2 from D to C.

Longitudinal Shear Load (VL or V1) Enter the longitudinal shear load VL from D to C in the units above. If the vessel is spherical then enter the shear load V1 from B to A.

Circumferential Moment (MC) Enter the circumferential moment MC or M1 in the units displayed above.


18-8

WRC 107\FEA

Longitudinal Moment (ML) Enter the longitudinal moment ML or M2 in the units displayed above.

Torsional Moment (MT) Enter the torsional moment in the units displayed above. For more information refer to Figure D for the WRC 107 Load Convention.

Vessel/Nozzle Centerline Direction Cosines For a finite element analysis the direction cosines are used to determine the angle between the nozzle and the vessel. Also note that the direction for a conical vessel is from the large end to small end. For WRC 107 analysis the centerlines of the vessel and nozzle must be perpendicular to each other. The direction vectors of the vessel and the nozzle centerline must NOT be collinear. In the global convention system users define the vessel and nozzle direction cosines with respect to a global axis. Then, defines the loads with respect to the same global axis. This system is especially useful when nozzle (or attachment) loads are computed from an analysis such as a pipe stress analysis in the global convention which can then be entered directly in to the program using the global convention system. The program uses the direction vectors to transfer the global forces and moments from a piping program such as CAESAR II (for each load case) into the traditional WRC 107 sign/load convention. Note: The sign of the vessel centerline direction vector can be positive or negative and follows the location of data point (A-D) convention defined by WRC 107, e.g. for vertical vessels, if point A is at the bottom of the nozzle, then the Y direction cosine of the vessel will be -1.0. Remember points A and B always lie along the direction of the vessel. The nozzle direction vector is defined as a vector pointing from the nozzle connection to the centerline of the vessel. For more information see Figure G for the Vessel/Nozzle Direction Cosines

Pop-Up Input Fields Enter the Diameter Basis for the Nozzle If the junction that is being analyzed is a nozzle, enter the diameter basis here. Select the nozzle's diameter basis from the pull-down menu.

Nozzle Wall Thickness Enter the nozzle wall thickness. WRC 107 will use this thickness when the hollow attachment is used. If the standard 12.5% mill tolerance is to be deducted, simply multiply the standard wall thickness by 0.875 directly on the spreadsheet.

Nozzle Diameter Enter the nozzle diameter. Both the nozzle diameter and thickness must be specified. The nozzle diameter should be entered in accordance with the nozzle diameter basis. The units are displayed above.



18-9

Nozzle Corrosion Allowance Enter the corrosion allowance for the nozzle.

Material Name Click the Material Database button to look up a material name from the Material Database. Click the Material Edit Properties button to change the properties of the selected material. If you type the name in this input cell, it will retrieve the first material it finds with a matching name. Some typical material names (standard ASME material name):


18-10

WRC 107\FEA

Plates & Bolting SA-516 55 SA-516 60 SA-516 65 SA-516 70 SA-193 B7 SA-182-F1 SA-182 F1 SA-182 F11 SA-182 F12 SA-182 F22 SA-105 SA-36 SA-106 B Stainless Steels SA-240 304 SA-240 304L SA-240 316 SA-240 316L SA-193 B8 Aluminum SB-209 SB-234 Titanium SB-265 1 Nickel SB-409 SB-424

Reinforcement Select the type of reinforcement (if present) from the list. Selecting a reinforcement type causes a pop-up window to appear for prompts concerning reinforcing pad or hub dimensions. In a finite element analysis attachments can have a reinforcement pad or hub type self-reinforcement. Results are available for the some critical locations such as the nozzle-shell junction and the edge of the pad. While in WRC 107 analysis (due to the limitations of the bulletin) only the reinforcement pad can be considered. When the reinforcing pad dimensions are included the program performs two analyses for this situation. The first analysis uses the nozzle OD and the vessel wall thickness plus the reinforcing pad thickness. The second analysis takes the pad into account by making the nozzle OD equal to the reinforcing pad diameter and assuming a solid attachment.



18-11

Parameter C11 (Full Length of Attachment) Attachments other than nozzles can be analyzed using the WRC 107 method. The dimension C11 is the FULL length of the attachment in the circumferential direction. Most often these types of attachments are lifting lugs or vessel support lugs.

Parameter C22 (Full Length of Attachment) The parameter C22 is the FULL length of the attachment in the longitudinal direction.

Pad Diameter Enter the diameter of the reinforcing pad along the surface of the vessel. This information will be used to calculate the stresses at the edge of the reinforcing pad using a solid attachment model. The reinforcement pad is explicitly modeled in the finite element analysis.

Pad Thickness Enter the thickness of the reinforcing pad. If external corrosion is to be considered, enter the corroded pad thickness. In WRC 107, when a pad is used the combined vessel+pad thickness is used for the stress computation at the edge of the nozzle. The corroded vessel thickness is used for the stress computation at the edge of the pad. The reinforcement pad is explicitly modeled in the finite element analysis.

Enter Pad Parameter C11(Full Length) With square/rectangle attachment, enter the FULL length of the PAD in the circumferential direction. The definition of C1 in WRC 107 is the half length of the attachment in the circumferential direction. The change was made for user convenience.

Enter Pad Parameter C22 (Full Length) With square/rectangle attachment, enter the FULL length of the PAD in the longitudinal direction. The definition of C1 in WRC 107 is the half length of the attachment in the longitudinal direction. The change was made for user convenience.

Hub Thickness/Hub Height/Bevel Height Enter the appropriate dimension based on the diagram below.

Figure A - Hub Nozzle Dimensions


18-12

WRC 107\FEA

Insert or Abutting Nozzle? If the nozzle is welded to the outside of the vessel wall, it is abutting the vessel wall. If the hole in the vessel is bigger than the nozzle OD and the nozzle is welded into the hole, it is inserted.

Nozzle Outside Projection Enter the projection of the nozzle from the vessel wall to the nozzle flange.

Nozzle Inside Projection Enter the projection of the nozzle into the vessel, measured along the centerline of the nozzle.

Thickness of Nozzle Insert (if Different) Enter the thickness of the internally projected part of the nozzle, if it is different from the nozzle thickness.

Weld Leg Size for Fillet between Nozzle and Shell / Pad It is an optional field. Enter the fillet leg size.

Input Nozzle Fatigue Curve Select the fatigue curve based on the type of material. Fatigue curves are listed in ASME Section VIII, Division 2, Appendix 5. Possible entries are. This input is only required if you performing fatigue analysis using the FEA option.

S. Number

Material

1

Low Carbon Steels, UTS <130 ksi

2

Low Alloy Steels to 700 degree F

3

Martensitic Stainless Steels to 700 degree F

4

Austenitic Stainless Steels to 700 degree F

5

Wrought 70 Copper, 30 Nickel.

6

Nickel-Chromium-Moly-Iron Alloys up to 800 degree F

Design Length of Section Enter the total length of the cylinder or a conical geometry.

Attached Shell Length This is an optional entry. Enter the length of the shell attached to the head. Set this value based on the proximity of the nozzle to the edge of the head, and of the concern for any discontinuity stress in this area.

Attached Shell Thickness This is an optional entry. Enter the thickness of the shell attached to the head. Set this value based on the proximity of the nozzle to the edge of the head, and of the concern for any discontinuity stress in this area. If left blank this entry defaults to the thickness of the head.



18-13

Aspect Ratio for Elliptical Heads The aspect ratio is the ratio of the major axis to the minor axis for the ellipse. For a standard 2:1 elliptical head the aspect ratio is 2.0.

Length of Straight Flange Enter the length of straight flange portion for Conical or Torispherical heads.

Inside Crown Radius for Torispherical Heads The crown radius for a torispherical head is referred to as the dimension L, per ASME Section VIII Div. 1. This dimension is usually referred to as "DR" in many head catalogues. Even though the head catalogues list these heads as being "OD" heads, the crown radius is given on the inside diameter basis. Note the illustrated picture in the catalogue and where the arrows for "DR" and "IKR" points to the inside of the head. For more information see Appendix 1-4 in the Code

Inside Knuckle Radius for Torispherical Heads This dimension is r, per ASME Section VIII Div. 1. This dimension is usually referred to as "IKR" in many head catalogues. Even though the head catalogues list these heads as being "OD" heads, the knuckle radius is given on the inside diameter basis. Note the illustrated picture in the catalogue and where the arrows for "DR" and "IKR" points to the inside of the head. For more information see Appendix 1-4 in the Code

Small End Diameter Enter the small end diameter for the cone.

Is There a Knuckle? Check here if this cone has a knuckle.

Knuckle Radius at Small End Enter the knuckle radius of the small end. Direction of a conical head or shell is from the large end to the small end. So, the positive vertical direction is when the large end of the cone is the bottom end and the small end of the cone is the top end.

Knuckle Radius at Large End Enter the Knuckle radius of the large end. Direction of a conical head or shell is from the large end to the small end. So, the large end of the cone is the bottom end and the small end of the cone is the top end.

Compute Maximum Radial Force/Compute Maximum Circumferential Moment/Compute Maximum Longitudinal Moment Often times a vessel designer would like to determine the maximum force or moment on an attachment while keeping the other 5 constant. By checking to one of these fields PVElite will iterate and determine the maximum force or moment to produce a desired stress intensity. If your geometry includes a reinforcing pad, PVElite will perform the same type analysis at the edge of the reinforcing pad. The above loads produce the highest local bending loads and will usually govern the design. This is why the shear loads and torsional moment are not options.


18-14

WRC 107\FEA

Compare Maximum Stress Intensity to This entry should be a stress value between 1.5 - 3 times the hot allowable stress for the vessel material as taken from Section II Part D of the ASME Code. The allowable used depends upon the type of loads. For example if the load is of sustained type (pressure, weight) then the allowable should be 1.5*hot allowable stress or if the loads are from thermal expansion then the allowable should be 3.0*hot allowable stress. PVElite will use this number to compare computed stress intensities if one of the Compute Maximum fields was checked. Note that in the results PVElite performs the analysis using the input values. After that has been completed, PVElite will then iterate for the maximum force or moment as it has been instructed to.

Override Angle Between Nozzle and Vessel? The program computes the angle between the vessel and the nozzle by taking the dot product between their direction cosines. Click here to override that computed value of angle. This value is used only for FEA.

Nozzle Orientation Reference Vector The nozzle orientation reference vector defines the reference axis from where the orientation of the nozzle can be measured by the nozzle orientation angle. For example, if nozzle orientation reference axis is along x-axis and nozzle orientation angle is zero then the nozzle is located along the x-axis as seen in figure below.

Figure B - Nozzle Orientation Angle from the Reference Vector

Nozzle Orientation Angle from the Reference Vector This is the angle that describes the nozzle position around the circumference of the vessel from the orientation reference vector. The reference orientation vector should be entered above on this dialog. For example, if the nozzle orientation reference axis is along the x-axis and the nozzle orientation angle is zero then the nozzle is located along the x-axis as seen in the previous figure.

Nozzle Offset from the Vessel Centerline Enter the offset distance from the Shell/Head Centerline to the Nozzle Centerline.



18-15

Nozzle Distance from Top End of the Vessel Enter the distance from the positive end of the vessel to the point where the nozzle or branch centerline intersects the vessel centerline.

WRC 107 Additional Input WRC 107 Version There are 3 options available here. The first option is the original August 1965 version of this industry standard. The second option is the March 1979 and option 3 is the March 1979 use B1 and B2. In 1979 the Welding Research Council noted that if certain curves were flipped, the computed stress results matched theoretical results more closely. In that same year an adjustment was made to allow this stress computation method to compute a maximum stress that did not lie on the stress points A, B, C or D. This is referred to as computation of the off-angle maximums. Thus, we can infer the third option is probably the most accurate.

Use Interactive Control In many instances, the geometric parameter Beta, which is computed for cylindrical shell geometry's, exceeds the parameter Gamma for certain WRC107 curves. When this occurs PVElite will pause and display a message "Beta too Big" or "Beta too Small". If the response to Use Interactive Control is "No" then PVElite will use the last point on the curve that is available. If the response to Interactive Control is "Yes" PVElite an optional input will pause and ask you to enter what you believe the value of the stress parameter should be. This will involve having the WRC107 bulletin with all of the curves available.

Include WRC 107 SIF (Kn,Kb) Check this field to include the WRC 107 Stress Concentrations (Kn & Kb). The program will estimate and use the stress concentration factors Kn and Kb per Appendix B of the WRC-107 Bulletin. For normal analysis, do not check this field. And DO NOT check the next field Pressure Stress Indices Per Div. 2. They should be checked when fatigue analysis is required. You may check ASME VIII Div.2 AD-160 to see if you need to consider fatigue effect. Please note that the program currently DOES NOT perform the fatigue analysis per Div.2 Appendix 4 & 5 rules. The program simply multiplies the stresses by the factors and/or indices to compute the peak stresses. These peak stresses can then be manually used to perform fatigue evaluation. For more information on fatigue analysis see "WRC-107 Elastic Analysis v/s Fatigue Analysis". You can access this information in the June 2000 edition of the COADE Mechanical Engineering News (pages 24-28) or via our Website www.coade.com/newsletters/jun00.pdf.

Fillet Radius Between Vessel & Nozzle (r) Enter the fillet radius between the nozzle and the vessel shell. The program will use this value to calculate the stress concentration factors Kn and Kb per Appendix B of the WRC-107 Bulletin. Entering 0 here will set Kn and KB = 1.0. If you have a re-pad, the same Kn and Kb will be used for the vessel and pad intersection.


18-16

WRC 107\FEA

Include Pressure Stress Indices Check this field to include the stress indices described in ASME Sec. VIII Div. 2, primarily to account for the stress intensification at vessel-nozzle junction under internal pressure. They are used to compute peak stresses, which are needed to perform fatigue analysis. The stress indices can be found in the Table AD-560.7 of the Code.

Compute Pressure Stress per WRC-368 Check this box to compute pressure, stresses in the shell and nozzle per WRC-368. WRC-368 provides a method for calculating the stresses in cylinder to cylinder intersections (such as cylinder to nozzle junction), due to the internal pressure and radial thrust loadings. Note: Using WRC-368 along with WRC 107/297 is not accurate when calculating the combined stress from pressure and external loads. For more information on WRC-368 pressure thrust see "Modeling of Internal Pressure and Thrust Loads on Nozzles Using WRC-368". You can access this information in the July 2001 edition of the COADE Mechanical Engineering News (pages 9-13) or via our Website www.coade.com/newsletters/jul01.pdf.

FEA Additional Input Specify File Name for FEA Enter the file name that will form the prefix for the FEA analysis files. Filenames can be any alphanumeric combination up to 7 characters in length without quotes and spaces. For example, noz and b012.

Specify FEA Mesh Density Select the type of mesh: Fine or Crude. When the user selects a fine mesh they will be prompted to specify the mesh density multiplier. A higher mesh density value produces a finer finite element mesh. Which produces more accurate results but takes more time to solve. Typical values are between 1-2. The CRUDE MESH option along with the PREVIEW THE FINITE ELEMENT MESH option can be used to check the initial mesh.

Specify S.C.F. for Vessel This is an optional input. This is the Notch Effect Multiplication factor for computing the peak stresses. They are defined in the ASME Section VIII, Division 2 Appendix 4. A typical value is 1.35. They will only affect the fatigue failure stress case.

Specify S.C.F. for Nozzle This is an optional input. This is the Notch Effect Multiplication factor for computing the peak stresses. They are defined in the ASME Section VIII, Division 2 Appendix 4. A typical value is 1.35. They will only affect the fatigue failure stress case.



18-17

Number of Operating Cycles This is an optional input. Used only to select the allowable fatigue stress from S-N curves. It defaults to 7000 cycles if not specified or if 0.

Number of Occasional Cycles This is an optional input. If zero then the occasional load is treated like a static load. If non-zero then it will be assumed that occasional load input is the "range" of occasional loads, and a fatigue analysis of occasional loads will be performed.

Do Not Cut Hole in Header for Branch? Check this box if there is no opening in the vessel due to the nozzle. For example, in case of a support trunnion there will not be an opening whereas an injector pipe will have one.

Consider Thermal Strains? Check this box if the nozzle and vessel are at different temperatures or, if there is a through the wall temperature gradient. Most analysis of single nozzles in pressure vessels "do not" require the analysis of thermal strains.

Vessel Inside Temperature, Vessel Outside Temperature, Nozzle Inside Temperature and Nozzle Outside Temperature Enter the inside and outside surface temperatures for the nozzle and the vessel, used for computing the thermal expansion.

Run Analysis in Silent Mode? Check this box to run in silent mode. In silent mode, when the program is running, the status windows from NozzlePro will not be visible. In some cases these windows provide additional information about possible errors.

Preview the Finite Element Mesh? Check this box to preview the finite element mesh for this problem. Then on running the analysis the finite element mesh will be shown.


18-18

WRC 107\FEA

Discussion of Results WRC 107 Stress Calculations The program computes stress intensities in accordance with WRC 107 and includes the effects of longitudinal and hoop stresses due to internal pressure. If the geometry includes a reinforcing pad, PVElite will perform two analyses on the geometry. The first analysis will compute the stresses at the edge of the nozzle. The second stress analysis will be at the edge of the reinforcing pad. PVElite uses the Lamé equation to determine the exact hoop stress at the upper and lower surface of the cylinder around the edge of the attachment. The hoop stress equations, as well as the longitudinal stress equation are as follows:

For spherical shells the program uses the following equation:

For each run performed a table of dimensionless stress factors for each loading will be displayed for review. Any table figure followed by an exclamation point (!) means that the curve figure for that loading has been exceeded.

Why are the stresses at Edge of the Pad the same as at the Edge of the Nozzle? Since the stress is a direct product of the stress factor, the stresses computed at the edge of the pad may be same as those at the edge of the nozzle if the curve parameter for that type of stress has been exceeded.

What are the Allowable Stresses? The stress intensities computed should typically be between 1.5 and 3.0 times the hot allowable stress for the vessel material at operating temperature. If the results are less than 1.5 Sa then the configuration and loading are acceptable. If the load is self-relieving, that is if it would relax or disappear after only a small rotation or translation of the attachment, the allowable stress intensity would increase to 3.0 Sa. Since many geometries do not fall within the acceptable range of WRC107, it may be necessary to use a more sophisticated tool to solve the problems where the diameter of the vessel is very large in comparison with the nozzle or where the thickness of the vessel or nozzle is small. An example of a more sophisticated tool would be a FEA (finite element analysis) program.



18-19

Figure C - WRC 107 Module Geometry for a Sphere

Figure D - WRC 107 Axis Convention for a Cylinder.

Spherical Shells

Cylindrical Shells


18-20

WRC 107\FEA

Spherical Shells

Cylindrical Shells

To Define WRC Axes:

To Define WRC Axes:

1. P-axis: Along the Nozzle centerline and positive entering the vessel.

1. P-axis: Along the Nozzle centerline and positive entering the vessel.

2. M1-axis: Perpendicular to the nozzle centerline along convenient global axis.

2 . MC-axis: Along the vessel centerline and positive to correspond with any parallel global axis.

3. M2-axis: Cross the P-axis into the M1 axis and the result is the M2-axis. To Define WRC Stress Points: u—upper, means stress on outside of vessel wall at junction. l—lower, means stress on inside of vessel at junction. A—Position on vessel at junction, along negative M1 axis. B—Position on vessel at junction, along positive M2 axis. C—Position on vessel at junction, along positive M2 axis. D—Position on vessel at junction, along negative M2 axis.

3. M2-axis: Cross the P-axis with the MC axis and the result is the ML-axis. To Define WRC Stress Points: u—upper, means stress on outside of vessel wall at junction. l—lower, means stress on inside of vessel at junction. A—Position on vessel at junction, along negative MC axis. B—Position on vessel at junction, along positive MC axis. C—Position on vessel at junction, along positive ML axis. D—Position on vessel at junction, along negative ML axis. Note: Shear axis "VC" is parallel, and in the same direction as the bending axis "ML." Shear axis "VL" is parallel, and in the opposite direction as the bending axis "MC."

WRC107 Stress Summations The ASME Section VIII, Division 2 code provides for a fairly elaborate procedure to analyze the local stresses in vessels and nozzles (Appendix 4-1 "Mandatory Design Based On Stress Analysis"). Only the elastic analysis approach will be discussed here. You should always refer to the applicable code if any of the limits described in this section are approached, or if any unusual material, weld, or stress situation exists, or there are non-linear concerns such as the material's operation in the creep range. The first step in the procedure is to determine if the elastic approach is satisfactory. Section AD-160 contains the exact method and basically states that if all of the following conditions are met, then fatigue analysis need not be done: a

The expected design number of full-range pressure cycles does not exceed the number of allowed cycles corresponding to an Sa value of 3Sm (4Sm for non-integral attachments) on the material fatigue curve. The Sm is the allowable stress intensity for the material at the operating temperature.

b

The expected design range of pressure cycles other than startup or shutdown must be less than 1/3 (1/4 for nonintegral attachments) the design pressure times (Sa/Sm), where Sa is the value obtained on the material fatigue curve for the specified number of significant pressure fluctuations.

c

The vessel does not experience localized high stress due to heating.

d

The full range of stress intensities due to mechanical loads (including piping reactions) does not exceed Sa from the fatigue curve for the expected number of load fluctuations.



18-21

Once the user has decided that an elastic analysis will be satisfactory, either a simplified or a comprehensive approach may be taken to the vessel stress evaluation. Both methods will be described in detail below, after a discussion of the Section VIII Div. 2 Requirements.

ASME Section VIII Division 2 - Elastic Analysis of Nozzle Ideally in order to address the local allowable stress problem, the user should have the endurance curve for the material of construction and complete design pressure/temperature loading information. If any of the elastic limits are approached, or if there is anything out of the ordinary about the nozzle/vessel connection design, the code should be carefully consulted before performing the local stress analysis. The material Sm table and the endurance curve for carbon steels are given in this section for illustration. Only values taken directly from the code should be used in design. There are essentially three criteria that must be satisfied before the stresses in the vessel wall due to nozzle loads can be considered within the allowables. These three criteria can be summarized as: Pm < kSmh Pm + Pl + Pb< 1.5kSmh Pm + Pl + Pb + Q < 3Smavg Where Pm, Pl, Pb, and Q are the general primary membrane stress, the local primary membrane stress, the local primary bending stress, and the total secondary stresses (membrane plus bending), respectively; and K, Smh, and Smavg are the occasional stress factor, the hot material allowable stress intensity, and the average material stress intensity (Smh + Smc) / 2. Due to the stress classification defined by Section VIII, Division 2 in the vicinity of nozzles, as given in the Table 4120.1, the bending stress terms caused by any external load moments or internal pressure in the vessel wall near a nozzle or other opening, should be classified as Q, or the secondary stresses, regardless of whether they were caused by sustained or expansion loads. This causes Pb to disappear, and leads to a much more detailed classification: Pm - General primary membrane stress (primarily due to internal pressure); Pl - Local primary membrane stress, which may include: Membrane stress due to internal pressure; Local membrane stress due to applied sustained forces and moments. Q - Secondary stresses, which may include: Bending stress due to internal pressure; Bending stress due to applied sustained forces and moments; Membrane stress due to applied expansion forces; Bending stress due to applied expansion forces and moments Membrane tress due to applied expansion moments Each of the stress terms defined in the above classifications contains three parts: two stress components in normal directions and one shear stress component. To combine these stresses, the following rules apply:


18-22

WRC 107\FEA

1

Compute the normal and shear components for each of the three stress types, i.e. Pm, Pl, and Q.

2

Compute the stress intensity due to the Pm and compare it against kSmh.

3

Add the individual normal and shear stress components due to Pm and Pl; compute the resultant stress intensity and compare its value against 1.5kSmh.

4

Add the individual normal and shear stress components due to Pm, Pl, and Q, compute the resultant stress intensity, and compare its value to against 3Smavg.

5

If there is an occasional load as well as a sustained load, these types may be repeated using a k value of 1.2.

These criteria can be readily found from Figure 4-130.1 of Appendix 4 of ASME Section VIII, Division 2 and the surrounding text. Note that the primary bending stress term, Pb, is not applicable to the shell stress evaluation, and therefore disappears from the Section VIII, Division 2 requirements. Under the same analogy, the peak stress limit may also be written as: Pl + Pb + Q + F < Sa The above equation need not be satisfied, provided the elastic limit criteria of AD-160 is met based on the statement explicitly given in Section 5-100, which is cited below: "If the specified operation of the vessel meets all of the conditions of AD-160, no analysis for cyclic operation is required and it may be assumed that the peak stress limit discussed in 4-135 has been satisfied by compliance with the applicable requirements for materials, design, fabrication, testing and inspection of this division."

Example Fatigue Curve (For Values of Sa)

Figure E - Fatigue Curve

The equations used in PVElite to qualify the various stress components can be summarized as follows:



18-23

Pm(SUS) < Smh Pm(SUS + OCC) < 1.2Smh Pm(SUS) + Pl(SUS) < 1.5Smh Pm(SUS + OCC) + Pl(SUS + OCC) < 1.5(1.2)Smh Pm(SUS + OCC) + Pl(SUS + OCC) + Q(SUS + EXP + OCC) < 1.5(Smc + Smh) If some of the conditions of in ASME VIII Div.2, AD-160 are not satisfied, you probably need to perform the formal fatigue analysis. Peak stresses are required to be calculated or estimated. You may consider using AD-560 "Alternative Rules for Nozzle Design" instead of Article 4-6 "Stresses in Openings for Fatigue Evaluation" to calculate the peak pressure stress for the opening. If all conditions of AD-560.1 through AD-560.6 are satisfied, the stress indices given in Table AD-560.7 may be used. If user clicked the corresponding box, the program will use these pressure stress indices to modify the primary stress due to internal pressure (hoop and longitudinal stresses). For external loads, the highest peak stress ais usually localized in fillets and transitions. If the user decides to use WRC107 stress concentration factors (Kn, Kb), the fillet radius between the Vessel and Nozzle is required. (If a reinforcing pad is used, the user can input the pad fillet radius.) The program will make a crude approximation and use WRC107 Appendix-B equations (3) and (4) to estimate Kn and Kb. The tension and bending stresses are thus modified using Kn and Kb respectively. The program outputs the local stresses for 4 pairs of points (upper and lower) at the intersection. The user should not direct the program to perform the stress summations. Instead the user should determine which stresses should be added based on locations in order to obtain the peak stress level, then use Appendix-4 & 5 rules and fatigue curves depending on operation cycles. Based on comparisons with finite element analysis, it is known that the top tip of the fillet weld on the nozzle usually experiences the highest peak stress due to external loads. So it is conservative to add all the peak stresses after including both pressure stress indices and concentration factors. Note that the stress summation may ONLY be used to check stress intensities, not stress levels. You need the peak stress level to perform fatigue analysis. The current stress summation routine does not compare stress level with fatigue allowables per Appendix-5. However, you may find the stress summation results useful to compare the combined effect due to the stress concentration factor and pressure stress indices. For more information on fatigue analysis see "WRC-107 Elastic Analysis v/s Fatigue Analysis". You can access this information in the June 2000 edition of the COADE Mechanical Engineering News (pages 24-28) or via our Website www.coade.com/newsletters/jun00.pdf.

Finite Element Analysis (FEA): Using the interface within PVElite and Paulin Research Group's NozzlePro program, you can perform FEA and WRC 107 within the same module. FEA can model more types of vessel and nozzle geometries. This modules causes the ASME Section VIII Div. 1 allowable stress values, which may be conservative in some cases. Users can modify to Div. 2 values if they want to. FEA generates graphical results showing various ASME stress states. The important results and a sample printout display below. The ASME overstressed areas are reported. ASME Overstressed Areas Pad Edge Weld for Nozzle 1 Pl 1.5(k)Smh Primary Membrane Load Case 2 20,116 18,000 Plot Reference: psi psi 1) Pl < 1.5(k)Smh (SUS,Membrane) Case 2 111%


18-24

WRC 107\FEA

1

The next report, the Highest Primary Stress Report, outlines the stresses at critical location like the nozzle-shell junction and the edge of the pad.

2

The Highest Secondary and fatigue Stress Reports are also provided.

3

Next, the program lists Nozzle Stress Intensification factors for use in a beam type pipe stress analysis program such as CAESAR II.

4

Then NozzlePro computes the maximum individual allowable loads and simultaneously acting allowable loads. Both Primary and Secondary loads are reported. SECONDARY Load

Maximum Individual Occurring

Conservative Simultaneous Occurring

Axial Force (lb.)

398030.

120631.

180946.

Inplane Moment (in. lb.)

5306513.

1137199.

2412363.

Outplane Moment (in. lb.)

3358105.

719650.

1526608.

Torsional Moment (in. lb.)

2343568.

710264.

1065396.

Pressure (psi)

344.

111.

111.

Type (Range):

PRIMARY Load

Realistic Simultaneous Occurring

Maximum Individual Occurring

Conservative Simultaneous Occurring

Realistic Simultaneous Occurring

Axial Force (lb.)

618455.

178300.

267450.

Inplane Moment (in. lb.)

5998639.

1222872.

2594104.

Outplane Moment (in. lb.)

5458219.

1182725.

2508939.

Torsional Moment (in. lb.)

2938301.

847110.

1270665.

Pressure (psi)

422.

111.

111.

Type (Range):

The conservative simultaneous loads will produce stresses that are approximately 60-to-70% of the allowable. The Realistic Allowable Simultaneous loads are the maximum loads that can be applied simultaneously, they produce stresses that are closer to 100% of the allowable. The Maximum Individual Occurring Primary Pressure can be taken as a finite element calculation of the MAWP for the nozzle. Nozzle-Shell junction flexibilities are also available. These flexibilities can be used to accurately model the flexibility of the junction and can be included in the pipe stress program that is used to model the piping system attaching to the nozzle. Thus, users will have a choice of performing either an WRC 107 or a finite element analysis from within the same module, without redundant input. As with any finite element program users should visually check the finite element mesh for errors and make sure the FEA results make sense from stress analysis perspective. Technical queries regarding FEA results should be addressed to Paulin Research Group (www.paulin.com).



18-25

Example Examples illustrating these principles are located in the PVElite\Examples directory.

Figure F - Vessel and Nozzle direction cosines

After confirming that the geometry guidelines per WRC 107 are met, the actual preparation of the WRC 107 calculation input can now begin. One of the most important steps in the WRC 107 procedure is to identify the correlation between the stress output global coordinates and the WRC 107 local axes. PVElite performs this conversion automatically. The user will, however, have to identify the vectors defining the vessel as well as the nozzle centerline. The following figure is provided to illustrate the definition of the direction vectors of the vessel and the nozzle.

Figure G - Converting Forces/Moments in CAESAR II Global Coordinates to WRC 107 Local Axes


18-26

WRC 107\FEA

Notice that in order to define a vessel direction vector, the user first needs to designate the output data points (A->D) as defined by the WRC 107 Bulletin. Note that the line between data points B and A defines the vessel centerline (except for nozzles on heads, where the vessel centerline will have to be defined along a direction which is perpendicular to that of the nozzle). Since, in the vessel/nozzle configuration shown, point A is assigned to the bottom of the nozzle, the vessel direction vector can be written as (0.0, -1.0, 0.0), while the nozzle direction vector is (1.0, 0.0, 0.0). The nozzle direction vector is always defined as the vector pointing from the vessel nozzle connection to the centerline of vessel. For different load cases (SUS, EXP, OCC), the restraint loads (forces and moments) can be obtained from typical piping stress analysis program like CAESAR II. These loads reflect the action of the piping on the vessel. The following data would then be entered into the WRC 107 program. You can use either the WRC-107 or global convention. The program will supply a pass/fail status at the end of the report. While on the input screen you can also toggle from one convention to another and the program will transform the loads automatically between the two conventions. Summary of Restraint Loads on the Vessel Load

X lb

Y lb

Z lb

MX ft. lb

MY ft. lb

MZ ft. lb

Sustained

-26

-1389

32

-65

127

4235

Expansion

8573

23715

-5866

31659

-5414

-525

WRC 107 Local Components Load

Force P(+X)

Force VL(-Y)

Force VC(+Z)

Moment T(-X)

Moment MC (+Y)

Moment ML(+Z)

Sustained

-26

-1389

32

-65

127

4235

Expansion

8573

23715

-5866

31659

-5414

-52583



18-27




CH AP TER

1 9

Chapter 19 LEGS and LUGS In This Chapter Introduction ................................................................................ 19-2 Discussion of Input ..................................................................... 19-3 Vessel Leg Input ......................................................................... 19-12 Leg Results ................................................................................. 19-14 Support Lug Input....................................................................... 19-15 Lifting Lug Input ........................................................................ 19-18 Output ......................................................................................... 19-21 Baseplate Input ........................................................................... 19-22 Baseplate Results ........................................................................ 19-25 Trunnion Input ............................................................................ 19-26 Trunnion Results......................................................................... 19-29 Example ...................................................................................... 19-30


19-2

LEGS and LUGS

Introduction This chapter discusses the LEG & LUG module. To use the LEG & LUG module click on the LEG & LUG icon on the toolbar or select it from the analysis menu. The basic capabilities of the LEG & LUG module are to analyze structural members (legs), support lugs and lifting lugs. The basic required information for each of these analysis types is shown below. Vessel design internal pressure Design temperature for the attachment Vessel outside diameter Weight of vessel operating and dry Vessel dimensions Additional horizontal force on vessel Location of horizontal force above grade


Chapter 19 LEGS and LUGS

19-3

Discussion of Input Main Input Fields The design temperature for the attachment is used to compute the material properties for attachment being analyzed. In most cases the actual attachment temperature will be different from the vessel design temperature. The controlling stress for support lug and vessel leg calculations is the yield stress. The material yield stress can be looked up in the tables in ASME Section II Part D. The weight of the vessel should be the weight of the vessel while it is operating. This should include operating fluid, trays, insulation etc. Support lug calculations should use the same loading conditions. However since vessels are typically lifted "dry" the empty weight of the vessel should be used when performing lifting lug calculations. There is a separate field for lifting weight of the vessel.

