AutoPIPE Training Workbook

AutoPIPE Training Workbook

Melbourne (SHIN) 11 February 2009

AutoPIPE Workbook – Melbourne 11Feb2009

11 February 2009

Sinclair Knight Merz 25 Teed Street PO Box 9806 Newmarket, Auckland New Zealand Tel: +64 9 913 8900 Fax: +64 9 913 8901 Web: www.skmconsulting.com COPYRIGHT: The concepts and information contained in this document are the property of Sinclair Knight Merz Limited. Use or copying of this document in whole or in part without the written permission of Sinclair Knight Merz constitutes an infringement of copyright. LIMITATION: This report has been prepared on behalf of and for the exclusive use of Sinclair Knight Merz Limited’s Client, and is subject to and issued in connection with the provisions of the agreement between Sinclair Knight Merz and its Client. Sinclair Knight Merz accepts no liability or responsibility whatsoever for or in respect of any use of or reliance upon this report by any third party.

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Table of Contents Contents 1. 2.

Introduction

5

1.1.

5

Documentation Conventions

AutoPIPE Basic Concepts 2.1.

AutoPIPE Interface

2.1.1. 2.1.2. 2.1.3. 2.1.4. 2.1.5. 2.1.6. 2.1.7.

Loading an Existing Model Screen Layout Dialogs Keyboard Equivalents Menu Structure Toolbars Hotkeys

2.2.

AutoPIPE Modelling Concepts

2.2.1. Understanding Pipe Segments

2.3.

Rules for Defining Segments

2.3.1. Graphical Tee Element 2.3.2. Understanding the Active Point 2.3.3. Controlling the Active Point With the Keyboard

3.

2.4.

Modification of Piping Geometry

2.4.1. 2.4.2. 2.4.3. 2.4.4. 2.4.5. 2.4.6. 2.4.7.

Basic Tasks Executing A Command Selecting Points and Components Inserting a Point or Component Modifying Points or Components Deleting Points or Components Selecting a Range (Creating a Selection Set)

6 6 6 6 7 7 8 8 8 9 9 10 11 12 13 13 14 14 14 14 15 15 16

Sample 1: Expansion Loops and Frame Supports

17 17 18 22 26 27 36 37 44 46 49 53 53 54 57 58

3.1.

Lesson 1: Model Definition

3.1.1. 3.1.2. 3.1.3. 3.1.4.

Exercise 1: Starting a New Model Exercise 2: Adding Piping Points and Supports Exercise 3: Inserting Multiple Pipe Spans Exercise 4: Inserting Supports at Multiple Points

3.2.

Lesson 2: Adding an Expansion Loop

3.2.1. 3.2.2. 3.2.3. 3.2.4.

Exercise 1: Performing the Stress Check Exercise 2: Adding an Expansion Loop Exercise 3: Stress Review Exercise 4: Supporting Expansion Loop

3.3.

Lesson 3: Final Stress Check

3.3.1. Exercise 1: Final Stress Check 3.3.2. Exercise 2: Generating a Stress Report

3.4.

Lesson 4: Adding a Frame Support

3.4.1. Exercise 1: How Frame Elements Are Different From Pipe Elements

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3.4.2. 3.4.3. 3.4.4. 3.4.5. 3.4.6. 3.4.7.

4.

Exercise 2: Frame Support Description Exercise 3: Inserting the First Frame Element Exercise 4: Inserting the Rest Of Frame Elements Exercise 5: Supporting the Frame Exercise 6: Connecting the Pipe To The Frame Assembly Exercise 7: Another Stress Check

Sample 2: Hanger Design & Equipment 4.1.

Lesson 1: Build Pump Suction Piping

4.1.1. Exercise 1: Problem Definition 4.1.2. Exercise 2: Set Default Node Numbering 4.1.3. Exercise 3: Add Segment A Piping Points 4.1.4. Exercise 4: Add a Tee Junction and Branching Pipe 4.1.5. Exercise 5: Change the Length of Pipe A10 To A15 4.1.6. Exercise 6: Insert Hanger and Perform Hanger Design 4.1.7. Exercise 1: Add a New Disconnected Segment 4.1.8. Exercise 2: Change Design Pressure for Discharge Line 4.1.9. Exercise 3: Generate Pump Report 4.1.10. Exercise 4: Specify Pump Properties 4.1.11. Exercise 5: Analyze and Show Pump Report

4.2.

5.

Student Exercise: Copy/Paste and Edit/Rotate Operations

68 68 68 72 73 77 86 87 92 101 102 103 104 110

Sample 3: Wind, Earthquake and Nonlinear Analysis

112

5.1. 5.2.

Lesson 1: Model Definition Lesson 2: Starting a New Model

5.2.1. 5.2.2. 5.2.3. 5.2.4. 5.2.5.

Exercise 1: Start a New Model to Create a New Model Exercise 2: Vessel Thermal Movement Exercise 3: Add Piping Geometry Up to the Guide Support Exercise 4: Add Guide Supports and Valve Exercise 5: Add the Rest of the Piping

5.3.

Lesson 3: Occasional Load Definitions

5.4.1. Exercise 1: Static Nonlinear Analysis 5.4.2. Exercise 2: Stress Results 5.4.3. Exercise 3: Support Lift-Off

112 114 114 117 118 122 127 137 138 139 144 144 147 148

Sample 4: Nozzle Flexibility, Cut short and Trunnion Supports

150

6.1. 6.2.

150 152 152 155 158 162 162 165 168

5.3.1. Exercise 1: Earthquake Loading Background and Definition 5.3.2. Exercise 2: Wind Load Definition

5.4.

6.

58 59 62 64 65 66

Lesson 4: Stress and Analysis Results

Lesson 1: Model Definition Lesson 2: Build Piping Model

6.2.1. Exercise 1: Starting a New Model 6.2.2. Exercise 2: Flexible Anchor and Flexible Joint 6.2.3. Exercise 3: Add Trunnion or Base Elbow Support at Bend

6.3.

Lesson 2: Build Piping model

6.3.1. Exercise 4: Add 45-Deg Bend 6.3.2. Exercise 5: Add Short Radius Bend 6.3.3. Exercise 6: Add a Designed Hanger Support

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6.3.4. Exercise 7: Change Pipe Data For the Schedule 80 Bend 6.3.5. Exercise 8: Add Flanges For the Bend

169 171

6.4.

172 174 177 179 179 182 184 185 185 186

Lesson 3: Add Nozzle Flexibility Element

6.4.1. Exercise 1: Adding a Flexible Nozzle

6.5.

Lesson 4: Add Cut Short or Cold Spring

6.5.1. Exercise 1: Add Cut-Short to a Pipe 6.5.2. Exercise 2: Perform Static Analysis With Cut Short 6.5.3. Exercise 3: Setting Load Combinations For Cut Short

6.6.

Lesson 5: Stress Results and Restraints Report

6.6.1. Exercise 1: Stress Results 6.6.2. Exercise 2: Expansion Joint Displacement 6.6.3. Exercise 3: Output Report

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1.

Introduction

1.1.

DOCUMENTATION CONVENTIONS

A number of conventions are maintained throughout Bentley Plant courseware to improve the identification and understanding of the information presented. Convention

Description

NOTE:

Precedes information of general importance.

HINT:

Precedes optional time saving information.

WARNING:

Precedes information about actions that should not be performed under normal operating conditions.

FILENAMES

Directory paths and file names are italicized. Example: \AUTOPLANT 3D directory, AUTOEXEC.BAT file.

Program Code

Excerpts from text or basic script files and script variables and statements appear in the font shown.

INPUT

Commands or information that must be manually entered is bolded in the font shown. Example: Select Setup> Drawing Preferences.

Menu & Buttons

Menu commands and dialog buttons appear in a Sans Serif font that stands out from normal body text. Example: After selecting Setup> Drawing Preferences from the Piping menu, press the OK button in the dialog.

Dialogs Field_Names

Dialog and database table names are italicized. Example: The Preferences dialog.

Select

Indicates that the command must be executed from a menu or dialog.

Pick

Indicates an item (component or point) that may be picked on a drawing. Throughout this manual, the menu command sequence required to execute a command will be explicitly defined in the text, while the associated toolbar button is presented in the margin.

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2.

AutoPIPE Basic Concepts This section introduces you to the AutoPIPE interface and the concept of piping segments. It also will show some basic tools in modifying the piping system.

2.1.

AUTOPIPE INTERFACE

2.1.1.

LOADING AN EXISTING MODEL h

TO LOAD AN EXISTING MODEL

1) Select File> Open> AutoPIPE Database (*.dat). A dialog like the one shown below is displayed.

2) Navigate to the directory where the file is stored. Select the desired filename from the Files list, and then press Open. The previously saved model and its data are now available for editing or report generation. The AutoPIPE interface is designed to simplify the task of creating, modifying, and reviewing models of any complexity.

2.1.2.

SCREEN LAYOUT Take some time to familiarize yourself with AutoPIPE's interface by examining the areas of the screen annotated below.

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2.1.3.

DIALOGS Dialogs present and request information.

2.1.4.

Press OK to accept the values in a dialog Some fields have an associated list of options from which the user can select. For example, there is a limited set of piping codes, and the user can always select the appropriate code from a list when the cursor is in the Piping Code field. This list is contained inside the dialog itself, and is opened by pressing on the adjacent to that field. The units that apply to a particular field are displayed in the status bar in the bottom right hand corner of the screen. To advance from field to field in a dialog, press the Tab key. Pressing OK from the dialog is the equivalent of pressing Enter. You can also advance the cursor by simply using the mouse to select the desired location. Options which are toggled ON are indicated by a 9. Positioning the cursor in that field and then pressing the left mouse button toggles the ON/OFF state. Press F1 key on any dialog field to obtain help on a particular field or parameter. To obtain "big picture" dialog help, press the Help button.

KEYBOARD EQUIVALENTS As you begin creating a model, you'll soon become familiar with AutoPIPE's use of dialogs to gather information from the user. Although the mouse can be used to navigate through the fields of a dialog, many users prefer the keyboard alternatives. Refer to the table below.

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Task

Keyboard

Advance to next field

Return to previous field

+

Accept values and close dialog Cancel values and close dialog

2.1.5.

MENU STRUCTURE All AutoPIPE commands can be accessed from the menu system. For a detailed description of the capabilities and functionality of a specific command, refer to the AutoPIPE On-line Help Menu Reference. The top menu that is displayed above the drawing area depends on the current mode of the program:

The standard menu is displayed when building or editing a model AutoPIPE can be placed in a Worksheet Mode, which displays a model's data in spreadsheet format.

Note that each of these menus has a toolbar associated with it. 2.1.6.

TOOLBARS AutoPIPE has three types of toolbars: command, view and components. Command toolbars are always docked directly beneath the main menu, and cannot be moved from this location. The component and view toolbar, on the other hand, can be moved from its position along the right and left side of the screen respectively and positioned as a "floating toolbar" in the modeling area of the screen. To reposition it, simply "drag" the title bar of the toolbar into the screen area. The toolbar will resize.

Hint:

2.1.7.

If you forget the use of a particular button, position cursor over it and wait a second or two. A ToolTip description is displayed beneath the button.

HOTKEYS

A number of AutoPIPE commands can be accessed directly from the keyboard using hotkeys. In AutoPIPE hotkeys are executed by holding down the control and then pressing a letter key. Page 8


Additionally, AutoPIPE also uses the function keys for some operations. Note that these hotkeys are displayed in the AutoPIPE pull-down menus next to the item it executes. 2.2.

AUTOPIPE MODELLING CONCEPTS

Experienced users of AutoPIPE have come to appreciate the speed and efficiency with which detailed, data-rich models can be created, modified, and reviewed. Ifyou are a novice user, it is important to understand some basic concepts of the program.

Models are created from individual pipe segments

Components are attached to the active point (cursor location)

The piping system geometry and properties can be modified

2.2.1.

UNDERSTANDING PIPE SEGMENTS

Each piping system is divided into a number of segments. As an example, the sample model shown below contains five segments labelled A through E. Piping models are entered into the program, segment by segment. They may be extended or modified at any time by either adding more segments or changing existing ones. The segments are labelled automatically (A through E in the example). If more than twenty-six segments are entered, the additional ones are labelled AA, AB, AC and so on. Although most of the piping segment definition is handled automatically with AutoPIPE, in some circumstances it is advantageous to plan the model in advance and divide it into logical "segments" before creating the system (see 'Rules for defining Pipe Segments'). Typically, a segment would begin and end at anchor points or a branch connection. However, as shown in Figure 2-1 on the facing page, at point D02, a pipeline may be divided into two or more contiguous segments. Whenever a tee/branch is inserted, AutoPIPE automatically assigns a new segment identifier. Each new segment begins with a different alpha character, making it easier for node numbering and easier to keep track of segments when reviewing input listings or output results. When defining a new system, AutoPIPE automatically displays the first Segment dialog (the first segment is segment A). In this dialog, the user must specify starting X,Y, Z coordinates of the Segment and input a Pipe identifier name. A Pipe identifier is used to assign properties. The Pipe identifier can be any name that the user wishes to use. It is a good idea to choose a meaningful name such as the first few letters of a line ID or something like 8"std (indicating 8" nominal diameter, standard schedule wall thickness) to help you keep track of pipe properties when reviewing the model. These properties will be applied to all components attached to that pipe identifier until otherwise specified by inputting a new pipe identifier name in one of the component dialogs. After inputting a new Pipe identifier name, the Pipe properties dialog will automatically be displayed for input. For example, if you define a Pipe identifier as a 4-inch line, then all following components will default to those same properties until the user types in a new Pipe

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identifier name on a component dialog. A segment can be made up of multiple pipe identifiers. Existing Pipe properties can be easily modified using either Modify> Properties of Pipe Identifier (which modifies that Pipe Identifier throughout the entire model, wherever it was used) or by graphical selection of a range of points and Modify> Pipe Properties Over Range. Note:

AutoPIPE makes extensive use of dialogs obtain user input. A discussion of techniques for navigating throughout the fields of a dialog is provided later in this chapter.

Figure 1 Pipe Segments

2.3.

RULES FOR DEFINING SEGMENTS A number of rules govern the definition of piping segments; they are listed as follows:

Each segment has a forward and backward direction and is entered as a sequence of points. AutoPIPE automatically keeps track of the local axis of the segment, making it convenient to insert intermediate points or components using the Length field. These points are automatically assigned alphanumeric names (which the user can override), with a maximum of four characters each. For example, in Figure 1, segment B is defined by points A03, B01, B02, B03, BM, and B05, all of which have default names. The default increment in point names is 1. This increment can be changed under Tools > Model Options > Edit. AutoPIPE can automatically renumber point names after editing using the Renumber button or Edit > Renumber. Wind loads and Hydrotest can be turned on and off on a segment by segment basis, so

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keep that in mind when creating your model. Also, AutoPIPE provides options to view the model, graphically select, delete, or view output results on a segment by segment basis.

Global coordinates must be entered for the first point of the first segment (default global coordinates of Segment A is 0,0,0). AutoPIPE automatically displays the first segment screen for the user. This is point A00 in the example. Then, each point along the segment is typically located by offsets from the preceding point, until the whole segment has been defined (e.g. points A00 to A06 for segment A). Subsequent segments typically begin at points which have been defined previously (point A03 in segment B is an example). These points are either branch points or continuation points (see below). Since these points have already been defined, entering coordinate data for them is not necessary. Although subsequent segments typically begin or end at an existing point, this is not necessary for the program to function correctly. It is often more convenient to start a disconnected segment in space using Insert> Segment or clicking on the Segment button, typing in the name of the first point (in this case, make sure that the name of the first point on the segment is not the name of a previously defined point), and assigning the starting X,Y,Z coordinates of that new Segment. For example, it may be more convenient to define suction and discharge sections as disconnected segments without having to model the equipment (see Pump Modeling Example in AutoPIPE on-line help). Also, the ability to handle disconnected segments is a big advantage when importing sections from a CAD model. A continuation point is established when a new segment is defined to begin at the end point of an existing segment (see point D02 in Figure 1). This is typically done to divide a long length of pipe into shorter segments or to turn on and off wind loads or hydrotest on a segment by segment basis. A tee branch connection point is any point which joins two or more pipe segments, and requires a multiple pipe connection (see points A03, and B05 in Figure 1) such as a tee or cross. A continuation point can be made into a branch point using Modify> Convert Point to> Tee. Cut and paste automatically creates a new segment.

When defining a segment, proceed from point to point along the segment. Check that everything at the current point has been specified before moving on to the next point. 2.3.1.

GRAPHICAL TEE ELEMENT In previous versions of AutoPIPE, users would have to insert a new segment at an existing run point in order to insert a tee branch connection. With the new Tee element, this procedure is no longer required (although users can still input a tee branch by inserting a segment at a run point if desired). The Tee element automates the insertion of tees and includes the offset distance from the previous point. For example, if a user wishes to insert a tee point on a header 1000mm away from his current point (active point), he clicks on the Tee button or Insert> Tee and inputs an

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offset of 1000mm as well as the tee type information for stress intensification purposes. The Tee element will automatically assign a new segment once the user begins to input the branch. AutoPIPE will keep this point a tee for stress intensification, even if the user does not create a branch. In some cases, users may choose not to input small diameter vent or drain pipe branches, but still want the stress intensification factor at the tee connection point. AutoPIPE displays a graphical symbol at Tee points enabling users to visually review tee locations. Users can also click on Tee arrows to easily switch between the header and branch side of the tee.

Users can convert an existing run point to a Tee using Modify > Convert point to >Tee command. 2.3.2.

UNDERSTANDING THE ACTIVE POINT After defining and inserting a segment, you'll notice that a small crosshair appears in the drawing area. This crosshair represents the currently active point. The active point is also displayed in the status area immediately below the drawing area.

When placing components, you should remain aware of the active point. After selecting a component type for insertion, AutoPIPE will automatically assume that you want the starting point of the component to be inserted at the active point. By default, AutoPIPE will increment the point to the next value and concatenate this with the letter that defines the current segment. For example, if you are inserting a run point on Segment A that contains nothing but an anchor point, the Run Point dialog will contain the value A01 in the Name of Point field. To designate an existing point as the active point, simply click on it with the mouse. The crosshairs should redisplay over that point and the Active Point status area should reflect the new point as well. In a complex model, you can click on the Go To Point button and type in your desired active point name. You can also use the arrow keys to control the location of the active point as described below. It is important to note that a given point may have two or more different segments. For example, in Figure 1, point A03 is a tee connection point, and is made up of point A03 segment A and point A03 segment B. The active point name and segment location is displayed in the bottom right hand corner of your screen. In order to toggle between multiple segments on the same Point location, it is usually more convenient to use the up and down arrow keys (see following section on keyboard commands).

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2.3.3.

CONTROLLING THE ACTIVE POINT WITH THE KEYBOARD As an alternative to the mouse, the "Active Point" crosshairs can be controlled using the keyboard. Key

Ö Õ × Ø

Task Move to the next point in the current segment (forward segment direction). Move to the previous point in the current segment (backward segment direction). When at a segment junction move to the next segment that connects to the current point (more than 2segments are possible). I

When at a segment junction, move to the previous segment that connects to the current point (more than 2 segments are possible). Move to the first point of the next segment.

Mave to the last point of the previous segment.

Move to the next intermediate soil point for the current soil region.

+ 2.4.

Move to the previous intermediate soil point for the current soil region.

MODIFICATION OF PIPING GEOMETRY It is not necessary for a piping system to be defined completely in a single AutoPIPE session, because AutoPIPE allows a wide variety of additions, deletions, and changes to be made. In particular:

New segments can be added at any time.

Previously defined segments can be extended at any time.

Existing segments can be modified, or can be deleted and replaced.

A complete system, or sections of a system, can be copied within the same job or between separate jobs with automatic renumbering. Components can be inserted, deleted, or modified at any time.

Warning:

As noted in the following sections, changes in data can lead to a variety of inconsistencies. AutoPIPE will detect most inconsistencies, and will display warning or error messages. However, AutoPIPE may not detect all of the possible Page 13


inconsistencies. Users must take care in making changes, and must review changes carefully to ensure that the modified geometry and properties are correct.

2.4.1.

BASIC TASKS This section lists simple techniques for accomplishing the following:

2.4.2.

Executing a command

Selecting a component

Inserting a component

Modifying a component

Deleting a component

Selecting a range of components (creating a selection set)

EXECUTING A COMMAND Commands can be executed in one of three ways:

Click on one of the buttons in a toolbar.

Select a command from the menu system

2.4.3.

SELECTING POINTS AND COMPONENTS

2.4.4.

Key-in the command. The hotkey for each command is underlined in the menu system. As an example, to insert a bend, simply type I to go into insert mode, then B. The key-in command option requires memorization of certain hotkeys, but is an extremely efficient method of input.

Click on it with the mouse. By clicking on the outer edge of a component, the component turns red to indicate that it is selected. If it is a two-point component such as a valve or flexible joint, the red indicates that the beginning point and end point of a two-point component have been selected. Graphically select a range of points (see following 'Selecting a Range of Points' section)

INSERTING A POINT OR COMPONENT

Position the cursor on the desired point by clicking on it, and then click on one of the component buttons from the toolbar. To insert an intermediate run point, or multiple run points, click on the Pipe Run button. Position the cursor on the insertion point, and then select the desired component from the

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Insert menu.

2.4.5.

Users can graphically select a range to insert across ranges of points with one command (see 'Selecting a Range') Place the cursor on the desired point, then use the keyboard equivalent menu commands to key-in the insertion Position the cursor over the desired button, press and hold the left mouse button, then "drag" the button off the toolbar and "drop" it onto the desired point by releasing the mouse button. This is known as the "drag and drop" technique.

MODIFYING POINTS OR COMPONENTS Use one of the techniques below to modify points or components.

Using the mouse, double click on the graphical representation of the component to open its associated dialog. Double click on a point to modify point offsets. Position the cursor on one of the points, or select a range of points, then right-click the component to be modified from the toolbar. Click on one of the points associated with the component, then select the component name from the Modify menu. Users can graphically select a range to modify across a range of points with one command (see 'Selecting a Range') Display the Input grids then select the appropriate grid tab and modify the value in the cell(s). Double clicking a row in the Input grids will display the Modify dialog. Note: Ctrl+Enter, Copy/Paste or Copy Down can be used to change values over multiple cells.

2.4.6.

DELETING POINTS OR COMPONENTS

Use one of the techniques below to delete existing points or components:

Select the unwanted component with the mouse then press the Delete key on the keyboard.

Select the unwanted component then press the Delete button on the command toolbar.

Position the cursor on one of the points, or select a range of points, then hold down the [Shift] and right-click the component to be deleted from the toolbar. Graphically select a range, and then select the corresponding component name from the Delete menu to delete across an entire range of points with one command (see Selecting a Range). Select the unwanted component then select the Edit> Delete menu command. Select it with the mouse or position the active point at that location, then select the corresponding component name from the Delete menu.

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Select the appropriate row in the Input Grids and Press the Delete key on the keyboard.

Note:

2.4.7.

Multiple rows can be deleted at time.

SELECTING A RANGE (CREATING A SELECTION SET) Selection of ranges is a powerful tool within AutoPIPE that users should become familiar with. By graphically selecting ranges of points, users can insert, modify, or delete components, properties, loads, and other data across ranges of points with one command or graphically select points to be included in the output reports. Also, selection of ranges is required in order to graphically cut, copy, or paste. There are several methods available to graphically select ranges of points. By using buttons or the Select menu or Input Grids, users can select by a number of different criteria such as by segment, point names, component type, pipe diameter and other parameters. In addition, users can create a mouse zoom box Window and click on the Select all points in Window button to select a range. Another common method used to select a range is to click on the first point in the range, press and hold the [Shift] key, then click on the last point in the range. The selection set will highlight in red. This is the same technique used to select ranges in Word, Excel, and other popular Windows programs. To create a selection set that includes components that are not part of a contiguous run, use the [Ctrl] key as follows: To add the first point, press and hold the [Ctrl] key. To add more components to this set, or delete points from this set press and hold the [Ctrl] key and select additional elements. Note that if during the creation of this set any two adjacent points are selected, the pipe between the points will be selected (red) and that is expected. The [Ctrl] selection method allows you to select a set of components that are not continuous. Alternatively, Select > Point enables buttons that can add or subtract from the selection set on a point by point basis. The Select > Range command, another method of creating a selection set, allows the user to input "From" and "To" points inside a dialog. In any Input Grid tab, select a group of rows or cells (same column) using [Ctrl] or [Shift] keys will highlight the selected points in red on the graphic. Note: The point symbol and names will be highlighted when selecting from the Points or Pres/Temp/PipeID tabs. These two tabs enable selection of all points in the model. The Pres/Temp/PipeID tab also provides a range selection up to and including the bend near or far points. All other grid tabs will highlight the component symbol and the thermal anchor movements tab will highlight the anchor symbol on the graphic.

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3.

Sample 1: Expansion Loops and Frame Supports In this chapter you will build a simple stress model. The model will be analyzed and will be found to be overstressed. You will find the cause of overstress and add an expansion loop to alleviate the problem. During this exercise you will learn the essential tools for performing piping stress analysis.

3.1.

LESSON 1: MODEL DEFINITION In this lesson you will learn the basics of building a new AutoPIPE model. You will be taught the basic dialogs and commands needed to start a new system. The model will consist of pipes, bends, anchors, vertical supports and guide supports. You will consider both dead weight (Gravity) and thermal loads. You will be using ASME B31.3 piping code for Process Piping throughout this training. Objectives The objectives of this Lesson are as follows:

Learn how to start AutoPIPE and start a new model

Learn how to add piping points and supports

Learn how to insert pipe spans

Learn how to insert supports at multiple points

The model you will build is shown below:

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3.1.1.

EXERCISE 1: STARTING A NEW MODEL h

TO START A NEW MODEL

1) From the Windows' Start menu, select AutoPIPE or select the icon from the Bentley AutoPIPE program group. 2) The AutoPIPE application opens. The starting screen is shown below.

3) Select File> New to open the New dialog shown below.

4)

Enter the file name sample 1a in the File name field and press Save. This will trigger four initial dialogs for each new model. These dialogs are the General Model Options for Page 18


entering the piping code, units used and installation temperature, the Segment dialog for defining the global coordinates of the starting point, the Pipe Identifier dialog for defining the first pipe cross section and that will be followed by the Pressure & Temperature dialog for defining the design pressure and temperature. Follow the instructions carefully as these steps cannot be undone except by re-starting the model again. Note:

AutoPIPE is not designed to run across a network. AutoPIPE documentation states “Network drives are not supported for the software and data files.” AutoPIPE will run across a network, but generally runs many times slower than for local files. Therefore it is recommended that data files be copied from their network location to a local drive for analysis, then be copied back to the network at completion. A suitable way to do this is to create a “reverse date” format folder (e.g. 090203 Calc 001) which contains all of the files and to copy this to the local location.

Note:

You can set the number of operating thermal/pressure cases and the temperature at installation (i.e. at the time when supports and anchors are set).

Note:

You can set SI units to be your default units by copying the SI.UNT file in the program folder into AUTOPIPE.UNT file.

5) The Segment dialog will open. In this dialog you can enter the global coordinates for the starting point in the model. Type 2000 for the pipe elevation DZ above the ground at A00.

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(Assuming the ground at the origin is at elevation 0). Also type 200STD in the Pipe data identifier field at A00 and Press OK.

6) Once you accept the Segment dialog, the Pipe Properties dialog will open since the pipe name 200STD is new to the system. Select 200 from the drop-down for the Nominal diameter, enter 1 for the Specific gravity of contents and select A53-B for the Pipe Material field as shown in the following figure. Press OK.

7) Once you accept the Pipe Properties dialog, the Pressure & Temperature dialog will show

up. Type 1.723 MPa in the Pressure field and 370 deg C in the Temperature field as follows. Press OK.

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Note:

Examine the status bar at the bottom of the AutoPIPE application. The lower right hand corner will always display the units associated with the active field. When you input values into the available fields the units for the field show in the bottom right-hand corner of the screen.

8) Once the Pressure & Temperature dialog is accepted, the point A00 will be shown at the middle of the view port.

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3.1.2.

EXERCISE 2: ADDING PIPING POINTS AND SUPPORTS In this lesson the piping system will be built starting at point A00. You will add the supports and anchors as you go along the pipe. h

TO ADD PIPING POINTS AND SUPPORTS

1) Now you will start routing the system. You will start with a rigid anchor at A00. Select Insert > Anchor or click on the icon. Press OK to accept the default rigid anchor properties.

2) Next you will insert a 6000 mm pipe to A01. Select Insert > Run and type ·-6000 in the DX field as shown below. Press OK.

3) Select View > Transparency and uncheck Anchor to disable Anchor transparency default in AutoPIPE as follows.

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4) The program will insert the pipe as shown below

5) Next you will add a vertical support "V-stop". Select Insert > Support, then select V-stop in the Support type field, or click on the icon on the component toolbar. The Support dialog opens as shown below.

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6) Set the Gap above the pipe to 0.000. Accept all the other default gap and friction settings (all zeros) and press OK. The view will be updated as shown in the following figure:

7) The support shows restraint below as well as above the pipe. This is true when the gaps are set to zero. If the gap above the pipe is non zero, AutoPIPE will show a plate symbol at the gap location. Also if the gap is greater than the pipe diameter the restraint will disappear. The setting for disappearance of the restraint can be adjusted under View > Settings > Support Gap Scale. 8) Next you will insert the pipe up to A02. Select Insert >Run to open the Run Point dialog and type 3000 in the Length field. Press OK to accept.

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Note:

You do not need to fill in the offsets as long as you are not changing the direction of the pipe. When you press the Tab key, you will notice the offsets are updated correctly.

9) Once you accept the dialog, the program graphics will be updated as follows.

10) Next you will add a vertical support "V-stop" at A02. Select Insert > Support > V-stop, or click the icon on the component toolbar.

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11) Accept the default gap and friction settings (all zeros). Press OK. The view will be updated as follows.

3.1.3.