Item Number Enter the a positive integer value (i.e. 1) in this cell. This number will not be used in the analysis but will be displayed on the screen while the program is executing.

Vessel Description Enter a meaningful descriptor for this analysis. This will be displayed on the screen and in the output reports. An example might be Cryogen - 1. An alphanumeric combination up to 15 characters may be used.

Design Pressure Enter the design pressure that the vessel will be operating at. The program does not use this value, however, the pressure will be an input item for WRC 107. This is also a good number to have for information purposes.

Design Temperature of Attachment The temperature entered in this cell should correspond to the temperature of the attachment in question. It would be reasonable to assume that vessel legs are much cooler than the actual metal temperature of the pressure vessel. The controlling stress for leg and support lug design is the yield stress of the material at the leg/lug temperature. If the attachment is not at ambient, enter the yield stress at that temperature. This value available in ASME Section II Part D. Alternately, the cold yield stress may be multiplied by the ratio of the hot allowable stress to the cold allowable stress. This should be acceptable in most cases.

Outside Diameter of Vessel Enter the outside diameter of the vessel to which the supports are attached. Any factors such as external corrosion should be accounted for at this time. PVElite will assume the vessel is one diameter from the top to the bottom of the vessel.

Shell Thickness Enter the shell thickness. This input is used only in the case of a support lug with a full reinforcement ring. Shell thickness is required to compute the Area and Moment of Inertia of the shell-ring junction.


19-4

LEGS and LUGS

Shell Corrosion Allowance Enter the shell corrosion allowance. This input, along with the shell thickness is used only in the case of a support lug with a full reinforcement ring. Shell thickness is required to compute the area and Moment of Inertia of the shell-ring junction.

Tangent to Tangent Length of Vessel Enter the vessel length from tangent to tangent. This value in combination with the next input parameter, will be used to compute the height of the top of the tower above grade. Knowing the elevation at the top, the wind pressure can be computed for the support lug and leg calculations.

Shell Material Click the Material Database button to look up a material name from the Material Database. Click the Material Edit Properties button to change the properties of the selected material. If you cannot find the material you need in the Material Database, you can add its specification and properties by selecting TOOLS/EDIT/ADD MATERIALS.

Type of Analysis Use the table below to determine the appropriate analysis type:

Analysis Type

Description

Support Lug

If the vessel rests on support lugs select this option. The program prompts you to enter all information necessary to determine the stress in these types of supporting attachments.

Vessel Leg

If the vessel rests on vessel legs select this option. The program prompts you to enter all information necessary to perform an AISC Unity Check on the vessel legs. This option also allows you to design the leg, baseplate and anchor bolts.

Lifting Lug

If the vessel is lifted by lug type attachments select this option. The program prompts you to enter information pertaining to the lifting lugs.

Trunnion

If the vessel is lifted by a trunnion select this option. The program prompts you to enter information pertaining to the trunnion design. Note: You can also perform a local stress analysis on the trunnion per WRC 107 methods.

Analyze Baseplate Check this box for designing the baseplate and anchor bolts per Moss and Bednar.

Additional Horizontal Force on Vessel Enter the additional horizontal force exerted on the vessel due to external loads. An example of such would be the reaction imposed by the thermal expansion of a piping system. For more information see Figure A - External Force Illustration.



19-5

Figure A - External Force Illustration

Location of Horizontal Force on Vessel Enter the location of the external force above the base point. For more information see Figure A - External Force Illustration.

Operating Weight of Vessel (total vertical load) Enter the total weight of the vessel in this cell. This weight should include all operating fluids, equipment loads, and other equipment attached to the vessel.

Height of Bottom Tangent Above Grade Enter the distance from the ground to the bottom tangent of the vessel. If you are performing a leg analysis this distance should be equal to the length of the legs. This value will be used along with the tangent to tangent length to determine the centroid where the wind loads and seismic shear loads are applied. These horizontal shear forces cause bending around the legs and support lugs. For more information see Figure A - External Force Illustration.

Occasional Load Factor (AISC A5.2) With many types of construction codes and occasional load factor can be used to increase the allowable stress for an event that is considered occasional in nature. Such occasional loads are Wind, Seismic, and the lifting of a vessel. The occasional load factor will be multiplied by the other terms in the allowable stress equation to get the overall allowable. If you do not wish to take credit for such an increase in the allowable, enter a 1 in this field. The default is 1.33.

Apply Wind Loads to Vessel If you wish to enter wind loads on your vessel check this field. You will then be prompted for the necessary parameters to compute the wind pressure on the vessel.


19-6

LEGS and LUGS

Apply Seismic Loads to Vessel If you wish to have a seismic analysis check this field. If you do so, the seismic zone or seismic factor Cs will be needed.

Pop-Up Input Fields Additional Area The user may wish to consider the additional area exposed to the wind from piping, platforms, insulation etc. PVElite will automatically compute an effective diameter with the input diameter known.

User Defined Wind Pressure On Vessel If your vessel specification calls for a constant wind pressure design, and you know what that pressure is, enter it here. Most Wind Design codes have minimum wind pressure requirements, so check those carefully. The wind pressure will be multiplied by the area calculated by the program to get a shear load and a bending moment. If you enter a positive number here, CodeCalc will use this number regardless of the information in the following cells.

Wind Design Standard Enables users to choose the wind design standard.The list below displays the options available: ASCE 7-93 ASCE 7-95 ASCE 7-98/02 / IBC 2003 UBC 94/97 To use wind codes not listed above users must compute and enter the design wind pressure and the program will multiply the wind pressure by the area to compute the wind load.

Force Coefficient (Cf) Enter the force coefficient (also known as shape factor) for the vessel here. This factor takes into account the shape of the structure. This factor is known as pressure coefficient, Cq in the UBC wind code. The acceptable range of input is between 0.5 and 1.2. This can be seen as, For ANSI A58.1 refer to Table 12 For ASCE 7-93 refer to tables 11-14, p21-22 For ASCE 7-95, refer to tables 6-6 to 6-10, p32-33 For ASCE 7-98, refer to tables 6-9 to 6-13 For ASCE 7-2002, refer to tables 6-18 to 6-22, p68-72 For UBC-1997 code, refer to table 16-H.



19-7

Importance Factor ( I ) Enter the value of the importance factor that you wish the program to use. The importance factor accounts for the degree of hazard to life and property. Please note the program will use this value directly without modification. Values of typical importance factors are listed below for ASCE 7-93, ASCE 7-95/98/02 and UBC 1997 standards. ASCE7-93: Following values are used for ASCE 7-93. In general this value ranges from .95 to 1.11.:

Category

100 mi from Hurricane Oceanline

At Oceanline

I

1.00

1.05

II

1.07

1.11

III

1.07

1.11

IV

0.95

1.00

Category Classification: I

buildings and structures not listed below

II

buildings and structures where more than 300 people congregate in one area

III


IV

buildings and structures that represent a low hazard in the event of a failure

Note that most petrochemical structures are 1, Importance I. ASCE-7-95/98/02: In general this value ranges from .77 to 1.15. It is taken from table 6-2 of the ASCE 95 standard or table 6-1 from the 98 standard.

Category


I

0.87

II

1.00

III

1.15

IV

1.15

In the 98 standard for Wind Speeds > 100 mph for category I, the importance factor can be 0.77. Category Classification: I

buildings and other structures that represent a low hazard to human life in the event of failure

II

buildings and structures except those listed in categories I, III and IV

III

buildings and structures that represent a substantial hazard in the event of a failure

IV


Note that most petrochemical structures are 1, Importance I.


19-8

LEGS and LUGS

UBC: For UBC 1997 code these values are listed as follows:

Category


I, Essential facilities

1.15

II, Hazardous facilities

1.15

III, Special occupancy structures

1.00

IV, Standard occupancy structures

1.0

Basic Wind Speed Enter the design value of the wind speed. The wind speeds will vary according to geographical location and/or to company/vendor standards. A few typical wind speeds in miles per hour display below: 85.0 miles per hour 100.0 miles per hour 110.0 miles per hour 120.0 miles per hour Note: Users should enter the lowest value reasonably allowed by the standards you are following, since the wind design pressure and thus force increases as the square of the speed.

Wind Exposure This category reflects the characteristics of ground surface irregularities for the site at which the structure is to be constructed. Use the table below to determine the appropriate exposure category For ASCE codes, the exposure categories are as follows

Exposure Category

Description

A

Large city centers with at least 50% of the buildings having a height in excess of 70 feet.

B

Urban and suburban areas, wooded areas, or other terrain with numerous closely spaced obstructions having the size of single family dwellings.

C

Open terrain with scattered obstructions having heights generally less than 30 feet. This category includes flat, open country and grasslands.

D

Flat, unobstructed coastal areas directly exposed to wind flowing over large bodies of water.

Note that most petrochemical sites use a value of 3 (exposure C).



19-9

UBC Exposure Factor UBC Exposure Factor as defined in UBC-91 Section 2312: Exposure Category

Description

B

Terrain with building, forest or surface irregularities 20 feet or more in height covering at least 20 percent or the area extending one mile or more from the site.

C

Terrain which is flat and generally open, extending one-half mile or more from the site in any full quadrant.

D

The most severe exposure with basic wind speeds of 80 mph or more. Terrain which is flat and unobstructed facing large bodies of water over one mile or more in width relative to any quadrant of the building site. This exposure extends inland from the shoreline 1/4 mile or 0 times the building (vessel) height, whichever is greater.


Height of Vessel Above Grade Enter the height of the vessel above the surface of the earth (grade).

Types of Hill Enter the type of hill. See ASCE 7-95 Fig. 6-2 for details. None 2-D Ridge 2-D Escarpment 3-D Axisymmetric Hill

Height of Hill or Escarpment (H) Enter height of hill or escarpment relative to the upwind terrain. See ASCE 7-95 Fig. 6-2 for details.

Distance to Site (x) Enter distance (upwind or downwind) from the crest to the building site. See ASCE 7-95 Fig. 6-2 for details.

Distance to Crest (Lh) Enter distance upwind of crest to where the difference in ground elevation is half the height of hill or escarpment. See ASCE 7-95 Fig. 6-2 for details.

Natural Frequency for the Structure (Fn) — Optional (Hz) Enter the natural frequency for the structure. If Fn < 1.0 Hz or TANTAN/OD > 4.0 the program uses ASCE 7-95 part 6.6 category III.


19-10

LEGS and LUGS

Pop-Up Input Fields Damping Ratio (beta) — optional Enter the damping ratio for the structure if you would like to use ASCE 7-95 part 6.6 category III (if Fn < 1.0 Hz or TANTAN/OD > 4.0).

Seismic Zone Select the seismic zone in which your vessel is operating. The seismic zones are pictured in ASCE #7 and reproduced below. A value of 0 will not increase the saddle reaction force. An Identifier of 5( zone 4) will produce the highest saddle load reactions. These values are derived from UBC. The basic equation for lateral G force is : Cs = Z I C / Rw : Rw = 3, C = 2.75, I = 1.0

Seismic Zone

Cs

0

0.0

1

0.069

2a

0.138

2b

0.184

3

0.275

4

0.367

Figure B - Seismic risk map of United States from the ASCE code



19-11

User Entered Seismic Zone Factor CS When you enter a valid seismic zone and leave this field blank or 0, CodeCalc will look the seismic zone factor up from the table shown below. This number is then used in conjunction with the operating weight of the vessel to compute the forces, which act on the saddle supports. If for any reason the table value of Cs is unacceptable, entry of a non-zero value will cause this to be used in lieu of the table value. This might occur if the building code in your project specifications is different from the one used by CodeCalc. Zone

Cs

0

0.0

1

0.069

2a

0.138

2b

0.184

3

0.275

4

0.367


19-12

LEGS and LUGS

Vessel Leg Input The number of vessel legs must be between 3 and 16. The program computes the number of legs for bending and shear of the vessel. PVElite must have a valid material from which to determine material properties. You can select the material from the Material Database by pressing the material database lookup button. If a material is not contained in the database, you can enter its specification and properties manually by selecting TOOLS/ EDIT/ADD MATERIALS, from the MAIN MENU. Currently there are 929 structural shapes in the AISC database. PVElite is intended to perform unity checks on Ibeam and angle type sections. AISC's method for computing unity checks for angle sections is rather complicated when compared to the corresponding method used for "I" type sections. Each beam section has a strong and weak orientation. If the beam is attached such that the tangent to the vessel is parallel to the beam's strong axis this designation is considered strong. If the designation is not strong it must be weak. If the legs are cross braced bending stresses are significantly reduced.

Number of Legs Enter the number of legs attached to the vessel. This number must be greater than or equal to 3 and less than 16. PVElite will determine the effective number of legs for bending and shear of the vessel.

Length of Legs Enter the distance from the bottom leg support point to the attachment point on the vessel. This length term is used in determining the legs resistance to bending. Long legs are more likely to buckle than shorter legs. The distance of the tangent line of the vessel above grade should always be equal to the length of the legs. If they are not the same PVElite will use the maximum of the two when determining the wind pressure and the location of the centroid.

Effective Leg End Condition Factor K (used in Kl/r) Enter in the value of K used as the effective end condition. This value usually ranges from 0.2 to 2.10. For design of pressure vessel legs a value of 1.0 is commonly used. If your design specs call out for a different value enter it here.

Material Specification for Legs Click the Material Database button to search for a material in the material database. Also, you can type the material name in this cell, and the system will retrieve the first material it finds with a matching name. Click the Material Edit Properties button to change the properties of the selected material. You can also create new materials by selecting the TOOLS/EDIT/ADD MATERIALS option on the MAIN MENU.

Leg Allowable Stress at Design Temperature The leg allowable stress is not used to check structural steel. The yield stress at the design temperature is used.



19-13

Leg Allowable Stress at Ambient Temperature The leg allowable stress is not used to check structural steel. The yield stress at the operating temperature is used.

AISC Member Designation Enter the shape type of the leg on which the vessel is sitting. A complete list of shapes can be found in the AISC structural steel handbook. All material shape information is current with the latest AISC code standard. An example of a shape type may be W8X40 or W36X300. A 2 by 1/4 inch angle section would have the designation L2X2X0.2500. This reference must be exact. If your design incorporates pipe legs, check the pipe-leg selection box and fill in the ID and the OD of the pipe leg.

Orientation to the Vessel Each I-beam and channel has a strong and weak orientation. This means that these sections are more easily bent around one as opposed to the other. If the member is attached such that the tangent to the vessel is parallel to the beams strong axis select the strong option, otherwise select the weak option. If the member is an angle and it is attached with one leg welded to the vessel or one flat welded to the vessel, select strong. If both legs are welded to the vessel select diagonal.

Are the Legs Cross-Braced If the legs are cross braced check this field. Cross bracing effectively stiffens the legs. Thus they will experience a minimum of bending stress.

Are the Legs Pipe Legs Check this box to activate the pipe ID and OD.

Pipe Legs Inside/Outside Diameter Enter the diameter of the pipe leg (as determined by which cell you are entering data for) that is attached to the vessel. You must account for any corrosion allowance to the inner or outer diameter when entering this value. Please verify that the inside diameter is less than the outside diameter.


19-14

LEGS and LUGS

Leg Results When a leg analysis is performed PVElite reads all of the data out of the structural database (AISC89.BIN). The resulting leg loads are compared to the allowable leg compression loads as outlined in AISC paragraph 1.5.1.3. Either the Kl/r > Cc or Kl/r < Cc formula will be shown as appropriate. The combination of stresses due to bending and compression will be compared to the allowable per AISC 1.6.1. This is generally termed the AISC unity check. If the result is greater than 1.0 the member has failed.



19-15

Support Lug Input If the number of support lugs to be analyzed is between 2 and 16. PVElite assumes that each support lug has two gussets equally spaced about a bolt hole. The distance between gussets is used to determine the bending stress in the lug bottom plate. The lug bottom plate is analyzed as a beam on simple supports, where the support spacing is the gusset spacing. The allowable stress in bending is 66 percent of the yield stress, per the AISC manual. In addition, the stress in the gusset is one half of the lug force divided by the gusset area. This compression is compared to the AISC compression allowable. Usually when analyzing stresses in the lug plate the stresses in the wall of the vessel at the attachment location should be checked. This can be accomplished by checking the box to perform WRC 107 analysis from within the support lug dialog.

Support Lug Reinforcing Ring ( None, Girder Ring ) Select girder ring if the support lugs are reinforced with rings. If there are no stiffening rings for the support lugs, select none.

Number of Support Lugs Enter the number of support lugs on which the vessel is supported. This number must be greater than 1 and less than 17.

Location of Support Lugs Above Grade Enter the height above grade to which the support lugs are attached to the vessel. This is used to determine the reaction load on each support lug.

Distance from Vessel OD to Support Contact Point Enter the distance from the outside wall of the vessel to where the support lug attaches to/rests on/ the supporting member. This distance should be as short as possible to minimize bending on the support lug and the vessel wall.

Material Specification for Support Lugs Enter the material that the lugs are made of. An example of a of a common material is SA-516 70. To properly initialize the material, type its name on this line even if the default is shown. Alternatively, you can select the material from the Material Database by clicking the Material Database lookup button. If a material is not contained in the database, you can enter its specification and properties manually by selecting TOOLS/EDIT/ADD MATERIALS, from the Main Menu.

Radial Width of Bottom Support Lug Plate The radial width of the support lug is how far from the vessel wall the plate extends. For more information see Figure B - Leg & Lug Module Geometry.

Lug Allowable Stress at Operating Temperature The lug allowable stress is not used as a failure comparison. The yield stress at the operating temperature is used.


19-16

LEGS and LUGS

Lug Allowable Stress at Ambient Temperature The lug allowable stress is not used as a failure comparison. The yield stress at the operating temperature is used.

Circumferential Length of Bottom Support Lug Plate Enter the distance measured along the vessel wall that the support lug plate extends.

Thickness of the Bottom Support Lug Plate Enter the thickness of the plate on which the gussets rest. The bottom support plate is analyzed as a beam on simple supports where the support spacing is the distance between gussets. The allowable stress is 66% of the yield stress per the AISC steel construction manual.

Distance Between Gussets Enter the gusset spacing in this cell. PVElite assumes that support lugs have two gussets, equally spaced about a bolt hole (support point).

Mean Width of Gusset Plate Enter the average width of the gusset plate. The width dimension is radially outward from the OD of the vessel. If the top and bottom of the gussets are different widths, add them up and divide the result by 2. For more information see Figure B - Leg & Lug Module Geometry.

Height of Gusset Plate Enter the distance along the axis of the vessel that the gusset plate extends. This length will be used in the AISC formulation to determine the stress in the gussets. For more information see Figure B - Leg & Lug Module Geometry.

Thickness of Gusset Plate Enter the thickness of the gusset plate. For more information see Figure B - Geometry for the Leg & Lug Module.

Radial Width of Top Bar Plate or Top Ring The radial width of the top bar/ring is how far from the vessel wall the top plate/ring extends. For more information see Figure B - Leg & Lug Module Geometry. Note:

If there is no top bar/ring, enter the top width of the gusset.

Thickness of Top Bar Plate or Top Ring Enter the thickness of the top bar plate/ring in the units above. If there is no top bar plate or top ring, enter 0 here.

Perform WRC 107 calculations on this Support Lug-Shell attachment ? Check this box if you want to perform WRC 107 calculations on the Support Lug to Vessel junction.



19-17

WRC 107 only addresses rectangular, square or round attachment shapes, but other shapes (e.g. support lug) can be modeled by converting to an equivalent rectangle which has: The same moment of Inertia The same ratio of length to width of the original attachment. Program uses this approach to convert the lug into an equivalent rectangle. This approach is referenced in WRC bulletin 198 by Dogde as, simple and direct, but is not derived by any mathematical or logical reasoning. So, very large or critical loads should, be examined in depth.

Pad Width and Length The reinforcing pad width is measured along the circumferential direction of the vessel. The pad width must be greater than attachment width. The length of the attachment is measured along the long axis of the vessel. If the box is checked to perform the analysis and the pad properties are entered in, the program will compute the stresses at the edge of the attachment and the edge of the pad. When computing the stresses at the edge of the attachment, program adds the pad thickness to the shell thickness.


19-18

LEGS and LUGS

Lifting Lug Input Generally there are two types of lifting lug orientations, flat and perpendicular. Flat lugs are generally welded below the top head seam and extend far enough above the seam for the lifting cables to clear the head and its nozzles. Perpendicular lugs (ears) are used to clear some obstruction at or near the top head (such as a body flange) by moving the support point away from the vessel shell. They are also used as tailing lugs. The width of the lug is its dimension in the direction of orientation described above. The length is in the vertical direction relative to the vessel. The length of the welds will also need to be entered. For flat lugs the weld at the bottom will usually be the same as the lug width. For perpendicular lugs the weld length will be the same as the thickness of the lug. PVElite will take the square root of the sum of the squares (W, N, and T) to determine the total shearing load. The forces W and N cause bending loads on flat lugs while W and T cause bending loads on perpendicular lugs. The corner of the weld group is where the stress will be checked at. Review the example problems, and see Figure A - External Force Illustration and Figure B for further clarification of input.

Material Specification for Lifting Lugs Enter the material that the lugs are made of. An example of a of a common material is SA-516 70. To properly initialize the material, type its name on this line even if the default is shown. Alternatively, you can select the material from the Material Database by clicking the Material Database button. If a material is not contained in the database, you can enter its specification and properties manually by selecting TOOLS/EDIT/ADD MATERIALS, from the Main Menu.

Lug Allowable Stress at Design Temperature The lug allowable stress is multiplied by 0.6 for comparison to the shear stress above the hole in the lifting lug. It is also multiplied by the occasional factor to get the allowable weld shear for combined loads.

Lug Allowable Stress at Ambient Temperature The lifting lug allowable stress at ambient temperature should appear in this cell. The allowable stress at the lug operating temperature is used for the allowable stress comparison.

Lug Orientation to Vessel Select "Perpendicular" if the lug extends radially away from the vessel wall. These lugs are referred to as ear-type lugs. They are typically used on the tops of horizontal vessels. If the lug extends in the same direction as the vessel axis, select "Flat." This is a flat orientation. If you are working with a perpendicular lug and there will be no bending stresses in the lug, you will need to set the offset dimensions (moment arms) to 0. The program will run, but may give some warnings. This type of lifting lug would be one on the top of a horizontal vessel and the vessel would be lifted by a spreader bar equally distributing the weight load directly over each lug. Thus there would be no bending.



19-19

Contract Width or Height (Per. Lug) of Lifting Lug The width of the lug is its dimension in the direction of orientation described in the lug orientation to vessel wall. For perpendicular lugs this is the total height of the lug.

Thickness of Lifting Lug Enter the thickness of the plate that the lifting lug was constructed from.

Diameter of Hole in Lifting Lug Most lifting lugs have a circular hole cut or drilled into them. Enter the diameter of this hole.

Radius of Semi-Circular ARC of Lifting Lug Enter the RADIUS of the semi-circular part of the lifting lug where the hole is located. Typically this will be circular on flat lugs and semi-circular on perpendicular lugs.

Height of Lug from Center of Hole to Bottom Enter the distance along the axis of the vessel from the center of the hole to the bottom of the lug.

Offset from Vessel OD to Center of Hole Enter the distance from the center of the hole to base of the lifting lug. For perpendicular lugs this will be to the vessel OD. If the orientation is flat, this will be one half the lug thickness.

Minimum Thickness of Fillet Weld Around Lug This minimum is usually the distance from the root to the surface of the fillet weld (root dimension), and is not the fillet weld leg size.

Length of Weld Around Sides of Lug Enter the length of the long welds on the side of the lifting lug. PVElite will multiply this value by two when determining the weld area.

Length of Weld Along Bottom of Lifting Lug Enter the length of the short weld. This is usually the bottom weld.

Lift Orientation Enter the vessel lift orientation for the lifting lug analysis. For more information see Figure D - Lifting Orientation.

Axial Force Enter the component of force on the trunnion along the axis of the vessel. For more information see Figure D Lifting Orientation.


19-20

LEGS and LUGS

Normal Force Enter the component of force on the trunnion perpendicular to the wall of the vessel. For more information see Figure D - Lifting Orientation.

Tangential Force Enter the component of force on the trunnion tangent to the wall of the vessel. For more information see Figure D Lifting Orientation.

Figure B - LEG & LUG Module Geometry



19-21

Output PVElite produces three basic types of results in the LEG & LUG module. Results for Legs, using the methods described by AISC, results for Lifting Lugs, using basic engineering principles, and results for Support Lugs, using AISC methods and formulae from pressure vessel textbooks and other engineering reference texts. The input for this module includes some basic vessel parameters such as the vessel tangent-tangent length, the diameter and the height of the bottom tangent above grade. If you are performing a Leg or Support Lug calculation, the program follows these basic steps in order to determine the loads. For evaluation of wind loads: 1

Determine the elevation of the top and bottom seam of the vessel.

2

Determine the wind pressure at both elevations, and take the average.

3

Determine the effective diameter of the vessel and its area.

4

Compute the centroid of the vessel.

5

Resolve the wind pressure and the area at the centroid.

For evaluation of seismic loads: 1

Determine the seismic zone factor from UBC table 23-I or use the one the user gave.

2

Multiply this value times the operating weight of the vessel.

3

Apply this load at the centroid of the vessel.

If both types of loadings are considered, PVElite will compute both and then choose the maximum of the two.


19-22

LEGS and LUGS

Baseplate Input Baseplate Thickness calculation is included in the vessel leg analysis for I-beam, pipe, and angle leg only, and can be activated by clicking the Analyze Baseplate check box. The design is based on the method for I-beam leg described in the Pressure Design Manual by D. Moss and is applied to the other leg shapes. PVElite will assume the following for all Baseplate Thickness calculations: Strong axis leg orientation Bolts are installed along the length sides only (B dimension). The leg is attached symmetrically on the baseplate. It is advisable to check the baseplate dimensions using the graphic feature of PVElite.

Main Input Fields Baseplate Design Methods

AISC In this method, the thickness of the baseplate is calculated by assuming the baseplate is in compression state; where as the anchor bolts are sized to resist the lifting force/moment. For more information refer to second edition of Pressure Vessel Design Handbook by Bednar page 153. In Analyze mode, the baseplate thickness is calculated using the input baseplate dimensions (B &D). However, in Optimize mode, the baseplate thickness is calculated by maximizing the use of the concrete strength. For more information refer to AISC Handbook page 3-106. The Total Number of Bolt per Base Plate is assumed to carry all the lifting load on the baseplate. It is up to the user to specify the location of each bolt. The Number of Bolt in Tension per Base Plate input is not required. The Distance from the Edge of the Leg to the Bolt Hole, the "z" dimension, is not required.. The program assumes the leg is attached symmetrically on the base plate.

Moss The Total Number of Bolt per Base Plate should be an even number. The program assumes that the bolts are located along the length (B) of the base plate as shown in the left figure. In case there is no wind/earth quake/horizontal loads, the Number of Bolt in Tension per Base Plate is not required. If there is wind/earth quake/horizontal loads, the Number of Bolt in Tension per Base Plate should be the number of bolts along one length dimension, shown as three bolts in the figure. When this input is left blank, its values is assumed to be half of the total number of bolts. The program assumes the leg is attached symmetrically on the base plate. The Distance from the Edge of the Leg to the Bolt Hole, the "z" dimension, is same along the width and along the length.



19-23

Baseplate Length B Enter the length "B" of the baseplate.

Baseplate Width D Enter the width "D" of the baseplate.

Baseplate Thickness BTHK Enter the available baseplate thickness.

Baseplate/Bolt Material Click the Material Database button to look up a material name from the database. If a material is not a contained in the database, you can enter its specification and properties manually by selecting TOOLS/EDITS/ADD MATERIALS from the Main Menu.

Distance from the Edge of the Leg to the Bolt Hole, "z" Enter the "z" dimension of the baseplate. For more information see Figure C - Baseplate Dimension.

Nominal Bolt Diameter Enter the nominal bolt diameter. The bolt diameters included in the program range from 0.5 to 4.0 inches. If you have bolts that are larger or smaller than this value, enter the nominal size in this field and also enter the root area of one bolt in the Root Area cell.

Bolt Corrosion Allowance If there is any corrosion allowance for the bolts then enter it here. The nominal bolt size is corrected for this allowance.

Thread Series There are three options for this entry: TEMA Bolt Table UNC Bolt Table User specified root area of a single bolt.

Bolt Root Area If your geometry uses bolts that are not the standard TEMA or UNC types you must enter the root area of a single bolt in this field.

Total Number of Bolts per Baseplate Enter the total number of bolts per baseplate. At least two bolts are needed for uplift situations. The program assumes that the bolts are located along the length "B" of the baseplate as shown in the figure below.


19-24

LEGS and LUGS

Number of Bolts in Tension per Baseplate Enter the total number of bolts in tension per baseplate. If there is an uplift the number of bolts in tension per Baseplate should be at least 1. If there is no uplift the number of bolts in tension per Baseplate is not required.

Nominal Compressive Stress of Concrete Enter the Nominal Compressive Stress of the Concrete to which the basering/baseplate is bolted. This value is f'c in Jawad and Farr of FPC in Meygesy. A typical entry is 3000 psi. Water Content (gal) per 94 lb. Sack of Cement

f'c 28 day Ultimate Compressive Strength (psi)

7.50

2000

6.75

2500

6.0

3000

5.00

3750

Figure C - Baseplate Dimension



19-25

Baseplate Results Baseplate analysis produces the following results: The thickness requirement is calculated using the 1.5 allowable plate bending stress and compared to the input thickness. The concrete bearing pressure is compared to the input allowable stress The anchor bolt size is analyzed at the bending level (D. Moss) and the overall vessel moment equilibrium (H. Bednar). In the absence of tension in the bolts, you should choose a practical bolt size.


19-26

LEGS and LUGS

Trunnion Input A hollow or solid circular trunnion with or without pad reinforcement can be analyzed using the TRUNNION DESIGN module. The main considerations regarding the trunnion design are stresses at the vessel/trunnion junction and on the trunnion itself. Bending stress, shear stress, bearing stress and the Unity Check are calculated and compared with the appropriate allowables. Local stresses at the junction can be analyzed using the WRC 107 Analysis Selection check box. The lifting orientation, vertical and horizontal positions, and the orthogonal input forces are needed for WRC 107 Analysis. PVElite assumes that the loads entered act on one trunnion. Typically vessels are lifted with two trunnions thus the load is divided between them. An option is to analyze the trunnion with the maximum load acting on that trunnion during the lift. The program multiplies this lifting load by the importance factor specified by the user. Before the analysis it is advisable to check the trunnion dimensions and the forces' magnitude and direction using the graphic feature in CodeCalc. The program does not subtract corrosion allowance (if any) and then enter the dimensions.

Main Input Fields Trunnion Type (Hollow or Solid) This input is required for performing shear and bending stress calculations and for WRC 107 Analysis.

Trunnion Outside Diameter Enter the outside diameter of the trunnion. For more information see Figure E - Trunnion Geometry.

Trunnion Thickness Enter the thickness of the trunnion. For more information see Figure E - Trunnion Geometry.

Projection Length Enter the projection length of the trunnion. For more information see Figure E - Trunnion Geometry.

Bail/Sling Width Enter the bail or sling width used during erection. This input is required for locating the lifting load only. No analysis is performed on the bail or sling. For more information see Figure E - Trunnion Geometry.