EXERCISE 3: INSERTING MULTIPLE PIPE SPANS In this lesson you will learn to insert multiple pipe spans. h

TO INSERT A PIPE SPAN

1) You will now insert 4 runs of 6000 mm. You will do that using the regular Insert > Run command, but you are going to back up using Shift-Tab key to the Generate Points field and type 4. Use the Tab key to the Length field and type 6000. You can use the Tab key

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again to update the offsets if you wanted to.

2) The graphics will be updated when you press OK. Press the View > All icon to view the full model.

3.1.4.

EXERCISE 4: INSERTING SUPPORTS AT MULTIPLE POINTS

In this lesson you will insert supports at multiple points along the pipe. h

TO INSERT SUPPORTS

1) You will now add two V-stops at A04 and A05. You can use the Ctrl-Click to select A04 and repeat the same for A05. Note:

Even though you are using the Ctrl-Click method (and not Shift-Click), since you are selecting consecutive points, the pipe between the points will be selected (red) and that is expected

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2) Select Insert > Support > V-stop. The supports are inserted after accepting the default support settings in the Support dialog. The supports are shown in the following figure.

You will now add the two guides at A03 and A06. First click at point A03 to clear the selection or use Select > Clear. This is very important as you do not want to insert guides at A04 and A05. Then use the Ctrl-Click to select A03 and repeat the same for A06. The point names will

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be highlighted in red as follows:

3) Select Insert > Support > Guide. The Support dialog will appear. You will use the default gap settings and friction for guide, press OK.

4) The resulting graphics is updated for the guides as follows.

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h

TO INSERT A BEND

1) Next you will insert the bend at A07. Note: When inserting bends using the Insert > Bend command or the icon The point where you wish to insert the bend should not exist in the model. If the point is already present , you use the Modify > Convert Point to > Bend or in the top toolbar instead. In either case the bend component is inserted in two or more steps. Let us see the steps needed to insert the bend using two different methods. FIRST METHOD 2) Insert the line leading to the bend point A07 using 3) Insert the line from the bend point A07 to bend point A08 using (Note: When A08 is not a bend point, use

to create the end of the bend.)

SECOND METHOD 4) Insert the line leading to bend point A07 using

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5) Insert the line following the bend point (A07 to A08) using 6) Click on A07 7) Click on

to convert the kink point A07 to a bend.

8) Adjust the radius and/or add midpoint by double clicking at the bendpoint A07. Although the second method is more intuitive, it actually takes more time. In step 2 of the second method, you would need to zero out the offsets as AutoPIPE assumes you are going in the same direction as the previous pipe.

9) Click on A06 to clear the selection range and select A06 as the insertion point. Select Insert > Bend to open the Bend Point dialog. Type 1500 in the Length field. Accept the default long radius (1.5D). Press F1 to review the information pertaining to the bend element. Note:

You can type over the radius field to set an arbitrary radius, e.g. type 1000 to specify a 5D radius inches (5 x 200 = 1000).

10) Next zoom on the bend point by creating a window around the bend point. This can be done by clicking on one corner and while holding down the left mouse button, drag to form the window as shown below. You can zoom by selecting the View > Box Zoom or use the right mouse button instead.

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11) The resulting graphics will show as follows:

12) You can change from single line view to solid view using View > Solid Model View or by the icon on the left toolbar.

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13) Notice the pipe leading to the bend point is shown in a different colour to indicate the bend is not finished. Next you will insert the bend point at A08. Select Insert > Bend to insert the bend and type -900 in the DZ field, press OK.

14) The graphic is updated to reflect the insertion of line A07 to A08 as follows. Notice the line is shown in a different colour to indicate an unfinished bend at point A08 this time.

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15) The last point A09 is a run point. Use Insert > Run or click on the icon to insert the run point A09. Type 3000 in the DY field and press OK.

16) The model is updated as shown below:

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h

TO INSERT AN ANCHOR

1) The last step is to insert the rigid anchor at A09. Select Insert > Anchor and press OK to accept the values in the Anchor dialog.

2) Now the model is completed and should look like this.

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3) Select View > All to display the full model.

3.2.

LESSON 2: ADDING AN EXPANSION LOOP Now that the piping is constructed and supports are placed, you need to perform a stress check per the piping code B31.3. You will learn how to identify the loading that causes the

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overstress. Examination of the deflected shape will help you rectify the problem. OBJECTIVES The objectives of this lesson are as follows:

3.2.1.

Learn how to perform a stress check

Learn how to add an expansion loop

Learn how to review the stress results

Learn how to support the expansion loop

EXERCISE 1: PERFORMING THE STRESS CHECK Before the stress check can be performed, the system needs to be analysed to determine forces, moments and displacements due to the loads prescribed. The loads you have in this case are due to the dead weight and the thermal/pressure load. Static analysis will cause assembly of the stiffness matrix of piping points and bends and will impose gravity and thermal loads to determine the pipe displacements and reactions. h

TO DEFINE A STATIC ANALYSIS

4) Select Load > Static Analysis Sets… The following dialogue displays:

5) Select Analysis Set No. 1 (click in the left hand column) and click Modify to display the dialog box below:

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6) Enable the Thermal case T1, then enable the Calculate pressure extension cases field. Note:

If you do not enable “Calculate pressure extension cases” you will not be able to change the option “Pressure before Temperature” in the non-linear analysis.

Note:

Throughout this tutorial, the term "enable" is used to denote instances where you should place a check mark in an option field. "Enabled" fields contain a checkmark, while "disabled" fields have no check mark.

7) Since we have defined gaps and friction on the guide supports that connect to the frames, we will need to enable Gaps/Friction/Soil field (if not already done so). By enabling this field AutoPIPE considers these non-linear boundary conditions during the static analysis. 8) Press OK to accept the remaining defaults and close the Static Load Cases dialog. 9) Since you enabled Gaps/Friction/Soil, AutoPIPE displays the Nonlinear Analysis dialog to allow customization of how the non-linear analysis is performed. Customization is only required if convergence problems occur during the analysis or a special load sequence is required. Therefore do not change maximum iterations, displacement tolerance, force tolerance, friction tolerance and friction scale factor. Enable the following options:

Use default sequence

Pressure before Temperature

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10) Press OK to accept the defaults and close the dialog. 11) Press OK to close the Analysis Sets dialog. h

TO PERFORM A STATIC ANALYSIS

12) Select Analyze > Static from the menu to start the static analysis. Static analysis will cause assembly of the stiffness matrix of piping points and bends and will impose gravity and thermal loads to determine the pipe displacements and reactions. Note:

The menu command Analyze > Static, and its accompanying toolbar icon have the same behaviour. Both will run the analysis using the last settings established in the Static Load Cases dialog. 13) AutoPIPE reports a static summary of the time taken to perform the analysis. Note that the Cancel button can be pressed at any time to discontinue the analysis.

14) Press OK from the status dialog after the analysis has completed successfully. Now that the model has been analysed, you can interactively review the results as described below. h

GRAPHICAL REVIEW OF CODE STRESSES

AutoPIPE provides a number of options for reviewing code stresses. The most commonly used option is the default stress ratio comparing the calculated stress to the stress allowable. 1) Select Tools > Model Options > Result. 2) The Result Model Options dialog displays.

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3) Make sure the Sustain margin (Y/N/E) option is set to E.

Note:

Sustain Margin (Y/N/E) “Y” always adds the sustain load margin to the expansion allowable stress. “N” never includes the sustain load margin to the expansion allowable stress. “E” adds the sustain load margin to the expansion allowable stress only when the calculated expansion stress exceeds the expansion allowable stress without the sustain load margin.

4) Click OK to save the change. 5) Select Result > Code Stresses 6) The Code Stresses dialog is displayed.

7) Press OK to accept the defaults. A colour-coded plot of stress ratios between piping points it displayed. A legend appears to the left of the model area, making it easy to quickly identify ranges of values along a piping system. As with the other interactive options in the Result menu, the crosshairs can also be positioned at any point to calculate the code stress data associated with an individual point.

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Drag the information dialog to the side of the modelling area. Doing so will alow you to view both the model and the data associated with selected points. Since you selected the default All combination, AutoPIPE will plot a stress envelope of all load combinations. It will also highlight the maximum stress point and will show the load combination that caused the highest stress. Hint:

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Notice the program places the cursor at the point of maximum stress A09. Also it displays in the top left corner of the plot, the name of the load combination TR:Amb to T1(1) (EXP) that causes the maximum stress. The stress ratio 3.97 is shown in red next to the point name. The Stresses dialog shows the actual stress, allowable stress and stress ratio for all three stress combinations. 8) Toolbar buttons are available for navigating from the least stressed to the most stressed points. The controls are shown below. Experiment with these buttons and note how the information dialog is updated with the new point information. Least Stressed

Previous Stressed

Next Stressed

Most Stressed

9) Press the Previous Stressed arrow from the VCR buttons on the top toolbar. The next point will be A07 N+ with a stress ratio of 2.41. Pressing the back arrow again will show the next highest stress point as A08 F - with a stress ratio of 1.94. At all these points, the combination Amb to T1 is the cause of the overstress. 10) In addition to the VCR type controls shown above, you can also pick on a point to display its associated stress data. Pick point A03. The information dialog is updated.

11) Now that you know the cause of this overstress, let us plot the deflected shape corresponding to this stress. Select Result > Displacement from the menu. The Deflected Shape dialog will be displayed. In order to see the displacement for Amb to T1, you need to select GP1T1{1} for the equivalent non-code load combination. You also need to check the Animate load case checkbox as shown below.

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12) Once you click OK, the deflected shape for thermal load will be animated.

The speed of animation is dependent on the size of the model and the graphics capability of your computer. In the Command Line section at the bottom of your screen you will see “Press(F)aster/(S)lower- 5”. To make the animation move more slowly press the “S” key once. This will reduce the speed from 5 to 4. You may use the feature to aid your interpretation of the model as necessary. You can also change the load combination that is being animated by using the VCR buttons. For example pressing

will change the animated load case to GP1{1}.

13) The maximum displacement is clearly at the bend point A07. Click on A07 N to get the displacement. Note:

Note the bend point A07 is not a real point on the pipe, it is just a geometric node and could lie outside the bend sometimes. For this reason, no displacements or stresses are defined for A07. In AutoPIPE we refer to A07 as the bend Tangent Page 43


Intersection Point, i.e. the point where the two bend tangents intersect. It holds all the geometric bend data, such as bend radius which in turn defines the near (N) and far (F) and mid (M) points of the bend.

Note:

Notice the maximum displacement is relatively large at 156 mm. AutoPIPE exaggerates the on screen displacement when plotting the deflected shape for clarity. Notice also that the cause of this stress is that all the thermal expansion in the line A00 to A07 is acting on the piping between A07 and A09. A logical way to reduce thermal stress is to make the piping more flexible to help accommodate the unavoidable thermal movements. Some ways of making the piping flexible is to add expansion loops or expansion joints. Expansion loops are more common, but you need a space to accommodate these loops. Expansion joints are handy when no room is available for loops, but they tend to be more expensive and do require more maintenance.

3.2.2.

EXERCISE 2: ADDING AN EXPANSION LOOP It is

clear that an expansion loop is a logical choice. The question is where the expansion loop should be placed. Typically expansion loops are placed at the middle or at equal distances to accommodate the large thermal displacements. You will insert the expansion loop between A03 and A04. Although it seems logical to delete the pipe A03 to A04 and start constructing the loop, this is not a recommended way in AutoPIPE as it will split the piping into two segments. You will use another approach; we call it the rubber-band procedure. We think of the pipe A03-A04 as a rubber-band and you will attempt to form the loop by stretching the rubber-band. The expansion loop is shown below. The steps to construct the WxLxH = 3000 x

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6000 x 900 loop is as follows:

h

TO ADD AN EXPANSION LOOP

1) It is recommended that you start at the upstream point when adding the loop. Click at A03 2) Insert a run point A10 at 1500 mm from A03 (just enter a length of 1500 mm). Use the command IR or the Insert > Run to insert the run. 3) Insert a bend point A11 at DZ= 900 mm. Use the command IB or the Insert > Bend to insert the bend. 4) Insert a bend point A12 at DY= -6000 mm 5) Insert a bend point A13 at DX= -3000 mm 6) Insert a bend point A14 at DY= 6000 mm 7) Insert a bend point A15 at DZ= -900 mm 8) Convert the starting point A10 to a bend using the icon or use Modify > Convert point to > bend. 9) Press the Show Pipe Length icon to show pipe length. The default settings will give 2 digits after the decimal point – it is recommended to reduce this to one. Use Tools > Model Options > Edit and set the Digits after decimal for coordinates to 1.

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10) The use of keyboard commands allows a faster entry of data points. To see all keyboard commands, press the I key and notice how the menu commands now have one letter underlined. This is the key to press for the command. 3.2.3.

EXERCISE 3: STRESS REVIEW Now that the expansion loop is added let us check the thermal stresses again. h

TO REVIEW THE STRESSES

1) Run Analyze > Static and accept default cases. 2) Select Result > Code stresses and select Amb to T1 {1} load combination as shown below.

3) The resulting stress plot will be shown as follows.

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4) You need to make a full check of all loads, including sustained stress or Gravity and longitudinal pressure stress. This can easily be done by repeating the code stress check and selecting the load combination All as follows.

5) The resulting stress plot will show as follows.

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Notice the maximum stress ratio is 1.65 at node A11 N. The cause of this overstress is shown as usual on the top left corner GR + MaxP {1} or the sustained stress. To visualise the problem you will look at the deflected shape for GR case which is the closest non-code combination to the code combination GR+MaxP. 6) Select Result > Displacement and then select load combination as follows.

7) The deflected shape will show as follows.

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3.2.4.

EXERCISE 4: SUPPORTING EXPANSION LOOP As can be seen the expansion loop is not well supported. You will add two supports 4500 mm away from A11 and A14. h

TO SUPPORT THE EXPANSION LOOP

1) Click on A11 and press IR on the keyboard to insert a run point for the support. Type 4500 in the Length field and press OK.

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2) Type IS at the command line then select a V-STOP support. Press OK.

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3) Now click on A13 and type IR. Type 1500 in the Length field and press OK.

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4) Type IS to insert a V-STOP support at A17. Press OK.

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3.3.

LESSON 3: FINAL STRESS CHECK Now that the loop appears well supported, you will attempt to perform a stress check. OBJECTIVES The objectives of this lesson are as follows:

3.3.1.

Learn how to complete the final stress check

Learn how to generate a stress report

EXERCISE 1: FINAL STRESS CHECK h 1)

TO START THE FINAL STRESS CHECK Select Analyze > Static to perform a static analysis of the existing load cases.

2) Select View > Show > Point Names to remove node names from the plot. Select View > Show > Length to remove element length.

3) Select Result > Code Stresses to display the code stress dialog and select the default All combination.

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4) The stress plot is shown as follows.

The maximum stress ratio is 0.43 at point A13 N+. It is caused by the combination Amb to T1 {1}. 3.3.2.

EXERCISE 2: GENERATING A STRESS REPORT h

TO GENERATE THE STRESS REPORT

1) Select Result > Output Report and check in all sub-reports. Do not check the Sort stresses option.