Trunnion Material Enter the material the trunnion is made of. Depending on the size and the availability, the trunnion can be made of pipe or sheet plate. To properly initialize the material, type its name in this field even if the default displays. If a material is not contained in the database, you can enter its specifications and properties manually by selecting TOOLS/EDIT/ADD MATERIALS from the Main Menu.



19-27

Reinforcement This input is required to perform the WRC 107 Analysis.

Ring Outside Diameter The ring outside diameter is only used to display a picture of the trunnion. This is not used in the calculations. For more information see Figure E - Trunnion Geometry.

Ring Thickness The ring thickness is only used to display a picture of the trunnion. This is not used in the calculations. For more information see Figure E - Trunnion Geometry.

Lift Orientation Enter the vessel lift orientation for the trunnion analysis. This value will be used to perform WRC 107 Analysis on the trunnion.

Axial Force Enter the component of force on the trunnion along the axis of the vessel. For more information see Figure D Lifting Orientation.

Normal Force Enter the component of force on the trunnion perpendicular to the wall of the vessel. For more information see Figure D - Lifting Orientation.

Tangential Force Enter the component of force on the trunnion tangent to the wall of the vessel. For more information see Figure D Lifting Orientation.

Importance Factor When the vessel is lifted from the ground it may be yanked abruptly. The importance factor takes this into account. This value typically ranges from 1.5 to 2.0 although values as high as 3.0 may be used. The program multiplies the lifting load by the importance factor.

Perform WRC 107 Analysis on Trunnion Click this box to perform WRC 107 Analysis on the trunnion/vessel junction.


19-28

LEGS and LUGS

Figure D - Lifting Orientation

Figure E - Trunnion Geometry



19-29

Trunnion Results The ring outer diameter and thickness are not used in the calculations; they are used to display a picture only. There are four passing criteria used to calculate the trunnion design bending stress, shear stress, bearing stress and the Unity Check. The following allowables are used: Bending Stress: 0.66 *Sy*Occfac Shear Stress: 0.40 *Sy*Occfac Bearing Stress: 0.75 *Sy*Occfac WRC 107 Analysis- local stresses at 8 points are evaluated and compared with the allowable (1.5 * Sallow). For more information see the WRC 107 module.


19-30

LEGS and LUGS



CH AP TER

2 0

Chapter 20 PIPES and PADS In This Chapter Introduction ................................................................................ 20-2 Discussion of Input ..................................................................... 20-3 Output ......................................................................................... 20-8 Example ...................................................................................... 20-9


20-2

PIPES and PADS

Introduction This chapter discusses the PIPE & PAD module in PVElite. PIPE & PAD computes the required wall thickness and area of replacement for ANSI B31.3 intersections. These area of replacement rules are based on the 1987 edition of ANSI B31.3 Chemical Plant and Petroleum Refinery Piping Code. Extruded outlet headers are also analyzed.


Chapter 20 PIPES and PADS

20-3

Discussion of Input Main Input Fields Intersection Number Enter an intersection number for this analysis. These should be positive integer values incremented by one.

Intersection Description Enter a 15 alphanumeric identifier for this intersection. This description will not be used in the analysis, however, it will be used in the error checker and in the output reports. This identifier should have some link to the actual intersection. An example might be "Int 12x4".

Design Pressure Enter the design pressure of the ANSI B31.3 intersection. This should be the pressure that the system will operate at continuously. Most of the internal computations for areas, wall thickness etc. involve the design pressure.

Design Temperature Enter the design temperature of the intersection. This temperature will be used to determine the allowable stress of the branch. The user may note that if a new temperature is input the allowable stress information of the branch is updated automatically.

Branch\Header\Pad Material Specification Enter the material specification in this cell. A list of materials can be found in the PVElite User Guide or you can select it from the Material Database by clicking the Material Database button. If a material is not contained in the database, you can enter its specification and properties manually by selecting TOOLS/EDIT/ADD MATERIALS, from the MAIN MENU. Valid piping materials available are: A-106 B

A-285 C

A-312 304

A-312 304L

A-312 316

A-312 316L

A-516 55

A-516 60

A-516 65

A-516 70

A-53 A

A-53 B

A-335 P1

A-335 P2

A-335 P5

A-335 P11

A-335 P22

A-537 CL1

Any material can be used as long as the hot and cold allowables are properly specified.

Allowable Stress, Operating The allowable stress of the material specified at the design temperature above should appear in this cell. This stress will appear automatically if a valid material is selected. If the temperature is changed the material properties will be updated automatically.


20-4

PIPES and PADS

Allowable Stress, Ambient The allowable stress of the material at ambient temperature above should appear in this cell. This stress will appear automatically if a valid material is selected.

Branch Dimension Basis Select the branch dimension basis in this field.

Pipe Normal or Actual Outside Diameter If actual was entered in the field immediately above, then enter the actual outside diameter of the branch in this cell. If nominal was entered above, enter the nominal outside diameter of the branch pipe. An example is "10" for a 10 inch pipe.

Actual Thickness of Branch/Header If the user has specified a 1 in the branch/header dimension basis field, then the actual wall thickness of the branch will be entered in this cell. PVElite will reduce the wall thickness according to B31.3 if appropriate values are entered for mill tolerance or corrosion allowance.

Nominal Thickness of Branch/Header Enter the schedule for the branch/header wall. Enter a value in this field only if you selected Nominal for the branch diameter and thickness basis. Otherwise enter a thickness in the field above. Type in the schedule for the branch, i.e. SCH 40. Available schedules are: SCH 10

SCH 80S

SCH 10S

SCH 100

SCH 20

SCH 120

SCH 30

SCH 140

SCH 40

SCH 160

SCH 40S

SCH STD

SCH 60

SCH-STG

SCH 80

SCH XX-STG

Mill Undertolerance, Percent The mill undertolerance accounts for manufacturing deficiencies when pipe is produced. If for example a value of 12.5 is entered, then the wall thickness of the pipe will be multiplied by (100 - 12.5)/100 or .875. This is essentially a reduction in wall thickness. Valid entries are between 0 and 99%.

Corrosion Allowance Enter the estimated allowance for corrosion in this field. The difference of (wall thickness - (corrosion allowance + mill tolerance)) must be greater than 0.



20-5

Basic Quality Factor for Longitudinal Joints The basic quality factor is used in the wall thickness calculations for pipes under internal pressure only. These factors are listed in the ANSI B31.3 piping code Table A-1B. For seamless and fully radiographed pipe this value is 1.0. For electric resistance welded and spot welded materials it is usually 0.85.

Angle Between Branch and Header Enter the angle between the centerline direction vector of the branch and the header. This is typically 90 degrees. The piping codes do not allow "hillside" type attachments. This angle is referred to as Beta and is shown in Figure A. This is the smaller angle between the axes.

Does the Branch Penetrate a Header Weld If the branch pipe passes through a weld seam on the header pipe check this field. Refer to ANSI B31.3 paragraph 304.3.3 under "t =" for more information.

Rate the Attached B16.5 Flange If a flange is attached to the branch pipe and you wish to rate it check this field.

Header Dimension Basis Enter the header dimension basis in this field. If the actual outside diameter is known select actual. If the nominal schedule of the header is known select nominal.

Reinforcing Pad Present If the intersection being analyzed has a reinforcing pad, check this field. If selected, PVElite will determine the area(s) available in the pad within the appropriate limits of reinforcement. In addition, PVElite will also report the required pad diameter based on the given pad thickness and the required pad thickness based on the given diameter.

Is There an Extruding Outlet ? If the branch connection for this intersection is formed by the extrusion process then check this box. If checked you will be prompted to enter in information required to determine the area in the extruded outlet.

Pop-Up Input Fields Class of the Attached B16.5 Flange If you answered Y to rate the attached B16.5 flange then enter the class of the flange attached to the nozzle neck. Available classes of flanges are: CL 150, CL 300, CL 400, CL 600, CL 900, CL 1500, CL 2500.

Grade of the Attached B16.5 Flange If the flange attached to the nozzle neck is to be rated then the grade of the flange must be entered here. The allowable grades of B16.5 flanges are:


20-6

PIPES and PADS

GR 1.1 Med C Steel

GR 1.14 9Cr-1Mo

GR 1.2 High C Steel

GR 2.1 Type 304

GR 1.4 Low C Steel

GR 2.2 Type 316

GR 1.5 C-1/2Mo

GR 2.3 Type 304L, 316L

GR 1.7 /2Cr-1/2Mo, Ni-Cr-Mo

GR 2.4 Type 321

GR 1.9 -1/4Cr-1/2Mo

GR 2.5 Type 347, 348

GR 1.10 2-1/4Cr-1Mo

GR 2.6 Type 309

GR 1.13 5Cr-1/2Mo

GR 2.7 Type 310

Pad Thickness Enter the thickness of reinforcing element in this cell. The user should take into consideration all allowances for corrosion.

Pad Diameter Along Header Surface Enter the length of the reinforcing element along the longitudinal axis of the header.

Thickness of Extruded Outlet, TX The dimension TX of an extruded outlet header is the corroded finished thickness, which is measured at a height equal to the radius of curvature above the outside surface of the header.

Height of Extruded Outlet, HX The dimension HX of an extruded outlet header is the height of the extruded outlet. This distance must be greater than or equal to the radius of curvature RX, of the outlet.

Inside Diameter of Extruded Outlet, DX DX is the inside diameter of the extruded outlet, which is measured at the level of the outside of the header. PVElite will automatically adjust the wall thickness of the outlet if the mill tolerance and/or the corrosion allowance is specified.

Radius of Curvature, RX, of Extruded Outlet RX is the radius of curvature of the external contoured part of the extruded outlet, which is measured in the plane containing the axes of both the header and the branch.



Figure A - Pipe and Pad Module Geometry

Figure B - Pipe and Pad Module Geometry Continued

Figure C - Extruded Outlet


20-7

20-8

PIPES and PADS

Output PVElite will generate output for maximum allowable working pressure new and cold as well as the corroded condition. Hydrotest pressure is calculated as the maximum allowable working pressure at the design condition times 1.5 the ratio of the allowable stress at ambient temperature to the allowable stress at the design temperature. The replaced area can only be within a certain zone. No credit will be given for reinforcement that lies outside of the zone. Please note that these zones are different for extruded outlets. If a reinforcing element is used PVElite will compute the required diameter for the given thickness and the required thickness for the given diameter. If a pad is used in conjunction with an extruded outlet header consult the piping code for details on this design. If the calculated diameter falls outside the limit of reinforcement a message such as "EXCEEDS D2" or "EXCEEDS L4" will be displayed. The MAWP for the given geometry is an estimate because of a slight non-linearity in the required thickness calculation. To verify the MAWP plug the value back into the analysis as the design pressure and check to see if the area required is equal to the area available.



20-9




CH AP TER

2 1

Chapter 21 BASE RINGS In This Chapter Introduction ................................................................................ 21-2 Calculations ................................................................................ 21-3 Discussion of Input ..................................................................... 21-9 Tailing Lug Analysis .................................................................. 21-16 Discussion of Input ..................................................................... 21-17 Discussion of Results.................................................................. 21-18 Example ...................................................................................... 21-19


21-2

BASE RINGS

Introduction The PVElite BASE RING module performs thickness calculations and design for annular plate baserings, top rings, bolting, and gussets. These calculations are performed using industry standard calculation techniques as described below.


Chapter 21 BASE RINGS

21-3

Calculations Calculation Techniques Thickness of a Base Ring Under Compression The equation for the thickness of the base ring is the equation for a simple cantilever beam. The beam is assumed to be supported at the skirt, and loaded with a uniform load caused by the compression of the concrete due to the combined weight of the vessel and bending moment on the down-wind / down-earthquake side of the vessel. The equation for the cantilever thickness is found in most of the common vessel design textbooks, including Jawad & Farr, Structural Analysis and Design of Process Equipment, page 434, formula 12.12: t

=

SQRT( 3 * fc * l ** 2 / s )

fc

=

bearing stress on the concrete

l

=

cantilever length of base ring

s

=

allowable bending stress of base ring (typically 1.5 times Code allowable).

Where

There are two commonly accepted methods of determining the bearing stress on the concrete. The approximate method simply calculates the compressive load on the concrete assuming that the neutral axis for the vessel is at the centerline. Thus the load per unit area of the concrete is, from Jawad & Farr equation 12.1, equal to fc

=

-W / A - M * c / I

W

=

Weight of vessel (worst case).

M

=

Bending moment on vessel (worst case).

A

=

Cross sectional area of base ring on foundation

c

=

Distance from the center of the base ring to the edge

I

=

Moment of inertia of the base ring on the foundation

Where

However, when a steel skirt and base ring are supported on a concrete foundation, the behavior of the foundation is similar to that of a reinforced concrete beam. If there is a net bending moment on the foundation, then the force upward on the bolts must be balanced by the force downward on the concrete. But because these two materials have different elastic moduli, and because the strain in the concrete cross section must be equal to the strain in the base ring at any specific location, then the neutral axis of the combined bolt/concrete cross section will be shifted in the direction of the concrete. Several authors, including Jawad & Farr (pages 428 to 433) and Megyesy (pages 70 to 73) have analyzed this phenomenon. The program uses the formulation of Singh and Soler, Mechanical Design of Heat Exchangers and Pressure Vessel Components, pages 957 to 959. This formulation seems to be the most readily adaptable to computerization, as there are no tabulated constants. Singh and Soler provide the following description of their method: In this case a neutral axis parallel to the Y-axis exists. The location of the neutral axis is identified by the angle alpha. The object is to determine the peak concrete pressure p and the angle alpha.


21-4

BASE RINGS

For narrow base plate rings an approximate solution may be constructed using numerical iteration. It is assumed that the concrete annulus under the base plate may be treated as a thin ring of mean diameter c. Assuming the foundation to be linearly elastic, and the base plate to be relatively rigid, Brownnell and Young have developed an approximate solution which, can be cast in a form suitable for numerical solution. Let the total tensile stress area of all foundation bolts be A. Within the limits of accuracy sought, it is permissible to replace the bolts with a thin shell of thickness t and mean diameter equal to the bolt circle diameter c, such that t = A / PI * c. We assume that the discrete tensile bolt loads, acting around the ring, are replaced by a line load, varying in intensity with the distance from the neutral plane. Let n be the ratio of Young's moduli of the bolt material to that of the concrete; n normally varies between 10 and 15. Assuming that the concrete can take only compression (non-adhesive surface) and that the bolts are effective only in tension (untapped holes in base plate), an analysis [similar to that given above] yields the following results: p

=

(2 * W + r2 * t * c * s) / [(t3 - t) * r1 * c]

s

=

(2 * (M - W * r4 * c) / (r2 * r3 * t * c ** 2)

alpha

=

acos [(s - n * p) / ( s + n * p )]

t3

=

width of base ring (similar to l in Jawad & Farr's equations above)

c

=

bolt circle diameter

Where

r1-r4 = four constants based on the neutral axis angle, and defined in Singh & Soler equations 20.3.12 through 20.3.17, not reproduced here. These equations give the required 7 non-linear equations to solve for 7 unknowns, namely p, c, alpha, and the ri (i = 1, 4) parameters. The simple iteration scheme described below converges rapidly. The iterative solution is started with assumed values of s and p; say so and po [the program takes these from the approximate analysis it has just performed]. Then alpha is determined via the above equation. Knowing alpha the dimensionless parameters r1, r2, r3, and r4 are computed. This enables computation of corrected values of p and s (say po' and so'). The next iteration is started with s1 and p1 where we choose: s1

=

.5 * (so + so')

p1

=

.5 * (po + po')

This process is continued until the errors ei and Ei at the ith iteration stage are within specified tolerances, (ei = Ei = 0.005 is a practical value), Where ei

=

(si' - si) / si

Ei

=

(pi' - pi) / pi

Actual numerical tests show that the convergence is uniform and rapid regardless of the starting values of so and po. Once the new values of bolt stress and bearing pressure are calculated, the thickness of the base ring is calculated again using the same formula given above for the approximate method.



21-5

Thickness of Base Ring Under Tension On the tensile side, if there is no top ring but there are gussets, there is disagreement on how to do the analysis. For example, Megyesy uses a 'Table F' to calculate an equivalent bending moment, Dennis R. Moss uses the same approach but gives the table (page 126-129), and Jawad & Farr use a 'yield-line' theory (page 435-436). Since Jawad & Farr is both accepted and explicit, the program uses their equation 12.13: t

=

SQRT{ (3.91 * F) / [Sy * ( x + y + z)]}

x

=

2*b/a

y

=

a / (2 * l)

z

=

d * ( 2 / a + 1 / [2 * l])

F

=

Bolt Load = Allowable Stress * Area

a

=

Distance between gussets

b

=

Width of base plate that is outside of the skirt

l

=

Distance from skirt to bolt circle

d

=

Diameter of bolt hole

Where

Thickness of Top Ring Under Tension If there is a top ring or plate, its thickness is calculated using a simple beam formula. Taking the plate to be a beam supported between two gussets with a point load in the middle equal to the maximum bolt load, we derive the following equation: t

=

SQRT(6 * M / s)

Where M = beam.

2 * Ft * Cg / 8.0, bending moment from Megyesy, beam formulas, case 11, fixed

Ft

=

Bolt Load = Allowable Stress * Area

s

=

Allowable stress, 1.5 * plate allowable

Z

=

Section Modulus, from Megyesy, Properties of Sections

Z

=

Wt * t2 / 6.0

Wt

=

(Do/2.- Ds/2.- db) = Width of Section

Required Thickness of Gussets in Tension If there are gussets, they must be analyzed for both tension and compression. The stress formula in tension is just the force over the area, where the force is taken to be the allowable bolt stress times the bolt area, and the area of the gusset is the thickness of the gusset times one half the width of the gusset (because gussets normally taper).


21-6

BASE RINGS

Required Thickness of Gussets in Compression In compression (as a column) we must iteratively calculate the required thickness. Taking the actual thickness as the starting point, we perform the calculation in AISC 1.5.1.3. The radius of gyration for the gusset is taken as 0.289 t per Megyesy, Fifth edition, page 404. The actual compression is calculated as described above, then compared to the allowed compression per AISC. The thickness is then modified and another calculation performed until the actual and allowed compressions are within one half of one percent of one another.

Base Ring Design When the user requests a base ring design, the program performs the following additional calculations to determine the design geometry.

Selection of Number of Bolts This selection is made on the basis of Megyesy's table in Pressure Vessel Handbook (Table C, page 67 in the fifth edition). Above the diameter shown, the selection is made to keep the anchor bolt spacing at about 24 inches.

Calculation of Load per Bolt This calculation is made per Jawad & Farr, equation 12.3: P

=

-W / N + 2 * M / (N * R)

Where



21-7

W

=

Weight of vessel

N

=

Number of bolts

R

=

Radius of bolt circle

M

=

Bending moment

Calculation of Required Area for Each Bolt This is just the load per bolt divided by the allowable stress.

Selection of the Bolt Size The program has a table of bolt areas, and selects smallest bolt with area greater than the area calculated above.

Selection of Preliminary Base Ring Geometry The table of bolt areas also contains the required clearances in order to successfully tighten the selected bolt (wrench clearances and edge clearances). The program selects a preliminary base ring geometry based on these clearances. Values selected at this point are the bolt circle, base ring outside diameter, and base ring inside diameter.

Analysis of Preliminary Base Ring Geometry Using the methods described above for the analysis section, the program determines the approximate compressive stress in the concrete for the preliminary geometry.

Selection of Final Base Ring Geometry If the compressive stress calculated above is acceptable, then the preliminary geometry becomes the final geometry. If not, then the bolt circle and base ring diameters are scaled up to the point where the compressive stress will be acceptable. These become the final base ring geometry values.

Analysis of Base Ring Thicknesses The analysis then continues through the thickness calculation described above, determining required thicknesses for the base ring, top ring, and gussets.

Basic Skirt Thickness The required thickness of the skirt under tension and compression loads is determined using the same formula used for the compressive stress in the concrete, except using the thickness of the skirt rather than the width of the base ring: s

=

-W / A - M * c / I

W

=

Weight of vessel (worst case).

M

=

Bending moment on vessel (worst case).

A

=

Cross sectional area of skirt.

c

=

Distance from the center of the base ring to the skirt (radius of skirt).

I

=

Moment of inertia of the skirt cross section.

Where


21-8

BASE RINGS

In tension this actual stress is simply compared to the allowable stress, and the required thickness can be calculated directly by solving the formula for t. In compression, the allowable stress must be calculated from the ASME Code, per paragraph UG-23, where the geometry factor is calculated from the skirt thickness and radius, and the materials factor is found in the Code external pressure charts. As with all external pressure chart calculations, this is an iterative procedure. A thickness is selected, the actual stress is calculated, the allowable stress is determined, and the original thickness is adjusted so that the allowable stress approaches the actual stress.

Stress in Skirt Due to Gussets or Top Ring If there are gussets or gussets and a top ring included in the base plate geometry, there is an additional load in the skirt. Jawad & Farr have analyzed this load and determined that the stress in the skirt due to the bolt load on the base plate is calculated as follows: s

=

(1.5 * F * b) / (PI * h * t ** 2)

F

=

Total load in one bolt = load on one gusset

b

=

Width of the gusset at the base

t

=

thickness of the skirt

h

=

height of the gusset.

Where

Jawad & Farr note that this stress should be combined with the axial stress due to weight and bending moment, and should then be less than three times the allowable stress. They thus categorize this stress as secondary bending. The program performs the calculation of this stress, and then repeats the iterative procedure described above to determine the required thickness of the skirt at the top of the base ring.



21-9

Discussion of Input Main Input Fields Base Ring Number The base ring number should start out at 1 and increment by 1 for each successive base ring analyzed. A blank entry for the base ring number will cause PVElite not to analyze the data for that base ring.

Base Ring Description Enter an optional alphanumeric description for the base ring to be analyzed. This may be a project number that will help keep track of the base ring.

Analyze or Design Base Ring The Base Ring program in PVElite can either analyze existing base rings or design new ones. Two valid entries are Analyze—Existing Base rings Design—New Base rings When in Design mode, PVElite may change the following items: Number of Bolts Size of Bolts Bolt Circle Diameter Outside Diameter of the Base ring Inside Diameter of the Base ring

Temperature of Base Ring Normally base rings operate at temperatures which are near ambient. If the base ring is at a higher temperature, enter it here, otherwise leave the default temperature.

Thickness of Base Ring (TBA) Enter the actual thickness of base ring. Any allowances for corrosion or mill tolerance etc. should be subtracted from this entered thickness. PVElite will compute the required base ring thickness using the simplified method and the neutral axis shift method. The user entered thickness value will be used only for comparison. Please refer to Figure A.

Base Ring\Skirt\Bolt Material Specification Enter the base ring material. Plate materials such as SA-516 70 and SA-36 are commonly used. You can select the material from the Material Database by pressing the Database button. If your material is not present, enter the allowable stresses at the base ring design metal temperature.


21-10

BASE RINGS

Allowable Stress at Operating Temperature If your base ring material is not in the database, enter the hot allowable stress here.

Allowable Stress at Ambient Temperature This field is for the base ring ambient allowable stress.

Inside Diameter of Base Ring (DI) Enter the inside diameter of the base ring. This entry must be greater than 0 and less than the bolt circle diameter and the base ring OD. If the you have specified the program to design the base ring, PVElite may change this value. A good approximation for the base ring ID should be entered when using either the analyze or design option. Please refer to Figure A.

Outside Diameter of Base Ring (DO) Enter the outside diameter of the base ring. This entry must be greater than the base ring ID and the bolt circle diameter. When in design mode, PVElite may change this value. Please refer to Figure A.

Nominal Bolt Diameter The nominal bolt diameters accepted by PVElite range between 1/2 and 4 inches (1.27 and 10.16) centimeters. Values outside of this range will not be accepted. When in design mode PVElite may change the nominal bolt diameter. The bolt diameters are



21-11

Bolt Size(inches)

Root Area (sq. in.)

1/2

0.126

5/8

0.202

3/4

0.302

7/8

0.419

1

0.551

1 1/8

.0728

1 1/4

0.929

1 3/8

1.155

11/2

1.405

1 5/8

1.680

1 3/4

1.980

1 7/8

2.304

2

2.652

2 1/4

3.423

2 1/2

4.292

2 3/4

5.259

3

6.324

3 1/4

7.487

3 1/2

8.749

3 3/4

10.108

4

11.566

This information was adapted from Jawad & Farr, Structural Analysis and Design of Process Equipment, (c) 1984, p 425.

Number of Bolts Enter the bolts that the base ring design calls for. If the BASE RINGS program is in design mode, it may change the number of bolts being used. The bolts are sized based on the maximum load per bolt in the operating case. The computation of the load per bolt is referenced in Jawad and Farr, equation 12.3. The number of bolts can be between 4 and 120.

Diameter at Bolt Circle (DC) Enter the diameter of the bolt circle. This value must be greater than the base ring Id and less than the base ring OD. When in design mode, PVElite may change the bolt circle diameter. Whenever this happens, it will be reported in the output. The word DESIGN will appear followed by the value and description of the input the program has changed. Please refer to Figure A.


21-12

BASE RINGS

Bolt Table The following bolt thread series tables are available: TEMA Bolt Table UNC Bolt Table User specified root area of a single bolt TEMA Metric Bolt Table British, BS 3643 Metric Bolt Table Irrespective of the table used, the values will be converted back to the user selected units. TEMA threads are National Coarse series below 1 inch and 8 pitch thread series for 1 inch and above bolt nominal diameter. The UNC threads available are the standard threads.

Nominal Compressive Stress of Concrete Enter the Nominal Compressive stress of the Concrete to which the base ring is bolted. This value is f'c in Jawad and Farr or FPC in Meygesy. A typical entry is 3000 psi.

Are Gussets to be Used? If your base ring design includes the use of gusset plates, check this field, otherwise continue.

Thickness of Top Ring Plate (TTA) (if any) If your base ring design incorporates a top ring, enter its thickness here. If a thickness greater than 0.0 is entered, PVElite will compute the required thickness of the top plate. If no top ring thickness is entered, PVElite will not perform top ring thickness calculations. Please refer to Figure A.

Radial Width of Top Ring/Plate (TOPWTH) (if any) Enter the radial width of the top ring or plate, if any. This is simply the half of (top ring OD - top ring ID). This value must be entered if you entered it in the last field, and must be positive. Please refer to Figure A.

Top Ring/Plate Type per Moss ( Type 3-Cap Plate, 4-Continuous Ring ) Enter the type of top ring or plate per Moss (Type 3 = Cap Plate, 4-Continuous Ring). Refer to Dennis Moss "Pressure Vessel Design Manual" p129. If type 3 or 4 is entered, the program will calculate per p130.

External Corrosion Allowance Enter the corrosion allowance that would be applied to the skirt, base plate, gussets and top ring. The external corrosion allowance will simply be added to the required thickness of these components.

Skirt Thickness Enter the thickness of the skirt here. This entry must be greater than 0. PVElite will automatically compute the required skirt thickness for both combinations of bending and axial stress. PVElite uses the ASME code compression allowable B for axial stresses.



21-13

Skirt Temperature If the skirt is at an elevated temperature, enter it here. Normally, skirts are at ambient temperature.

Outside Diameter of Skirt at Base (DS) Enter the skirt OD at the junction of the skirt and base ring. This value should be greater than the base ring ID and less than the base ring bolt circle. Please refer to Figure A.

Joint Efficiency for Skirt Weld at Bottom Head Enter the joint efficiency for the weld that joins the skirt to the bottom head. This value depends on the weld detail used. Typical values range between 0.49 and 1.0.

Skirt Diameter at Bottom Head Enter the diameter of the skirt at the bottom head of the vessel. Not all skirts are cylindrical. Some skirts are cone shaped and as such have different diameters at the top and bottom.

Dead Weight of Vessel Enter the weight of the vessel with all peripheral equipment (ladders, cages, catwalks, packing) etc. The working fluid of the vessel should not be included here. This entry is optional and can be 0.

Operating Weight of Vessel Enter the operating weight of the vessel here. This includes all contents and associated "hardware". This value must be greater than 0.

Test Weight of Vessel Enter the test weight of the vessel here. This weight will include the fluid used for the hydrotest of the vessel. This entry is optional and can be 0.

Operating Moment of Base Ring Enter the total moment exerted on the skirt by the wind, reboilers, attached piping etc. when the vessel is operating. This value must be greater than 0.

Test Moment on Base Ring Enter the test moment on the base ring. The entry for the test moment is optional and can be 0.

Are Stress Multipliers to be Used? If you wish to increase the allowable stress the program uses for the skirt design, check this field.


21-14

BASE RINGS

Pop-up Input Fields User-Specified Root Area of a Single Bolt If your base ring design calls out for special bolts, enter the root area of a single bolt in this filed. Note, however, this option is mutually exclusive from the design option. If this condition is detected, the numbers from Table 2 (UNC) will be used.

Thickness of Gusset Plates (TGA) Enter the thickness of the gusset plates to be used for this base ring. Any allowances for corrosion should be considered when making this entry. Please refer to Figure A.

Temperature for Gussets (if not ambient) Enter the temperature for the gusset plates. Normally, the gussets will operate at ambient temperature. If the temperature is above ambient, enter it here.

Height of Gussets (HG) Enter the gusset dimension from the base ring to the top of the gusset plate. The forces in the skirt are transmitted to the anchor bolts through the gussets. Please refer to Figure A.

Distance from Bolts to Gussets (CG) Enter the distance from a bolt to the nearest gusset. Normally, each bolt will have two gussets. This distance would be 1/2 of the spacing between the gusset plates. Please refer to Figure A.

Average Width of Gusset Plates Enter the average width of the gusset plates.

Number of Gussets per Bolt Enter the number of gussets per bolt. Usually, each bolt will have 2 gusset plates associated with it. For base rings that have a large number of bolts, this may not always be the case. In these occasions, each bolt may have a single gusset plate associated with it.

Elastic Modules for Plates The elastic modulus is used to determine the allowable stress for plates in compression according to AISC. This is a required value. For most common steels, this value is 29E6 psi.

Factor for the Skirt Allowable at the Skirt Top This factor is multiplied by the skirt operating allowable wherever it is used. For example: The skirt allowable stress at the top would be = stress multiplier X joint efficient X skirt operating allowable. If you do not wish to use this value, enter a 1.00 for this value. This multiplier is usually between 1 and 2.



21-15

Skirt Comp Allowable Mult for (B) at Base (OPE) This factor will be multiplied by the Code compression allowable B for the operating case. PVElite will look at the minimum of this factor times its allowable and the skirt yield stress times its allowable multiplier. This minimum value will then be used, as a comparison to the actual compressive stress in the skirt.

Skirt Comp Allowable Mult for (B) at Base (TEST) This factor will be multiplied by the Code compression allowable B for the test case. PVElite will look at the minimum of this factor times its allowable times 1.5 and the skirt yield stress times its allowable multiplier. This minimum value will then be used, as a comparison to the actual compressive stress in the skirt.

Skirt Comp Allowable Mult for (SY) at Base (OPE) PVElite will multiply the skirt yield stress by this factor. The minimum of this result and the basic hot allowable stress times its factor will be the skirt operating allowable stress. This minimum value will then be used, as a comparison to the actual compressive stress in the skirt.

Skirt Comp Allowable Mult for (SY) at Base (TEST) PVElite will multiply the skirt yield stress by this factor. The minimum of this result and the basic hot allowable stress times its factor will be the skirt test allowable stress. This minimum value will then be used, as a comparison to the actual compressive stress in the skirt.

Figure A - BASE RING Geometry


21-16

BASE RINGS

Tailing Lug Analysis

Figure B - Tailing Lug Edit Window

The Tailing Lug calculation is included in the base ring analysis for a single or dual type design as depicted in Figure B Tailing Lug Edit Window. The design is based on a lift position where bending does not occur on the tailing lug. The main considerations for the design are the section modulus, shear, and bearing stress at the pinhole and the weld strength. The location of the center of the pinhole will be assumed radially at the edge of the outer most of the top ring or the base ring, which ever is larger. In the absence of the top ring/plate the height of the tailing lug is required. The tailing lug is assumed to be the same material as the gusset or base ring. Note that all input fields pertain to one tail lug.



21-17

Discussion of Input Tailing Lug Input Perform Tailing Lug Analysis Click this check box to perform the Tailing Lug analysis.

Tail Lug Type Select the type of tailing lug (single or dual) used and illustrated on the figure below.

Centerline offset Enter the offset dimension (OS) for the dual tailing lug design only.

Lug Thickness Enter the lug thickness of the tailing lug.

Pin Hole Diameter Enter the pin hole diameter. The center of the pin hole will be placed radially in-line with the larger of the outer most edge of the top ring or the base ring (OD).

Weld Size Thickness Enter the leg weld size.