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2) Scroll the report to the model input listing for point A11 as shown. Notice that AutoPIPE lists the SIF and flexibility for the pipe bend at A11.

3) Now look at the support data listing.

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4) And the bend data listing.

5) These Model Input listing reports can also be viewed directly using Tools > Model Input Listing and can be edited using the input grid. 6) Next scroll to the Support Forces report. Note that the support forces given are in terms of the User Non Code Combinations, not the Code Combinations. You will learn later how to disable load combinations from the reports.

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7) Now scroll to Code Compliance report. Notice that AutoPIPE defined all the necessary load cases for the code check. These are the sustained, expansion and hoop stresses.

8) Points A11 N+ and A11 F- are inside the bend and will have an SIF typically larger than 1.00. Points A11 N- and A11 F+ are outside the bend and will typical have an SIF of 1.00 and hence a lower stress. 9) Use File > Save As to save a copy of sample 1a model. 3.4.

LESSON 4: ADDING A FRAME SUPPORT Here you will see how to model a frame support. Frames supports are often not needed for performing static analysis. However, they are very useful when performing dynamic analysis as the stiffness and mass of the support could change system resonant frequencies. Frame elements are often used when trying to match the measured frequency response of the system. OBJECTIVES Page 57


The objectives of this lesson are as follows:

3.4.1.

Learn the difference between pipe and frame elements

Learn to simulate support stiffness and mass by using a frame support.

EXERCISE 1: HOW FRAME ELEMENTS ARE DIFFERENT FROM PIPE ELEMENTS Although pipe elements are modelled using beam elements, frame elements are very different in many ways.

Frame elements cannot have a stress check performed. You can review beam displacements and forces but not stresses.

You cannot edit frame elements in the grid.

You cannot insert mass points or intermediate points to a frame.

3.4.2.

Frame elements cannot have pressure or temperature data applied

Frame element section modulus or inertia vary with direction (Ix and Iy are usually different). The beta angle of the frame determines its orientation. Frame element design is based on buckling criteria which is not the case for most piping codes. Since you cannot add pipes to the mid point of a bend, frame elements can be useful in modelling dummies, trunnions or base elbow supports. If temperature is important, you can add a short frame and then connect another pipe. You can also make a tee next to (not at) the Near or Far point of the bend for adding an elbow support as a branch. Frame elements do not have a segment assigned.

EXERCISE 2: FRAME SUPPORT DESCRIPTION You will replace the guide at A03 with the frame as shown below. You still need to have the guide to connect the pipe to the frame. The pipe is assumed resting on the frame support. Since AutoPIPE uses centreline dimensions (as in line mode), the frame node (3) should be 211 mm below the pipe point A03. The distance is the average of the OD of the pipe (219.1 mm) and the depth of the beam (203.2 mm).

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Section: Australian Beam: 200UCx46.2 Point 3 is (203 + 219.1) / 2 = 211mm below A03

DN200 STD

A03

211 = (203 + 209.1) / 2

3

200UCx46

3.4.3.

EXERCISE 3: INSERTING THE FIRST FRAME ELEMENT The best way to start building the frame is to start with frame element M1 joining nodes 3 and 4. Since you need the coordinates of node 3 we need the global coordinates of node A03. 1) In order to get A03 coordinates we will use View > Pipe Properties (or press function key F3) as follows:

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2) Since the point 3 is 211 mm below A03, the Y coordinate should be 2000 – 211 = 1789 mm. 3) Select Insert > Beam Section Properties, then under Section Type press Select.

4) Under Australian sections select UC Shape, then select UC200x46.2 in the right hand window. Press OK to accept.

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5) You will then see the Beam Section Properties dialogue updated as shown below.

6) Select Insert > Frame and type 3 in the From Node I. Tab to the X field and type 0. Tab again and type 1789 in the Z field. Type -15000 in the X field. Type 4 in the To Point J. Type 2400 in the DY field. Select 1 UC200x46.2 for Section ID. The Beta angle causes a rotation of the beam and is not needed here. Press OK to construct the beam.

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7) The beam will show as follows:

3.4.4.

EXERCISE 4: INSERTING THE REST OF FRAME ELEMENTS The first beam is typically the hardest to construct. 1) To construct beam 4-5, click on point 4 and then Select Insert > Frame. Type 5 in the To Point J. Tab to the DY field and type -1789. Press OK and the beam will show as shown.

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2)

Now continue the same way for beams 3-2. Click on point 3 and then Select Insert > Frame. Type 2 in the To Point J. Tab to the DY field and enter -2400. Press OK and the beam will show as shown.

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3) Now continue the same way for beams 2-1. Click on point 2. and then Select Insert > Frame. Type 1 in the To Point J. Tab to the DY field and type -1789. Press OK and the beam will show as shown in the following figure.

3.4.5.

EXERCISE 5: SUPPORTING THE FRAME It may seem funny that you need to support the frame, which itself is acting as a support. In AutoPIPE the frame element is not a support and hence needs to be supported. If you did not support the frame you will get an unstable system message during the analysis. This frame assembly needs anchors at nodes 1 and 5. 1) Click on node 1 and select Insert > Anchor and press OK. Repeat to insert another anchor at node 5. The plot will be updated as follows:

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3.4.6.

EXERCISE 6: CONNECTING THE PIPE TO THE FRAME ASSEMBLY You also need to connect the pipe point A03 to point 3 on the frame otherwise the frame and the pipe systems are completely independent. This can be done simply by modifying the current guide support at A03. 1) Double click on the guide you will notice the field "Connected to" is set to Ground. This is the default value for all supports, but it is not true here. You will specify node 3 as the Connected to point instead.

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2) The graphics will be updated and will notice a slight change in the guide symbol as shown. Press OK to close. 3) This completes the model for the frame support.

3.4.7.

EXERCISE 7: ANOTHER STRESS CHECK Now that you added the frame support you will check to see if the static analysis results will be affected. So you will run static analysis and follow with code stress check. h

TO START ANOTHER STRESS CHECK

1) Select Analyze > Static to perform a static analysis of the existing load cases.

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2) Select Result > Code Stresses to display the Code Stress dialog and select the default All combination.

3) The stress plot is shown as follows:

4)

Notice the stresses are almost identical with those obtained without the frame support. The frame support effect is minimal on static analysis results.

This concludes this exercise.

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4.

Sample 2: Hanger Design & Equipment In this chapter you will build a new piping model. This chapter contains an example system with an API 610 pump and a spring hanger. It shows how to define the pump and produce the pump report.

4.1.

LESSON 1: BUILD PUMP SUCTION PIPING In this lesson you will define the problem and start a new model. You will set the node increments and add anchor and piping points to the model. OBJECTIVES The objectives of this Lesson are as follows:

4.1.1.

Learn the definition of the problem

Learn how to set node number increment

Learn how add a piping segment

Learn how to add a tee junction

Learn how to add a branching pipe

Learn how to change a length of pipe

Learn how to insert a hanger

EXERCISE 1: PROBLEM DEFINITION The following shows the initial piping model Sample 2.

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h 1)

Property

Value

Piping Code

B31.3

Pressure

10.3 bar(g)

Temperature

260 deg C

Material

A106 Gr B

Corrosion Allowance

1.5 mm

Insulation

50mm wool

Contents Spec. Grav.

1.0

Main Pipe

DN150 STD

Branch Pipe

DN100 STD, Welding Tee

Valve

Gate Class150, WN Flanges

Hanger

Initially undesigned

TO START THE NEW MODEL Select File > New, and type Sample 2 in the File Name field and press Save as shown below.

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2) In the General Model Options dialog, select B31.3 Process Piping & 2006 as the piping code & edition, SI as the units files for input & output, Z as the vertical axis direction, 21 deg C as the ambient temperature, as shown below and press OK.

3) In the Segment dialog, type 150STD in the Pipe Data Identifier field as shown and press OK.

4) Since the pipe is new, the Pipe Properties dialog will open to enter the pipe cross section properties as shown. Type 150 in the Nominal Diameter field, STD in the Schedule field, 1.5 mm in the Corrosion field, 50 in the Insulation Thickness field, and Wool in the Insulation Material field. Also type 1 in the Specific Gravity field and select A106-B for the Pipe Material field. Notice how the units are shown in the lower right corner of the main AutoPIPE window when the cursor is the field. Move the cursor above the Density data and see the units display as a tooltip. Press OK when done.

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5) The Pressure & Temperature dialog will automatically display to enter the pressure and temperature dependent material properties. Type 1.034 in the Pressure field and 260 in the Temperature field. Press the Tab key and notice how the material properties are updated based on the material library.

6. Press OK and the model will show as follows:

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4.1.2.

EXERCISE 2: SET DEFAULT NODE NUMBERING h

TO SET THE DEFAULT NODE NUMBERING

1) Now you will set the node name increment to 5 so that default names become A00, A05, A10, etc. Load the Tools > Model Options > Edit to open the Edit Model Options dialog and type 5 in the Default point name offset field as follows. Press OK when done.

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4.1.3.

EXERCISE 3: ADD SEGMENT A PIPING POINTS Here you will add all segment A piping points. You will start by adding the anchor at A00 and then add piping points and bends along the segment. h

TO ADD SEGMENT A PIPING POINTS

1) Select Insert > Anchor and press OK to accept rigid anchor properties.

2)

Select Insert > Run and type 3050 in the Offset - DY field and press OK. This will cause AutoPIPE to add a Run point 3050 mm away from A00.

3) Select View > Solid Model View and the plot will look as follows:

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4) Now we will insert a bend point at A10. Select Insert > Bend and set the Length field to 1025 as shown.

5) The piping geometry is updated as shown below.

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6) Note how the line A05-A10 is shown with a light colour to indicate that the bend is not finished. The bend will be drawn when the pipe or bend following it is drawn. Next you will insert the bend point at A15. Select Insert > Bend and type·-900 in the DZ field and press OK as shown.

7) The updated graphics will show the completed bend at A10, but not at A15 as shown.

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8) Now you will complete segment A by placing a run point at A20. Select Insert > Run and type 1525 in the DX field as shown. Press OK to close.

9) After inserting a rigid anchor at A20, the piping model will be as shown in the following figure.

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4.1.4.

EXERCISE 4: ADD A TEE JUNCTION AND BRANCHING PIPE In this lesson you will add a reducing tee branch and enter the attached piping with bends, valves and flanges. h

TO CONVERT A POINT TO A TEE

Since point A05 already exists, we will convert it to a tee first before starting the branching pipe. 1) Select A05 and select Modify > Convert point to > Tee to modify run point to a tee. You will notice 3 blue arrows are created next to the tee point. Zoom around the tee point. To zoom, click and keep the mouse pressed while dragging it to form a box. Now right-click to perform the zoom. Select the branch arrow to make it red as shown in the following figure.

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2) After selecting the branch arrow, notice that the segment name in the bottom of the dialog changes from A to B to indicate a new segment B. Now, since you are on segment B, any runs or bends inserted will belong to this new segment. Select Insert > Bend to insert a bend point. Type 900 in the DZ field and type 100STD in the Pipe Identifier field since this is a reducing tee. problem with adding bend on new branch from tee- don’t get option to add new pipe identifier – field is grayed out.

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3) Since the Pipe Identifier 100STD is new, the Pipe Properties dialog is displayed. Type 100 in the Nominal Diameter field, STD in the Schedule field, 1.5 mm in the Corrosion field, 50 in the Insulation Thickness field, and Wool in the Insulation Material field. Also type 1 in the Specific Gravity field and select A106-B for the Pipe Material field.

4) After panning and zooming the window the piping will show as follows. Notice that the pipe A05 to B05 is shown in lighter colour to indicate an incomplete bend. The bend is completed when the next run point B10 is inserted.

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5) Select Insert > Run to insert a pipe run from B05 to B10. Type -600 in the DX field.

6) Press OK to update.

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AutoPIPE does not allow insertion of a component like a valve (reducer, expansion joint or nozzle) after bend or tee points. In order to insert these components a run point is necessary. In this case, B10 can serve as our starting point for the valve. You could not have done that at B05. h

TO INSERT THE VALVE AND FLANGES

1) Next you will insert the flanged gate valve with Class 150 rating. Select Insert > Valve and fill in the valve Type as GATE-F and the Pressure rating as 150. Notice the valve length, weight and surface area factor is retrieved from the AutoPIPE library. If you need to know what a surface area factor is press F1 while in the surface area factor box to see help on this box.

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2) Press OK to close the Valve dialog. The valve will appear when the dialog closes. To insert the mating flanges for the valve, you will first select the valve and then insert both flanges at one time. Select the beginning of the valve (B10) and while holding the Shift key click on the end point B15 of the valve. You will see the valve highlighted in red as shown.

3) Select Insert > Flange to insert both mating flanges. Select the Flange type WELDNECK from the drop-down, a Pressure Rating of 150 and Joint End Type as Butt Weld and press OK.

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4) The graphics is updated as shown below.

h

TO INSERT A PIPE RUN

5) Next you will insert a pipe run from the valve to the anchor. First you need to clear the selection. This can be done easily by clicking on B15. Select Insert > Run to insert the pipe as shown. Use the default length of 600 as shown in the following figure and press OK.

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6) The graphic is updated as follows.

7) Now you need to insert an anchor. Select Insert > Anchor to add the rigid anchor as follows.

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8) Now you have finished inserting segment B. The model will be as shown below.

9) Select View > Show > Length to show the pipe lengths:

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4.1.5.

EXERCISE 5: CHANGE THE LENGTH OF PIPE A10 TO A15 You will now learn the different ways to change a pipe length in AutoPIPE. You will update the length from 900 mm to 4500 mm. By far the easiest and most logical way is to use the input grid. But we will also discuss other options. h

TO CHANGE A PIPE LENGTH

1) Start the Input Grid if it is not shown already.

2) Click on the row with From point as A10. Type 4500 to replace 900 in the Length field.

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Note:

Notice while editing that a pencil is shown on the left of the row to indicate the row is being edited. Also notice that point A15 is highlighted in red. You will notice the length is updated once you leave the length field.

3) Another method of changing the length is to select the pipe A10 to A15 and use the command Edit > Move/Stretch and type 3600 in the DZ field. 4) The final method is to double click on end point of run A15 and change the length to 4500 and make sure to check the option Apply offset to following points.

4.1.6.

EXERCISE 6: INSERT HANGER AND PERFORM HANGER DESIGN In this lesson you will learn to add a hanger support and perform a hanger design. h

TO ADD A HANGER

1) First you will insert the undesigned hanger at A10 N (Near or first node on the bend). Select A10 N and then select Insert > Support > Spring.

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2) Enable the Undesigned check box as you will perform the hanger design in AutoPIPE. Press OK when done and the model will be updated as shown in the following figure.

3) Now that the hanger is present you will perform a hanger design. In order to do a proper design for the hanger, you need to free supports close to the hanger. So set a hanger release for anchors at A20 and B20 in the Z direction. Double-click the edge of the anchor A20 or select Modify > Anchor. Check Z in the Release for hanger selection group. Press OK to close.

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4) Repeat the same for anchor B20. The release will cause the hanger to carry more gravity load and hence a larger size hanger will typically be selected. This hanger release is only applied when Analyze > Hanger Selection is performed. When using Analyze > Static the actual anchor stiffness is used. 5) Select Analyze > Hanger Selection and the Hanger dialog will show as follows.

The rigid hanger criterion is used for deciding whether to use a rigid hanger (V-stop) versus a spring hanger. AutoPIPE will select a rigid hanger if the thermal movement at the support location is less than 2.54 mm per the default setting and this is a reasonable value for design. The Load variation ratio is the ratio of the difference between hot and cold spring loads to the hot load value. A 25% variation between cold and hot load is a reasonable value. You may select a smaller value for some systems. If AutoPIPE cannot find a hanger that satisfies the load variation, it will select a Constant support (that has a zero variation between hot and cold loads). The difference between hot and cold loads is the main reason for selecting a hanger. If a hanger is replaced with a rigid support, lift-off could occur under operating thermal load. This will cause the hot load to be zero and the cold load to be large. When the hot load is zero, the weight of the piping under hot condition will be supported on the adjacent equipment nozzles causing an overstress at these locations. After the analysis is done, the program will show a test file of the possible spring hangers. The first hanger listed is the one assigned by AutoPIPE. You would need to either manually set the spring rate and cold load or change the load variation ratio to force selection of another spring. 6) After you accept the Hanger dialog the hanger report will be shown as follows:

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The selected hanger has a spring rate of 91.1 N/mm and a cold load of 5881.8 N. These values will be automatically entered in the Hanger dialog. Notice that if the load variation is set to 10%, the second hanger will be selected. Note also that the hot load (4949.3 N) is the same for all selected springs and the same applies to thermal movement (10.24 mm). HANGER SELECTION PROCEDURE Only gravity (dead weight) and thermal loading is analyzed.

A rigid restraint (V-Stop) replaces hanger for the gravity (GR) load case and anchor releases are applied. The calculated support reaction is the "hot load" to be carried by the hanger. The hot load value in this case is 4949.3 N. The rigid restraint is removed for thermal load cases (T1) and no anchors are released. The magnitude of vertical thermal displacement is the free travel distance. The calculated thermal movement in the vertical direction at A10 N is 10.24 mm in this case. If the supported point moves up under gravity load, a spring is not required. If the travel distance is less than the specified "rigid hanger displacement criterion", a rigid restraint is selected. Using the calculated hot load and travel distance, the cold load is calculated from the specified spring manufacturer table. If both hot and cold loads are within a spring's operating range, that spring is selected. Otherwise, the next size in the table is checked.

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Cold Load = Hot Load + Movement *Spring Rate

"Spring load variation" of the selected spring is checked against the user specified "permissible load variation". Load Variation = (Cold Load -Hot Load) I Hot Load

If no spring is found, the process is repeated for multiple springs.

If no spring is found, a constant force hanger is selected.

All possible springs are reported.

A Static analysis must be performed after the Hanger run

Grinnell Pre-Engineered spring hangers SIZE AND SERIES SELECTION

Note:

Refer to end of this manual for A3 copy of Grinnell spring hanger table shown above.

You will build the pump discharge which is disconnected from the pump suction line. You will start by inserting a new segment and add the piping starting at the discharge DN 80 nozzle. You will then insert a DN80 x DN100 reducer, a check valve and a gate valve as shown. The discharge pressure is 13.79 bar(g). The ANSI A40 pump dimensions are given as well. The pump center as required by API 610 is along the shaft, midway between the pedestals (or pump supports). For proper check for pumps, both suction and discharge piping should be included in the same AutoPIPE model.

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OBJECTIVES The objectives of this lesson are as follows:

4.1.7.

Learn how to add a pump discharge line

Learn how to change the design pressure for a discharge line

Learn how to generate a pump report

Learn how to edit the operations

EXERCISE 1: ADD A NEW DISCONNECTED SEGMENT h

TO ADD A NEW DISCONNECTED SEGMENT

1) Select Insert > Segment and fill in the data as in the following table. You will use B20 as

your reference point for coordinates of the disconnected point C00.

Name

Description

Name of first point

C00

Offset from which point

B20

DZ

317.5 mm

DX

-102 mm

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Pipe data identifier

80STD

2) Press OK. Once you accept the Segment dialog, the Pipe Properties dialog will be displayed to enter properties of the new identifier 80STD. Type 80 in the Nominal Diameter field, STD in the Schedule field, 1.5 mm in the Corrosion field, 50 in the Insulation Thickness field, and Wool in the Insulation Material field. Also type 1 in the Specific Gravity field and select A106-B for the Pipe Material field. Press OK to close.

3) After this is done, you will notice the cursor placed at the starting point COO of the new segment as shown:

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h

TO ADD PIPE AND A REDUCER

1) Now you will add the pipe C00-C05 and then insert the 80x100 reducer. Select Insert > Run to add a pipe run as follows: Press OK to close.

2) The view will be updated as shown in the following figure.

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3) Next you will add a 80x100 reducer. Select Insert > Reducer and type in a Length of 152 mm and select 100STD pipe identifier as follows:

4) You will then see a screen that advises the piping material has changed. In this case no change is required, however in some systems you may wish to make a change at this point. Press OK to close.

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5) The view is updated as shown in the following figure.

h

TO ADD CHECK AND GATE VALVES

It is common to have check and gate valves in the discharge piping. First, you will insert the check valve followed with a gate valve. You will assume that these valves are butt welded. 1) Select Insert > Valve and select SCHECK-B (buttwelded swing check) from the Type dropdown and 150 from the Pressure rating drop-down as shown. The length and weight are retrieved from the AutoPIPE.lib file. Select Butt Weld from the Joint End Type dropdown. Press OK to close.

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2) Next you will insert the gate valve. Select Insert > Valve and select GATE-B from the Type drop down and 150 from the Pressure rating drop down and tab to the Length field to update the length as shown. Select Butt Weld from the Joint End Type dropdown. Press OK to close.

3) The view will be updated as follows:

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h

TO ADD THE BEND, RUN AND ANCHOR

1) Select Insert > Bend and accept the default length of 300 mm and press OK as shown in the following figure.

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2) Now you will complete the bend and insert the attached pipe to C30. Select Insert > Run and type 1500 mm in the DY field. Press OK to close.

3) Now use Ctrl-Click at C00 and C30. This will make the node names red.

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4) Select Insert > Anchor to add rigid anchors at these two points simultaneously.

This will finalize the input for the discharge piping. In the next section you will enter the API 610 pump properties and generate a pump report.

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4.1.8.

EXERCISE 2: CHANGE DESIGN PRESSURE FOR DISCHARGE LINE Now you will update the design pressure for the discharge line. The discharge pressure is 13.79 bar(g). So you will select the discharge piping and change the design pressure. h

TO CHANGE THE DESIGN PRESSURE

1) To select the segment, click on C00 and then use Shift-Click on C30. This will highlight segment B in red as shown.

2) Select Modify > Operating Pressure Temperature to update the discharge pressure. Type 1.379 MPa in the Pressure field as shown and press OK.

3) A note will display about updating valve data. Press OK.

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4) Now to display the pressure, select View > Show > Operating Pressure and the Show Pressure dialog will show as follows. Press OK to accept the default.

5) Finally, select View > Show > Reset to clear the pressure display.

4.1.9.

EXERCISE 3: GENERATE PUMP REPORT In this section you will add the ANSI 4x3 (A40) pump and you will use API 610 pump report to check the loads on the suction and discharge nozzles and also at the centre of the pump. The ANSI pump dimensions are given below:

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The pump will not appear in the graphic. You can specify the properties but it will not appear on the dialog like other AutoPIPE components. You will look at cold (GR) and hot (GR+T1) reactions. First you will define the pump properties and then analyze the model and generate a pump report. 4.1.10.

EXERCISE 4: SPECIFY PUMP PROPERTIES 1) Select Tools > Rotating Equipment and specify the following data. Type P101 for Equipment ID and specify Pump for the Type field. 2) Select B20 from the Suction Point drop-down and End from the Location field (since the suction nozzle is at the end of the shaft). 3) Set the Discharge Point as C00 and specify Location as at the Top of the shaft. Keep the default Table 2 factor as 2.00. Specify the Pump Orientation as Horizontal with its Shaft Axis in the Global Z direction. 4) Since you cannot have a point for the centre of the pump, the pump centre is defined

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relative to the suction nozzle B20. So type B20 in the Reference Point field and specify DX as -260.35 mm as shown below. Press OK to close.

4.1.11.

EXERCISE 5: ANALYZE AND SHOW PUMP REPORT h

TO ANALYZE THE PUMP

1) Firstly define a static analysis - select Load > Static Analysis Sets… The following dialogue displays:


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3) Enable the Thermal case T1, then enable the Calculate pressure extension cases field. 4) Enable Gaps/Friction/Soil field (if not already done so). 5) Press OK to accept the remaining defaults and close the Static Load Cases dialog. 6) Since you enabled Gaps/Friction/Soil, AutoPIPE displays the Nonlinear Analysis dialog to allow customization of how the non-linear analysis is performed. Customization is only required if convergence problems occur during the analysis or a special load sequence is required. Therefore do not change maximum iterations, displacement tolerance, force tolerance, friction tolerance and friction scale factor. Enable the following options:



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7) Press OK to accept the defaults and close the dialog. 8) Press OK to close the Analysis Sets dialog. h


9) Select Analyze > Static from the menu to start the static analysis. Static analysis will cause assembly of the stiffness matrix of piping points and bends and will impose gravity and thermal loads to determine the pipe displacements and reactions. 10) Press OK from the status dialog after the analysis has completed successfully. Now that the model has been analysed, you can interactively review the results as described below. 11) Next you will look at the default non-code combinations typically used for support or nozzle loads. Select Tools > Combinations and examine the third tab for Non-Code Comb. as follows.

12) Notice that there are three Non-Code load combinations:

Gravity{1}

Thermal{1}

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Pressure{1}

GP1{1}

GP1T1{1}

13) Gravity is the cold reaction load, GP1T1{1} is the hot reaction load while T1 = (GP1T1{1}) - Gravity is the difference between hot and cold loads. This difference T1 while useful for estimating code expansion stress range, is meaningless for pump nozzle loads. So you are going to disable T1 in the output report. T1 is typically used to show deflections causing the code combination Amb to T1 stress. Therefore disable the Print option for combination Thermal 1{1}. Similarly we are not interested in the Pressure 1{1} or GP1{1} combinations. Disable these and press OK to close.

14) Select Result > Output Report and uncheck Select/Unselect all reports and check Equipment as shown below. Press OK to close.

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15) The output will show the details for the reaction loads and will give a “*” whenever a certain reaction exceeds API 610 allowable. For the cold reactions Gravity{1}, the loads appear below the allowable stress, while for the hot reaction GP1T1{1} it is much higher than the allowable load. This ratio is 15.02 for moment My reaction as shown:

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Note:

AutoPIPE pump report shows all reaction forces and moments in terms of the local API 610 axes in which z is the vertical axis and x is the shaft axis. The transformation from global to local axes is defined at the top of the pump report.

API 610 Fig 23 Compressor and turbine reports can be generated in the same manner. For these reports, the centre of the equipment is not required and that simplifies the calculations and limits it to the Page 109


inlet and exit nozzles. 4.2.

STUDENT EXERCISE: COPY/PASTE AND EDIT/ROTATE OPERATIONS In this exercise you will add an intermediate point to start another branch thru a copy/paste operation. You will then rotate part of the copied piping. The original and final piping are shown below.

Before After

h

TO COPY AND ROTATE THE MODEL SEGMENT

1) Add an intermediate point A25 between A00 and A05. Click on A00 and Use Insert > Run. Accept the default length of 1525 mm. 2) Select the two segments B and C using Select > Segment and click on one point on segment B and another on segment C and then click on Finish. 3) Use Edit > Copy and specify A05 as the reference point where copied objects are to be connected. 4) Unselect all points by clicking on A25 and to signify the insertion point for the pasted object. 5) Use Edit > Paste and select the default to connect to selected points.

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6) Select segment E and follow by Edit > Rotate. 7) Select E00 as the centre of rotation and specify 180 degree rotation around the vertical Z axis.

8) You would need to add a new pump P102. For this click on Tools > Rotating Equipment and select P101. Rename P101 to P102. and modify the suction nozzle, the discharge nozzle and the reference points: B20

►

D20

C00

►

E00

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5.

Sample 3: Wind, Earthquake and Nonlinear Analysis In this sample problem you will learn how to perform nonlinear analysis due to supports gaps and friction. You will also learn how to set up loads for earthquake and wind loads. Application of Vessel

5.1.

LESSON 1: MODEL DEFINITION In this section we will present sample 3 model characteristics. PIPING LOADS Property

Value

Pressure

8.62 bar(g)

Temperature

343 deg C DZ = 9.5 mm @ A00 DZ = 12.7 mm @ A15

Earthquake load

E1: X = 0.3g, Z = 0.2g E2: Y = 0.3g, Z = 0.2g

Wind load

W1: Wind in X direction W2: Wind in Z direction Ground Elevation = 3050 mm below A00 ASCE Wind Profile Location: California near coastline Importance Factor = 1

PIPING GEOMETRY Property

Value

Piping Code

B31.3

Material

A53 Grade B

Corrosion Allowance

1.2 mm

Insulation

50 mm Calcium Silicate


0.86

Main Pipe

DN150 STD

Valve

NS, BW connection, Weight=75 kg, Surface Area Factor = 4.3

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Sample 3

Earthquake load cases:

Piping Code: B31.3 T = 343°C, P = 8.62 bar(g) Pipe = DN150 STD wall Material = A53 Gr B Sp. gr = 0.86 Insulation = 50m, Calc. Sil. Corrosion = 1.2mm

25mm gap above pipe

E1: X = 0.3g, Z = 0.2 g E2: Y = 0.3g, Z = 0.2 g Wind Load Cases:

1200 5490

Ground elevation = 3050 below A00 Use ASCE wind profile Location: California near coast Importance factor = 1 Wind Direction: W1 = X, W2 = Y

1200 450

friction coefficient = 0.30

Defl. = 12.7mm up

3660 1050

1295 600

Z 1200

A00 friction coefficient = 0.35 Defl. = 9.5mm up

X

1200

Y

305 610 457 610 305

Valve Data: Wt = 75 kg SAF = 4.3 Weld type = Butt Weld

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5.2.

LESSON 2: STARTING A NEW MODEL In this exercise you will build the model OBJECTIVES The objectives of this lesson are as follows:

5.2.1.

Learn how to start a new model

Learn how to specify vessel thermal expansion

Learn how to add the rest of the piping system

EXERCISE 1: START A NEW MODEL TO CREATE A NEW MODEL 1) Select File > New, and type Sample 3 in the File name field.

2) In the General Model Options dialog, select B31.3 Process Piping & 2006 as the piping code & edition, SI as the units files for input & output, Z as the vertical axis direction, 21 deg C as the ambient temperature, as shown below and press OK.

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3) In the Segment dialog, type 150STD in the Pipe Data Identifier field as shown and press OK.

4) Since the pipe is new, the Pipe Properties dialog will open to enter the pipe cross section properties as shown. Type 150 in the Nominal Diameter field, STD in the Schedule field, 1.2 mm in the Corrosion field, 50 in the Insulation Thickness field, and Calc in the Insulation Material field. Also type 0.86 in the Specific Gravity field and select A53-B for the Pipe Material field. Press OK when done.