Lug Height (only if no top ring) Enter the tailing lug height measured form the top of the base ring.


21-18

BASE RINGS

Discussion of Results The tailing lug design consists of a three-part analysis: The base ring assembly ( base ring, skirt and top ring), The strength of weld The tailing lug itself It is assumed that bending does not occur in the tailing lug. In the absence of the top ring only the base ring and the decay length (e) are considered for the section modulus calculation. The table below lists the allowable stresses used to check the design strength. Stress Type

Allowable Value

Shear at Pin Hole

0.4 Sy

Bearing Stress

0.75 Sy

Weld Stress

0.49 Sallow



21-19




CH AP TER

2 2

Chapter 22 THIN JOINTS In This Chapter Introduction ................................................................................ 22-2 Purpose, Scope and Technical Basis........................................... 22-3 Discussion of Input Data............................................................. 22-4 Example ...................................................................................... 22-11


22-2

THIN JOINTS

Introduction THIN JOINTS calculates the stresses in a metal bellows expansion joint of the type typically used in piping systems and heat exchangers. The module does elastic stress analysis for the stresses due to the internal and external pressures, and closing or opening of the joint. The maximum combined stress is used to calculate the cycle life of the joint, which is based on the appropriate formula in the ASME Code, Section VIII, Division 1, Appendix 26 Edition 2004 A-05.


Chapter 22 THIN JOINTS

22-3

Purpose, Scope and Technical Basis The THIN JOINT module enables engineers and designers to evaluate or design metal bellows expansion joints. Since the module uses ASME Code procedures for evaluating these joints, the calculations are acceptable to fabricators, engineering contractors, and petrochemical companies. Thus a consistent design basis and a simple way to perform the calculations will be established, and individual engineers will be effective in evaluating these critical components. The module calculates the required thickness and elastic stresses using formulas in ASME Section VIII Code, Division 1, Appendix 26. These formulas take into account both internal and external pressures, and axial joint movement. The appendix covers both reinforced and un-reinforced expansion joints for U-shaped and toroidal types with multiple convolutions and up to a 0.2 inch nominal thickness. Each curve in Appendix 26 was digitized. The program picks points off of the curves and interpolates for the results used in the stress calculations. These parameters are displayed as part of the output. If the selected joint is reinforced or un-reinforced PVElite will perform the various stress and cycle life computations for that joint type. Thus, there will be no extraneous output for a joint type that is not of interest. In addition, for reinforced expansion joints, the stresses in the reinforcing element and any bolted fastener, which may be holding the ring together are calculated as well.


22-4

THIN JOINTS

Discussion of Input Data Main Input Fields Item Number Displays the thin walled expansion joint number. This should typically start at 1 and increase by one for each expansion joint in the file.

Description Displays an alphanumeric description of the expansion joint in this field. This should relate in some way to the expansion joint i.e. (a project id).

Design Cycle Life, Number of Cycles Displays the number of cycles that the expansion joint is to be designed for. This value is to be compared to the total number of cycles that this design will be capable of handling.

Design Temperature Displays the design temperature of the expansion joint. During normal operation, expansion joints typically run cooler than the piping/pressure vessel. Determine that temperature and enter it here.

Design Internal Pressure Displays the internal pressure to be exerted on the expansion joint.

Design External Temperature The program will automatically update materials properties for external pressure calculations when you change the design temperature. The design external pressure at this temperature is a completely different design case than the internal pressure case. Therefore this temperature may be different than the temperature for internal pressure. Many external pressure charts have both lower and upper limits on temperature. If your design temperature is below the lower limit, use the lower limit as your entry to the program. If your temperature is above the upper limit the component may not be designed for vacuum conditions.

Design External Pressure Displays the design pressure for external pressure analysis. This should be a positive value, i.e. 14.7 psia. If you enter a zero in this field the program will not perform external pressure calculations.

Value

Result



0.00

No External Calculation

14.7

Full Vacuum Calculation

22-5

Design Length of Section Displays the cumulative design length of the bellow section. For the U-Shaped type bellows, the bellow design length can be determined by multiplying the total number of convolution (N) and convolution pitch (q). The design length will also be used to perform the external pressure analysis. For more information refer to the following figures.

Thin Joint Type Select the Thin Joint Type using the figures below.

U-Shaped

Figure A - U-Shaped Thin Joint


22-6

THIN JOINTS

Toroidal

Figure B - Toroidal Thin Joint

Reinforcement/Collar Information Enable this box to activate the reinforcement dialog for entering ring and collar information.

Expansion Joint Bellows Material Typical expansion joints are formed from various materials: stainless steels, monels, and inconels. An example of a material is SA-516 70.

Allowable Stress at Operating Temperature Enter the allowable stress of the bellows material at the operating temperature. If your material is not in the tables, you must enter the properties manually.

Allowable Stress at Ambient Temperature Enter the allowable stress of the bellows material at the ambient temperature. If your material is not in the tables, you must enter the properties manually.

Elastic Modulus at Design Temperature Enter the modulus of elasticity for the bellows material at the bellows operating temperature. Tables of elasticity versus temperature can be found in the ANSI/ASME B31.3 CODE for PRESSURE PIPING table C-6.

Elastic Modulus at Ambient Temperature Enter the modulus of elasticity for the bellows material at the bellows ambient temperature. Tables of elasticity versus temperature can be found in the ANSI/ASME B31.3 CODE for PRESSURE PIPING table C-6.

Poisson's Ratio Displays Poisson's ratio for the bellow material (vb).



22-7

Inside Diameter of Bellows Displays the inside diameter of the bellows (Db). This value will normally be equal to the pipe or vessel inside diameter. Some geometries are larger in diameter than the attached cylinder. Thus, the bellows ID will be larger than the vessel/pipe id. For more information refer to Figures A and B.

Convolution Depth The convolution depth is the distance from the top of the convolution to the trough of the convolution. This is referred as the variable w in the ASME Code. For more information refer to Figure A.

Convolution Pitch The convolution pitch is the distance between the tops of successive bellows convolutions. This is referred to as q in the ASME Code. For more information refer to Figure A.

Expansion Joint Opening Per Convolution Deltaq is the total equivalent axial displacement range per convolution. For example, for a total design movement of 1 inch with an expansion joint that had 8 convolutions, this would result in deltaq = 1/8 = 0.125 in/conv.

Number of Convolution Displays the total number of convolutions

Nominal Thickness of One Ply Displays the nominal thickness (t) of the plate that the expansion joint is to be made of before it is pressed or formed. Expansion joints are typically thin compared to the matching pipe. The final thickness of bellow is referred to nt in Figures A and B.

Number of Plies Displays the total number of plies (n) used to form the bellow wall. The final thickness of bellow is referred to as nt in Figures A and B.

End Tangent Length Displays the End Tangent Length as described as Lt in Figure A. The Lt variable is required for the U-Shaped bellows analysis only.

Fatigue Strength Reduction Factor Displays the fatigue strength reduction factor (Kg) per the ASME code Appendix 26. This factor accounts for geometrical stress concentration factors due to thickness variations; weld geometries, surface notches or environmental conditions. The range of factor Kg is between 1 and 4 with its minimum value for smooth geometrical shapes and its maximum for 90 degree welded corners and fillet welds.


22-8

THIN JOINTS

Fatigue strength reduction factors can be determined from theoretical, experimental, or photo elastic studies.

Material Condition Select the method of which the U-Shaped bellow is being made of. This selection will be used to determine the multiplier Kf for the combined meridional membrane and bending stress allowables.

Material Condition

Kf

Annealed

1.5

Formed

3.0

Reinforcing Ring Present Some applications of expansion joints include a continuous reinforcing ring, which lies in the convolutions. If your application includes a reinforcing ring, enable this field.

Fastener Bolt Present If the expansion design includes a reinforcing ring, it may be held together by a bolted geometry in lieu of a welded ring geometry. If your application includes a fastener, enable this field.

Pop-Up Input Fields Mean Diameter Enter the mean diameter (Dm) of toroidal bellows convolution. For more information refer to Figure B.

Distance Between Attachment Weld Enter the distance between toroidal bellows attachment welds (Lw). For more information refer to the toroidal bellows in Figure B.

Convolution Mean Radius Enter the mean radius of toroidal bellows convolution (r) as depicted in the toroidal bellows in Figure B.

Reinforcing Ring Present? Check the check box to enable the entries for the reinforcing ring information.

Reinforcing Ring Material Enter the reinforcing ring material. An example of a material is SA-516 70. You can select the material from the Material Database by clicking the Database button. If a material is not contained in the database, you can enter its specification and properties manually by selecting TOOLS/EDIT/ADD MATERIALS, from the Main Menu.

Ring Material Allowable Stress at Operating Temperature Enter the allowable stress of the ring material at the operating temperature. If your material is not in the tables, these properties must be entered manually.



22-9

Ring Material Allowable Stress at Ambient Temperature Enter the allowable stress of the ring material at the ambient temperature. If your material is not in the tables, these properties must be entered manually.

Cross Sectional Diameter Enter the ring cross sectional diameter (Dr). For more information refer to Figure A.

Elastic Modulus at Design Temperature Enter the modulus of elasticity (Er) for the ring material at the bellows design temperature. Tables of elasticity versus temperature can be found in the ANSI/ASME B31.3 CODE for PRESSURE PIPING table C-6.

Weld Joint Efficiency Enter the longitudinal weld joint efficiency for reinforcing ring (Cwr) (see UW-12).

Fastener Bolt Present? Check this box to enable the entries for the bolt information.

Fastener Bolt Material Enter the fastener material. An example of a material is SA-516 70. You can select the material from the Material Database by clicking the Database button. If a material is not contained in the database, you can enter its specification and properties manually by selecting TOOLS/EDIT/ADD MATERIALS, from the Main Menu.

Fastener Bolt Material Allowable Stress at Operating Temperature Enter the allowable stress of the fastener bolt material at the operating temperature. If your material is not in the tables, these properties must be entered manually.

Fastener Bolt Material Allowable Stress at Ambient Temperature Enter the allowable stress of the fastener bolt material at the ambient temperature. If your material is not in the tables, these properties must be entered manually.

Effective Length of Fastener Bolt Enter the effective length of one reinforcing fastener (Lf) that is being stressed. This is typically the distance from the center of the nut to the center of the head on the bolt. For more information refer to Figure A.

Fastener Cross-Sectional Area Enter the cross-sectional metal area of one reinforcing fastener (Af) that retains the ring.

Elastic Modulus at Design Temperature Enter the modulus of elasticity for the fastener material (Ef) at the bellows design temperature. Tables of elasticity versus temperature can be found in the ANSI/ASME B31.3 CODE for PRESSURE PIPING table C-6.


22-10

THIN JOINTS

Collar Present? Check this box to enable the entries for the collar information.

Collar Material Enter the collar material. An example of a material is SA-516 70. You can select the material from the Material Database by clicking the Database button. If a material is not contained in the database, you can enter its specification and properties manually by selecting TOOLS/ EDIT/ADD MATERIALS, from the Main Menu.

Collar Material Allowable Stress at Operating Temperature Enter the allowable stress of the collar material at the operating temperature. If your material is not in the tables, these properties must be entered manually.

Collar Material Allowable Stress at Ambient Temperature Enter the allowable stress of the collar material at the ambient temperature. If your material is not in the tables, these properties must be entered manually.

Cross Sectional Thickness Enter the collar cross sectional thickness (tc). For more information refer to Figures A and B.

Cross Sectional Length Enter the collar cross sectional length (Lc). For more information refer to Figure A. For the toroidal bellows, Lc is determined by dividing the collar cross section area with the collar thickness.

Elastic Modulus at Design Temperature Enter the modulus of elasticity (Ec) for the collar material at the bellows design temperature. Tables of elasticity versus temperature can be found in the ANSI/ASME B31.3 CODE for PRESSURE PIPING table C-6.

Weld Joint Efficiency Enter the longitudinal weld joint efficiency for tangent collar (Cwc) (see UW-12)



22-11




CH AP TER

2 3

Chapter 23 THICK JOINTS In This Chapter Introduction ................................................................................ 23-2 Discussion of Input Data............................................................. 23-4 Discussion of Results.................................................................. 23-10 Example ...................................................................................... 23-11


23-2

THICK JOINTS

Introduction This module applies to fixed tubesheet exchangers, which require flexible elements to reduce shell and tube longitudinal stresses, tubesheet thickness, or tube-to-tubesheet joint loads. Light gauge bellows type expansion joints within the scope of the Standards of the Expansion Joint Manufacturers Association (EJMA) are not included within the purview of this paragraph. The analysis contained within these paragraphs are based upon the equivalent geometry used in "Expansion Joints for Heat Exchangers" by S. Kopp and M.F. Sayre; however, the formulas have been derived based upon the use of plate and shell theory. Flanged-only and flanged-and-flued types of expansion joints can be analyzed with this method. (TEMA 8th Edition, Paragraph RCB-8, page 61). The formulas contained in the module are applicable based on the following assumptions: Applied loadings are axial Torsional loads are negligible The flexible elements are sufficiently thick to avoid instability. The flexible elements are axisymmetric. All dimensions are in inches and all forces are in pounds. (TEMA Eighth Edition, Paragraph RCB-8.1, page 61: note that other systems of units may be used for input and output, since the program converts these to inches and pounds for its internal calculations.) The sequence of calculations used by the program is as follows: 1

Select a geometry for the flexible element per RCB-8.21 (user input)

2

Determine the effective geometry constants per RCB-8.22.

3

Calculate the flexibility factors per RCB-8.3.

4

Calculate the flexible element geometry factors per RCB-8.4.

5

Calculate the overall shell spring rate with all contributions from flexible shell elements per RCB-8.5.

6

Calculate "FAX" for each condition as shown in Table RCB-8.6. This requires that you run the PVElite TUBESHEET module to determine the differential expansion and shellside and tubeside equivalent pressures.

7

Calculate the flexible element stresses per RCB-8.7

8

Compare the flexible element stresses to the appropriate allowable stresses per the Code, for the load conditions as noted in step 6.

9

Modify the geometry and rerun the program if necessary.

Note:

More than one analysis may be needed to evaluate the hydrotest and uncorroded conditions.

Thick Expansion joints can also be designed in the TUBESHEET module. This integration allows PVElite to automatically transfer the needed information between the tubesheet and the expansion joint calculation. Figure A shows the geometry for the THICK JOINT module. (TEMA Figure RCB-8.21 and RCB-8.22). Both the input geometry and the equivalent geometry used for the analysis are shown. The discussion of input data below uses the nomenclature shown on this figure.


Chapter 23 THICK JOINTS

23-3

The stresses computed from the TEMA standard are compared to their respective allowables, as per APP-5 in ASME code Sec. VIII Div. 1. The cycle life is also computed to address the fatigue consideration.

Figure A - Thick Joint Module Geometry

Figure B - Flanged Only Expansion Joint


23-4

THICK JOINTS

Discussion of Input Data Main Input Fields Expansion Joint Number Enter an ID number for the expansion joint. This may be the item number on the drawing, or numbers that start at 1 and increase sequentially.

Expansion Joint Description Enter an alphanumeric description for this item. This entry is optional.

Design Temperature for Shell and Expansion Joint Enter the temperature associated with the internal design pressure. PVElite will automatically update materials properties for BUILT-IN materials when you change the design temperature. If you entered the allowable stresses by hand, you are responsible to update them for the given temperature.

Expansion Joint Inside Diameter Enter the inside diameter of the expansion joint bellows. Note that this is not the diameter at the shell, but the inside diameter at the outside of the bellows. This value is shown on Figure A as 'ID'.

Expansion Joint Outside Diameter Enter the outside diameter of the expansion joint bellows. Note that this is not the diameter at the shell, but the outside diameter at the outside of the bellows. This value is shown on Figure A as 'OD'.

Expansion Joint Flange (Minimum) Wall Thickness Enter the minimum thickness of the flange or web of the expansion joint, after forming. This will usually be somewhat thinner than the unformed metal. This value is shown on Figure A as 'te'.

Expansion Joint Corrosion Allowance Enter the corrosion allowance for the expansion joint. This value will be subtracted from the minimum thickness of the flange or web for the joint.



23-5

Material Name Enter the ASME code material specification as it appears in the ASME material allowable tables. Alternatively, you can select the material from the Material Database by clicking the Database button. If a material is not contained in the database, you can enter its specification and properties manually by selecting TOOLS/EDIT/ADD MATERIALS, from the Main Menu. Note that the program uses the external pressure charts to determine the modulus of elasticity and material type for the analysis.

Allowable Stress at Design Temperature This entry is automatically filled in by the program by entering a material specification. When you change the internal design temperature, or the thickness of the shell, the program will automatically update this field, but only for BUILT-IN materials. If you enter the allowable stress by hand, be sure to double check your entry to assure conformance with the latest edition of the ASME Pressure Vessel Code Section II Part D at the design temperature.

Expansion Joint Allowable Stress at Ambient Temperature This entry is automatically filled in by the program by entering a material specification. When you change the internal design temperature, or the thickness of the shell, the program will automatically update this field, but only for BUILT-IN materials. If you enter the allowable stress by hand, be sure to double check your entry to assure conformance with the latest edition of the ASME Pressure Vessel Code Section II Part D at the ambient temperature.

Shell Inside Diameter Enter the inside diameter of the shell at the point where the expansion joint is attached. This value is shown on Figure A as 'G'.

Shell Wall Thickness Enter the actual wall thickness of the shell at the point where the expansion joint is attached. This value is shown on Figure A as 'ts'.

Shell Corrosion Allowance Enter the corrosion allowance for the shell wall.

Shell Cylinder Length Enter the length of the shell cylinder to the nearest body flange or head. TEMA Paragraph RCB 8-21 included the following note: lo and li are the lengths of the cylinders welded to the flexible shell elements except, where two flexible shell elements are joined with a cylinder between them, lo or li as applicable shall be taken as half the cylinder length. If no cylinder is used, lo and li shall be taken as zero.


23-6

THICK JOINTS

Entering a very long length for this value will not disturb the results, since the TEMA procedure automatically takes into account the decay length for shell stresses and uses this length if less than the cylinder length. This value is shown on Figure A as 'li'.

Expansion Joint Inside Knuckle Offset (Straight Flange) Enter the distance from the shell cylinder to the beginning of the knuckle for an expansion joint with an inside knuckle. Enter the distance from the shell cylinder to the intersection of the expansion joint web and the shell diameter for joints with a square inside corner. Note that in both cases this distance is frequently zero. This value is shown on Figure A as 'fa'.

Expansion Joint Inside Knuckle Radius Enter the knuckle radius for an expansion joint with an inside knuckle. Enter zero for an expansion joint with a sharp inside corner. This value is shown on Figure A as 'ra'.

Expansion Joint Outside Knuckle Offset Enter the distance from the outer cylinder to the beginning of the knuckle for an expansion joint with an inside knuckle. Enter the distance from the outer cylinder to the intersection of the expansion joint web and the outer diameter for joints with a square outside corner. Note that in both cases this distance is frequently zero, and that for an expansion joint with a outside radius but no outside cylinder, this distance is the distance from the end of the knuckle to the symmetrical centerline of the joint. This value is shown on Figure A as 'fb'.

Expansion Joint Outside Knuckle Radius Enter the knuckle radius for an expansion joint with an outside knuckle. Enter zero for an expansion joint with a sharp outside corner. (Flanged Only) This value is shown on Figure A as 'rb'.

Number of Flexible Shell Elements Enter the Number of flexible shell elements in the flanged/flued expansion joint. As shown in Figure B above.



23-7

Is There an Outer Cylinder? Check this field if there is a cylindrical section attached to the expansion joint at the OD. This will always be true when you have an expansion joint with only a half convolute. It may also be true when there is a relatively long cylindrical portion between two half convolutes, as in the case of certain inlet nozzle geometries for heat exchangers.

Differential Expansion Pressure (from Tubesheet) You need to run the PVElite TUBESHEET program in order to determine this value. It is listed in the output from the TEMA tubesheet analysis of fixed tubesheet exchangers.

Shellside Design Pressure You do not need to run the PVElite TUBESHEET program to get this value - it is simply the design pressure for the shell.

Shellside Prime Design Pressure (from Tubesheet) You need to run the PVElite TUBESHEET program in order to determine this value. It is listed in the output from the TEMA tubesheet analysis.

Shellside Prime Design Pressure (from Tubesheet) Corroded You need to run the PVElite TUBESHEET program in order to determine this value. It is listed in the output from the TEMA tubesheet analysis. The TUBESHEET module computes the Shellside Prime Design Pressure, in both corroded and uncorroded conditions.

Tubeside Design Pressure You do not need to run the PVElite TUBESHEET program to get this value - it is simply the design pressure for the channel.

Tubeside Prime Design Pressure (from Tubesheet) You need to run the PVElite TUBESHEET program in order to determine this value. It is listed in the output from the TEMA tubesheet analysis.

Tubeside Prime Design Pressure (from Tubesheet) Corroded You need to run the PVElite TUBESHEET program in order to determine this value. It is listed in the output from the TEMA tubesheet analysis. The TEMA TUBESHEET module computes the Tubeside Prime Design Pressure, in both corroded and uncorroded conditions.


23-8

THICK JOINTS

Analyze Differential Expansion? Check this field if you wish to run an analysis for this case. We recommend that you analyze all the cases at first, but you may wish to eliminate some cases that are not controlling from the final printout.

Differential Expansion Pressure (from Tubesheet) Corroded You need to run the PVElite TUBESHEET program in order to determine this value. It is listed in the output from the TEMA tubesheet analysis. The TEMA TUBESHEET module computes the Differential Expansion Pressure, in both corroded and uncorroded conditions.

Analyze Shellside Pressure Check this field if you wish to run an analysis for this case. We recommend that you analyze all the cases at first, but you may wish to eliminate some cases that are not controlling from the final printout.

Analyze Tubeside Pressure Check this field if you wish to run an analysis for this case. We recommend that you analyze all the cases at first, but you may wish to eliminate some cases that are not controlling from the final printout.

Analyze Shellside + Tubeside Pressure Check this field if you wish to run an analysis for this case. We recommend that you analyze all the cases at first, but you may wish to eliminate some cases that are not controlling from the final printout.

Analyze Shellside + Differential Expansion Check this field if you wish to run an analysis for this case. We recommend that you analyze all the cases at first, but you may wish to eliminate some cases that are not controlling from the final printout.

Analyze Tubeside + Differential Expansion Check this field if you wish to run an analysis for this case. We recommend that you analyze all the cases at first, but you may wish to eliminate some cases that are not controlling from the final printout.

Analyze Shellside + Tubeside + Differential Expansion Check this field if you wish to run an analysis for this case. We recommend that you analyze all the cases at first, but you may wish to eliminate some cases that are not controlling from the final printout.




23-9

Pop-Up Input Fields Outer Cylindrical Element Thickness Enter the actual wall thickness of the outer cylindrical element at the point where the expansion joint is attached. This value is shown on Figure A as 'to'.


Outer Cylindrical Element Length Enter the length of the outer cylinder to the nearest body flange or head, or to the centerline of the convolute. TEMA Paragraph RCB 8-21 includes the following note: lo and li are the lengths of the cylinders welded to the flexible shell elements except, where two flexible shell elements are joined with a cylinder between them, lo or li as applicable shall be taken as half the cylinder length. If no cylinder is used, lo and li shall be taken as zero. Entering a very long length for this value will not disturb the results, since the TEMA procedure automatically takes into account the decay length for shell stresses and uses this length if less than the cylinder length. This value is shown on Figure A as 'lo'.


23-10

THICK JOINTS

Discussion of Results The three most significant results for the THICK JOINT analysis are the spring constant for the joint, the stresses in the joint, and the cycle life for the joint. These are discussed below.

Spring Constant The program does not calculate the deflection of the joint. Instead it calculates the spring constant for the joint, which can be used in the Tubesheet program or elsewhere to determine the effect of the joint on the heat exchanger design.

Stresses The program calculates the combined meridional bending and membrane stresses in the expansion joint and the attached cylinders. According to ASME, Section VIII, Division 1, Appendix CC, this stress should be limited to KS, where K is 1.5 for flat sections (the annular ring or cylinders) and 3.0 for curved areas of the inner and outer torus (or sharp corners). S is the basic allowable stress for the expansion joint material at operating temperature. Note, however, that this stress limit applies only to the stresses due to pressure - stresses due to deflection are limited by fatigue considerations rather than stress allowables. Thus the program only prints the allowable membrane plus bending stress for the case of shellside pressure.

Cycle Life The cycle life of the joint is analyzed using the rules in the ASME Code, Section VIII, Division 1, Appendix CC. For Series 3xx stainless steels, nickel-chromium iron alloys, nickel-iron chromium alloys and nickel-copper alloys, the equation for cycle life is as follows: N < [(2.2)/(( 14.2*Kg*Sn)/Eb - 0.03 )]^2.17 For carbon and low alloy steels, Series 4xx stainless steels, and high alloy steels, the equation for cycle life is: N < [(2.0)/(( 15*Kg*Sn)/Eb - 0.011 )]^2.17 Where: Kg = The fatigue strength reduction factor which accounts for the geometrical stress concentration factors due to local thickness variations, weld geometries, and other surface conditions. The range of Kg is 1.0 <= Kg <= 4.0 with its minimum value for smooth geometrical shapes and its maximum for 90 deg. welded corners and fillet welds. The program uses a Kg of 1.0 when the knuckle radius is greater than three times the expansion joint thickness. Sn = The maximum combined meridional membrane and bending stress range in a flexible element due to the cyclic components of pressure and deflection. Eb = The modulus of elasticity at design temperature. The program determines both the modulus of elasticity and the material type from the name of the external pressure chart given by the user.



23-11




CH AP TER

2 4

Chapter 24 ASME TUBESHEETS In This Chapter Introduction ................................................................................ 24-2 Purpose, Scope, and Technical Basis.......................................... 24-3 Discussion of Input Data............................................................. 24-4 Discussion of Results.................................................................. 24-26 Example ...................................................................................... 24-28


24-2

ASME TUBESHEETS

Introduction This module computes the required thickness for tubesheets and shell/channel/tube stresses according to the ASME Code Section VIII Division 1 part UHX, Edition 2004 A-05. Tubesheet types that are addressed are U-tube, fully fixed and floating. PVElite also computes the allowable Tube-Tubesheet joint load per ASME Sec. VIII Appendix A. Flanged and flued (thick) expansion joint for a fixed tubesheet is also analyzed per TEMA standard, 8th edition and ASME Sec. VIII Div. 1 Appendix 5.


Chapter 24 ASME TUBESHEETS

24-3

Purpose, Scope, and Technical Basis The ASME TUBESHEETS module is based on the ASME Code Section VIII Division 1 part UHX. This module will also compute loads on the tubes and compare them to their allowable loads per the appropriate equation in Appendix A. Gasketed geometries for both fixed, floating and U-tube exchangers are also analyzed as well as the thickness of the flanged extension (the TEMA equation has been used). This module is good for both square or rectangular tube patterns. When this module is executed it will display the output including equations for a given input. Afterwards, PVElite will iterate for the required thickness of the tubesheet. The shell side and tubeside corrosion allowances will then be added to these final results. PVElite also performs the plasticity calculations for fixed tubesheets if high discontinuity stresses exist at the attachment between the tubesheet and shell or channel. PVElite contains all of the graphs and functions that appear in section UHX. Program analyzes all the load cases as per the section UHX, which includes various combinations of pressure and temperature, in both the uncorroded and corroded (if specified) conditions. A summary table is provided at the end of the output. User can choose to view the detailed printout of any load case. Program can also analyze a thick expansion joint attached to a fixed tubesheet. The expansion joint spring rate and stresses are computed per TEMA standard. The actual stresses are then compared with the allowables provided in ASME Sec. VIII Div. 1, Appendix 5 to check the joint's adequacy.

Figure A - Geometry for ASME Tubesheet Program


24-4

ASME TUBESHEETS

Discussion of Input Data Main Input Fields Item Number Type an ID number for the tubesheet. This may be the item number on the drawing, or numbers that start at 1 and increase sequentially. Note, that more than one pressure or temperature case can be run. Press the + key, enter a new tubesheet number and change the relevant input items.

Tubesheet Description Type an alphanumeric description for this item. This entry is optional. Entering a description will help you keep up with each item when reviewing the output.

Shell/Channel Merge Use this option to import data from the Shells and Heads module. Select the shell you want to add to the model, and press enter, all the appropriate data for that shell is copied in automatically.

Shell Design Pressure Type the design pressure for the shell side of the exchanger. If the shell side has external pressure, enter a negative pressure. The program will add this pressure with the positive pressure on the tube (channel) side.

Shell Wall Thickness Type the minimum wall thickness for the shell of the exchanger. The program uses this value to calculate the characteristic diameter for all tubesheets. It is used in the computation of Beta as well as the spring rate and other factors.

Shell Corrosion Allowance Type the shell side corrosion allowance for the exchanger. This value is used to calculate the corroded thickness of the shell.

Shell Inside Diameter Type the uncorroded inside diameter of the exchanger shell.

Shell Temperature for Internal Pressure Enter the design metal temperature for the shell. This is the design temperature for determining allowable stresses only. This temperature is not assumed to be the metal temperature for thermal expansion. There is a separate input field for the actual metal temperature.

Channel Design Pressure Type the design pressure for the tube side of the exchanger. If the tube side has a vacuum design condition, enter a negative pressure. The program will add the absolute value of this pressure with the positive pressure on the other side.



24-5

Channel Wall Thickness Type the minimum wall thickness for the channel of the exchanger. The program uses this value to calculate the characteristic diameter for all tubesheet types. An example of such a parameter is the Beta dimension for fixed tubesheet exchangers.

Channel Corrosion Allowance Type the tube side corrosion allowance for the exchanger. This value is used to calculate the corroded thickness of the channel.

Channel Inside Diameter Type the uncorroded inside diameter of the exchanger channel.

Channel Temperature for Internal Pressure Enter the design metal temperature for the shell. This is the design temperature for determining allowable stresses only. This temperature is not assumed to be the metal temperature for thermal expansion. There is a separate input field for the actual metal temperature.

Shell/Channel/Tubesheet/Tube/Bolt Material Specification Type the ASME code material specification. The program will display all the materials matching the name and occurrence number. Alternatively, you can click the Material Database button to search for a material name in the Material Database. Click the Material Edit Properties button to change the properties of the selected material. If a material is not contained in the database, you can manually enter its specification and properties by selecting TOOLS, EDIT/ADD MATERIALS, from the Main Menu.

Allowable Stress, Operating Temperature This entry is automatically filled in by the program by entering a material specification. When you change the design temperature the program will automatically update this field, but only for BUILT-IN materials. If you enter the allowable stress by hand, be sure to double check your entry to assure conformance with the latest edition of the ASME Pressure Vessel Code Section II Part D at the design temperature.

Allowable Stress, Ambient Temperature The program automatically fills in this entry by entering a material specification. If you enter the allowable stress by hand, be sure to double check your entry to verify conformance with the latest edition of the ASME Pressure Vessel Code Section II Part D.

Tube Design Temperature Enter the design temperature of the tubes. This value will be used to look up the allowable stress values for the tube material from the material tables.

Is Welded Material Specified (not Seamless) Check this box if the tube has a longitudinal weld seam or in other words it (not seamless) and the material allowables are for welded product.


24-6

ASME TUBESHEETS

For computing allowable Tube-Tubesheet Joints loads, the allowable stress of a seamless tube is needed. If the user selected a welded tube and enables this check box, then the tube allowable stress is divided by 0.85 to an equivalent allowable of a seamless tube. This is per the note in ASME Sec. VIII Div. 1 UW-20.3 and App. A.

Tube Wall Thickness Enter the wall thickness of the tubes. This value is used to determine the total tube area and stiffness. The following table displays thicknesses for some common tube gauges:

B.W.G. Gauge

Thickness (Inches)

B.W.G. Gauge

Thickness (Inches)

7

.180

17

.058

8

.165

18

.049

10

.134

19

.042

11

.109

22

.028

13

.095

24

.022

14

.083

26

.018

15

.072

27

.016

16

.065

Tube Corrosion Allowance Enter the corrosion allowance for the tube.

Number of Tubes Holes Enter the number of tube holes in the tubesheet. This value is used to determine the total tube area and stiffness. Note: tubes.

For U-tube exchangers, the number of tube holes in the tubesheet is normally equal to 2 times the number of

Tube Pattern (Triangular, Square) Enter the pattern of the tube layout. The tube diameter, pitch, and pattern are used to calculate the term 'eta' in the tubesheet thickness equation. These rules are same for triangular and rotated triangular layouts. The rules are also the same for square or rotated square layouts. In the ASME code square patterns have a 90º layout angle and triangular patterns have a 60º angle.