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5) The Pressure & Temperature dialog will automatically display to enter the pressure and temperature dependent material properties. Type 0.862 MPa in the Pressure field and 343 °C in the Temperature field and press the Tab key and notice how the material properties are updated based on the material library.

6) When you press OK the model will show as follows.

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5.2.2.

EXERCISE 2: VESSEL THERMAL MOVEMENT Here you will add the vessel at A00 with its thermal upward movement. h

TO ADD THERMAL MOVEMENT

1) Select Insert > Anchor and type 9.5 mm in the vessel thermal movement DZ. The thermal movement can be estimated by multiplying the thermal expansion coefficient of the vessel material by the length of the vessel and the change in temperature. For radial growth of the vessel, the vessel radius is used instead of the vessel length. Press OK to accept rigid anchor properties

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5.2.3.

EXERCISE 3: ADD PIPING GEOMETRY UP TO THE GUIDE SUPPORT In this exercise you will add all of the piping up to the guide support. h

TO ADD PIPING

1) Select Insert > Bend and type 600 for the DZ offset and press OK. This will cause AutoPIPE to add a bend point 600 mm away from A00.

2) Select View > Solid Model View and the plot will look as follows. Note that the bend is not finished and is plotted in a lighter colour. The bend will be completed after the connecting pipe or bend is drawn.

3) Now you will insert another bend point at A02. Select Insert > Bend and type -1050 mm in

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the DX field as shown below. Press OK to close.

4) The piping geometry is updated as shown below.

5) Note how the bend A01 is completed, but the new bend at A02 is not. Next you will insert the bend point at A03. Select Insert > Bend and type 1295 in the DY field as shown below. Press OK to close.

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6) The updated graphics will show the completed bend at A02, but not at A03 as shown in the following figure.

7) Next you will insert another bend point at A04. Select Insert > Bend and type·-1200 in the DZ field as shown. Press OK to close.

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8) The piping geometry is updated as follows.

9) Next you need to insert the pipe run leading to the guide support. Select Insert > Run and type -300 in the DX field as shown below. Press OK to close.

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10) The piping geometry is updated as follows.

5.2.4.

EXERCISE 4: ADD GUIDE SUPPORTS AND VALVE In this section you will add both guides with a friction factor of 0.35 and 1000 mm upward gap. You will also add the non-standard valve in between. h

TO ADD THE GUIDE SUPPORTS

1) At A05 select Insert > Support > Guide support. Type 1000 in the Gap up field and 0.35 in the Friction coefficient field as follows. Press OK to close.

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2) The piping is updated as shown below:

Note:

h

Notice that the upward support is removed for large gaps greater than the pipe diameter. This setting can be changed under View > Settings > Support Gap Scale. TO ADD THE VALVE

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1) Next you need to enter the valve, but you need to insert a pipe run up to the start of the valve. Select Insert > Run and type 610 in the Length field as shown. Press OK to close.


3) Now you are ready to insert the valve. Select Insert > Valve and select NS for valve Type from the drop-down, 150 for Pressure rating. Type 457 in the Length field, 75 kg in the Weight field, 4.3 in the area factor field and select Butt Weld in the Joint End Type field as shown below. Press OK to close.

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5) Next you will add a pipe run point needed to insert the second guide support. Select Insert

> Run to insert a pipe run and type 600 in the Length field. Press OK to close.

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7)

Select Insert > Support > Guide to insert the second guide support. Since this support is identical to the previous one, accept the default settings as shown below. Press OK to close.

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8) The piping is updated as shown below.

5.2.5.

EXERCISE 5: ADD THE REST OF THE PIPING Now that the support is inserted you will continue with the rest of the piping points and supports. h

TO INSERT PIPING COMPONENTS

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1)

Select Insert > Bend to insert a bend point at A09. Type 305 in the Length field as shown. Press OK to close.

2)

Insert another bend at A10. Type -1200 in the DY field. Press OK to close.

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3)

Select Insert > Bend and type 3600 in the DY field as shown. Press OK to close.

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4)

Select Insert > Run to add a run point up to the vertical support point A12. Type·-1200 in the DX field as shown. Press OK to close.

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5)

Select Insert > Support > V-stop to insert a vertical support. Type 0 in the Gap above pipe field and 0.3 in the Friction coefficient field as shown. Press OK to close.

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6)

Select Insert > Run to add a run point up to the second vertical support point A13. Type 450 in the Length field as shown. Press OK to close.

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7)

Select Insert > Support > V-stop to insert a vertical support. Type 25 in the Gap above pipe field and 0.3 in the Friction coefficient field as shown. Press OK to close.

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8) Select Insert > Bend and type 1200 in the Length field as shown. Press OK to close.

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9) Select Insert > Run to add a run point up to the vessel at A15. Type·-450 in the DZ field as shown. Press OK to close.

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10) Select Insert > Anchor and enter vessel thermal movement DY as 12 as shown. Press OK to

close.

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This completes the piping geometry. Next you will add Earthquake and Wind loads. 5.3.

LESSON 3: OCCASIONAL LOAD DEFINITIONS In this lesson you will define the earthquake and wind loads. OBJECTIVES The objectives of this lesson are as follows:

Learn how to define earthquake loads

Learn how to define wind loads Page 137


5.3.1.

EXERCISE 1: EARTHQUAKE LOADING BACKGROUND AND DEFINITION Earthquake loads are typically defined using the UBC (Uniform Building Code) or IBC (International Building Code). The load intensity will depend on the location or zone factor of the area, the soil conditions, structural period and the importance factor. The code provides a procedure to estimate the earthquake loads as a function of the mass of the structure. A typical equation for building structures is given by: F=a*W Where a = Combination of several factors such as zone, soil, period and importance W = Weight of building floor where force is applied Since any ground movement will induce forces of the amplitude (Ground Acceleration)*Mass, the term is the equivalent earthquake ground acceleration. Refer to UBC 1997 sections 1630 and 1632 for more information. AutoPIPE allows you to enter this equivalent earthquake acceleration using Load > Static Earthquake command. AutoPIPE units for ground acceleration are g's. If E1 is 0.3g in the xdirection, then AutoPIPE will apply a static load in the x-direction to every mass point in the system. The magnitude of this x-force is 0.3g*Mass at the point. This is equivalent to applying 30% of the weight at the node in the horizontal x-direction. Since horizontal earthquake movement is often accompanied with vertical movement, this vertical movement is typically less than 2/3 of the horizontal movement. For piping supported on buildings, the earthquake forces are also proportional to the height of the supporting point, since points above ground are expected to move more than points near the ground. This effect of changes in equivalent earthquake load with height can be applied using the Static Point EQ factor or the static member EQ factor. This is typically applied to a range of points around the supported point. h

TO DEFINE EARTHQUAKE LOADS

In this problem we will assume the design acceleration is a = 0.3g and hence we will define 2 earthquake load cases El and E2 for both horizontal directions. We will assume a vertical acceleration of 0.2g (0.3*2/3 = 0.2g) and will apply loads in both horizontal directions. 1) Start the Load > Static Earthquake and type 2. in the Number of earthquake load cases field. For Case E1 enter X, Yand Z accelerations of 0.3, 0.0. and 0.2. For Case E2 enter 0.0, 0.3. and 0.2 as follows. Press OK to close.

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2) AutoPIPE has three ways of applying earthquake loads. The easiest is the static earthquake load shown here. The other two methods are Response Spectrum and Time History analysis. These two other methods require dynamic analysis and resonance frequency and shape estimation. System frequencies will change during support lift-off. This frequency change due to support lift-off cannot be captured in AutoPIPE and is a limitation of the Modal Analysis procedure used in AutoPIPE. For this reason AutoPIPE will close all gaps and set friction to zero during all dynamic analysis. The advantage of Static Earthquake Analysis is that support lift-off can be simulated and the analysis procedure is usually faster and simpler. 5.3.2.

EXERCISE 2: WIND LOAD DEFINITION Both the UBC (Uniform Building Code) and ASCE (American Society of Civil Engineers) provide methods of estimating wind loads on tubular structures. AutoPIPE has both procedures implemented for easier application of the Wind loads. Wind loads depend on the terrain (coast, city center) and map location.

h

Load

Properties

Wind load

W1: Wind in Xdirection W2: Wind in Z direction Ground Elevation = 3050mm below A00 ASCE Wind Profile Location: California near coastline Importance Factor = 1

TO DEFINE WIND LOADS

1) Start the Wind load by selecting Load > Wind and type 2 in the Number of wind cases. Type -10 as the Ground elevation for wind and accept the other default values by pressing OK. If you need some information about any parameter, just click on the box and type F1 for help. The wind shape factor is used only for Profile method since the shape factor is defined in

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both the UBC and ASCE methods. ASCE method requires that the wind application method to be Projected, which means both normal and longitudinal wind force components are applied.

2) Once you accept this form the individual wind load cases dialog will show. You will notice W1 case displayed on the first line. Select ASCE for the Wind specification type as follows:

3) To find the correct Basic Wind Speed, type F1 in the box and the following window will show.

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4) From this you can clearly say that the basic wind speed is 85 mph in California. For other locations in the US you can click on the link for a map of the US. To find what exposure category to use, again type F1 in the input box and the following will show after pressing on the link.

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For coastal terrain, Exposure D would be the appropriate one to use. 5) Again you can consult online help for Gust factor. The value of 0.85 is used in most cases and is valid for structures with frequencies > 1 Hz. This factor can also be used to apply wind speed up over hills (Kzt) for piping on an isolated hill. 6) The force coefficient Cf is the equivalent of Wind Shape Factor. Since pipes are rounded, they attract less wind force than a flat plate of the same projected wind area. Typically variations of wind shape factor are 0.5 to 1.2. The Automatic option would produce a shape factor of 0.70 in most cases. The analysis summary will show the variation of the shape factor with height. AutoPIPE does not apply wind load on frames and if needed these should be applied using the concentrated or distributed load option. 7) Now complete the wind load data. Type 85.00 in the Basic wind speed at 33ft field, type D in the Exposure category field, type 0.85 in the Gust effect factor field, type Automatic in the Force coefficient field, type 1.00 in the Importance factor field and select Global X as the Wind direction as shown in the following figure.

8) When you press OK, the Wind case W2 will show. Since the two cases are identical except for wind direction, select Global Z as the Wind direction as shown and press OK.

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9) Now that we have defined the wind loads, let us look at the wind load summary. Use Tools > Model Input Listing and uncheck all sub-reports except for Loads summary as follows. Press OK to close.

10) The resulting file will show as follows.

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5.4.

LESSON 4: STRESS AND ANALYSIS RESULTS In this section you will perform the static analysis and review the resulting stress. OBJECTIVES The objectives of this lesson are as follows:

5.4.1.

Learn how to analyze non linear static loads

Learn how to interpret the stress results

Learn how to get support lift-off

EXERCISE 1: STATIC NONLINEAR ANALYSIS h

TO DEFINE A STATIC ANALYSIS

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3) Enable the Thermal case T1, Earthquake cases E1 & E2, the Wind cases W1 & W2, then enable the Calculate pressure extension cases field. 4) Enable Gaps/Friction/Soil field (if not already done so). By enabling this field AutoPIPE considers non-linear boundary conditions during the static analysis. Page 145


5) Press OK to accept the remaining defaults and close the Static Load Cases dialog.

6) Since you enabled Gaps/Friction/Soil, AutoPIPE displays the Nonlinear Analysis dialog to allow customization of how the non-linear analysis is performed. The first set of options is for nonlinear iteration control. Customization is only required if convergence problems occur during the analysis or a special load sequence is required. 7) The Friction scale factor is for scaling support friction values in the model. The UBC requires that friction be ignored for earthquake analysis. The Initial case for Occasional loads is defaulted to GR. This means that Wind and Earthquake loads are applied in the cold condition (at ambient temperature). In order to apply all occasional loads under the hot condition we will use OP1 as the initial state. Therefore do not change maximum iterations, displacement tolerance, force tolerance, friction tolerance and friction scale factor. Enable the following options:

Ignore friction – E1 to E10



Initial case for Occ. loads: = OP1

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8) Press OK to accept the default nonlinear options. 9) Press OK to close the Analysis Sets dialog. h


1) Select Analyze > Static from the menu to start the static analysis. Static analysis will cause assembly of the stiffness matrix of piping points and bends and will impose gravity and thermal loads to determine the pipe displacements and reactions. 2) AutoPIPE reports a static summary of the time taken to perform the analysis. Note that the Cancel button can be pressed at any time to discontinue the analysis.

3) Press OK from the status dialog after the analysis has completed successfully. Now that the model has been analysed, you can interactively review the results as described below. 5.4.2.

EXERCISE 2: STRESS RESULTS At the end of the analysis let us look at the stress results. h

TO DETERMINE THE STRESS RESULTS

1) Use Results > Code Stresses and the following dialog will be displayed.

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2) Press OK and the stress results will be shown as.

3) Note that the maximum stress ratio is 0.35 at node A11 N+. The cause of this overstress is load case Amb to T1{1} as shown on the top left corner of the plot. 5.4.3.

EXERCISE 3: SUPPORT LIFT-OFF Due to the thermal the system has support lift-off, it is important to identify these support points. The following exercise will show you how to identify such points. h 1)

TO GET A SUPPORT LIFT-OFF Select ResuIt > Grids. Select the Support tab and uncheck all load cases except GP1T1{1}. Scroll the horizontal bar on the bottom to see GlobalDZ data column. Notice the support A12 with positive Z movement of 16.79 indicating lift-off. When you have too many supports, you can double-click on the GlobalDZ title to sort supports with increasing or decreasing support movement. Click on the left of the line with support point A13 and you will see the support point highlighted in the model as follows

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2) Generate an output report using Result > Output Report and select Support, Code Compliance and Analysis Summary as shown.


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6.

Sample 4: Nozzle Flexibility, Cut short and Trunnion Supports In this sample problem you will learn how to model nozzle flexibility, flexible anchors, and flexible joints and how to add trunnion supports. You will also learn how to add a bend with a thicker pipe than the adjacent pipe and how to construct a 45-deg bend and short radius bends.

6.1.

LESSON 1: MODEL DEFINITION In this section we will present sample3 model characteristics. The system geometry and piping loads will be specified as shown below. PIPING LOADS Property

Value

Pressure

10.34 bar(g)

Temperature

149 deg C

Cut short or Cold spring

12.7 mm between hanger and 45 deg bend

PIPING GEOMETRY Property

Value

Piping Code

B31.3

Material

CS Cold allowable Sc = 82.7 MPa Hot allowable Sh=82.7 MPa

Corrosion Allowance

None

Insulation

None


0.85

Main Pipe

DN200 STD

Flexible Joint

Length = 150 mm Axial Stiffness = 175 N/mm Y·shear Stiffness = 219 N/mm Z·shear Stiffness = 219 N/mm Torsional Stiffness = 8015 N.m/deg V-bending Stiffness = 4007 N.m/deg Z-bending Stiffness =4007 N.m/deg Weight = 9.1 kg Pressure Area = 322.6 cm2

Nozzle Data

Use WRC 297 flexibility method Vessel Diameter = 1524 mm Vessel Thickness = 19 mm

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L1=L2=1524 mm Trunnion

Use P4 frame – 600 mm long at midpoint of bend

Hanger Data

Cold Load = 703 kg, K= 43.8 N/mm Place at bend Near Point

Elbow with hanger

DN200 Sch 80 pipe

Flanges

Assume all Class 150 Slip-On flanges

12.7 mm cut short Cold load 6900 N Spring rate 43.8 N/mm

Sample 4 1829

1829 1372 610

DN200 SCH 80 elbow

1372 SR elbow, flanged at each end

45 deg horiz.

Class 150 DN200 STD WT CS Sc = 82.7 MPa Sh = 82.7 MPa

1800

457 75 mm lg nozzle

Vessel 1524mm OD, 19mm thick Class 150

762 600 trunnion, DN100 STD pipe

1524 1524

A00

Anchor flex. N/mm X=26,300 Y=43,800 Z=43,800

Flexible joint data Length = 150mm Stifness Axial 175 N/mm Y‐shear 219 N/mm Z‐shear 219 N/mm Torsion 8015 Nm/deg Y‐bending 4007 Nm/deg Z‐bending 4007 Nm/deg Weight = 9.1 kg Pressure area = 322.6 cm2

Z

X

Y

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6.2.

LESSON 2: BUILD PIPING MODEL You will start a new system sample4 by selecting File > New from the menu. OBJECTIVES The objectives of this lesson are as follows:

6.2.1.

Learn how to build a new model

Learn how to add flexible anchor and flexible joint

Learn how to add trunnion or base elbow support

Learn how to add 45-deg bend

Learn how to add short radius bend

Learn how to add a designed hanger support

Learn how to change pipe data for the elbow

Learn how to add bend flanges

EXERCISE 1: STARTING A NEW MODEL h

TO START A NEW MODEL

1) Select File > New, and enter a File name of Sample 4.

2) In the General Model Options dialog, select B31.3 Process as the Piping Code as shown below, 2006 as the Edition, SI as Units file name – Input & - Output, Z as Vertical axis direction, 20 deg C as Ambient temperature and press OK.

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3)

In the Segment dialog, type 200STD in the Pipe data identifier field as shown and press OK.

4)

Since the pipe is new the Pipe Properties dialog will follow to enter the pipe cross section properties as shown. Type 200 in the Nominal Diameter field, 0.85 in the Specific gravity of contents field and select CS in the Pipe Material field. The library will populate 82.74 MPa in the Cold allowable field and 206.84 MPa for the Minimum yield field and 330.95 MPa for the Ultimate field. Press OK when done.

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5) The Pressure & Temperature dialog will automatically display to enter the temperature and temperature dependent material properties. Enter 1.034 MPa for the pressure, 149 deg C for the temperature and 82.74 MPa for the hot allowable as shown:

6) When you press OK the model will show as follows.

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6.2.2.

EXERCISE 2: FLEXIBLE ANCHOR AND FLEXIBLE JOINT h

TO ADD A FLEXIBLE ANCHOR

1) Select Insert > Anchor and select Flexible from the Anchor Type drop-down. In the Trans. Stiff. field type 43,800 for X, 26,300 for Y and 43,800 for Z stiffness. Press OK to close.

2) Select Insert > Flange and select Slip-On from the Flange type drop-down, 150 from Pressure rating and Double-Welded Slip-On from the Connection to pipe field as follows. Press OK to close.

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3) Select Insert > Run and type -300 in DX field as shown. Press OK to close.

4) Select View > Solid Model View and use pan and zoom to set view as shown below.

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h

TO INSERT A FLEXIBLE JOINT

1) Starting from current point A01, select Insert > Flexible Joint and enter the data as shown. Press OK to close.

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6.2.3.

EXERCISE 3: ADD TRUNNION OR BASE ELBOW SUPPORT AT BEND h

TO ADD A TRUNNION OR BASE ELBOW

1) Select Insert > Bend and type 325 in the Length field and check the Midpoint option. You need a mid point so you can connect the trunnion support at the middle of the elbow. Use the default location of the midpoint at 50.0 % along the bend. Press OK to close.

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2) Select Insert> Bend and type 1800 in the DZ field as shown. Press OK to close.

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(check)

3) Select Insert > Beam Section Properties, then under Section Type press Select. Under American sections select Pipe, then select PIPE4SCH40 in the right hand window. Press OK to accept.

4) You will then see the Beam Section Properties dialogue updated as shown below.

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5) Now click on A03 M (bend mid point). Make sure the point name shown at the bottom of the screen is A03 M and then select Insert > Frame. Tab to the Point J field and type in 1. Tab again and type·-600. in the DZ field. Select 1 PIPE4SCH40 in the Section ID dropdown. Press OK to close.

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6) Now click on the end of the frame (Point 1) and enter select Insert> Anchor. Press OK to accept rigid anchor properties. The frame with the anchor support will be as shown below.

6.3.

LESSON 2: BUILD PIPING MODEL

6.3.1.

EXERCISE 4: ADD 45-DEG BEND 1) Click on A04 and select Insert > Bend and type 600. in the DY and -600. in the DX fields as shown to make the 45-deg bend. The 45-deg bend entry does not differ from any other bend, the only difference is that you will have two offsets to enter and these offsets are equal for 45-deg bend. Press OK to close.

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2) Zoom and pan to bring the view as shown above. The next point is a run point, so you will use Insert > Run to insert run point A06. Type·-1800 in the DX field and press OK.

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3) Now use Insert > Bend to insert run point A07. Type 1800 in the Length field and press OK.

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6.3.2.

EXERCISE 5: ADD SHORT RADIUS BEND h

TO ADD A SHORT RADIUS BEND

1) Select Insert > Bend and select Short for the Radius of the bend. This means the bend radius is equal to the Nominal Diameter of the pipe. The radius for a long radius bend is 1.50 times the Nominal Diameter. You need to remember to set the radius back to long as the default for bend radius will change to short after this insert operation. Type -1350 in the DZ fields as shown in the following figure. Press OK to close.

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2) Select Insert > Bend and select Long for the bend Radius. Also type 1350 in the DY field as shown. Press OK to close.

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3) Use Insert > Run and type -450 in DZ field as shown. Press OK to close.

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6.3.3.

EXERCISE 6: ADD A DESIGNED HANGER SUPPORT h

TO ADD A DESIGNED HANGER SUPPORT

1) Click on A07 N and then select Insert > Support > Spring to insert a spring hanger. Uncheck the Undesigned checkbox and type 6900 N in the Cold load field and 43.8 N/mm in the Spring rate field as follows:

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6.3.4.

EXERCISE 7: CHANGE PIPE DATA FOR THE SCHEDULE 80 BEND The bend is already inserted using a STD schedule. You will select the completed bend and attempt to change the pipe properties for the bend. You will keep the schedule as is for the rest of the piping. h

TO CHANGE THE PIPE DATA FOR THE SCHEDULE 80 BEND

1) Click on A07 N and then use Shift-Click at A07 F. You will see the bend highlighted in red as shown below.

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2) Select Modify > Pipe Properties Over a Range. The Pipe Properties dialog will show up. Type 200SCH80 for the Pipe Identifier. Select 200 for the Nominal Diameter and 80 for Schedule as shown.

You will see a warning message when you press OK to this dialog. This warns you that the cold allowable data is not available for the generic CS material. Press OK to the warning message.

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6.3.5.

EXERCISE 8: ADD FLANGES FOR THE BEND In AutoPIPE there is no flanged bend as a separate component. In order to insert a flanged bend you would need two flanges on each side of the bend. The flanges have to be located at the Near (N) or Far (F) points or at a point with the same coordinates as these two points. Although the weight of the flange may not be exactly at the Near or Far points, the flanges need to be inserted there if they are to be considered in the calculation of the bend flexibility and stress intensification factor. A flanged bend is typically stiffer since it is restricted from ovalling while bending. The increased stiffness would lead to smaller stress intensification factors (SIF) for the bend. The bend report in the Model Input Listing would list the number of flanges connected to the bend for SIF and flexibility considerations. It is important to review this report as the usage of the bend is meant to give more flexibility to the piping. h

TO ADD FLANGES TO THE BEND

1) You will attempt to insert flanges at both ends at the same time. So you will first select both points on the bend by clicking on A08 N and then using Shift-Click at A08 F. You will see the bend highlighted in red as shown below.

2) Select Insert > Flange and select a SLIP-On for Flange type, 150 for Pressure rating and Double-welded Slip-on as Connection to pipe as follows. Press OK to close.

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3) This will cause one flange to be inserted at A08 N and another at A08 F. Next repeat the last step above to insert mating flanges. There will be a total of 4 flanges when the bend is flanged at both ends. The result is shown below:

6.4.

LESSON 3: ADD NOZZLE FLEXIBILITY ELEMENT OBJECTIVES The objectives of this lesson are as follows:

Learn about Modelling nozzle flexibility

Learn how to add a flexible nozzle

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BACKGROUND ON MODELING NOZZLE FLEXIBILITY The addition of a nozzle flexibility element is meant to model the vessel shell flexibility. Assuming a rigid nozzle would attract large reaction forces at the nozzle and would be too conservative for vessel design. AutoPIPE nozzle flexibility element makes it very easy to estimate shell flexibility using several methods. For cylindrical vessels, the WRC297 and Bijlaard are the preferred methods. For cylindrical tanks with large diameters (order of 30 m), the API650 method is the preferred method. For reduced tee branches, the ASME Class 1 piping formula is appropriate. For nozzles on spherical or tori-spherical heads, the Spherical method is the most appropriate and is based on Bijlaard and is also part of the PD5500 British piping code. The nozzle element is a modified and simplified expansion joint element. While the expansion joint element has 6 stiffnesses, the nozzle element will have only 3 stiffnesses. The three stiffness are, radial, circumferential bending and longitudinal bending stiffnesses. Two shear and torsion stiffnesses are not applied to the nozzle element. Also for the nozzle element, the radial load due to pressure is not added as in the case of the flexible joint. The radial pressure thrust can be added automatically in WinNozl when calculating nozzle stresses. AutoPIPE will not calculate stresses in the nozzle or the connected vessel. It is recommended that the anchor reaction forces calculated in AutoPIPE be used in WinNozl for evaluating nozzle as well as vessel or shell stresses per the applicable ASME Div I or II, PD5500, KHK and API 650 codes. AutoPIPE can transmit these forces directly to WinNozl to minimise errors. When modelling the nozzle, the length between the nozzle flange and vessel wall should be modelled as a pipe element. The nozzle element should always be short; and the shorter it is the more accurate the model. It should be centred at the wall of the shell since it is meant to model the bending flexibility of the shell wall. The best way to model the nozzle flexibility element is to start it at outer face of the vessel and end it the inner face. The total length would then be the vessel thickness Modeling Nozzle Flexibility

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Pipe Element L = 75mm

Nozzle Flexibility Element L = 19mm

Vessel D = 1524mm T = 19mm L1=L2=1524mm

6.4.1.

EXERCISE 1: ADDING A FLEXIBLE NOZZLE h

TO ADD A FLEXIBLE NOZZLE

1) Click on A10 and select Insert > Flange. Select Slip-On for the flange Type, 150 for Pressure rating and Double-welded Slip-on as the Connection to pipe. Press OK to close. 2) Repeat Insert > Flange to insert a second mating flange. 3) Use Insert > Run and type 75 mm in the Length field to model the pipe between the mating

flanges and the vessel face A10 to A11. 4) Click on View > Single Line View to change to single line view and zoom as shown.

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5) Now, select Insert > Nozzle and enter the data as follows. Press OK to close.

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6) Adding a nozzle flexibility element is not enough. You need to support the end of the nozzle element using an anchor. There is no automatic support added to the nozzle. So select Insert > Anchor and select Rigid and press OK.

7) Select View > Solid Model View.

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8) Select View > All to get full model view as follows.

6.5.

LESSON 4: ADD CUT SHORT OR COLD SPRING Cut short or as often referred to as cold spring, is the process of cutting short the pipe by a small amount so as to distribute the load evenly between hot and cold conditions. Since the pipe is short, it is pulled together using a large reaction force equivalent to the cold spring load in the pipe. For example if a vessel is expected to grow by 50 mm under hot conditions it would have a high hot reaction at the nozzle while the cold reaction may be very low. It is Page 177


common practice to specify about half the hot movement as a cut short in order to even out the hot and cold loads. This concept can only apply to equipment and support reactions which are often subject to a different piping code, e.g. ASME Boiler and Pressure Vessel Code. In all B31 piping codes, the effect of cold spring should not be taken into account when calculating the expansion stresses. This is attributed to the fact that the B31expansion stresses already assume yielding since the allowable stress range can reach 2.5*Sh or: (1.25*Sc + 0.25*Sh) + (Sh-SL) Where Sh and Sc are the material hot and cold allowable stresses respectively and SL is the calculated sustained stress at the point. 2.5Sh can be attained when Sc = Sh and SL is zero. Under yielding conditions, any initial stresses due to cold spring are expected to dissipate and a permanent plastic deformation will take place. This is the reason why many engineers get surprised when disconnecting the pipe a few years later about the lack of any spring forces that existed at cold conditions during construction. The question remains how do we account for cold spring and what load case should we add it to? One approach is to apply it to the default load case GR. In this way it will automatically apply to both cold and hot conditions, since AutoPIPE uses GR as an initial state for thermal loads. But why should we add it if the code does not allow it? That is true. You should never use stress results with cut-short analysis on. For this reason you would need to perform two separate analyses. First analysis is without cut short in which you review the code stresses and produce the code stress report. Second analysis is with cut-short in which you exclude code stress results and only report support reactions and nozzle loads for hot and cold conditions. Some people avoid doing two separate analyses by including cut-short under a separate user case U1. This way they will not enter in the code stress calculations unless they add U1 to the sustained and expansion stresses which they should not. They then add U1 to non-code cases as follows: Cold reactions: GR+U1 Hot reactions: GP1TI +U1 OBJECTIVES The objectives of this lesson are as follows:

Learn how to add cut-short to a pipe

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6.5.1.

Learn how to perform static analysis with cut-short

Learn how to set the load combinations for cut-short

EXERCISE 1: ADD CUT-SHORT TO A PIPE In this sample you will use the last approach as it will help us demonstrate how to add new user non-code combinations. h

TO ADD CUT-SHORT TO A PIPE

1) Select A06 and then select Insert > Xtra Data > Cut short to insert a cut short at A06. Select U1 for the Load case to combine with, and enter 12 mm for the Enter amount of cut short as shown. Press OK to close.

2) Since load combinations are not defined till after the analysis is done, we will add the new load combinations after performing the first analysis. 6.5.2.