Tube Outside Diameter Enter the outside diameter of the tubes. This is usually an exact fraction, such as .5, .75, .875, 1.0, or 1.25. The tube diameter, pitch, and pattern are used to calculate the term 'eta' in the tubesheet formulas. These rules are same for triangular and rotated triangular layouts. The rules are also the same for square or rotated square layouts.



24-7

Tube Pitch Enter the tube pitch, the distance between the tube centers. The tube diameter, pitch, and pattern are used to calculate the term "eta" in the tubesheet thickness equation. These rules are same for triangular and rotated triangular layouts. The rules are also the same for square or rotated square layouts.

Radius to Outermost Tube Hole Center Enter the distance from the centerline of the exchanger to the centerline of outermost tube.

Distance Between Innermost Tube Centers (UL) ASME defines this input as the largest center-to-center distance between adjacent tube rows. This is not the tube pitch. If there are no pass partitions then this value must be 0.

Length of Expanded Portion of Tube The expanded portion of a tube is that part which is radially expanded outward. When the tube is expanded it is also pressed into the tubesheet. Simply enter this expanded length. Some tubes are welded into place and this value may be 0. The maximum this value can be is the thickness of the tubesheet.

Tube Side Pass Partition Groove Depth (hg) Enter the tube side pass partition groove depth.

Length of Tubes Enter the length of the tubes. For U-tubesheet exchanger this is the straight length of the tube. For fixed tubesheet exchanger this is the overall length from the inside face of one tubesheet to the inside face of the other tubesheet. This value is used to determine the thermal expansion of the tubes.

Enter the Unsupported Tube Span, SL and Tube End Condition, K for MAX (k*SL) For computing the allowable tube compression, the values of k and SL are required. Where, SL - Unsupported Span of the tube k - Tube end condition corresponding to the span SL. The table below displays the different values of k:

K

End Condition for unsupported spans between ...

0.6

two tubesheets

0.8

a tubesheet and a tube support

1.0

two tube supports

For the worst case scenario enter the values of k and SL that the give maximum combination of k*SL. SL for example, could be the distance between the tubesheet and the first baffle or the tube span between two support baffles.


24-8

ASME TUBESHEETS

Type of Tubesheet Choose the type of tubesheet that you will be analyzing. ASME has four distinct types of tubesheets for analysis purposes. These are Fixed and U Tube, Stationary and Floating tubesheets. A fixed tubesheet exchanger is one that is subject to loads arising from differential thermal expansion between the tubes and the shell. It consists of stationary tubesheets on both sides. A fixed tubesheet exchanger can be further classified into Configurations A, B, C or D. U Tube exchangers can be categorized as integral with the shell, channel, both or gasketed on both sides.



24-9

Floating tubesheet heat exchangers consist of a stationary tubesheet and a floating tubesheet. Based on the selected tubesheet type, the program will automatically reset other inputs on this dialog, such as tubesheet gasketed with which side or tubesheet integral with which side. Some Tubesheet configurations are illustrated below: Tubesheet is integral with the Shell and is gasketed on the Channel side and is not extending as a flange.

Tubesheet is integral with the Shell and is gasketed on the Channel side and is extending as a flange.

Tubesheet is gasketed on both the Shell and the Channel sides and is not extended as a flange. In an alternative arrangement the tubesheet is extending as a flange.

Tubesheet is integral with both the Shell and the Channel. This is a fixed tubesheet exchanger; flanged and flued expansion joint is used to reduce the differential thermal expansion between the tubes and the shell.

Stationary and U-Tube Tubesheet Configurations Permitted per ASME Section UHX:


24-10

ASME TUBESHEETS

a

Tubesheet integral with both the shell and the channel.

b

Tubesheet integral with the shell, gasketed with the channel and extended as a flange.

c

Tubesheet integral with the shell, gasketed with the channel and not extended as a flange.

d

Tubesheet gasketed with both the shell and the channel

e

Tubesheet integral with the channel, gasketed with the shell and extended as a flange.

f

Tubesheet integral with the channel, gasketed with the shell and not extended as a flange.

Floating Tubesheet Configurations Permitted per ASME Section UHX: A

Tubesheet integral

B

Tubesheet gasketed and extended as a flange.

C

Tubesheet gasketed and not extended as a flange.

D

Tubesheet internally sealed

Fixed Tubesheet Configurations Permitted per ASME Section UHX: a

Tubesheet integral with both the shell and the channel.

b

Tubesheet integral with the shell, gasketed with the channel and extended as a flange.

c

Tubesheet integral with the shell, gasketed with the channel and not extended as a flange.

d

Tubesheet gasketed with both the shell and the channel

Type of Floating Heat Exchanger Choose the floating tubesheet exchanger, the following types are listed in the ASME code: Floating tubesheet exchanger with an immersed Floating head. Stationary tubesheet can be configuration a, b, c, d, e, or f and floating tubesheet can be configuration A, B, or C. Floating tubesheet exchanger with an Externally Sealed Floating head. Stationary tubesheet can be configuration a, b, c, d, e, or f and floating tubesheet is configuration A. Floating tubesheet exchanger with an Internally Sealed Floating head. Stationary tubesheet can be configuration a, b, c, d, e, or f and floating tubesheet is configuration D.

Tubesheet Metal Design Temperature Type the design metal temperature for the tubesheet. This is the design temperature for determining allowable stresses only. This temperature is not assumed to be the metal temperature for thermal expansion. There is a separate input field for the actual metal temperature.

Tubesheet Thickness Enter the appropriate tubesheet thickness. For all types of exchangers, the complete initial calculations will be performed and printed using the original tubesheet thickness. PVElite will converge on the minimum required tubesheet thickness for the given loading condition.



24-11

Tubesheet Corrosion Allowance Shell Side Enter the tubesheet corrosion allowance for the shell side. This value is combined with the tubesheet corrosion allowance channel side to calculate the corroded thickness of the tubesheet.

Tubesheet Corrosion Allowance Channel Side Enter the tubesheet corrosion allowance for the channel side. This value is combined with the tubesheet corrosion allowance on the shell side to calculate the corroded thickness of the tubesheet.

Enter the Outside Diameter of the Tubesheet This value is referred to as "A" in the ASME code. For tubesheets extended as flange, this will be the diameter of the extended portion of the tubesheet.

Tubesheet Gasket (None, Shell, Channel, Both) Select NONE if the tubesheet is not gasketed on either side. Select SHELL if the gasket is only on the shell side of the exchanger. Select CHANNEL if the gasket is only on the channel side of the exchanger. Select BOTH if the gaskets are on both sides of the exchanger.

Tubesheet Integral With Select the side to which the Tubesheet is integral with.

Tubesheet Extended as Flange Check this box to indicate that the tubesheet is extended as flange for bolting.

Enter Dimension G for Backing Flange (for Tubesheets with Backing Ring) or Gc for Tubesheets Gasketed with Shell and Channel This input is used for two types of ASME tubesheet geometries: If the tubesheet has a backing ring, then enter the G dimension for the backing ring. G is the mid point of the contact between the backing flange and the tubesheet. In this case it is a required input. If the tubesheet is gasketed with both the Shell and the Channel, then enter the channel gasket reaction diameter, Gc in this input. The program computes the Shell gasket reaction diameter, Gs from the gasket/flange properties specified. In this case, this input is optional, required only if Gc is different from Gs.

Is There a Shell Band The shell band can be used to reduce the bending stresses in the tubesheet, shell, or channel. Fixed tubesheets where the shell is integral to the tubesheet, configuration a, b, or c, can have a different thickness of shell adjacent to the tubesheet. The band of a shell can be of a different material as well. If that is the case then check this box.


24-12

ASME TUBESHEETS

Figure B - Shell Band Input

Total Area of Untubed Lanes (Al) Enter the total area of all the untubed lanes on the tubesheet. It is limited to 4*Do*p. Where Do = Equivalent diameter of outer limit circle. p = tube pitch

Expansion Joint Type Select the appropriate expansion joint type. The following options are available. None - Select this option when there is no expansion joint in the heat exchanger. Thin Expansion Joint - Select this option if the expansion joint is a bellows type expansion joint. The figure below shows an unreinforced bellows type expansion joint. In this case you should use the Thin Joint module to design the bellows type expansion joints (both reinforced and unreinforced). Then specify the computed spring rate.

Figure C - Thin Expansion Joint

Thick Expansion Joint - Select this option if the expansion joint is:



24-13

Flanged and flue Flanged only No flanged or no flue. You can specify 2 design options: Existing - specify the spring rate for the expansion joint Analyze - specify the expansion joint geometry and let the program compute spring rate and stresses. For more information, see Figure D - Thick Expansion Joint.

Expansion Joint Design Option The following options are available: Existing - Select this option if you already know the spring rate of the flanged/flued expansion joint. Analyze - Select this option if you want the program to compute the spring rate of the expansion joint and stresses induced in the expansion joint

Corroded Expansion Joint Spring Rate If there is no expansion joint, enter a zero (0.0). If there is a thin walled expansion joint, then either enter a one (1.0) or enter the actual spring rate. If there is a thick walled expansion joint, either enter the actual spring constant for the joint or let the Tubesheet module compute it using the rules per the TEMA standard RCB-8.

Uncorroded Expansion Joint Spring Rate Enter the Expansion Joint Spring rate in uncorroded condition. Different inputs for the uncorroded and corroded spring rates are required for running the multiple load cases in both conditions.

Figure D - Thick Expansion Joint

Expansion Joint Inside Diameter (ID) Enter the inside diameter of the expansion joint, shown as "ID" in the figure above. The program uses this value to calculate the force on the cylinder, and the equivalent pressure of thermal expansion.

Expansion Joint Outside Diameter (OD) Enter the outside diameter of the expansion joint, shown as "OD" in the figure above.


24-14

ASME TUBESHEETS

Expansion Joint Flange (Minimum) Wall Thickness (te) Enter the minimum thickness of the flange or web of the expansion joint, after forming. This is usually thinner than the unformed metal. This value is shown as te, in the above figure.

Expansion Joint Corrosion Allowance Enter the corrosion allowance for the expansion joint. This value will be subtracted from the minimum thickness of the flange or web for the joint. Some common corrosion allowances are listed below: 0.0625 inches (2 mm)

1/16"

0.125 inches (3 mm)

1/8"

0.25 inches (6 mm)

1/4"

Expansion Joint Knuckle Offset (Straight Flange) (fa) Enter the distance from the shell cylinder to the beginning of the knuckle for an expansion joint with an inside knuckle.

Expansion Joint Outside Knuckle Offset (fb) Enter the distance from the outer cylinder to the beginning of the knuckle for an expansion joint with an outside knuckle. Enter the distance from the outer cylinder to the intersection of the expansion joint web and the outer diameter for joints with a square outside corner. Note that in both cases this distance is frequently zero, and that for an expansion joint with an outside radius but no outside cylinder, this distance is the distance from the end of the knuckle to the symmetrical centerline of the joint.



24-15

Expansion Joint Inside Knuckle Radius (ra) Enter the knuckle radius for an expansion joint with an inside knuckle. Enter zero for an expansion joint with a sharp inside corner.

Expansion Joint Outside Knuckle Radius (rb) Enter the knuckle radius for an expansion joint with an outside knuckle. Enter zero for an expansion joint with a sharp outside corner. (Flanged Only)

Number of Flexible Shell Elements Enter the number of flexible shell elements in the flanged/flued expansion joint. Two flexible shell elements constitute 1 convolution of the Expansion Joint.

Shell Cylinder Length ( Li ) Enter the length of the shell cylinder to the nearest body flange or head. TEMA Paragraph RCB 8-21 includes the following note: lo and li are the lengths of the cylinders welded to the flexible shell elements except, where two flexible shell elements are joined with a cylinder between them, lo or li as applicable shall be taken as half the cylinder length. If no cylinder is used, lo and li shall be taken as zero. Entering a very long length for this value will not disturb the results, since the TEMA procedure automatically takes into account the decay length for shell stresses and uses this length if it is less than the cylinder length.

Outer Cylinder on the Thick Expansion Joint Check this field if there is a cylindrical section attached to the expansion joint at the OD. This will always be true when you have an expansion joint with only a half convolution (1 FSE). It may also be true when there is a relatively long cylindrical portion between two half convolutions, as in the case of certain inlet nozzle geometries for heat exchangers.



24-16

ASME TUBESHEETS

Pop-Up Input Fields Fillet or Groove Weld Leg Length If the tubes on your exchanger are welded to the tubesheet, then enter the fillet weld or groove weld leg length. Some designs incorporate either only a groove or fillet weld. Sometimes both are used. These values are used to determine the weld strengths and the required weld sizes. Refer to paragraph UW-20 in the ASME Code for more details.

Weld Type Following options are available for the connecting tube/tubesheet welds: Full Strength

A full strength tube-to-tubesheet weld is one in which the design strength is equal to or greater than the maximum allowable axial tube strength. In other words the joint is at least as strong as the tube.

Partial Strength

A partial strength weld can be designed based on the actual tube-tubesheet axial load

Seal Weld/No Weld

No calculations are performed in this case.

Information on these weld types can be found in the ASME Code Section VIII Division 1 paragraph UW-20.

Design Strength This term is Fd as defined in the Code paragraph UW-20. The design strength should not be greater than Ft (tube strength), which is t(do - t)Sa. This value is used to determine the minimum acceptable fillet/groove weld size that connects the tube to the tubesheet. This value is required for U-tube tubesheet exchanger. But, is optional for fixed and floating tubesheet exchangers. For partial strength tube-to-tubesheet welds on fixed/floating tubesheet exchangers, the higher of the actual tube-totubesheet load and the user entered design strength will be used to size welds. For full strength tube-to-tubesheet welds on fixed/floating tubesheet exchangers, tube strength (Ft) is used to size welds.

Method for Computing Allowable loads for Tube-to-Tubesheet Joints The following methods are available: ASME Sec. VIII Div. I App. A

This method is available for fixed and floating tubesheet heat exchangers. It covers many types of tube-tubesheet joints, such as welded, brazed and expanded.

ASME Sec. VIII Div. I UW-20 This method provides rules for computation of allowable loads for Full strength and Partial strength Tube-Tubesheet welds.

Classification for Tube Joint Connection (1 - 11) Enter a value between 1 and 11 based on the following table from the ASME VIII appendix A table A-2.



24-17

Type

Joint

Description

Fr.(test)

Fr.(no test)

1

a

Welded only, a >= 1.4t

1.00

.80

2

b

Welded only t <= a < 1.4t

.70

.55

3

c

Brazed examined

1.00

.80

4

d

Brazed not fully examined

0.50

.40

5

e

Welded a >= 1.4t, exp.

1.00

.80

6

f

Welded a < 1.4t,exp,2 grooves

.95

.75

7

g


.85

.65

8

h


.70

.50

9

i

Expanded 2 or more grooves

.90

.70

10

j

Expanded single groove

.80

.65

11

k

Expanded no grooves

.60

.50

Is Tube-Tubesheet Joint Tested Check this box if the Tube-Tubesheet joint is tested. In that case the program will use the higher value of factor fr from the table A-2 in ASME code, Sec VIII, Div 1.

ASME Tube Joint Reliability Factor Enter a value between .40 and 1.0 based on the following table from ASME VIII appendix A table A-2. This is needed when the tube connection class is not specified above. See the table above for these factors.

Interface pressure, Po and Pt Enter the Interface pressures, Po and Pt, between the tube and the tubesheet hole Po

Interface Pressure that remains after expanding the tube at fabrication.

Pt

Interface Pressure due to differential thermal growth.

These pressures are usually established analytically or experimentally. But, must consider the effect of change in material strength at operating temperature. This input is required only for the tube joint types i, j and k, as defined in table A-2 in ASME Sec VIII, Div-1 App. A.

Corroded Expansion Joint Spring Rate If there is no expansion joint, enter a zero (0.0). If there is a thin walled expansion joint, enter a one (1.0). If there is a thick walled expansion joint, enter the actual spring constant for the joint. The expansion joint spring rate should be calculated using the PVElite THICKJNT program, the rules in TEMA RCB-8, or a similar analysis technique. The spring rate reported from the THICKJNT program is reported in units of pounds per inch.


24-18

ASME TUBESHEETS

Uncorroded Expansion Joint Spring Rate If there is no expansion joint, enter a zero (0.0). If there is a thin walled expansion joint, enter a one (1.0). If there is a thick walled expansion joint, enter the actual spring constant for the joint. The expansion joint spring rate should be calculated using the PVElite THICKJNT program, the rules in TEMA RCB-8, or a similar analysis technique. The spring rate reported from the THICKJNT program is reported in units of pounds per inch. The uncorroded and corroded spring rates are required for running the multiple load cases in uncorroded and corroded condition.

Expansion Joint Projection from Shell ID For fixed tubesheet heat exchangers that have an expansion joint enter the value ( wj ). This distance is measured from the ID of the shell to the ID of the expansion joint. This geometry is illustrated in section UHX of ASME Code VIII Div. 1 pressure vessel code.

Metal Temperatures It is important, especially when evaluating fixed tubesheets without expansion joints or floating tubesheets, that you enter accurate values for metal temperatures for each operating condition. You may have to run the analysis more than once to check several metal temperature cases. Frequently the metal temperatures will be less severe than the design temperatures, due to thermal resistances. For example, if the shellside fluid has a good heat transfer coefficient and the tubeside fluid has a relatively poor heat transfer coefficient, then the tube temperature will be quite close to the shell temperature. Don't forget to evaluate the condition of shellside or tubeside loss of fluid. Especially for shellside loss of fluid, this design condition may govern the exchanger design. Tubesheet Metal Temperature at the Rim. Enter the actual metal temperature for the tubesheet at the rim, under realistic operating conditions. Shell Metal Temperature at Tubesheet. Enter the actual metal temperature for the shell at the tubesheet, under realistic operating conditions. Channel Metal Temperature at Tubesheet. Enter the actual metal temperature for the channel at the tubesheet, under realistic operating conditions. The following metal temperatures are required only for fixed tubesheet exchangers. Mean Shell Metal Temperatures. Enter the actual metal temperature for the shell along its length, under realistic operating conditions. Mean Tube Metal Temperatures. Enter the actual metal temperature for the tube along its length, under realistic operating conditions. Refer to TEMA standard, section T-4 (8th Ed.) for guidance to compute the Mean Metal Temperatures.

Run Multiple Load Cases for Fixed Tubesheet ? Check this box if you want to run multiple load cases for the tubesheet design, per the ASME standard. This is a requirement of the ASME code.



24-19

Load Case #

Corroded

Uncorroded

1

Fvs+Pt-Th+Ca

Fvs+Pt-Th-Ca

2

Ps+Fvt-Th+Ca

Ps+Fvt-Th-Ca

3

Ps+Pt-Th+Ca

Ps+Pt-Th-Ca

4

Fvs+Fvt+Th+Ca

Fvs+Fvt+Th-Ca

5

Fvs+Pt+Th+Ca

Fvs+Pt+Th-Ca

6

Ps+Fvt+Th+Ca

Ps+Fvt+Th-Ca

7

Ps+Pt+Th+Ca

Ps+Pt+Th-Ca

8

Fvs+Fvt-Th+Ca

Fvs+Fvt-Th-Ca

Note: Fvt, Fvs - User defined Shellside and Tubeside vacuum pressures or 0.0. Ps, PT - Shell side and Tube-side Design Pressures. Th - With or without Thermal Expansion. Ca - With or without Corrosion Allowance

Enter the Shell/Channelside Vacuum Pressures When analyzing the design with the multiple load cases, the user can specify shell/channel side vacuum pressures. This should be a positive entry. For example for full atmospheric vacuum condition enter a value of 15.0 psig. If no value is specified then 0 psi will be used.

Select Load Cases for Detailed Printout When analyzing the design with the multiple load cases, the program will generate summarized results for all the load cases in tabular form. To see the detailed equations and intermediate calculations for one or more load cases select those load cases.

Is This a Pressure Only Case? The program designs the tubesheet under all the load cases. If you manually want to run the load cases then use this input. If you check this box the allowable stress amplification factor of 2 will be used and there will be no stresses due to differential thermal expansion.

Enter the ID of the Flanged Portion (required in some cases) Enter the internal diameter of the shell/channel or floating head to which the tubesheet is gasketed. If this input is left blank, the program uses either the shell or channel internal diameter, based on, the side the tubesheet is gasketed on. But, this input is needed for a floating tubesheet exchanger that is gasketed to the floating head. For tubesheets that are gasketed with both the shell and channel, this input is for the shell side.

Enter the OD of the Flanged Portion (required in some cases) Enter the outer diameter of the flanged portion (shell/channel/floating head) to which the tubesheet is gasketed.


24-20

ASME TUBESHEETS

If this input is left blank, it is set equal to the tubesheet OD. Specify this input, for cases where flanged portion OD is different from the tubesheet OD. For tubesheets that are gasketed with both the shell and channel, this input is for the shell side.


Flange Face Outer Diameter Enter the outer diameter of the flange face. The program uses the minimum of the flange face outer diameter and the gasket outer diameter to calculate the outside flange contact point, but uses the maximum in design when selecting the bolt circle. This is done so that the bolts do not interfere with the gasket. The program uses the maximum of the flange face ID and the gasket ID to calculate the inside contact point of the gasket.

Gasket Inner Diameter Enter the inner diameter of the gasket. The program uses the maximum of the flange face ID and the gasket ID to calculate the inner contact point of the gasket.


Specify Gasket properties m and y Note:

For gasket properties, refer to the table in the Flange Module.




Facing Sketch

Description

1a

flat finish faces

1b


1c


1d


2

1/64 inch nubbin

3


4


5


6


24-21



Full Face Gasket Options ASME Sec. VIII Div. 1 does not cover the design of flanges for which the gasket extends beyond the bolt circle diameter. A typically used method for the design of these types of flanges is from the Taylor Forge Flange Design Bulletin. This method is implemented in the program. Gaskets for the Full face flanges are usually of soft materials such as rubber or an elastomer, so that the bolt stresses do not go too high during gasket seating. The program adjusts the flange analysis and the design formulae to account for the full face gasket. There are 3 Full Face Gasket Flanges options:


24-22

ASME TUBESHEETS

Program Selects: Instructs the program to automatically make the determination if this is a full face gasket flange, depending upon the input. If the gasket ID and OD matches with Flange ID and OD dimensions respectively (except for a blind flange) then it is determined to be a full face flange. See the figure below.




Width of Partition Gasket Enter the width of the pass partition gasket. Using the gasket properties specified and the known width, PVElite will compute the effective seating width and compute the gasket loads contributed by the partition gasket.



24-23

Specify Partition Gasket properties m and y Note:

For gasket properties, refer to the table in the Flange Module.

Specify Face Facing Sketch for Partition Gasket Using Table 2-5.2 of the ASME code, select the facing sketch number for the partition gasket.





Nominal Bolt Diameter Enter the nominal bolt diameter. The tables of bolt diameter included in the program range from 0.5 to 4.0 inches.

Thread Series The following bolt thread series tables are available: TEMA Bolt Table UNC Bolt Table User specified root area of a single bolt TEMA Metric Bolt Table British, BS 3643 Metric Bolt Table Irrespective of the table used, the values will be converted back to the user selected units. TEMA threads are National Coarse series below 1 inch and 8 pitch thread series for 1 inch and above bolt nominal diameter. The UNC threads available are the standard threads.

Number of Bolts Enter the number of bolts to be used in the flange analysis. This is usually an even number.


24-24

ASME TUBESHEETS

Fillet Weld Between Flange and Shell/Channel Enter the fillet weld height between the tubesheet flange and the shell or channel outside surface. PVElite will use this number to calculate g1 (hub thickness at the large end).

Operating Flange Bolt Load (Wm1) Specify the alternate operating bolt load such as from the mating flange. This value will be used if it is greater than the operating bolt load computed by the program.

Seating Flange Bolt Load (Wm2) Specify the alternate seating flange bolt load such as from the mating flange. This value will be used if it is greater than the seating bolt load computed by the program.

Flange Design Bolt Load (W) Specify the alternate flange design bolt load such as from the mating flange. This value will be used if it is greater than the flange design bolt load computed by the program.

Thickness of Extended Portion of Tubesheet Enter the flange thickness. This thickness will be used ion the calculation of the required thickness. The final results should therefore, agree with this thickness to within about five percent. Since the ASME Code does not have a single equation to compute this required thickness, the appropriate formula from TEMA 8th edition was used.

Design Temperature for Integral Part Enter the actual metal temperature for either the channel or shell part. This temperature will be used to retrieve the elastic properties from the material tables.

Shell Band Material Specify the material for the shell band. This material can be different than the shell material.

Shell Band Input Fixed Tubesheets in which the shell is integral to the tubesheet configuration A, B, or C, can have a different thickness of shell adjacent to the tubesheet. The band of shell can be made of a different material as well. This procedure can be used to reduce the bending stresses in the tubesheet, shell, or channel. Refer to Figure B.

Outer Cylindrical Element Thickness Enter the actual wall thickness of the outer cylindrical element at the point where the expansion joint is attached. This value is shown on Figure D as 'to'.




24-25

Outer Cylindrical Element Length Enter the length of the outer cylinder to the nearest body flange or head, or to the centerline of the convolute. TEMA Paragraph RCB 8-21 includes the following note: lo and li are the lengths of the cylinders welded to the flexible shell elements except, where two flexible shell elements are joined with a cylinder between them, lo or li as applicable shall be taken as half the cylinder length. If no cylinder is used, lo and li shall be taken as zero. Entering a very long length for this value will not disturb the results, since the TEMA procedure automatically takes into account the decay length for shell stresses and uses this length if less than the cylinder length. This value is shown on Figure D as 'lo'.


24-26

ASME TUBESHEETS

Discussion of Results Part UHX of the Code is divided into four major sections. The first section discusses u-tube exchangers, the second discusses fixed tubesheet exchangers, the third section discusses floating tubesheet exchangers and the fourth section discusses tube-to-tubesheet joint weld. There is a sequence of steps to follow when performing calculations for each type of exchanger. PVElite will perform each step and print the applicable formula substitution and answers for each step. All results shown are for the given geometry. In addition, the program will iterate for the minimum thickness of the tubesheet. If needed PVElite will also perform the second elastic iteration if high discontinuity stresses exist. The program can run multiple load cases for the fixed tubesheet design as per the ASME code. The table below displays the load cases that are considered for a fixed tubesheet exchanger.

Load Case #

Corroded

Uncorroded

1

Fvs+Pt-Th+Ca

Fvs+Pt-Th-Ca

2

Ps+Fvt-Th+Ca

Ps+Fvt-Th-Ca

3

Ps+Pt-Th+Ca

Ps+Pt-Th-Ca

4

Fvs+Fvt+Th+Ca

Fvs+Fvt+Th-Ca

5

Fvs+Pt+Th+Ca

Fvs+Pt+Th-Ca

6

Ps+Fvt+Th+Ca

Ps+Fvt+Th-Ca

7

Ps+Pt+Th+Ca

Ps+Pt+Th-Ca

8

Fvs+Fvt-Th+Ca

Fvs+Fvt-Th-Ca

Note: Fvt, Fvs - User defined Shell side and Tubeside vacuum pressures or 0.0. Ps, PT - Shell side and Tube-side Design Pressures. Th - With or without Thermal Expansion. Ca - With or without Corrosion Allowance

When running these load cases the program automatically adjusts the allowable stresses based on if it is a pressure only load case or pressure + thermal load case. Upset conditions may need to be analyzed. You can enter your own shell/channel vacuum pressures for the multicase analysis, e.g. 0, 15 psi. This will simulate one of the process fluid streams being stopped, while the other stream continues. In addition to satisfying stress criteria for the tubesheet, the tubes must also be capable of withstanding the axial forces imposed on them due to differential thermal expansion. These forces must be less than the allowable force on the tube per the ASME code equations (App A or UW-20). Tube stresses are also checked against the criteria in section UHX.. Finally, discontinuity stresses must be less than their allowables. If these allowables are exceeded, PVElite will perform a second elastic iteration. This is where the plasticity of the integral component is considered. Typically, when this iteration is performed, the stress values will decrease below their allowable values. If for any reason they do not, the geometry of the unit must be reconsidered.



24-27

If your tubesheet contains a center groove, the groove depth should be subtracted from the overall tubesheet thickness. Bending stress at the junction of shell/channel and tubesheet can also be reduced by having a local shell band adjacent to the tubesheet.

Display of Results on Status Bar As the user enters the data, program performs the calculation and displays the important results on the status bar. Any error messages are also displayed. This allows a quick design of the tubesheet and makes it easier to try various configurations to select the best one. Any failures are indicated in red. Here is a sample:

Designing a Thick Expansion Joint in the Tubesheet Module: After you input the thick expansion joint geometry in the Tubesheet module, the program uses the following process to design the expansion joint: 3. Compute the expansion joint spring rate 4. Use the expansion joint spring rate in the fixed tubesheet calculations 5. Use the results of the tubesheet calculation, along with the prime pressures, P’s, P’t, and Pd (computed using the TEMA standard) to compute the expansion joint stresses. 6. Run a corresponding expansion joint calculation for each tubesheet load case. The program displays the results for the worst case. (detailed results are also available).


24-28

ASME TUBESHEETS



CH AP TER

2 5

Chapter 25 HALF-PIPES In This Chapter Introduction ................................................................................ 25-2 Purpose, Scope, and Technical Basis.......................................... 25-3 Discussion of Input Data............................................................. 25-4 Discussion of Results.................................................................. 25-7 Example ...................................................................................... 25-9


25-2

HALF-PIPES

Introduction HALF-PIPE performs pressure calculations for half-pipe jackets attached to cylindrical shells using the ASME Code, Section VIII, Division 1 rules.


Chapter 25 HALF-PIPES

25-3

Purpose, Scope, and Technical Basis HALF-PIPE performs required thickness and Maximum Allowable Working Pressure calculations for cylindrical shells with half-pipe jackets attached. The module is based on the ASME Boiler and Pressure Vessel Code, Section VIII, Division 1, Edition 2004 A-05. Specifically, the module is based on the rules in Paragraph EE-1, Appendix EE. HALF-PIPE first performs shell thickness calculations based on both the internal pressure and the externally applied half-pipe jacket pressure. In addition to the thickness calculations, the jacket MAWP is computed for both the input shell thickness and the required shell thickness. Once the required thickness of the shell is determined, the half-pipe jacket thickness is calculated. Finally, based on the shell and jacket thicknesses, an appropriate fillet weld size is calculated. It is important to note the limitations of HALF-PIPE. First, the half-pipe jacket analysis performed is only valid for the cylindrical geometries shown in Figure EE-4. These are the only two geometries addressed by paragraph EE-1. The analysis of rectangular or square jacketed geometries is not supported. The second limitation on the HALFPIPE module is the acceptable Nominal Pipe Sizes. Appendix EE only includes charts for Nominal Pipe Sizes 2, 3, and 4. Therefore, Nominal Pipe Sizes greater than 4 or less than 2 will not be accepted in the input. Although there are no charts for Nominal Pipe Sizes 2.5 and 3.5, the HALF-PIPE Module will accept these sizes and perform iterations between the given charts. Additionally, if the half-pipe is a nonstandard pipe size or has a formed radius, the actual radius is used in the calculations. HALF-PIPE takes full account of corrosion allowance. Actual thickness values and corrosion allowances are entered, and the program adjusts thicknesses and diameters when making calculations for the corroded condition.

Figure A - Acceptable HALF-PIPE Module Geometries


25-4

HALF-PIPES

Discussion of Input Data Main Input Fields Item Number Enter the Shell Section ID number. This may be the item number on the drawing, or numbers that start at 1 and increase sequentially.

Half-Pipe Section Description Type an alphanumeric description for this item. This entry is optional.

Inside Diameter of Shell Type the inside diameter of the shell or head. The value entered should be the uncorroded dimension of the inside diameter. This analysis is only valid for cylindrical shells, therefore, inputting inside diameter values for torispherical, elliptical, spherical, or conical heads will produce erroneous results. Please refer to 'Din' in Figure A.

Thickness of Shell Type the thickness of the shell used to withstand the internal pressure. This thickness value will be tested to see if it can withstand both the internal shell pressure and the externally applied jacket pressure. Please refer to 'Ts' in Figure A.

Internal Pressure in Shell Type the internal design pressure used in the vessel analysis. This value will be used as an initial check on the required thickness of the shell. The value entered should be a positive value, i.e. 14.7 psia.

Design Temperature for Internal Pressure Type the temperature associated with the internal design pressure. PVElite will automatically update material properties for BUILT-IN materials when you change the design temperature. If you entered the allowable stresses by hand, you are responsible for updating them for the given temperature.

Shell Section Material Name Type the ASME code material specification as it appears in the ASME material allowable tables. Alternatively, you can select the material from the Material Database by right clicking and selecting DATABASE, while the cursor is in this field. If a material is not contained in the database, you can enter its specification and properties manually by selecting TOOLS/EDIT/ADD MATERIALS, from the Main Menu.