EXERCISE 2: PERFORM STATIC ANALYSIS WITH CUT SHORT

Now that the model is completed, let us analyze the system. Since you have a flexible joint that will open under pressure, you would need to include the axial pressure forces that will open the flexible joint. This can be done by enabling pressure analysis.

h

TO PERFORM STATIC ANALYSIS WITH CUT SHORT


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5) Enable the Thermal case T1, User case U1 then enable the Calculate pressure extension cases and Cut-short analysis fields. Both U1 and cut-short analysis need to be checked for inclusion of cut short analysis. Note that cut-short analysis will automatically un-check and hence needs to be checked every time you perform static analysis. Checking Calculate pressure extension will enable you to look at flexible joint opening due to pressure. 6) Enable Gaps/Friction/Soil field (if not already done so). By enabling this field AutoPIPE considers non-linear boundary conditions during the static analysis. Page 180


7) Press OK to accept the remaining defaults and close the Static Load Cases dialog.

8) Since you enabled Gaps/Friction/Soil, AutoPIPE displays the Nonlinear Analysis dialog to allow customization of how the non-linear analysis is performed. The first set of options is for nonlinear iteration control. Customization is only required if convergence problems occur during the analysis or a special load sequence is required. 9) In order to apply all occasional loads under the hot condition we will use OP1 as the initial state. Therefore do not change maximum iterations, displacement tolerance, force tolerance, friction tolerance and friction scale factor. Enable the following options:

Ignore friction – E1 to E10



Initial case for Occ. loads: = OP1

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10) Press OK to accept the default nonlinear options. 11) Press OK to close the Analysis Sets dialog. h


12) Select Analyze > Static from the menu to start the static analysis. Static analysis will cause assembly of the stiffness matrix of piping points and bends and will impose gravity and thermal loads to determine the pipe displacements and reactions. 13) AutoPIPE reports a static summary of the time taken to perform the analysis. Note that the Cancel button can be pressed at any time to discontinue the analysis.

14) Press OK from the status dialog after the analysis has completed successfully. Now that the model has been analysed, you can interactively review the results as described below. 6.5.3.

EXERCISE 3: SETTING LOAD COMBINATIONS FOR CUT SHORT In this section you will set up load cases needed for cut short analysis. As mentioned earlier you need the cold reaction GR+U1 and the hot reaction GP1T1+U1. Now let us look at the default non-code cases and identify the cases you need.

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1) Select Tools > Combinations and click on the Non-Code Comb. tab to show the available load combinations as follows.

2) You can see that the combination for hot reaction is available, but not the cold reaction GR+U1. You also see combinations that are not needed (Gravity{1}, Thermal 1{1}, Pressure 1{1}, User 1{1}) and so you will attempt to disable these later. 3) Click New to create a new user defined combination and type in the Combination name field and set the other data as follows. Press OK to close.

4) Now disable the combinations you would like to exclude in your report. Uncheck the load combinations under Print shown in the following dialog. Press OK when done.

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5) Now repeat the same for the code combinations by using the tab Code Comb. as follows

6) Uncheck the case Sus.+U1 as it is not applicable since we cannot add cut short to code stresses. Also the case Max Range is redundant since it is the same as Amb to T1. Press OK to close. 6.6.

LESSON 5: STRESS RESULTS AND RESTRAINTS REPORT You will review the stress results both interactively and through an output report. OBJECTIVES The objectives of this lesson are as follows:

Learn to interpret the stress results

Learn how to review expansion joint displacement due to pressure

Learn to interpret the restraints report

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6.6.1.

EXERCISE 1: STRESS RESULTS 1) Use ResuIts > Code Stress and the stress plot will be shown as follows. Press OK to close.

The maximum stress ratio is 0.57 and is caused by GR+Max P{1} (SUS) as shown on the top left corner. The maximum stress occurs at point A03 F -. 6.6.2.

EXERCISE 2: EXPANSION JOINT DISPLACEMENT 1)

Next we will show the expansion of the flexible joint due to pressure. Select ResuIt > Displacement and then select load case GP1T1U1{1} and Animate load case as follows.

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2) Next we will look at the output report. 6.6.3.

EXERCISE 3: OUTPUT REPORT In this exercise you will review the output report. h

REVIEWING THE OUTPUT REPORT

1) Use Result > Output Report and select the sub-reports as follows

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2) The output report will show as follows.


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SPRING HANGERS Spring Hanger Size and Series Selection How to use the selection table:

In order to choose a proper size hanger, it is necessary to know the actual load which the spring is to support and the amount and p p line movement from the cold to the hot position. p direction of the pipe Find the actual load of the pipe in the load table. As it is desirable to support the actual weight of the pipe when the line is hot, the actual load is the hot load. To determine the cold load, read the spring scale, up or down, for the amount of expected movement.

The chart must be read opposite from the direction of the pipe’s movement. The load arrived at is the cold load. If the cold load falls g of the hanger g selected,, relocate the outside of the workingg load range actual or hot load in the adjacent column and find the cold load. When the hot and cold loads are both within the working range of a hanger, the size number of that hanger will be found at the top of the column.

Should it be impossible to select a hanger in a particular series such that both loads occur within the working range, consideration should be given to a variable spring hanger g or a constant support pp hanger. g The cold load is calculated byy with a wider workingg range adding (for up movement) or subtracting (for down movement) the product of spring rate times movement to or from the hot load.

Cold load = (hot load) ± (movement) x (spring rate) A key criteria in selecting the size and series of a variable spring is a factor y This is a measurement of the percentage p g change g in known as variability. supporting force between the hot and cold positions of a spring and is calculated from the formula: Variability = (Movement) x (Spring Rate) / (Hot Load) If an allowable variability is not specified, good practice would be to use 25% as recommended by MSS-SP-58.

Load Table (N) for Selection of Hanger Size Hanger size

Working Range (mm) unshaded Shaded Rows Show Overtravel Figure No. Quad. Triple 98 B-268 82 51

0

51

102

152

203

38

0

38

76

114

152

25

0

25

51

76

102

13

0

13

25

38

51

B-268 Only 000 00

6

0

6

13

19

25

0

1

Hanger size

Fig. 82, Fig. B-268, Fig. 98, Triple & Quadruple Spring 2 3 4 5 6 7

8

9

10

11

12

13

Fig. 82, Fig. B-268, Fig. 98, Triple & Quadruple Spring 14 15 16 17 18

19

20

21

22

31.1

84.5

191.3

280.3

360.4

467.2

627.4

841.0

1121.34

1495.11

2002.39

2669.85

3470.8

4,539

6,007

8,010

10,679

14,417

20,024

26,698

35,553

47,212

62,741

83,433

111,266

31.1

89.0

195.8

293.7

373.8

485.0

654.1

876.6

1170.28

1557.41

2086.93

2781.09

3617.64

4,730

6,256

8,343

11,124

15,018

20,860

27,811

37,031

49,183

64,913

86,908

115,903

35.6

97.9

204.7

302.6

391.6

507.3

680.8

916.6

1214.78

1619.71

2171.48

2892.34

3760.04

4,917

6,510

8,677

11,569

15,619

21,693

28,923

38,513

51,150

67,970

90,388

120,539

40.0

106.8

213.6

315.9

404.9

525.1

707.5

947.8

1263.73

1682

2251.57

3003.58

3906.88

5,108

6,759

9,011

12,014

16,219

22,529

30,036

39,990

53,121

70,586

93,863

125,176

44.5

115.7

222.5

329.3

422.7

547.3

734.2

983

1308.23

1744.3

2336.12

3114.82

4049.27

5,295

7,008

9,344

12,459

16,820

23,361

31,148

41,472

55,088

73,198

97,338

129,812

48.9

124.6

231.4

338.2

436.1

565.1

756.5

1015

1357.17

1806.6

2420.66

3226.07

4196.11

5,487

7,258

9,678

12,904

17,421

24,198

32,261

42,949

57,059

75,815

100,813

134,449

53.4

133.5

240.3

351.5

449.4

582.9

783.2

1050

1401.67

1868.89

2505.21

3337.31

4338.5

5,673

7,511

10,012

13,349

18,021

25,030

33,373

44,431

59,026

78,427

104,293

139,081

53.4

137.9

249.2

360.4

467.2

605.2

809.9

1086

1450.62

1931.19

2585.3

3448.55

4,485

5,865

7,760

10,346

13,794

18,622

25,866

34,486

45,908

60,997

81,043

107,768

143,718

62.3

151.3

258.1

373.8

480.6

623.0

836.6

1121

1495.11

1993.49

2669.85

3559.8

4,628

6,052

8,010

10,679

14,239

19,223

26,698

35,598

47,390

62,964

83,655

111,244

148,355

62.3

155.7

262.5

387.1

493.9

640.8

863.3

1157

1544.06

2055.78

2754.39

3671.04

4,775

6,243

8,259

11,013

14,684

19,824

27,535

36,710

48,867

64,931

86,272

114,719

152,991

66.7

169.1

271.4

396.0

511.7

663.0

889.9

1193

1588.56

2118.08

2838.94

3782.28

4,917

6,430

8,512

11,347

15,129

20,424

28,367

37,823

50,349

66,902

88,884

118,199

157,628

71.2

178.0

280.3

409.4

525.1

680.8

916.6

1228

1637.51

2180.38

2919.03

3893.53

5,064

6,621

8,762

11,681

15,574

21,025

29,204

38,935

51,826

68,869

91,500

121,674

162,264

75.6

182.4

289.2

422.7

542.9

703.1

943.3

1264

1682

2242.67

3003.58

4004.77

5,206

6,808

9,011

12,014

16,019

21,626

30,036

40,048

53,308

70,840

94,112

125,149

166,901

80.1

191.3

298.1

431.6

556.2

720.9

965.6

1295

1730.95

2304.97

3088.12

4116.02

5,353

6,999

9,260

12,348

16,464

22,226

30,872

41,160

54,785

72,807

96,729

128,624

171,533

84.5

200.2

307.0

445.0

569.6

738.7

992

1330

1775.45

2367.27

3172.67

4227.26

5,495

7,186

9,514

12,682

16,909

22,827

31,704

42,273

56,267

74,778

99,341

132,104

176,170

89.0

209.1

315.9

453.9

587.4

760.9

1019

1366

1824.4

2429.56

3252.76

4338.5

5,642

7,378

9,763

13,016

17,354

23,428

32,541

43,385

57,744

76,745

101,957

135,579

180,807

93.4

218.0

324.8

467.2

600.7

778.7

1046

1402

1868.89

2491.86

3337.31

4,450

5,785

7,565

10,012

13,349

17,799

24,029

33,373

44,497

59,226

78,716

104,569

139,055

185,443

93.4

222.5

329.3

480.6

614.1

796.5

1072

1437

1917.84

2554.15

3421.86

4,561

5,932

7,756

10,261

13,683

18,244

24,629

34,210

45,610

60,703

80,683

107,185

142,530

190,080 194,716

97.9

235.8

338.2

489.5

631.9

818.8

1099

1473

1962.34

2616.45

3506.4

4,672

6,074

7,943

10,515

14,017

18,689

25,230

35,042

46,722

62,185

82,654

109,797

146,010

102.3

244.7

347.1

502.8

645.2

836.6

1126

1508

2011.29

2678.75

3586.5

4,783

6,221

8,134

10,764

14,350

19,134

25,831

35,878

47,835

63,663

84,621

112,414

149,485

199,353

106.8

249.2

356.0

516.2

663.0

858.8

1148

1544

2055.78

2741.04

3671.04

4,895

6,363

8,321

11,013

14,684

19,579

26,431

36,710

48,947

65,144

86,592

115,026

152,960

203,990

111.2

258.1

364.9

525.1

676.4

876.6

1175

1575

2104.73

2803.34

3755.59

5,006

6,510

8,512

11,262

15,018

20,024

27,032

37,547

50,060

66,622

88,559

117,642

156,435

208,626

115.7

267.0

373.8

538.4

689.7

894.4

1201

1611

2149.23

2865.64

3840.13

5,117

6,652

8,699

11,516

15,352

20,469

27,633

38,379

51,172

68,103

90,530

120,254

159,915

213,259

120.1

275.9

382.7

547.3

707.5

916.6

1228

1646

2198.17

2927.93

3920.23

5,228

6,799

8,891

11,765

15,685

20,914

28,234

39,216

52,285

69,581

92,497

122,871

163,390

217,895

Working Range (mm) unshaded Shaded Rows Show Overtravel Figure No. 82 B-268 98 Triple Quad 6

13

25

38

51

0

0

0

0

0

6

13

25

38

51

13

25

51

76

102

19

38

76

114

152

25

51

102

152

203

254

191

127

64

32

124.6 124 6

284.8 284 8

391.6 391 6

560.7 560 7

720.9 720 9

934.4 934 4

1255

1682

2242.67 2242 67 2990.23 2990 23 4004.77 4004 77

5,340 5 340

6,942 6 942

9,077 9 077

12,014 12 014

16,019 16 019

21,359 21 359

28,834 28 834

40,048 40 048

53,397 53 397

71,062 71 062

94,468 94 468

125,483 125 483

166,865 166 865

222,532 222 532

32

64

127

191

254

51

38

25

13

6

124.6

293.7

396.0

574.0

734.2

952.2

1282

1718

2291.62

3052.53

4089.32

5,451

7,088

9,269

12,264

16,353

21,804

29,435

40,884

54,509

72,540

96,435

128,099

170,341

227,168

6

13

25

38

51

129.0

302.6

404.9

582.9

752.0

974.5

1308

1753

2336.12

3114.82

4173.86

5,562

7,231

9,456

12,517

16,687

22,249

30,036

41,716

55,622

74,022

98,406

130,711

173,820

231,805

133.5

311.5

413.8

596.3

765.4

992

1335

1789

2385.06

3177.12

4253.96

5,673

7,378

9,647

12,766

17,020

22,694

30,637

42,553

56,734

75,499

100,373

133,328

177,296

236,442

137.9

320.4

422.7

609.6

783.2

1015

1362

1824

2429.56

3239.42

4338.5

5,785

7,520

9,834

13,016

17,354

23,139

31,237

43,385

57,847

76,981

102,344

135,940

180,771

241,078

Spring Rate (N/mm) 82

Spring Rate (N/mm)

–

–

5.25

7.35

9.46

12.3

16.5

22.1

29.4

39.2

52.5

70.0

91.1

119.1

157.6

210.1

280.2

378.2

525.3

700.4

931.6

1239.8

1646.0

2188.8

2919.0

82

1.23

2.63

2.63

3.68

4.73

6.13

8.23

11.0

14.7

19.6

26.3

35.0

45.5

59.5

78.8

105.1

140.1

189.1

262.7

350.2

465.8

619.9

823.0

1094.4

1459.5

B-268

98

–

–

1.23

1.75

2.28

2.98

4.03

5.43

7.35

9.81

13.1

17.5

22.8

29.8

39.4

52.5

70.0

94.6

131.3

175.1

232.9

309.9

411.5

547.2

729.7

98

Triple

–

–

0.88

1.23

1.58

2.10

2.80

3.68

4.90

6.48

8.76

11.7

15.2

19.8

26.3

35.0

46.8

63.0

87.6

116.8

155.3

206.6

274.4

364.7

486.4

Triple

Quadruple

–

–

0.70

0.88

1.23

1.58

2.10

2.80

3.68

4.90

6.65

8.76

11.4

14.9

19.8

26.3

35.0

47.3

65.7

87.6

116.4

155.0

205.8

273.7

364.9

Quadruple

B-268

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