Shell Allowable Stress at Design Temperature The program automatically fills in this entry by entering a material specification. When you change the internal design temperature, or the thickness of the shell, the program will automatically update this field, but only for BUILT-IN materials. If you enter the allowable stress by hand, be sure to verify your entry to assure conformance with the latest edition of the ASME Pressure Vessel Code Section II Part D at the design temperature.



25-5

Shell Allowable Stress at Ambient Temperature The program automatically fills in this entry by entering a material specification. When you change the internal design temperature, or the thickness of the shell, the program will automatically update this field, but only for BUILT-IN materials. If you enter the allowable stress by hand, be sure to verify your entry to assure conformance with the latest edition of the ASME Pressure Vessel Code Section II Part D at the ambient temperature.

Shell Corrosion Allowance Type the corrosion allowance. The program adjusts both the actual thickness and the inside diameter for the corrosion allowance you enter.

Joint Efficiency for Longitudinal Seams Type the efficiency of the welded joint for shell sections with welded seams. This will be the efficiency of the longitudinal seam in the cylindrical shell. Refer to Section VIII, Div. 1, Table UW-12 for help in determining this value.

Nominal Pipe Size of Half-Pipe Jacket Type the nominal pipe size of the half-pipe jacket. The pipe size entered must lie within the range of values supported in ASME Section VIII, Div. 1, Appendix EE. The supported sizes range between NPS 2 inch and NPS 4 inch. If working in SI units, the proper conversion values must be entered. For example, if working with a NPS 50 pipe, the corresponding SI value of 5.08 cm must be entered. The following table lists the accepted values for the NPS.

English Input NPS

NPS

SI

2.0 in

50

5.08 cm

2.5 in

65

6.35 cm

3.0 in

80

7.62 cm

3.5 in

90

8.89 cm

4.0 in

100

10.16 cm

Radius of Formed Half-Pipe Jacket Type the radius of the formed half-pipe. This value will be used rather than the standard nominal pipe sizes. Please refer to 'r' in Figure A.

Thickness of Half-Pipe Jacket Type the thickness of the jacket used to withstand the internal pressure. If the thickness value of the jacket is not adequate to withstand the internal pressure, an acceptable thickness will be determined. Therefore, if the program is used for design purposes, enter a minimal value for jacket thickness. Please refer to 'Tjck' in Figure A. The program will determine an appropriate pipe schedule through iteration.


25-6

HALF-PIPES

It is important to note that the program selected pipe schedules include a standard mill tolerance of 0.875 (a reduction of 12.5%). This tolerance will not, however, be included in the user input value of thickness. This allows users to include their own mill tolerance in their input value, without having this value further adjusted.

Design Pressure in Jacket Type the internal design pressure used in the half-pipe jacket analysis. This value will be used to determine the required thickness of both the shell and the jacket. The value entered should be a positive value, i.e. 14.7 psia.

Design Temperature for Jacket Pressure Type the temperature associated with the internal jacket pressure. PVElite will automatically update material properties for BUILT-IN materials when you change the design temperature. If you entered the allowable stresses by hand, you are responsible for updating them for the given temperature.

Jacket Material Name Type the ASME code material specification as it appears in the ASME material allowable tables. Alternatively, you can select the material from the Material Database by clicking the DATABASE button. If a material is not contained in the database, you can enter its specification and properties manually by selecting TOOLS/EDIT/ADD MATERIALS, from the Main Menu.

Jacket Allowable Stress, Design Temperature The program automatically fills in this entry by entering a material specification. When you change the internal design temperature, or the thickness of the jacket, the program will automatically update this field, but only for BUILT-IN materials. If you enter the allowable stress by hand, be sure to verify your entry to assure conformance with the latest edition of the ASME Pressure Vessel Code Section II Part D at the design temperature.

Jacket Allowable Stress, Ambient Temperature The program automatically fills in this entry by entering a material specification. When you change the internal design temperature, or the thickness of the jacket, the program will automatically update this field, but only for BUILT-IN materials. If you enter the allowable stress by hand, be sure to verify your entry to assure conformance with the latest edition of the ASME Pressure Vessel Code, Section II Part D at the ambient temperature.

Corrosion Allowance of Jacket Type the corrosion allowance. The program adjusts both the actual thickness and the inside diameter for the corrosion allowance you enter. Please refer to 'CAJ' in Figure A.



25-7

Discussion of Results Shell Thickness Calculations The first calculation HALF-PIPE performs is the required thickness of the shell due to the internal pressure. This value of required thickness is calculated using Equation 1 from Paragraph UG-27 of the ASME Code. The corroded value of thickness is used in this calculation. Because the exterior of the shell wall is also used as the internal halfpipe jacket wall (for more information see the figure displayed under the Purpose, Scope and Technical Basis section ), both the corrosion allowance of the shell and the corrosion allowance of the jacket must be accounted for. Both the calculation and the result are displayed in this section of the output. Once the required thickness due to inside pressure is determined, the required thickness due to the external pressure (jacket pressure) is determined and displayed. This value is obtained through the pressure calculations discussed in the next section.

Pressure Calculations for Input Shell Thickness The calculations displayed in this section of the output are the external (jacket) pressure calculations, performed using the input value of shell thickness. The first step in the pressure calculations is to determine the K-factor from the appropriate chart. The chart is selected based on the Nominal Pipe Size of the jacket and the K-factor is a factor of the shell inside diameter and the shell thickness. Both the chart and K-factor are displayed in the output. As stated earlier, for Nominal Pipe Size 2.5 or 3.5, an iteration is performed between the charts to obtain the K-factor. When this is the case, the output will display the two charts from which the iteration was performed. The next step in the external pressure calculations is to determine the longitudinal stress. This calculation accounts for the corrosion allowance by using a corroded value of the shell inside radius, as well as the corroded value of the shell thickness. Using the longitudinal stress and the previously determined K-factor, the permissible jacket pressure is determined using Equation 1, Paragraph EE-1, Appendix EE. The permissible jacket pressure is considered the Maximum Allowable Working Pressure for the input shell thickness, and it is compared to the input jacket design pressure.

Half-Pipe Jacket Thickness Calculations The input jacket thickness is tested to see if it is adequate to withstand the internal pressure of the jacket. The calculation is based on Equation 2, Paragraph EE-1, Appendix EE. As in previous calculations, the corrosion allowance is included in the thickness calculation. If the input thickness is not adequate, the program iterates for an appropriate pipe thickness. The iteration begins with Schedule 5S pipe and continues on until an acceptable schedule is found. As mentioned in the Discussion of Input Data section of this chapter, the program selected pipe schedule is adjusted by a standard mill tolerance value (0.875). The user input value of thickness, however, does not use the mill tolerance adjustment. In the event that the input thickness is not adequate, both the selected pipe schedule and the adjusted thickness are displayed in the output.

Minimum Fillet Weld Size Calculations As mentioned in Paragraph EE-1, "The fillet weld attaching the half-pipe jacket to the vessel shall have a throat thickness not less than the smaller of the jacket or shell thickness." Therefore, the program selects the smaller of the


25-8

HALF-PIPES

two thicknesses, multiplies by a weld factor (1.414), and uses this value as the minimum fillet weld size. The output report indicates which of the two thicknesses that the calculation was based upon.

Summary of Results The first values displayed in the summary section are the shell thickness values. The echo of the input thickness is displayed along with the results of the two required thickness calculations. The comparison of these results provides a quick check of whether the thickness of the shell is governed by the internal or external pressure. The next three displayed values are the jacket pressure results. The input design pressure is shown along with the MAWP for both the input thickness and the required thickness. The next displayed values are those of the half-pipe jacket thickness. The input thickness is shown along with the required thickness. Additionally, if the input thickness is not adequate, the thickness selected by the program is displayed. Finally, the minimum fillet weld size is shown.



25-9




CH AP TER

2 6

Chapter 26 LARGE OPENINGS In This Chapter Introduction ................................................................................ 26-2 Purpose, Scope and Technical Basis........................................... 26-3 Discussion of Input Data............................................................. 26-4 Example Problem........................................................................ 26-5


26-2

LARGE OPENINGS

Introduction PVElite analyzes flat heads as discussed in Chapter 4 of this manual. However, the program will also analyze a large nozzle in the welded flat head that has a large centrally located opening. This program is based on the ASME Code Section VIII Division 1, Appendix 2 and Appendix 14 of the 2004 Edition with 2005 addenda.


Chapter 26 LARGE OPENINGS

26-3

Purpose, Scope and Technical Basis This module computes three different kinds of stresses which act on flat heads that have a hole or nozzle whose inside diameter is greater than 1/2 of the outside diameter of the flat head. Geometries with or without an attached nozzle may be analyzed. The first step in this process is to analyze the flange as a flat head and determine the total moment acting on the flange for the operating case. Since there is no gasket, the gasket seating case is neglected. The radial flange, tangential flange and longitudinal hub stresses are computed in accordance with Appendix 2. These three stresses, Sr*, St*, Sh* and some geometry constants are used to determine the actual radial, tangential, and longitudinal hub stresses. Two sets of stresses are computed, one for the head/shell juncture, and the second for the opening head juncture. If all of the computed stresses are below the allowable stresses, the geometry is considered satisfactory. If any stress is greater than its allowable, the geometry must be reconsidered.

Figure A - Attached Nozzle Geometry

Figure B - Geometry for an opening without an attached nozzle


26-4

LARGE OPENINGS

Discussion of Input Data Main Input Fields Opening Diameter Bn: Enter the new (un-corroded) inside diameter of the nozzle.

Large End Hub Thk (g1s) Enter the thickness of the large end of the hub inside the shell labeled g1(shell) in Figure A and Figure B.

Small End Hub Thk (g0s) Enter the thickness of the small end of the hub inside the shell labeled g0(shell) in Figure A and Figure B.

Hub Length (hs) Enter the length of the hub inside the shell labeled h(shell) in Figure A and Figure B.

Large Eng Hub (g1n) Enter the thickness of the large end of the hub of the nozzle labeled g1(nozzle) in Figure A and Figure B.

Small End Hub Thk (g0n) Enter the thickness of the small end of the hub of the nozzle labeled g0(nozzle) in Figure A and Figure B.

Hub Length (hn) Enter the length of the hub of the nozzle labeled h(nozzle) in Figure A and Figure B.


Chapter 26 LARGE OPENINGS

26-5

Example Problem The example problems illustrating these principles are located in the program installation directory/Examples directory.



CH AP TER

2 7

Chapter 27 RECTANGULAR VESSELS In This Chapter Introduction ................................................................................ 27-2 Purpose, Scope and Technical Basis........................................... 27-3 Discussion of Input Data............................................................. 27-10 Discussion of Results.................................................................. 27-18 Example Problem........................................................................ 27-20


27-2

RECTANGULAR VESSELS

Introduction RECTANGULAR VESSELS performs internal pressure calculations for rectangular vessels using the ASME Code, Section VIII, Division 1 rules.


Chapter 27 RECTANGULAR VESSELS

27-3

Purpose, Scope and Technical Basis RECTANGULAR VESSELS performs stress calculations and Maximum Allowable Working Pressure calculations for the rectangular, obround, and circular vessels described in the ASME Boiler and Pressure Vessel Code, Section VIII, Division 1, 2001, A-2003, Appendix 13. The calculations are taken from sections 13-6 through 13-13. The module will analyze the following vessels: Fig. 13-2 (a)(1) - Vessel with equal long-side and short-side thickness. (Figure A) Fig. 13-2 (a)(2) - Vessel with differing long-side thickness. (Figure B) Fig. 13-2 (a)(3) - Vessel with rounded corners. (Figure C) Fig. 13-2 (a)(4) - Reinforced vessel. (Figure D) Fig. 13-2 (a)(5) - Non-continuous reinforced vessel with rounded corners.(Figure E) Fig. 13-2 (a)(6) - Non-continuous reinforced vessel with rounded corners. (Figure F) Fig. 13-2 (a)(7) - Rectangular vessel with single stay plate/row of bars. (Figure G) Fig. 13-2 (a)(8) - Rectangular vessel with two stay plates/rows of bars. (Figure H) Fig. 13-2 (b)(1) - Obround vessel. (Figure I) Fig. 13-2 (b)(2) - Reinforced obround vessel. (Figure J) Fig. 13-2 (b)(3) - Obround vessel with single stay plate/row of bars. (Figure K) Fig. 13-2 (c)(1) - Circular vessel with single diametral plate. (Figure L) The program first performs ligament efficiency calculations for those vessels with holes in the side plates. The membrane and bending ligament efficiencies are used to adjust the stress calculations at the mid-side of the plates. The ligament efficiency calculations are based on section 13-6, and are performed for both uniform and multi diameter hole patterns. Once the ligament efficiencies are determined, the individual stress calculations are performed. Membrane, bending, and total stress calculations are performed as prescribed by the Code in Sections 13-7 through 13-13. These stresses are compared to their allowables, and a highest percentage of allowable calculation is performed. The final calculation performed by the RECTANGULAR VESSEL module is the Maximum Allowable Working Pressure calculation. The program computes a M.A.W.P. for all three types of stresses (Membrane, Bending, and Total). Additionally, depending on the specific geometry of those vessels stayed by bars, an additional M.A.W.P. is computed per Equation 2 of UG-47. RECTANGULAR VESSEL takes full account of the corrosion allowance. The program uses the corroded condition for all dimensions in its calculations. The only exception is the reinforcement calculations. The reinforcing member is assumed to be entered in its corroded state.


27-4

RECTANGULAR VESSELS

Figure A - Rectangular vessel with equivalent long side thickness (Type A1)

Figure B - Rectangular vessel with different long side thickness (Type A2)



Figure C - Rectangular vessel with rounded corner (Type A3)

Figure D - Reinforced rectangular vessel (Type A4)


27-5

27-6

RECTANGULAR VESSELS

Figure E - Non-continuously reinforced rectangular vessel (Type A5)

Figure F - Non-continuously reinforced vessel with rounded corners (Type A6)



Figure G - Vessel stayed by stay plate/stay bars (Type A7 or A7-B)

Figure H - Vessel stayed by stay plates/stay bars (Type A8 or A8-B)


27-7

27-8

RECTANGULAR VESSELS

Figure I - Obround vessel (Type B1)

Figure J - Reinforced obround vessel (Type B2)

Figure K - Obround vessel stayed by stay plate/stay bars (Type B3 or B3-B)



Figure L - Circular vessel stayed by single diametral plate (Type C1)


27-9

27-10

RECTANGULAR VESSELS


Description Enter a maximum 15 character alphanumeric description for this item. This entry is optional.

Design Internal Pressure Rectangular Vessel Enter the internal design pressure. The internal design pressure is a required entry. For vessel type C1 (Figure 20K), this is the entry for P1. If analyzing vessel type C1 be aware that the P1 value is associated with only one of the two chambers. If both chambers are operating at the same pressure, then an equal value must be entered for P2.

Design Temperature for Internal Pressure Enter the temperature associated with the internal design pressure. PVElite automatically updates the materials properties for BUILT-IN materials when you change the design temperature. If you entered the allowable stresses by hand, you are responsible to update them for the given temperature.

Material Name Enter the ASME code material specification as it appears in the ASME material allowable tables. Alternatively, you can select the material from the Material Database by clicking the Database button. If a material is not contained in the database, you can enter its specification and properties manually by selecting TOOLS/ EDIT/ADD MATERIALS, from the Main Menu.

Material Allowable Stress at Design Temperature The program automatically fills in this entry by entering a material specification. When the material temperature is specified, all material properties associated with that temperature will be automatically updated for materials that appear in the database. If you enter the allowable stress by hand, be sure to double check your entry to assure conformance with the latest edition of the ASME Pressure Vessel Code Section II Part D at the design temperature.

Material Allowable Stress at Ambient Temperature The program automatically fills in this entry by entering a material specification. If you enter the allowable stress by hand, be sure to double check your entry to assure conformance with the latest edition of the ASME Pressure Vessel Code Section II Part D at the ambient temperature.



27-11

Minimum Yield Stress for This Material Enter the yield stress for this material. The ASME Code, Section II Part D lists the yield stress for the material at ambient temperature. For many kinds of analysis, this is the appropriate value to enter. If you need to use the yield stress at design temperature, you can probably find it in the ASME Code, Section II Part D. If analyzing a reinforced vessel this is a required entry for both the shell material and the reinforcement material. These entries are used in determining an allowable stress for both bending and total stresses, and if this entry is left blank, the program will assume zero for the allowable stress.

Figure Number for Type of Vessel Enter the ID of the type of rectangular vessel to be analyzed. The possible ID types are as follows: ID

Figure

Vessel Type

A1

A

Rectangular vessel with equal long-side plate thickness

A2

B

Rectangular vessel with unequal long-side thickness

A3

C

Rectangular vessel with rounded corners

A4

D

Reinforced rectangular vessel

A5

E

Non-continuously reinforced rectangular vessel

A6

F

Non-continuous reinforced with rounded corners

A7

G

Rectangular vessel with single stay plate

A7-B

G

Rectangular vessel with single row of bars

A8

H

Rectangular vessel with two stay plates

A8-B

H

Rectangular vessel with double row of bars

B1

I

Obround vessel

B2

J

Reinforced obround vessel

B3

K

Obround vessel with single stay plate

B3-B

K

Obround vessel with single row of bars

C1

L

Circular vessel with single diametral plate

Short-Side Length Dimension Enter the design length of the short-side of the vessel. This dimension is dependent on the particular vessel being analyzed. For Figure:


27-12

RECTANGULAR VESSELS

A1

H

Inside length of long-side of vessel

A2

h


A3

L1

Half-length of short-side minus the corner radius

A4

H

Inside length of short-side of vessel

A5

L3

Half-length of short-side of vessel

A6

L3

Half-length of short-side of vessel

A7

h


A7-B

h


A8

h


A8-B

h


B1

2R

Inside Diameter of Rounded Short-side

B2

2R


B3

2R


B3-B

2R


C1

*** No Entry Required ***

Minimum Thickness of Short-Side Plate Type the minimum thickness of the short-side plate used to build the vessel, or the minimum thickness measured for an existing vessel. The short-side thickness value is a required entry for all vessel types. For those vessels that the Code specifies a single thickness (A3 and C1), the short-side thickness is used for both t1 and t2.

Joint Efficiency for Welded Seams Enter the efficiency of the welded joint for vessels with welded joints. This joint efficiency value will be used to adjust the corner and the mid-side allowable stress values. The mid-side joint efficiencies will not be used if there are holes on the side of the vessel. Instead, the ligament efficiencies will be used to adjust the actual stress values. Please be sure to refer to Section VIII, Div. 1, Table UW-12 for help in determining this value. Typical values are 1.00 Full Radiography 0.85 Spot X - Ray 0.70 No - Radiography

Threaded Holes in Plates If the plate has uniform or multi diameter holes, check this field in order to enter the pitch, diameter, and depth parameters. Ligament efficiency calculations will be performed in order to adjust the calculated actual stress values.

Type of Reinforcement Enter the index for the type of reinforcement on the rectangular vessel. When a reinforced vessel is selected, the first responses are those of the pitch distance and the delta value.



27-13

Long-Side Length Dimension Enter the design length of the long-side of the vessel. This dimension is dependent on the particular vessel being analyzed. For Figure: A1

h


A2

h

Inside length of long-side vessel

A3

L2

Half-length of long-side minus the corner radius

A4

h


A5

L4

Half-length of long-side

A6

L4

Half-length of long-side of vessel

A7

h


A7-B

h


A8

h


A8-B

h


B1

L2


B2

L2


B3

L2


B3-B

L2


C1

*** No Entry Required ***

Minimum Thickness of Long-Side Plate Type the minimum thickness of the long-side plate used to build the vessel, or the minimum thickness measured for an existing vessel. Per Appendix 13, vessels A3 and C1 (Figure 20C and 20K, respectively) are assumed to have equivalent long and short-side thicknesses. Thus, the long-side thickness is not a required entry for these two vessel types.

Minimum Thickness of End Plate Type the minimum thickness of the end plate. If a valid thickness is entered, the end plate will be analyzed per UG34. If the thickness value entered is zero, or left blank, no calculations will be performed on the end plate.

Corrosion Allowance Type the appropriate corrosion allowance. The program adjusts the actual thickness and the inside diameter of the vessel, and adjusts the actual thickness and the outside diameter of the stay plate/bar.

C Factor for End Closure Plate/Vessel Head The C Factor is used in the equation to compute the required thickness of welded end plates. Typical values are 0.2 or 0.3. See UG-34 for details.


27-14

RECTANGULAR VESSELS

Pop-Up Input Fields Design External Pressure Type the design external pressure for figure A1 or A2 if you wish to have the external pressure calculations performed. When entered, external pressure stress calculations as well as vessel stability calculations will be performed.

Modulus of Elasticity If an external pressure has been input, enter the Elastic Modulus of the material from Subpart 3 of Section II, Part D at design temperature.

Length of Vessel Type the length dimension of vessel type C1.

Minimum Thickness of 2nd Long-Side Plate Type the minimum thickness of the 2nd long-side plate used to build the vessel, or the minimum thickness measured for an existing vessel. This entry is only used in the analysis of vessel type A2 (Figure B). Appendix 13 allows vessels of this type to have differing long-side thickness. If analyzing a type A2 vessel this is a required entry.

Radius of Corner Section Type the radius of the corner section for vessels A3 and A5. The program assumes each of the corner sections to have equivalent radii.

Pitch Distance Between Reinforcement Type the maximum pitch distance between reinforcing members. This value must be greater than or equal to the width of the reinforcing member.

C-Factor The C-factor is an attachment factor for braced and stayed surfaces. This factor is taken from UG-47, and will default to 2.1.

Delta Type the material parameter used to calculate pitch. Materials listed in Appendix 13, Table 13-8(3):



27-15

Material

English

SI

Carbon Steel

6000

15754.54

Austenitic SS

5840

15334.42

Ni-Cr-Fe

6180

16227.17

Ni-Fe-Cr

6030

15833.31

Aluminum

3560

9347.69

Nickel Copper

5720

15019.33

Unalloyed Titanium

4490

11789.65

Unreinforced Length Dimension Enter the unreinforced length dimension for vessel A6 (Figure F). This dimension is L11 for the short-side and L21 for the long-side.

Minimum Thickness/Diameter of Stay Plate/Rod (T3) Enter the minimum thickness of the stay plate, or the diameter of the rod, if analyzing a stayed vessel. This is a required entry if analyzing type A7, A7-B, A8, A8-B, B3, or B3-B.

Minimum Thickness/Diameter of Stay Plate/Rod (T4) Enter the minimum thickness of the stay plate, or the diameter of the rod, if analyzing a stayed vessel. This is a required entry if analyzing type A8, or A8-B.

Is the Stay Plate/Rod Welded to the End Plate? If you do not check this box, PVElite will perform the end plate calculations based on the entire long-side length. If you do check this box, the program will use the dimensions of the compartment formed by the stay plate.

Pitch Distance Between Bars Type the maximum pitch distance between stay bars. This value must be greater than or equal to the calculated maximum pitch of the stay bars.

Vessel Radius Type the inside radius of the vessel type C1.

Pressure in 2nd Compartment Type the internal pressure of the 2nd compartment in vessel C1. You must enter an internal design pressure that is less than or equal to P1. In the event that the two compartments have equivalent pressure, the value entered for P2 must equal the value entered for P1. If left blank, a value of zero is used for P2.


27-16

RECTANGULAR VESSELS

Center to Center Distance Between Poles Type the maximum pitch distance between holes in the side plates of the vessel being analyzed. This pitch distance is shown in Figure M. This value must be greater than the hole's diameter.

Figure M - Plate with Multi Diameter Holes

Diameter of Hole Type the diameter (d0, d1, d2) of the hole of corresponding length (T0, T1, T2). If the hole is of uniform diameter, then a value for d0 is the only required entry. Refer to Figure M. The values for d0, d1, and d2 must be entered in decreasing diameter size.

Depth of Hole Type the depth (T0, T1, T2) of the hole of corresponding diameter (d0, d1, d2). If the hole is of uniform diameter, then a value for T0 is the only required entry. Refer to Figure M. The sum of the values for T0, T1, and T2 must equal to the entire side thickness.

Type of Reinforcing Ring Three types of reinforcement are available: Reinforcing Ring Type None—No reinforcing ring. Simple Bar Geometry—Enter the width, thickness, and length (if necessary) of the bar. Section—Enter the area, moment of inertia, and distance to ring centroid.

Distance from Outside of Vessel Type the distance from the outer surface of the vessel to the outermost point on the reinforcing bar or beam.

Width of Reinforcing Member Type the width of the reinforcing member. This value is the distance that the reinforcement remains in contact with the vessel wall. This value cannot be greater than the reinforcement pitch, as that would indicate that the reinforcement if overlapping.



27-17

Length of Reinforcing Member For vessel type A5, this entry represents the entire length of the discontinuous reinforcement. No entry is required for other vessel types. General Beam Section—Type the moment of inertia, cross-sectional area, and the distance from the centroid.

Cross-Sectional Area of Reinforcing Section Type the cross sectional area for the beam section which is being used as reinforcement.

Moment of Inertia of Reinforcing Member Type the moment of inertia for the beam section which is being used as a reinforcement, in the direction parallel to the surface of the vessel.

Centroid Distance from Outside of Vessel Type the distance from the surface of the vessel to the centroid of the reinforcing ring. This distance should be measured normal to the vessel surface.

Length of Reinforcing Member For vessel type A5, this entry represents the entire length of the discontinuous reinforcement. No entry is required for other vessel types. In all cases the program includes the vessel wall in the calculation of the moment of inertia.


27-18

RECTANGULAR VESSELS

Discussion of Results Ligament Efficiency Calculations When the side plates have uniform or multi diameter holes, ligament efficiency calculations are performed according to Section 13-6. For the case of uniform diameter holes, the ligament efficiency factors em and eb for membrane and bending stresses, respectively, are considered to be the same. In the case of multi diameter holes (see Figure M), the neutral axis of the ligament may no longer be at mid thickness of the plate; in this case, for bending loads, the stress is higher at one of the plate surfaces than at the other surface. If the calculated values of em and eb are lower than the entered midpoint joint efficiencies, the calculated stress values are divided by these calculated ligament efficiencies. It is important to note that if the stresses have been adjusted by the ligament efficiencies, then the calculations for the allowable stresses will assume an E value of 1.0. This avoids incorrectly increasing the stress values while decreasing the allowables at the same time.

Reinforcement Calculations The reinforcement calculations performed for vessels A4, A5, and B2 (Figures D, E, and J), are discussed in section 13-8. The rectangular vessel program only addresses those vessels in which the reinforcement on opposite side plates has the same moment of inertia. Additionally, the reinforcement for vessels A4 and B2 is assumed to be continuous, while A5 is assumed to be non-continuous. The first reinforcement calculation is that of the maximum pitch between reinforcing member center lines. Equation 1 of UG-47 is used to set a basic maximum distance. Using this maximum value, equations (1a)-(1d) in Section 13-8 are used to obtain a maximum value for both the long and short-side plates. The minimum calculated value shall be considered the maximum distance between reinforcement center lines. In addition to the above calculations, the geometry of the reinforcement must be checked. Specifically, the width of the reinforcing members cannot physically exceed the pitch. Once the pitch is determined, the moment of inertia of the composite section (shell and reinforcement) is determined by the Area-Moment method. The moment of inertia calculations are performed for locations where the plate is in compression, and then also performed for locations where the plate is in tension. Equation (2) of Section 13-8 is used to calculate the maximum width of the shell plate which can be used to compute the effective moments of the composite section at locations where the shell plate is in compression. At locations where the shell plate is in tension, an effective width equal to the actual pitch distance is used in the computations.

Stress Calculations The stress calculations are performed for membrane, bending, and total stresses. The calculations are performed for both the inner and outer surface of the long and short-side plates. These actual stress values are displayed along with their allowables in tabular form. A positive (+) stress indicates tensile stress, while a negative (-) stress indicates compressive stress. As previously discussed, the calculated values for the membrane and bending stresses are adjusted by the ligament efficiency calculations if em and eb are less than the joint efficiency E. At the mid-side locations, the stresses are increased by dividing the calculated value by the membrane or bending ligament efficiency. In the event that the plates have holes but the ligament efficiencies are higher than the joint efficiency E, there is no adjustment to the stress calculations, rather the allowables are adjusted by the value E.



27-19

Calculations performed on stay plates/bars are membrane stresses, and these stresses are used in the M.A.W.P. calculations for membrane stresses. Computation of the stresses on end plates is performed if a thickness value for the end plate is input. The calculations are performed per UG-34 with a C factor entered by the user. These stresses are not used in the computation of the MAWP.

Allowable Calculations Membrane stresses are in general compared to the adjusted allowable stress, SE. Note that for reinforced members the program compares the membrane stress to the lower of the plate allowable stress or beam allowable stress. Note also that when there are holes in the side, the joint efficiency may be set to 1.0 in favor of a membrane efficiency which is factored into the actual stress calculation as necessary. Bending stresses and total stresses are in general compared to 1.5 times the adjusted allowable stress, SE. Note that for reinforced members the program compares the actual stress to the lower of the plate allowable stress or beam allowable stress, and also to the lower of 2/3 times the plate yield stress or beam yield stress. It chooses the lowest of these four combinations as the allowable for reinforced cases. Note also that when there are holes in the side, the joint efficiency at the mid-side may be set to 1.0 in favor of a membrane efficiency which is factored into the actual stress calculations as necessary.

Highest Percentage of Allowable Calculations After performing the actual stress calculation and computing the allowable stresses at all locations, the program computes the highest stress/allowable ratio for each of the three stress types. The program displays the highest percentage of the allowable used, and the actual stress value that this percentage relates to.

MAWP Calculations The Maximum Allowable Working Pressure is calculated for each of the three stress types. The computation of the M.A.W.P. is performed by setting the stress equations equal to the allowables, and solving for P. The minimum computed P value is considered to be the maximum allowable working pressure for the particular stress type. When analyzing vessels A7-B or A8-B (Figures G and H stayed by bars), an additional pressure rating is computed. If the long-side height is greater than the pitch of the stay bars, then a pressure rating is computed per Eq. (2) of UG47 with the long-side height substituted for the pitch. If this value of pressure is less than the previously calculated M.A.W.P.s, then this becomes the vessel pressure rating. Similarly for vessel B3-B (Figure K stayed by bars), if (L2 + R/2) is greater than the pitch, then an additional pressure rating is computed per Eq. (2) of UG-47 with (L2 + R/2) substituted for the pitch.

External Pressure Calculations External pressure calculations are performed on vessel A1 and A2 if the user has entered a value for the external pressure. These calculations are performed per Appendix 13, Section 13-14. First, the external pressure is substituted for the internal pressure, and the calculations discussed previously are performed again. Next, the four side plates and the end plates are checked for stability per equation (1) of 13-14(b). Finally, the entire cross section is checked for column stability in accordance with equation (1) from paragraph 13-14(c).


27-20

RECTANGULAR VESSELS

Example Problem The example problems illustrating these principles are located in the program installation directory/Examples directory.


CH AP TER

2 8

Chapter 28 WRC 297/ANNEX G In This Chapter Introduction ................................................................................ 28-2 Discussion of Input Data............................................................. 28-3 Sample Calculation ..................................................................... 28-9 Discussion of Results.................................................................. 28-10


28-2

WRC 297/ANNEX G

Introduction The WRC 297/Annex G analysis module performs local stress calculations on cylinder to cylinder attachments according to the Welding Research Council's bulletin number 297 or PD 5500, Annex G. Additionally, it also analyzes cylinder on a sphere, solid attachment on either a cylinder on a sphere, per PD 5500 Annex G.


Chapter 28 WRC 297/ANNEX G

28-3


Description Enter a maximum 15 character alphanumeric description for this item. This entry is optional.

Diameter Basis for Vessel The dimension basis can be specified on either inside (ID) or outside (OD) dimension basis.

Vessel Diameter Type the actual diameter of the vessel using the Id or OD as specified above.

Vessel Wall Thickness Type the wall thickness of the vessel. This thickness should be measured at the intersection of the nozzle and the vessel.

Vessel Corrosion Allowance Type the corrosion allowance if there is any. The program will adjust the ID and thickness appropriately.

Design Pressure The design pressure will be used to compute membrane stresses on the nozzle and vessel wall. It will also be used to compute axial pressure thrust if instructed to do so.

Design Temperature This is design temperature for the vessel. This value is used to look up allowable stresses for the vessel and nozzle materials from the ASME Section II Part D material table.

Vessel Material The vessel material can be typed in or selected from the Material Database. Right click on this field to access the properties for this material or access the database.

Vessel/Nozzle Stress Concentration Factor This value typically varies from 1 to 3 and is a function of the quality of the weld and the local dimensions in the immediate vicinity of the weld. Stress concentration factors are a measure of a very local stress riser because of sharp corners, no fillet radii, etc. This stress concentration factor will apply for the stress calculations in the vessel and Nozzle on both the inside and outside of the vessel.


28-4

WRC 297/ANNEX G

This stress concentration factor is not used in any way with the pressure stress calculations. This input is only active when WRC 297 method is selected.

Attachment Type Select the type of attachment. If WRC 297 method is selected then only round attachment type (a cylinder) permissible. If PD5500, Annex G is selected than the option include, round, square or rectangular.

Diameter Basis for Nozzle The dimension basis can be specified on either inside (ID) or outside (OD) dimension basis.

Diameter of Nozzle Type the actual inside or outside diameter of the nozzle as appropriate.

Nozzle Wall Thickness Type the minimum nozzle wall thickness at the shell to nozzle junction. This value should include any allowances for mill tolerance.

Nozzle Corrosion Allowance Type the corrosion allowance for the nozzle. This value typically ranges from 0 to 3/16" or more depending on the service and design specifications.

Does Attachment cut a hole in the shell ? Check this box if the attachment makes a hole in the vessel. Example of a hole being cut would be a nozzle. On the other hand, a trunnion is a case where no hole is cut in the shell. The program applies a stress concentration factor if hole is cut in the shell. This input is only used for PD5500, Annex G.

Enter Full Attachment Length in Longitudinal Direction (2*Cx) Attachments other than nozzles can be analyzed using the PD 5500 Annex G method. If one is analyzing the junction of a square/rectangular solid and a cylinder or sphere, enter the FULL length of the attachment in the longitudinal direction. A square or a rectangular attachment on a sphere is converted to an equivalent round attachment of radius ro, as follows: ro = Sqrt(Cx * Cy) This input is only used for PD5500, Annex G.

Enter Full Attachment Length in Circumferential Direction (2*Cy) Attachments other than nozzles can be analyzed using the PD 5500 Annex G method. If one is analyzing the junction of a square/rectangular solid and a cylinder or sphere, enter the FULL length of the attachment in the circumferential direction. A square or a rectangular attachment on a sphere is converted to an equivalent round attachment of radius ro, as follows: ro = Sqrt(Cx * Cy)



28-5

This input is only used for PD5500, Annex G.

Is There a Reinforcing Pad? If the nozzle has a pad, check this button and you will be prompted to enter in the diameter of the pad along the vessel surface and the pad thickness. This will cause the program to perform stress calculations at the edge of the pad.

Axial Force P (In WRC 107) or FR (In PD5500) Type the value for the load which is trying to push or pull the nozzle in/out of the vessel. The program does not account for the effect of pressure thrust. In WRC 107 convention: Positive loads try to "push" the nozzle while negative loads try to "pull" the nozzle. While in PD 5500 convention Positive loads try to "pull" the nozzle while negative loads try to "push" the nozzle. The following Figure A and Figure B should clarify these conventions.

Shear Force VC (In WRC 107) or FC (In PD5500) Type the longitudinal shear load VC (or FC in BS 5500 convention) in the units above. Enter this value in accordance with the convention used, either WRC 107 or PD 5500. The following Figure A and Figure B should clarify these conventions.

Shear Force VL (In WRC 107) or FL (In PD5500) Type the longitudinal shear load VL (or FL in PD 5500 convention) in the units above. Enter this value in accordance with the convention used, either WRC 107 or PD 5500. The following Figure A and Figure B should clarify these conventions.

Torsional Moment MT Type the torsional moment in the units displayed above. Enter this value in accordance with the convention used, either WRC107 or PD 5500. The following Figure A and Figure B should clarify these conventions.

Circumferential Moment MC Enter the circumferential moment MC or M1 in the units displayed above. Enter this value in accordance with the convention used, either WRC 107 or PD 5500. The following Figure A and Figure B should clarify these conventions. Note that this moment has opposite signs in these conventions.

Longitudinal Moment ML Enter the longitudinal moment ML or M2 in the units displayed above. Enter this value in accordance with the convention used either WRC107 or PD 5500. The following Figure A and Figure B should clarify these conventions.

Add Axial Pressure Thrust? If this box is checked the force due to pressure times the internal pipe area will be added to or subtracted from the radial load "P".

Use Stress Indices (AD 560.7)? If this box is checked the nominal computed pressure stress on the vessel wall as defined in paragraph AD-560.7 will be multiplied by the stress indices as they are listed in that paragraph of the ASME Code Section VIII Division 2. This is essentially the computation of the surface stress intensity. If the design specification requires the use of these indices, check this box. Please note that these indices are not used in the calculation of the pressure stress on the nozzle. The program will multiply the pressure stress on the nozzle by a factor of 1.2.


28-6

WRC 297/ANNEX G

Figure A - WRC 107 Naming Convention

Figure B - PD 5500 Naming Convention



28-7

Additional Input for PD 5500, Annex G Allowable Stress Increase Factor (Membrane + Bending) This factor is multiplied by the allowable stress f, to obtain an allowable stress for the maximum membrane plus bending stress intensity. These stresses are in rows 27, 28 and 29 in the printout samples in PD 5500 Annex W. At the attachment junction (Nozzle neck) this factor normally has a value of 2.25 or lower. At the edge of the pad, this factor is normally 2.0.

Print the Membrane Stress? Check this box to compute membrane stress at the attachment junction and enter the allowable stress intensity factor for it. The example in Annex W does not compute the Membrane stress at attachment edge. As, the membrane stress should already be checked by the user when selecting the wall thickness. Moreover, the membrane stress computed per Annex G, at the attachment edge contains intensified stresses due to the presence of the hole.

Allowable Stress Increase Factor (Membrane) This factor is multiplied by the allowable stress f, to obtain an allowable stress for the maximum membrane stress intensity. These stresses are in rows 32, 33 and 34 in the printout samples in PD 5500 Annex W. This entry normally has a value of 1.2 or lower at the edge of the reinforcement pad. The example in Annex W does not compute the Membrane stress at attachment edge. As, the membrane stress should already be checked by the user when selecting the wall thickness. Moreover, the membrane stress computed per Annex G, at the attachment edge contains intensified stresses due to the presence of the hole. If you would like to check the membrane stress at attachment junction then click the corresponding check box and enter the allowable stress intensity factor for it. The allowable stress intensity factor in this case would be higher than the factor at pad edge.

Stiffened Length of Vessel Section Type the length of the vessel on which this nozzle lies. For vessels without stiffeners or cones this would be the entire vessel length accounting for the heads as necessary. This value is used along with the Distance from Left Tangent field to compute the equivalent length for off center loading.

Nozzle Inside Projection If this nozzle has a projection inside of the vessel, enter that length into this field. This value is used to determine the pressure stress intensification factor from the graphs in Section 3 of the PD 5500 Code. These curves for Cers/eps have been digitized and are used by the program. All of the curves for protruding and flush nozzles are included for analysis.

Offset from Left Tangent Line Type the distance that the centerline of the nozzles is with respect to the left tangent line or appropriate line of support. This value is used in conjunction with the vessel length to compute the equivalent length for off center loading.

Is the Location of the Nozzle in the Vessel Spherical?


28-8

WRC 297/ANNEX G

If the nozzle is located within the spherical portion of an elliptical or torispherical head or is in a spherical head then check this box. If you are entering this data manually ensure that you are entering the spherical diameter. This is especially important for nozzles located in elliptical heads. Checking this box causes the program to access the various curves used to compute the spherical factors for nozzles connected to spheres per ANNEX G.

Reinforcing Pad Thickness Enter the thickness of the reinforcing pad. Several geometric constants are computed using the shell thickness. For the stress analysis case for the edge of the nozzle the pad thickness will be included. Please note that WRC 297 does not specifically address the "reinforcing pad case". This is analyzed in a consistent manner with the WRC 107 pad method.

Reinforcing Pad Diameter Enter the reinforcing pad diameter along the surface of the vessel. This value will be used when the program computes the stresses at the edge of the reinforcing pad.

Enter Full Re-pad Length in Longitudinal Direction (2*Cx) Attachments other than nozzles can be analyzed using the PD 5500 Annex G method. If one is analyzing the junction of a square/rectangular solid and a cylinder or sphere, enter the FULL length of the reinforcing pad (if present) in the longitudinal direction. A square or a rectangular attachment on a sphere is converted to an equivalent round attachment of radius ro as follows: ro = Sqrt(Cx * Cy) This input is only used for PD5500, Annex G.

Enter Full Re-Pad Length in Circumferential Direction (2*Cy) Attachments other than nozzles can be analyzed using the PD 5500 Annex G method. If one is analyzing the junction of a square/rectangular solid and a cylinder or sphere, enter the FULL length of the reinforcing pad (if present) in the circumferential direction. A square or a rectangular attachment on a sphere is converted to an equivalent round attachment of radius ro as follows: ro = Sqrt(Cx * Cy) This input is only used for PD5500, Annex G.



28-9

Sample Calculation The example problems illustrating these principles are located in the program installation directory/Examples directory.


28-10

WRC 297/ANNEX G

Discussion of Results The WRC 297 Stress Evaluation method computes stress intensities in the nozzle and vessel wall at the junction of the intersection on the upper and lower surface at eight different points. Typically, stress intensities can be compared with the yield stress of the material at operating temperature. However, you should read the WRC 297 bulletin carefully for further clarification and evaluation of stress results. Since this method produces quite a bit of output, it may be useful to use the option to produce only the summary of results. To do this use the TOOLS/CONFIGURATION option (Miscellaneous tab) and check the appropriate box to produce the results in a summary fashion. Note that this directive will affect all of the generated reports in the file.


CH AP TER

2 9

Chapter 29 Appendix Y In This Chapter Introduction ................................................................................ 29-2 Purpose, Scope, and Technical Basis.......................................... 29-3 Gasket and Gasket Factors.......................................................... 29-4 Example ...................................................................................... 29-5


29-2

Appendix Y

Introduction This module performs stress evaluations of Class 1, category 1, 2, or 3 flanges that form identical flange pairs. This module conforms to the latest version of the ASME Code Section VIII Division 1 Appendix Y, Edition 2004 A-05.


Chapter 29 Appendix Y

29-3

Purpose, Scope, and Technical Basis The analysis of an Appendix Y flange is similar in many ways to the Appendix 2 evaluation. However, these flanges have metal-to-metal contact outside the bolt circle, unlike the types evaluated in Appendix 2. These flanges typically have a soft, self sealing o-ring gasket that sits in the recess of one of the flange faces. The loads on the flanges are generated in a very similar manner to those in Appendix 2. The actual stress evaluation however is different. This program evaluates flanges with or without hubs. A category 1 flange is an integral flange. The integral type must have the hub information specified. A category 2 flange is a loose type flange with a hub where the hub strengthens the assembly. A category 3 flange is a loose type flange where no credit is taken for the strengthening effect of the hub. Based on user input (especially flange type and hub information), the category is automatically determined.


29-4

Appendix Y

Gasket and Gasket Factors One critical value the program computes is the diameter of the load reaction. This value is termed G and is a function of where the gasket sits on the flange face. The value of G is typically the average of the gasket inner and outer diameters. For these types of flanges the gasket ID is usually equal to the flange face ID and the gasket OD is usually equal to the flange face OD. Two other important factors are m and Y. The value of m is the leak pressure ratio and Y is the gasket design seating stress. This Appendix takes these gaskets to be self sealing (see the definition of Hg in the Code). Thusly the m and Y factors should both be 0.0. If any other value is entered the user values will be echoed but the program will use values of 0.0 for both.


Chapter 29 Appendix Y

29-5




CH AP TER

3 0

Chapter 30 Miscellaneous Topics In This Chapter Heading Edit ............................................................................... 30-2 Heading Manipulation and Material Properties .......................... 30-3 Discussion of Input ..................................................................... 30-6


30-2


Heading Edit Heading Edit mode allows the user to input and edit the heading and the title page for the current job. The Set Title button is used to overlay a default title page into the title page text area. If desired this page can be customized by editing the file Title.Hed. This is an ASCII Text file and can modified with Notepad, Edit or any other ASCII text editor.


Chapter 30 Miscellaneous Topics

30-3

Heading Manipulation and Material Properties Element materials may be selected for the Material Database button. When clicking the Material button, the following screen displays:

Material Database


30-4


By selecting and clicking material name, the material parameters display.

Click OK to load the material name and the appropriate material parameters are loaded in the element. These parameters may be reviewed and modified through the Material Edit Window by pressing Enter when the cursor is in the Material field. The Material Edit Window lets you display and modify the material properties of the current element or detail. Note that if the material is newly selected, the data displayed here are directly from the program's material database, otherwise the data are from the data structure of the current element or detail. If a newly selected material can not be found in the program's material database, the program will assume that is a "user-defined material", in this case the you must define all material properties in this window.



The following buttons are available in this window: OK - Allows you to save the data to the memory then close the window. Cancel - Allows you to close the window without saving the data. Help - Displays information about this window.


30-5

30-6


Discussion of Input Input Data Material Name Enter the name of the material for this element. This program contains a database which includes most of the materials in the ASME Code, Section II, Part D, Table 1A, 1B, and 3.

TEMA Number The TEMA number is used to determine the modulus of elasticity for a material at design temperature. These values range from 1 to 52 and are located in the TEMA Tubesheet chapter.

Keyboard Commands The following movements are defined for the keyboard within the program:



Begin line

Begin list

Delete character

Delete prev. char

Delete window

End line

End list

Exit

Help

Hot key

Insert toggle

Left word

Mark

Maximize

Menu control

Minimize

Move window

Next cell

Next Character

Next field

Next window

Page down

Page up

Previous cell

Previous character

Previous field

Refresh

Right word

Select

Size window

System button

Mouse Operation The following movements are defined for the mouse within the program:


30-7

30-8


In Window Objects: Choose Select

In Vessel Graphics: Select element Select detail

Allowable Stress at Ambient Temperature Enter the allowable stress for the element material at ambient temperature. ( The ambient temperature for most vessels will be 70° F or 100° F or 30° C). You can find this value in the ASME Code, Section II, Part D, Table 1A, 1B, and 3. Under normal circumstances, the program will look up this allowable stress for you. If you enter a valid material name in the Material Input field, the program will search its database and determine the allowable stress for the material at ambient temperature, and enter it into this cell. The program will also determine the stress when you select a material name from the Material Selection window. Allowable Stress at Operating Temperature Enter the allowable stress for the element material at operating temperature. ( The operating temperature for most vessels is defined to be the same as the design metal temperature for the internal pressure). You can find this value in the ASME Code, Section II, Part D, Table 1A, 1B, and 3. Under normal circumstances, the program will look up this allowable stress for you. If you enter a valid material name in the Material Input field, the program will search its database and determine the allowable stress for the material at ambient temperature, and enter it into this cell. The program will also determine the stress when you select a material name from the Material Selection window.

Allowable Stress at Hydrotest Temperature Enter the allowable stress for the element material at Hydrotest temperature. ( The hydrotest temperature for most vessels will be 40° F or 70° F or 10° C). You can calculate this value in the ASME Code, Section II, Part D, Table 1A, 1B, and 3. Most times the allowed hydrotest stress will just be 1.3 times the allowable stress for the vessel at ambient temperature. Under some circumstances you may choose to use an allowable hydrotest stress of 0.9 times the yield stress of the material at ambient temperature. This is especially helpful in the case of a tall vertical process tower where the hydrotest pressure is increased by the height of the water used for testing. Use of the higher hydrotest allowable stress may prevent the hydrotest case from controlling the thickness of the vessel. Under normal circumstances, the program will look up this allowable stress for you. If you enter a valid material name in the Material Input field, the program will search its database and determine the allowable stress for the



30-9

material at ambient temperature, and enter it into this cell. The program will also determine the stress when you select a material name from the Material Selection window. There is an option for PVElite to always use 0.9 times the yield stress when determining the hydrostatic test allowable stress. This check box is on the Design/Analysis Constraints screen.

Nominal Density of this Material Enter the nominal density of the material. Note that the program will use this value to calculate component weights for this analysis. The typical density for carbon steel is 0.2830 lbs/in3.

P Number Thickness Enter the thickness for the P number. Table UCS-57 of the ASME Code, Section VIII, Division 1 lists the maximum thickness above which full radiography is required for welded seams. This thickness is based on the P number for the material listed in the allowable stress tables of the Code. If a seam is partially radiographed and the required thickness exceeds the P number thickness, PVElite will automatically change the joint efficiency to 1.0 as stated in the Code.

Yield Stress, Operating Enter the yield stress for the material at operating temperature. This value is found in the ASME Code, Section II, Part D. PVElite will automatically look up the yield stress from the Yield Stress database. Unfortunately, not all materials have a yield stress at design temperature or the database may be ambiguous. In that case, it is your responsibility to enter the appropriate value for the yield stress.

UCS-66 Chart Number Enter values 1 through 4 to specify the UCS-66 Carbon Steel Material Curves A through D, respectively. Enter 0 for materials which are not carbon steel. Note that the Material Database returns the non-normalized curve number; adjust the curve number if you are using a normalized material produced to fine grain practice. In some cases materials are impact tested when they are produced. Such an example is SA-350 LF2. For these classes of materials a value of 5 will alert PVElite that this material is impact tested.

External Pressure Chart Name The program uses the chart name to calculate the B value for all external pressure and buckling calculations. It is important that you enter the name correctly. Under normal circumstances, the program will look up this chart name for you. If you enter a valid material name in the Material Input field, the program will search its database and determine the allowable stress for the material at ambient temperature, and enter it into this cell. The program will also determine the stress when you select a material name from the Material Selection window. The following are the acceptable external pressure chart names:


30-10


Carbon Steel Materials CS-1

UCS-28.1, Carbon and Low Alloy, Sy<30000

CS-2

UCS-28.2, Carbon and Low Alloy, Sy>30000

CS-3

UCS-28.3, Carbon and Low Alloy, Sy>38000

CS-4

UCS-28.4, SA-537

CS-5

UCS-28.5, SA-508, SA-533, SA-541

CS-6

UCS-28.6, SA-562 or SA-620

Heat Treated Materials HT-1

UHT-28.1, SA-517 and SA-592 A, E, and F

HT-2

UHT-28.2, SA-508 Cl. 4a, SA-543,B,C

Stainless Steel (High Alloy) Materials HA-1

UHA-28.1, Type 304

HA-2

UHA-28.2, Type 316, 321, 347, 309, 310, 430B

HA-3

UHA-28.3, Type 304L

HA-4

UHA-28.4, Type 316L, 317L

HA-5

UHA-28.5, Alloy S31500



Non Ferrous Materials NFA-1

UNF-28.2, AL3003, O and H112

NFA-2

UNF-28.3, AL3003, H14

NFA-3

UNF-28.4, AL3004, O and H112

NFA-4

UNF-28.5, AL3004, H34

NFA-5

UNF-28.13, AL5154, O and H112

NFA-6

UNF-28.14, C61400 (Aluminum Bronze)

NFA-7

UNF-28.17, AL1060, O

NFA-8

UNF-28.18, AL5052, O and H112

NFA-9

UNF-28.19, AL5086, O and H112

NFA-10

UNF-28.20, AL5456, O

NFA-11

UNF-28.23, AL5083, O and H112

NFA-12

UNF-28.30, AL6061, T6, T651, T6510 and T6511

NFA-13

UNF-28.31, AL6061, T4, T451, T4510 and T4511

NFA-14

UNF-28.32, AL5454, O and H112

NFC-1

UNF-28.9, Annealed Copper

NFC-2

UNF-28.10, Copper-Silicon A and C

NFC-3

UNF-28.11, Annealed 90-10 Copper Nickel

NFC-4

UNF-28.12, Annealed 70-30 Copper Nickel

NFC-5

UNF-28.43, Welded Copper Iron Alloy Tube

NFC-6

UNF-28.48, SB-75 and SB-111 Copper Tube

NFN-1

UNF-28.1, Low Carbon Nickel

NFN-2

UNF-28.6, Ni

NFN-3

UNF-28.7, Ni Cu Alloy

NFN-4

UNF-28.8, Annealed Ni Cr Fe

NFN-5

UNF-28.15, Ni Mo Alloy B

NFN-6

UNF-28.24, Ni Mo Cr Fe

NFN-7

UNF-28.25, Ni Mo Cr Fe Cu

NFN-8

UNF-28.27, Ni Fe Cr Alloy 800

NFN-9

UNF-28.29, Ni Fe Cr Alloy 800H

NFN-10

UNF-28.33, Ni Moly Chrome Alloy N10276

NFN-11

UNF-28.34, Ni Cr Fe Mo Cu Alloys G and G-2


30-11

30-12


NFN-12

UNF-28.36, Cr Ni Fe Mo Cu Co, SB-462, 463, etc.

NFN-13

UNF-28.37, Ni Fe Cr Si Alloy 330

NFN-14

UNF-28.38, Ni Cr Mo Grade C-4

NFN-15

UNF-28.39, Ni Mo Alloy X

NFN-16

UNF-28.40, Ni Mo Alloy B-2

NFN-17

UNF-28.44, Ni Cr Mo Co N06625 (Alloy 625)

NFN-18

UNF-28.45, Ni Mo Cr Fe Cu (Grade G-3)

NFN-19

UNF-28.46, Ni Mo Cr Fe Cu (Grade G-3, >3/4)

NFN-20

UNF-28.47, Work Hardened Nickel

NFT-1

UNF-28.22, Unalloyed Titanium, Grade 1

NFT-2

UNF-28.28, Unalloyed Titanium, Grade 2

NFT-3

UNF-28.42, Titanium, Grade 1

NFZ-1

UNF-28.35, Zirconium, Alloy 702

NFZ-2

UNF-28.41, Zirconium, Alloy 705

You may add material data to the standard Material Database using the Edit/Add Materials option from Tools on the Main Menu.


CH AP TER

3 1

Chapter 31 Vessel Example Problems In This Chapter Vessel Example .......................................................................... 31-2


31-2

Vessel Example Problems

Vessel Example The example problems illustrating these principles are located in the program installation directory/Examples directory.


Index

Index 1 1.60D.5 • 6-1 1.60D10 • 6-1 1.60D2 • 6-1 1.60D5 • 6-1 1.60D7 • 6-1

3 3D Viewer • 3-1

A A Road Map for PVELITE • 3-3 About the Documentation • 1-9 Above Ground Height • 6-1 Absolute • 6-1 Abutting Nozzle Insertion • 5-1 Acc Based Factor Fv • 6-1 Acc.Based Factor Fa • 6-1 Acceleration Zone • 6-1 ACCEPTANCE OF TERMS OF AGREEMENT BY THE USER • 2 Acts During Wind or Seismic • 5-33 Actual Diameter and Thickness • 5-15 Actual Nozzle Diameter Thickness • 12-14 Actual or Nominal Diameter of Nozzle • 5-15, 12-7 Actual Schedule of Nozzle • 12-8 Actual Thickness of Flange • 15-6 Actual Thickness of Head • 15-5 Actual Thickness of Nozzle • 5-15 Actual Thickness of Shell • 12-6 AD-540.2 sketch b • 3-1 Adding Details • 3-1, 3-46 Additional Reinforcing Pad Data • 5-27 Additional Area • 16-8, 19-6 Additional Data for Reinforcing Pad • 5-1 Additional Input for PD 5500, Annex G • 28-7 Allowable Calculations • 27-19 Allowable Stress at Ambient Temperature • 124, 15-5, 17-6 Allowable Stress At Ambient Temperature • 164 Allowable Stress at Design Temperature • 12-4, 15-5, 17-7 Allowable Stress At Operating Temperature • 16-3 Also Perform Soehren's Calculation? • 15-12

1

Amplification Factor ac • 6-1 Analysis • 3-11 Analysis Menu • 10-8 Analysis, Performing an • 10-1 Analyze Menu • 3-1, 3-25, 10-1 Analyzing Heat Exchangers • 9-4 Analyzing Individual Vessel Components Details • 3-55 Angle Between Nozzle and Shell • 5-1, 5-13 Angle Between Nozzle and Shell (Usually 90) entered in descript • 5-1 Angle Sections Rolled the Hard Way • 6-1 ANSI Flange MAWP • 7-1 API 579 Introduction • 11-14 Appendix 14 Large Opening • 4-15 Appendix Y • 29-1 Apply Longitudinal Loads to Vessel • 16-5 Apply Seismic Loads to Vessel • 16-5 Apply Wind Loads to Vessel • 16-5 Are There Axial Forces on the Cone? • 14-6 Area 2 Setting • 5-1 Area Calculations for Small Nozzles • 10-1 Area Of Tube Layout • 17-11 Area1 Setting • 5-1 ASCE • 6-1 ASCE - 95 Seismic Data • 6-50 ASCE 7-88 Seismic Data • 6-1, 6-42 ASCE 7-93 Importance Factor • 6-1 ASCE 7-93 Seismic Data • 6-1 ASCE 95 Wind Data • 6-1, 6-24 ASCE Roughness Factor • 6-1 ASCE Wind Data • 6-1, 6-18 ASCE7-93 Seismic Data • 6-44 ASCE-95 Seismic Data • 6-1 ASME Code Weld Type • 5-1, 5-27 ASME TUBESHEETS • 24-1 ASME UG-99(b) • 6-1 ASME UG-99(b) footnote 32 • 6-1 ASME UG-99(b) footnote 34 • 6-1 ASME UG-99(c) • 6-1 Aspect Ratio (D/2H) for Elliptical Heads • 16-15 Assigning Detail • 5-4 Assigning Details to Elements • 5-1 Attachment Factor • 4-14 Axial Thickness of Reinforcing Ring • 14-9

B B16.5 Flange • 5-1 B16.5 Flange, Grade for Attached • 5-1 Back Ring Actual Thickness • 15-13

Printed on 15 December, 2005


2

Backing Ring Inside Diameter • 15-13 Bar Thickness • 6-1 Base Elevation • 6-1 Base Plate Length • 16-7 Base Plate Thickness • 16-7 Base Plate Width • 16-7 BASE RINGS • 4-21, 21-1 Baseplate Input • 19-22 Baseplate Length • 5-1, 5-38 Baseplate Results • 19-25 Baseplate Thickness • 5-1, 5-39 Baseplate Width • 5-1, 5-38 Basering Analysis • 4-21 Basering Dialog • 4-19 Basic Wind Speed • 16-10, 19-8 Blind Flange Thickness for Reinforcement • 3-1 Body Flange • 4-16 Bolt Correction Factor • 3-1 Bolt Root Area • 15-13 Bolted Cover Mating Flange • 9-47 Bottom Lug Support Plate, Length of • 5-1 Bottom Plate, Thickness of • 5-1 Bottom Support Plate • 5-1 British Standard BS5500 • 7-1 British Wind Code BS-6399 • 6-37 Brownell and Young Method of Design • 4-21 Building Heat Exchangers • 9-11

C Calculated Value of M for Torispherical Heads • 10-1 Calculating and Displaying Vessel-Analysis Results • 7-3 Calculations • 21-3 Calculator • 3-35 Carbon Steel Materials • 30-10 Category Value • 6-1 Center Web Height • 5-1 Centerline Dimension • 5-1 Centerline Dimension (B) • 5-37 Centerline Offset • 4-1, 4-23 Channel Corrosion Allowance • 17-8 Channel Design Pressure • 17-7 Channel Inside Diameter • 17-8 Channel Metal Design Temperature • 17-8 Channel Wall Thickness • 17-8 Check Saddle Webs, & Base Plate • 16-5 Class for Attached B16.5 Flange • 5-13, 12-11 COADE Technical Support Phone Numbers • 112


Code Case 2168 for Nozzle Design • 6-1 Code Case 2260/2261 • 3-1 Coefficient Cd • 6-1 Combination Method • 6-1 Component Analysis • 7-1, 7-11, 8-2, 8-5 Component Analysis Main Menu • 10-1 Component Analysis Module • 10-1 Component Analysis Tutorial • 10-1 Componsite Stiffener Height • 5-1 Computation Control Tab • 10-1 Cone Actual Thickness • 14-5 Cone Axial Length • 14-6 Cone Corrosion Allowance • 14-5 Cone Description • 14-4 Cone Diameter at Large End • 14-5 Cone Diameter at Small End • 14-5 Cone Diameter Basis (ID, OD) • 14-5 Cone Half Apex Angle • 14-6 Cone Joint Efficiency • 14-5 Cone Length • 4-11 Cone Number • 14-4 Cone\Cylinder\Ring\Knuckle Material Name • 14-4 Configuration • 10-1 Conical Head or Shell Segment • 4-11 CONICAL SECTIONS • 14-1 Construction Type • 6-1 Corroded Expansion Joint Spring Rate • 17-16 Corroded Hydrotest • 6-1 Corrosion Allowance • 4-5, 16-3 Create / Review Units • 3-33 Crest Distance • 6-1 Critical Damping Ratio • 6-1 Cross Sectional Area • 5-10 Cross Sectional Area of Reinforcing Section • 14-9 Cross Sectional Area of Stiffening Ring • 16-14 Cross-Sectional Area • 5-1 Crown Radius • 4-10 Crown Radius for Torispherical Heads • 16-15 Cylindrical Shell • 4-8

D Damping Factor • 6-1 Datum Line Distance • 6-1 Default units file • 10-1 Defining the Basic Vessel • 3-45 Defining the Details • 5-7 Density of Lining • 5-49 Density of Liquid on Tray • 5-40


Index

Density of Material • 30-9 Density of Packing • 5-44 Density Of Stored Liquid • 16-4 Depth of Groove in Tubesheet • 17-14 Depth of Groove Weld Between Nozzle and Vessel • 5-17, 12-12 Depth of Groove Weld between Pad and Nozzle Neck • 5-27 Depth of Groove Weld Between Pad and Nozzle Neck • 12-13 Description • 12-4, 17-6 Design and Analysis of Vessel Details • 3-15 Design Data • 6-1, 6-3 Design External Pressure • 4-7, 12-4 Design Internal Pressure • 4-6, 6-1, 12-4 Design Internal Temperature • 6-1 Design Modification • 6-1, 6-11 Design Pressure • 6-1 Design Pressure + Static Head • 6-1 Design Temperature • 15-4 Design Temperature for External Pressure • 4-7 Design Temperature for Internal Pressure • 4-6 Design Wind Speed • 6-1 Detail Definition Buttons • 5-1, 5-5 Detail ID • 5-1 Details, Definition of • 5-1 Diagnostic Menu • 10-20 Diagnostics Menu • 3-1, 3-36, 10-1 Diameter and Thickness, Actual • 5-1 Diameter at Leg Centerline • 5-1 Diameter of Bolt Circle • 15-6 Diameter of Nozzle, Actual • 5-1 Diameter of Outer Tube Limit Circle • 17-11 Diamter, Minimum • 5-1 Differential Design Pressure (Used if > 0.0) • 1710 DISCLAIMER • 4 Discussion of Input • 16-3, 18-3, 19-3, 20-3, 219, 21-17, 30-6 Discussion of Input Data • 5-50, 11-5, 11-18, 124, 13-5, 14-4, 15-4, 17-6, 22-4, 23-4, 24-4, 254, 26-4, 27-10, 28-3 Discussion of Results • 4-24, 11-27, 12-14, 1318, 14-10, 15-14, 16-16, 17-31, 18-18, 21-18, 23-10, 24-26, 25-7, 27-18, 28-10 Distance between Gussets • 5-1, 5-30 Distance from Outside Diameter or Diameter at Leg Centerline • 5-41 Distance From Saddle to Vessel Tangent • 16-6

3

Distance From the Flange Centroid to Head Centerline • 15-12 Distance From Vessel Centerline To Saddle Base • 16-5 Distance from Vessel OD to Lug Midpoint • 5-1, 5-29 Distance or Straight Flange Length • 4-4 Distance to Centroid of Reinforcing Section • 14-9, 16-14 Distance to Crest (Lh) • 16-11, 19-9 Distance to Ring Centroid • 5-1, 5-10 Distance to Site • 6-1 Distance to Site (x) • 16-11, 19-9 Do you want to set Area1 or Area 2 to 0 • 5-14 DXF File Generated by PVElite During Runtime • 3-61 DXF File Generation Option • 3-1, 3-58

E E for Plates • 5-38 Earthquake Load Calculation • 7-1 EarthQuake Parameters Fa and Fv • 6-1 Edit / Add Materials • 3-33 Edit Menu • 10-1, 10-7 Effective Material Diameter and Thickness Limits • 12-15 Efficiency of Shell Seam Through Which Nozzle Passes • 12-8 EigenSolver • 3-1 El Centro • 6-1 Element Additional Data • 4-8 Element Basic Data • 4-3 Element Data • 4-1 Element's Diameter • 4-4 Element's From Node • 4-1, 4-3 Element's To Node • 4-1, 4-4 Elliptical Head • 4-8 Enter Required Thickness • 12-6 Enter the Aspect Ratio for Elliptical Heads • 1211 Enter The Attachment Factor For Welded Flat Heads • 12-11 Enter the Large Diameter for Non-circular Flat Heads • 12-11 Enter the Shell Design Length for External Pressure • 12-10 Enter Tube-Tubesheet Joint Information • 17-9 Enter Unsupported Tube Span SL For Max (k*SL) • 17-10 Entering PVElite • 3-44


4

ENTIRE AGREEMENT • 3 Equipment Class • 6-1 Error Checking • 3-1, 3-10, 7-1 ESL Installation on a Network • 2-11 ESL Menu • 3-1, 3-42, 10-1, 10-22 Example • 11-28, 12-17, 13-22, 14-12, 15-16, 16-20, 17-36, 18-27, 19-30, 20-9, 21-19, 2211, 23-11, 24-28, 25-9, 29-5 Example Problem • 26-5, 27-20 Expansion Joint Data • 9-28 Expansion Joint Design Option • 17-16 Expansion Joint Inside Diameter • 17-16 Expansion Joint Knuckle • 17-17 Expansion Joint Type • 17-15 Exposure Constant • 6-1 External Design Pressure • 14-4 External Design Temperature • 14-4 External Pressure calculations • 7-1 External Pressure Calculations • 27-19 External Pressure Chart Name • 30-9 External Pressure Results • 14-10 External Pressure Results for Heads: • 15-14 External Software Lock • 2-4 Extra Weight • 16-4

F Failure Path Calculations • 12-16 FEA Additional Input • 18-16 File Manager • 30-1 File Menu • 3-1, 3-22, 10-1, 10-5 Finished Thickness • 4-5 Fireproofing with Insulation • 5-1 Flange Analysis • 4-16 Flange Distance to Top • 6-1 Flange Face Facing Sketch • 15-11 Flange Face Inner Diameter • 15-8 Flange Face Outer Diameter • 15-7 Flange Input Data • 4-20 Flange Material • 5-28 Flange Merge • 17-14 Flange Type • 5-28 FLANGES • 4-16, 4-20, 13-1 Floating Head Description • 15-4 Floating Head Identification Number • 15-4 Floating Head Type (b, c, d) • 15-4 FLOATING HEADS • 15-1 Floating Tubesheets • 9-36 Flohead Calculation • 10-1 Force Coefficient (Cf) • 16-8, 19-6 Force Factor • 6-1


Force in X, Y, or Z Direction • 5-1, 5-33 Force Modification Factor • 6-1 Force/Moment Combination Method • 5-33 Forces and Moments • 5-1, 5-33 Friction Coefficient Between the Saddle and the Foundation, mu • 16-13 From Node • 5-1 Full Face Gasket Options • 15-6

G Gasket and Gasket Factors • 29-4 Gasket Inner Diameter • 15-8 Gasket Outer Diameter • 15-8 Gasket Thickness • 15-11 GENERAL • 4 General Vessel Data • 6-1 Generating Output • 8-2 Grade for Attached B16.5 Flange • 5-13, 12-12 Groove Weld Between Nozzle and Vessel • 5-1 Groove Weld between Pad and Nozzle Neck • 51 Gussets • 5-1 Gussets Height • 5-1 Gussets, Mean Width • 5-1 Gussets, Thickness of • 5-1 Gust Response Factor • 6-1

H Half Apex Angle • 4-12 Half Apex Angle for Conical Sections • 12-11 Half Pipe Jacket • 5-50 HALF-PIPES • 25-1 Head Factor • 4-8 Head Joint Efficiency • 16-6 Head Thickness • 16-6 Head Type • 16-6 Heading Edit • 30-2 Heading Manipulation and Material Properties • 30-3 HEAT EXCHANGERS • 9-1 Heat Treated Materials • 30-10 Heat-Treated Materials • 30-10 Height above Ground • 6-1 Height of Center Web • 5-1, 5-39, 16-8 Height of Composite Stiffener • 5-1, 5-38 Height of Gussets • 5-1, 5-30 Height of Hill (H) • 6-1 Height of Hill or Escarpment (H) • 16-11, 19-9 Height of Liquid Column, Operating • 12-5 Height of Liquid on Tray • 5-1, 5-40


Index

Height of Packed Section • 5-1, 5-43 Height of Stiffener from Shell Surface • 16-15 Height of Vessel Above Grade • 16-11, 19-9 Height/Length of Insulation • 5-1 Height/Length of Insulation / Fireproofing • 5-47 Height/Length of Lining • 5-1, 5-49 Height/Length of Liquid • 5-1, 5-45 Help Menu • 3-1, 3-43, 10-1, 10-23 Higher Long Stresses • 6-1 Highest Percentage of Allowable Calculations • 27-19 Hill Height • 6-1 Hills, Types of • 6-1 Hillside Nozzle Cylinder • 5-21 Hillside Nozzle in Head • 5-26 HOOPS' License Grant • 4 Horizontal Force Factor • 6-1 HORIZONTAL VESSELS • 16-1 Hydro. Allowable Unmodified (Y/N) • 6-1 Hydrotest Calculations • 7-1 Hydrotest Position • 6-1 Hydrotest Type • 6-1 Hydrotest, Seismic • 6-1 Hydrotest, Wind • 6-1

I IBC • 6-1 IBC-2000 Earthquake Parameters • 6-54 Impact Factor • 6-1 Importance Factor • 6-1 Importance Factor ( I ) • 16-9, 19-7 Include Hydrostatic Head Component • 12-5 Include Missing Mass Components • 6-1 India's Earthquake Standard IS-1893 RSM and SCM • 6-1, 6-49 Input Echo • 7-1 Input Menu • 3-1, 3-18 Input Processor • 3-1 Input Processors • 3-1 Insert Nozzle or Abutting Nozzle • 5-16, 12-8 Inside Crown Radius (L) of the Torispherical Head • 12-11 Inside Crown Radius of Head • 15-5 Inside Depth of Flange From Flange Face to Attached Head • 15-13 Inside Diameter at Base • 4-18 Inside Diameter of Flange • 15-6 Inside Diameter of Ring • 5-1, 5-9 Inside Head Depth • 4-9

5

Inside Knuckle Radius of Torispherical Head • 12-11 Inspecting the Model in 3D • 3-40 Installation Options • 6-1, 6-8 Installing PVElite • 2-7 Insulation • 5-1, 5-47 Insulation Density • 5-1, 5-47 Insulation or Fireproofing, Thickness of • 5-1 Intermediate Calculations for Flanged Portion of Head: • 15-14 Internal Design Pressure • 14-4 Internal Design Temperature • 14-4 Internal Pressure • 6-1 Internal Pressure Calculations • 7-1 Internal Pressure Results • 14-10 Internal Pressure Results for the Head: • 15-14 Internal Temperature • 6-1 Introduction • 1-1, 4-2, 5-2, 5-50, 6-2, 7-2, 9-2, 11-2, 12-2, 13-2, 14-2, 15-2, 16-2, 17-2, 18-2, 19-2, 20-2, 21-2, 22-2, 23-2, 24-2, 25-2, 26-2, 27-2, 28-2, 29-2 Invoking the Drawing • 3-1, 3-61 IS 875 Wind Code • 6-1, 6-27 Is the Flange Slotted • 15-12 Is The Nozzle Outside the 80% Diameter Limit • 12-6 Is There A Backing Ring? • 15-12 Is This a Heat Exchanger • 6-1 Is This a Manway or Access/Inspection Opening • 12-6 Is this a Welded Internal • 5-32 Item Number • 16-3, 17-6 Iterative Results Per Pressure, Area , And UG45 • 12-16

J Jacket • 11-8, 11-29 Joint Efficiency for Longitudinal and Circumferential Seams • 4-6 Joint Efficiency of Nozzle Neck • 5-1, 5-16 Joint Efficiency of Shell Seam through which Nozzle Passes • 5-1, 5-16

K Keyboard Commands • 30-6 Knuckle Bend Radius, Large End • 14-9 Knuckle Bend Radius, Small End • 14-9 Knuckle Radius • 4-10 Knuckle Ratio for Torispherical Heads • 16-15 Knuckle Thickness, Large End • 14-9


6

Knuckle Thickness, Small End • 14-9

L Large Cylinder Actual Thickness • 14-7 Large Cylinder Axial Length • 14-7 Large Cylinder Corrosion Allowance • 14-7 Large Cylinder Joint Efficiency • 14-7 Large Diameter Nozzle Calculations • 12-15 Large End Knuckle Radius • 4-12 Large End Knuckle Thickness • 4-13 Large End Reinforcing (None, Bar, Section, Knuckle, Knuckle-Bar, Knuckle-Section) • 147 LARGE OPENINGS • 26-1 Lateral Nozzle in Cylinder • 5-23 Leg Orientation • 5-1, 5-41 Leg Results • 19-14 Legs • 5-1, 5-41 LEGS and LUGS • 19-1 Legs, Length of • 5-1 Legs, Number of • 5-1 Length of Bottom Lug Support Plate • 5-30 Length of Expanded Portion of Tube • 17-10 Length of Legs • 5-42 Length of Partition Gasket • 15-11 LICENSE GRANT • 2 Lifting Lug Input • 19-18 Ligament Efficiency Calculations • 27-18 Liguid on Tray • 5-1 LIMITATIONS OF REMEDIES • 3 LIMITED WARRANTY • 3 Lining • 5-1, 5-49 Lining Density • 5-1 Lining, Thickness of • 5-1 Liquid • 5-1, 5-45 Liquid Density • 5-1, 5-45 Liquid Height From Bottom Of Tank • 16-4 Liquid on Tray, Density of • 5-1 Load Case • 6-1 Load Cases • 9-32 Loads and Design Constraints • 3-1 Local Shell Thickness • 5-1, 5-17 Location of Reinforcing Ring (Shell, Cone) • 149 Longitudinal Allowable Stresses • 7-1 Longitudinal Stress Constants • 7-1 Longitudinal Stresses • 7-1 Lug Bearing Width • 5-1, 5-29 Lug Distances from Base • 6-1 Lug Height • 5-1


Lug Height (only if no Top Ring • 4-1 Lug Height (only if no Top Ring) • 4-23 Lug Midpoint • 5-1 Lug Thickness • 4-1, 4-23 Lug Width • 5-1 Lugs • 5-1, 5-29

M M.A.W.P. and Static Head • 6-1 Main Input Fields • 5-51, 11-5, 12-4, 13-5, 14-4, 15-4, 16-3, 17-6, 18-3, 19-3, 20-3, 21-9, 22-4, 23-4, 24-4, 25-4, 26-4, 27-10, 28-3 Main Menu • 3-1, 3-21, 10-4 Material Allowable Stress, Ambient Temperature • 14-5 Material Allowable Stress, Design Temperature • 14-4 Material Definition • 30-3 Material Name • 4-5, 30-6 Material Specification • 15-4, 16-3 Material Yield Stress • 5-1, 5-38 Mating Flange Design Bolt Load (W) • 15-13 Mating Flange Loads? • 15-12 Mating Flange Operating Load (WM1) • 15-13 Mating Flange Seating Load (WM2) • 15-13 MAWP Calculations • 27-19 Max. Mapped Res. Acc. Sl • 6-1 Max. Mapped Res. Acc. Ss • 6-1 Maximum Allowable Pressure New & Cold • 12-4 Mean Width of Gussets • 5-1, 5-30 Merge Shell • 16-5 Metal Temperature • 6-1 Mexican Wind Code 1993 • 6-30 Minimum Design Metal Temperature • 12-15 Minimum Diameter and Thickness • 5-1, 5-15 Minimum Metal Temperature • 6-1 Miscellaneous Tab • 10-1 Miscellaneous Topics • 30-1 Miscellaneous Weight • 5-32 Modification of Reinforcement Limit • 12-6 Modification of Reinforcing Limits • 5-14 Moment about X, Y, or Z Axis • 5-1, 5-33 Moment of Inertia • 5-1, 5-9 Moment of Inertia of Reinforcing Section • 14-9 Moment of Inertia of Stiffening Ring • 16-14 Moment Reduction Factor Tau • 6-1 Mouse Operation • 30-6


Index

N Name of Section Type • 5-10 Natural Frequency Calculation • 7-1 Natural Frequency for the Structure (Fn) — Optional (Hz) • 19-9 NBC Seismic Data • 6-1, 6-47 NBC Wind Data • 6-1, 6-22 Network Installation / Usage • 2-10 Nominal Density of Material • 30-9 Nominal Density of this Material • 30-9 Nominal Diameter and Thickness • 5-1, 5-15 Nominal Schedule of Nozzle • 5-1, 5-16 Nominal Thickness of Nozzle • 12-8 Non Ferrous Materials • 30-11 Non-Circ. Small Diameter • 4-15 Non-Ferrous Materials • 30-11 Notes on Network ESLs • 2-12 Novell File Server ESL Installation • 2-11 Novell Workstation ESL Installation • 2-11 Nozzle Analysis • 5-1, 5-12 Nozzle Angle Geometry • 12-9 Nozzle Corrosion Allowance • 5-1, 5-16, 12-8 Nozzle Description • 5-1, 5-13 Nozzle Design Modifications • 6-1, 6-14 Nozzle Design Pressure • 6-1 Nozzle Dialog Data • 5-11 Nozzle Diameter Basis • 5-1, 5-15, 12-7 Nozzle Diameter Limit • 5-1 Nozzle In a Cylinder • 5-20 Nozzle In a Head • 5-24 Nozzle Input Data • 5-1, 5-13 Nozzle Insertion • 5-1 Nozzle Inside Projection • 5-1, 5-17, 12-13 Nozzle Material Specification • 5-1, 5-14 Nozzle Orientation • 5-18 Nozzle Outside Projection • 5-1, 5-16, 12-12 Nozzle Schedule • 5-1 Nozzle Size and Thickness Basis • 5-1, 5-15, 127 Nozzle Thickness • 3-1, 10-1 Nozzle Thickness Limit • 5-1 Nozzle Weight • 5-1 Nozzle, Thickness of Actual • 5-1 Nozzles • 5-1 NOZZLES • 12-1 Nozzles, Small • 3-1 Nubbin Width • 15-11 Number of Bolts • 15-6 Number of Desired Cycles • 17-18

7

Number of Flexible Shell Elements • 17-18 Number of Grooves • 17-11 Number of Legs • 5-42 Number of Lugs • 5-31 Number of Ribs • 5-39, 16-7 Number of Splits in Backing Ring (0, 1, OR 2) • 15-13 Number of Trays • 5-40 Number of Tube Holes • 17-9

O OD as the Basis for the shell Radius in Zick • 31 Offset Distance from Cylinder/Head Centerline • 5-1 Offset Distance from Cylinder/Head Centerline (L1) • 5-13 Offset from Centerline • 5-1, 5-32 Operating Liquid Density • 12-5 Optional Steps • 7-9 Ordinate Type • 6-1 Other Input Processors • 3-7 Outer Cylinder on the Thick Expansion Joint • 17-18 Output • 19-21, 20-8 Output Menu • 3-1, 3-26, 10-1, 10-9 Output Review • 3-1 Output Review and Report Generation • 3-13 Output/Review • 8-1 Outside Diameter of Flanged Portion • 15-5 Outside Diameter of Ring • 5-1, 5-9 Outside Diamter • 5-1 Overall Height of Lug • 5-30 Overall M.A.W.P. and Static Head • 6-1 Overall Width of Lug • 5-30 Overriding Nozzle Weight • 5-18 Overview • 2-2

P P instead of MAWP for UG-99B • 10-1 P Number Thickness • 30-9 Packed Section Height • 5-1 Packing • 5-1, 5-43 Packing Density • 5-1 Pad Length • 5-1, 5-31 Pad Material • 5-1, 5-27 Pad Outside Diameter along Vessel Surface • 51, 5-27 Pad Outside Diameter Along Vessel Surface • 12-13


8

Pad Thickness • 5-1, 5-27, 5-31, 12-13 Pad Weld Leg Size as Outside Diameter • 5-1, 527 Pad Weld Leg Size at Outside Diameter • 12-13 Pad Width • 5-1, 5-27, 5-31 Parameters, Required • 3-1 Partition Gasket Column for Gasket Seating: • 15-12 Partition Gasket Design Seating Stress Y: • 1512 Partition Gasket Factor M • 15-11 Partition Gasket Nubbin Width • 15-12 Partition Gasket Thickness • 15-12 Perform Area Calculations for Small Nozzles • 12-7 Perform Saddle Check • 5-38 Perform Tailing Lug Analysis • 4-23 Perform WRC 107 Calc • 5-1, 5-31 Performance Criteria Factor P • 6-1 Performing an Analysis • 10-24 Performing the Analysis • 3-53 Perimeter Of Tube Layout (if Needed) • 17-10 Physical Maximum for Nozzle Diameter Limit • 5-14, 12-12 Physical Maximum for Nozzle Thickness Limit • 5-14, 12-12 Pin Hole Diameter • 4-1, 4-23 PIPES and PADS • 20-1 Plates • 5-1 Platform Clearance • 5-1, 5-35 Platform End Angle (degrees) • 5-1, 5-34 Platform Force Coefficient • 5-1, 5-35 Platform Grating Weight • 5-1, 5-35 Platform Height • 5-1, 5-35 Platform Length • 5-1 Platform Length (Non- Circular) • 5-36 Platform Railing Weight • 5-1, 5-35 Platform Start Angle (degrees) • 5-1, 5-34 Platform Weight • 5-1, 5-35 Platform Width • 5-1, 5-35 Platform Wind Area • 5-1, 5-35 Platform Wind Area Calculation • 5-1 Platform Wind Area Calculation [Installation \ Misc. Options] • 5-35 Platforms • 5-1, 5-34 Plotting the Vessel Image • 3-1 Pop-up Input Fields • 11-8, 21-14 Pop-Up Input Fields • 12-10, 13-14, 14-8, 15-13, 16-7, 17-18, 18-8, 19-6, 19-10, 20-5, 22-8, 239, 24-16, 27-14


Pre-1999 Addenda • 10-1 Precautionary Note • 9-49 Pressure Chart Name, External • 30-9 Print Intermediate Calcs for External Pressure • 12-11 Printing Equations and Substitutions • 3-1 Printing or Saving Reports to a File • 10-1, 10-31 Printing the Graphics • 10-31 Printing the Reports • 10-1, 10-31 Printing Water Volume in Gallons • 3-1, 10-1 Printout in Rows, External • 10-1 Program Structure and Control • 3-1, 3-2 Program Support / User Assistance • 1-10 Projection from Bottom • 6-1 Projection from Top • 6-1 Purpose of this Chapter • 10-2 Purpose, Scope and Technical Basis • 5-50, 9-3, 11-3, 14-3, 15-3, 22-3, 26-3, 27-3 Purpose, Scope, and Technical Basis • 11-15, 123, 13-3, 17-3, 24-3, 25-3, 29-3 PVElite Analysis • 7-1 PVElite Quick Start • 3-44 PVElite Startup • 3-1

Q Quick Start with PVElite • 3-1

R Radial Nozzle in Cylinder • 5-21 Radial Nozzle in Head • 5-25, 5-26 Radial Width of Bottom Support Plate • 5-1, 529 Radial Width of Reinforcing Ring • 14-9 Radial Width of Top Plate/Ring • 5-1, 5-30 Radiography, Degree of • 6-1 Range Type • 6-1 Rating of attached flange • 12-7 Recording the Model • 3-1 Recording the Model - Plotting the Vessel Image • 3-47 RECTANGULAR VESSELS • 27-1 Redesign Pads to Reinforce Openings • 6-1 Reinforcement Calculations • 27-18 Reinforcement Calculations Under External Pressure • 14-11 Reinforcement Calculations Under Internal Pressure • 14-10 Reinforcing Limits, Modification of • 5-1 Reinforcing Pad • 12-9 Reloading last file at Startup • 10-1


Index

Report Content • 10-1 Report Generation • 3-1 Required and Available Areas • 12-14 Required Parameters, Setting Up • 3-1 Required Thickness Calculations: • 15-14 Required Thickness of Nozzle • 12-8 Required Thickness of Shell and Nozzle • 12-14 Response Modification Factor R • 6-1 Response Modification R • 6-1 Response Spectrum • 6-1, 6-56 Response Spectrum Name • 6-1 Results • 11-12 Results for a Whole Vessel • 10-1 Review • 8-2 Review Screen • 8-2 Reviewing the Results • 3-1, 3-54 Reviewing the Results - The Output Option • 101, 10-30 Rib Thickness • 5-1, 5-39 Ribs, Number of • 5-1 Rigging Data • 6-1 Ring Centroid Distance • 5-1 Ring Diameter, Outside • 5-1 Ring Inside Diameter • 5-1 Ring Material • 5-1, 5-9 Ring, Thickness of • 5-1 Rings • 5-1, 5-8 Risk Factor • 6-1 Roughness Factor • 6-1 Round Thickness to Nearest Nominal Size? • 3-1 Running the Analysis • 3-1

S Saddle Bearing Angle • 16-6 Saddle Check • 5-1 Saddle Contact Angle • 5-1 Saddle Contact Angle (degrees) • 5-38 Saddle Dimension A • 5-1, 5-38 Saddle Reaction Force Factor • 16-4 Saddle Wear Plate Design • 16-17 Saddle Width • 16-6 Saddles • 5-1, 5-37 Sample Calculation • 28-9 Section Identifier • 5-1, 5-42 Section Type • 5-1 Seismic • 5-1 Seismic Coefficient Av • 6-1 Seismic Coefficient Ca • 6-1 Seismic Coefficient Cc • 6-1 Seismic Coefficient Cv • 6-1

9

Seismic Data • 6-1, 6-41 Seismic Design Category • 6-1 Seismic Design Code • 6-1 Seismic for Hydrotest • 6-1 Seismic for Hydrotest, Percent • 6-1 Seismic Load Input in G's • 6-1, 6-51 Seismic Zone • 6-1, 16-11, 19-10 Select the Addenda for the Material Database • 10-1 Selection of Reinforcing Pad • 12-15 Set Area 1 or Area 2 Equal To 0 • 12-7 Setting Up the Required Parameters • 3-59 Shear and Bending Moments due to Wind and Earthquake • 7-1 Shell and Head Diameter Basis • 16-5 Shell Corrosion Allowance • 12-6, 17-7 Shell Cylinder Length (Li) • 17-18 Shell Design Pressure • 17-6 Shell Diameter • 12-5, 16-6 Shell Diameter Basis (ID or OD) • 12-5 Shell Inside Diameter • 17-7 Shell Joint Efficiency • 16-6 Shell Length Tangent toTangent • 16-6 Shell Mean Metal Temperature • 17-7 Shell Metal Design Temperature • 17-7 Shell or Head Type • 12-5 Shell Side (External) Corrosion Allowance • 155 Shell Side (External) Design Pressure • 15-4 Shell Thickness • 16-6 Shell Thickness, Modification of • 6-1 Shell Tr Value • 5-1, 5-17 Shell Wall Thickness • 17-7 Shell, Nozzle or Pad Material Name • 12-4 Shell\Channel Tube\Tubesheet\ Bolt Material Specification • 17-6 SHELLS • 11-1 Shock Scale X|Y dir • 6-1 Site Distance • 6-1 Skirt Support with Basering • 4-17 Small Cylinder Actual Thickness • 14-6 Small Cylinder Axial Length • 14-6 Small Cylinder Corrosion Allowance • 14-6 Small Cylinder Joint Efficiency • 14-6 Small End Knuckle Radius • 4-13 Small End Reinforcing (None, Bar, Section, Knuckle, Knuckle-Bar, Knuckle-Section) • 146 Soehren's Calculations: • 15-14 Software Installation on a Network Drive • 2-10


10

Soil Factor • 6-1 Soil Type • 6-1 Special Service • 6-1 Specifying Global Data • 3-1 Specifying Global Data - Loads and Design Constraints • 3-49 Spherical Cover / Backing Device • 9-42 Spherical Head • 4-11 SRSS • 6-1 Stainless Steel (High Alloy) Materials • 30-10 Standard Bar Ring • 6-1 Starting CodeCalc from PVElite • 10-3 Starting the Alternative Nozzle Layout Method • 5-19 Starting the Installation Procedure • 2-5 Steps for Calculating and Displaying VesselAnalysis Results • 7-1 Stiffener Type • 6-1 Stiffening Ring Location • 16-14 Stiffening Ring Material Properties • 16-14 Stiffening Ring Present • 16-5 Stiffening Ring Properties • 16-14 Stiffening Rings for External Pressure, Selecting • 6-1 Straight Length of Tubes • 17-10 Stress Calculations • 27-18 Stress due to Combined Loads • 7-1 Summary - Seeing Results for a Whole Vessel • 10-32 Sump Head? • 4-9, 4-10, 4-13 Support Lug Input • 19-15 Swap Diameter Basis • 4-7 System and Hardware Requirements • 2-3

T Tail Lug Type • 4-1, 4-23 Tailing Lug Analysis • 4-1, 4-22, 21-16 Tailing Lug Input Data • 4-23 Take Cone as Lines of Support for External Pressure? • 14-8 Tapped Hole Area Loss • 5-1, 5-17 TEMA Classification • 17-15 TEMA Number • 30-6 TERM • 2 Terrain Category • 6-1 The Input Processor • 3-4 The Installation/Configuration Process • 2-1 The Review Screen • 8-3 THICK JOINTS • 23-1 Thickness of Bottom Plate • 5-30


Thickness of Gussets • 5-30 Thickness of Insulation or Fireproofing • 5-47 Thickness of Lining • 5-49 Thickness of Ribs • 16-7 Thickness of Ring • 5-9 Thickness of Top Plate/Ring • 5-30 Thickness of Wear Plate • 5-38 Thickness of Web • 16-7 Thickness, Minimum • 5-1 THIN JOINTS • 22-1 Thread Series • 15-6 To Node Diameter • 4-11 Tools Menu • 3-1, 3-12, 3-27, 10-1, 10-10 Top Plate/Ring • 5-1 Top Plate/Ring, Thickness of • 5-1 Toricone Dialog • 4-12 Toriconical • 4-12 Torispherical Head • 4-10 Total Axial Force on Large End for External Pressure Case • 14-8 Total Axial Force on Large End for Internal Pressure Case • 14-8 Total Axial Force on Small End for External Pressure Case • 14-8 Total Axial Force on Small End for Internal Pressure Case • 14-8 Total weight and detail moment • 7-1 Tower Deflection, Allowable • 3-1 TRADEMARKS • 5 Tray Spacing • 5-1, 5-40 Tray Weight Per Unit Area • 5-1, 5-40 Trays • 5-1, 5-40 Trays, Number of • 5-1 Trunnion Input • 19-26 Trunnion Results • 19-29 Tube Corrosion Allowance • 17-9 Tube Design Temperature • 17-8 Tube Hole Diameter • 17-11 Tube Input Data • 9-22 Tube Mean Metal Temperature • 17-8 Tube Outside Diameter • 17-9 Tube Pattern (Triangular, Square) • 17-9 Tube Pitch • 17-9 Tube Sheet Type • 17-11 Tube Side (Internal) Corrosion Allowance • 15-5 Tube Side (Internal) Design Pressure • 15-4 Tube Wall Thickness • 17-9 Tubesheet Clamped • 17-15 Tubesheet Corrosion Allowance Channel Side • 17-14


Index

Tubesheet Corrosion Allowance Shell Side • 1714 Tubesheet Design Code • 17-6 Tubesheet Extended as Flange? • 17-14 Tubesheet Gasket (None, Shell, Channel, Both) • 17-14 Tubesheet Metal Design Temperature • 17-13 Tubesheet Properties • 9-16 Tubesheet Thickness • 17-14 Tubesheet Type and Design Code • 9-11 TUBESHEETS • 9-2, 17-1 Tutorial Problem Printout • 10-1, 10-33 Tutorial/Master Menu • 3-1 Types of Hill • 16-11, 19-9

U UBC 1997 Earthquake Data • 6-1, 6-52 UBC Earthquake Importance Factor • 6-1 UBC Horizontal Force Factor • 6-1 UBC Near Source Factor • 6-1 UBC Seismic Coefficient CA • 6-1 UBC Seismic Coefficient CV • 6-1 UBC Seismic Data • 6-1, 6-45 UBC Seismic Zone • 6-1 UBC Wind Data • 6-1, 6-20 UBC Wind Importance Factor • 6-1 UCS-66 Chart Number • 30-9 UG-45 Minimum Nozzle Neck Thickness • 1214 Uncorroded Expansion Joint Spring Rate • 17-16 Updates • 1-11 Use Code Case 2260? • 10-1 Use Pre-99 Addenda Division 1 only • 3-1 User Border Creation • 3-1, 3-59 User Defined • 6-1 User Defined G for Floating Tubesheet • 17-14 User Defined Longitudinal Force • 16-13 User Defined Wind Pressure On Vessel • 16-8, 19-6 User Entered Seismic Zone Factor CS • 16-12, 19-11 User-Defined Hydrostatic Test Pressure • 6-1 User-Defined MAWP/MAPnc • 6-1 User-Defined Wind Profile • 6-1, 6-29 Using Review • 8-4

V Velocity Zone • 6-1 Vessel Analysis Calculations • 7-1 Vessel Centerline, Distance or Offset • 5-1

11

Vessel Components (Details), Individual • 3-1 Vessel Description • 16-3 Vessel Design Pressure • 16-3 Vessel Design Temperature • 16-3 Vessel Detail Data • 5-1 Vessel Details, Design and Analysis of • 3-1 Vessel Example • 31-2 Vessel Example Problems • 31-1 Vessel Leg Input • 19-12 Vessel OD • 5-1 Vessel Translates During Occasional Load • 542 Vessel, Basic Definition of • 3-1 Vibration Period • 6-1 View Menu • 3-1, 3-37, 10-1, 10-21 Vortex Shedding • 6-1

W Wall Thickness for Axial Stress, Selecting • 6-1 Wall Thickness for External Pressure, Selecting • 6-1 Wall Thickness for Internal Pressure, Selecting • 6-1 Wear Pad Extension Above Horn of Saddle • 16-7 Wear Pad Thickness • 16-7 Wear Pad Width • 16-7 Wear Plate Contact Angle (degrees) • 5-1, 5-38 Wear Plate, Thickness of • 5-1 Web Location • 5-1, 5-39 Web Location Center or Side • 16-8 Web Thickness • 5-1, 5-39 Weight • 5-1 Weight of Details • 7-1 Weight of Elements • 7-1 Weight of One Lug • 5-1, 5-30 Weight, Miscellaneous • 5-1, 6-1 Weights • 5-32 Weld Leg Size Between Inward Nozzle and Inside Shell • 5-1, 5-17, 12-12 Weld Leg Size for Fillet Between Nozzle and Shell or Pad • 5-1, 5-16, 12-13 Weld Size Calculations • 12-15 Weld Size Thickness • 4-1, 4-23 Weld Strength Calculations • 12-16 Welded Flat Head • 4-14 What Applications are Available? • 1-5 What Distinguishes PVElite From our Competitors? • 1-4 What is PVElite? • 1-2


12


What is the Purpose and Scope of PVElite? • 1-3 Width of Partition Gasket • 15-11 Width of Saddle • 5-1, 5-37 Width of Wear Plate • 5-1, 5-38 Wind • 5-1 Wind & Seismic Data • 6-1, 6-16 Wind Data • 6-1, 6-17 Wind Deflection • 7-1 Wind Design Code • 6-1 Wind Design Standard • 16-8, 19-6 Wind Exposure • 16-10, 19-8 Wind for Hydrotest • 6-1 Wind Load Calculation • 7-1 Wind Load Diameter Multiplier • 4-5 Wind Profile Data • 6-1 Wind Shape Factor • 3-1 Wind Speed • 6-1 Wind Zone Number • 6-1 Windows Server Installation • 2-11 WRC 107 Additional Input • 18-15 WRC 107 Stress Calculations • 18-18 WRC 107\FEA • 18-1 WRC 297/ANNEX G • 28-1 WRC107 Stress Summations • 18-20

X XY Coordinate Calculations • 7-1

Y Yield Stress, Operating • 30-9

Z Zero Period Acceleration • 6-1 Zone Number • 6-1


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COADE, Inc. 12777 Jones Rd., Suite 480 Houston, Texas 77070 Phone: (281)890-4566 Fax: (281)890-3301 E-mail: [email protected] WWW: www.coade.com

PVElite USER GUIDE 2006 V E R S I O N ( L A S T R E V I S E D 1/2006 )


PVElite-Manual.pdf

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