02
23.09.10
Issued for Acceptance
JK
GA
GA
01
08.06.10
Issued for Review
JK
GA
GA
Made by
Chk'd by
Disc. appr.
Rev.
Issued date
Description
LM Proj. appr.
Client appr.
Contractor
Client:
Contract No.:
NSBU-061201 Project no:
Project title
160012 Document type:
GREATER EKOFISK AREA DEVELOPMENT
Platform(s)
RA
Area(s):
BD01
System(s):
A00
G00
Document title:
PIPE SUPPORT PROCEDURE Document no.:
Page:
Rev.:
BD01-AK-P-06042
02
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TABLE OF CONTENTS
1. 1.1 1.2 1.2.1 1.2.2 1.3 1.4 1.5 1.6 1.7 1.7.1 1.7.2 1.7.3 1.7.4
Introduction Revision history General Work included Work excluded Definitions Location Environmental Environment al data Compliance with statutory regulations Normative and informative references Normative references Informative references Apparent conflict conflict in requirements requirements Deviation from specifications specifications
7 7 8 8 8 8 9 9 9 10 10 11 11 11
2. 2.1 2.1.1 2.1.2 2.1.3 2.1.4 2.1.5 2.1.6 2.1.7 2.1.8 2.2 2.2.1 2.2.2 2.2.3 2.2.4
Scope of work For engineering engineering contractor Pipe support modelling & drawing Pipe support on engineering isometrics Interface with structural department Interface with mechanical department Interface with piping stress group Multidiscipline Multidiscipline interface Pipe support index Spring index For fabrication contractor Final preparation, drawing, bracing & material take off Temporary pipe supports Pipe support location tolerances Pipe support design requirements
11 11 11 11 12 12 12 12 12 12 13 13 13 13 13
3. 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.7.1 3.7.2 3.7.3 3.7.4 3.7.5 3.7.6 3.8 3.9 3.10
Design basis General Layout considerations considerations Expansion Deflections Explosion drag/blast Design factors and acceptance criterias Loads Acting loads Hydrostatic load Wind 16 Blast 16 Acceleration Run-up & spray load Design loads Welded pipe support framework Welded attachment to pipe (WA)
13 13 14 14 14 14 15 16 16 16
17 17 17 17 18
Greater Ekofisk Area Development Pipe support procedure
3.11 3.12 3.12.1 3.13 3.13.1 3.13.2 3.13.3 3.13.4
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Acoustic fatigue Bolted pipe support frame connections Bolt holes Temporary supports Interfaces Hydro test Fastening for transport Tagging
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18 18 18 18 18 19 19 19
4. 4.1
Pipe spans Guide spans
19 19
5. 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9
Pipe support locations Personnel hazard Maintenance Equipment requirements Spring location Pipe supports on equipment equipment Use of existing structure Pipe supports from another pipe Pipe support in module / area volumes Pipe Flange supports
20 20 20 20 20 20 20 20 20 20
6. 6.1 6.2 6.3
Structural steel interface No-go areas Bolted supports on structural flanges Heavy pipe support loads to structural steelwork
21 21 21 21
7. 7.1 7.2 7.2.1 7.2.2 7.2.3 7.3 7.4 7.4.1 7.4.2 7.4.3 7.5 7.5.1 7.6 7.7 7.8 7.9
Material specification Fabrication Welding General Fabrication welding Welded attachment to piping Painting Inspection and non destructive examination (NDE) Inspection / NDE of pipe support structure Inspection / NDE of welded attachment to piping Inspection / NDE of welded attachment to structure Selection of materials Temperature limitations Bolts and nuts (U-bolts and U-straps inclusive) Material for attachments clamped or welded to the pipe Welding between stainless/alloy stainless/alloy steel and carbon steel Preferred rolled sections
21 21 22 22 22 22 22 22 22 22 22 22 23 23 24 25 25
8. 8.1 8.1.1 8.1.2 8.1.3 8.2
Pipe support identification and documentation documentation Outline description of pipe support system Documents for identification and documentation of pipe supports Engineering isometrics Pipe support index Pipe support numbering
26 26 26 26 26 26
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8.2.1 8.2.2 8.3
Pipe support numbering Pipe support numbering in area borders Document numbering system
26 27 27
9. 9.1 9.2 9.3 9.4 9.5
Pipe support detail drawing Drawing layout Positioning Positioni ng information informatio n on pipe support drawing Material list Iso/Stress iso numbers on pipe support drawing Location references
27 27 27 28 28 28
10. 10.1 10.2 10.3 10.4 10.5 10.5.1 10.5.2 10.6 10.6.1 10.6.2 10.7 10.7.1
Detail design General Standard pipe support components / framing Special supports Surface of contact between pipe/pS detail and ps structure Supporting of carbon steel pipes Non insulated carbon steel pipes Insulated carbon steel pipes Supporting of stainless and alloy steel pipes Non insulated stainless and alloy steel pipes Insulated stainless and alloy steel pipes Supporting of GRE/GRP pipes Non insulated and insulated GRE/GRP pipes
28 28 28 28 28 29 29 29 29 29 29 29 30
11. 11.1 11.1.1 11.1.2 11.2 11.3 11.4 11.5 11.6 11.7 11.8 11.9 11.9.1 11.9.2 11.9.3 11.9.4 11.10 11.11 11.12
Standard pipe support details Shoes Welded shoes and trunnions Clamped shoes Wear plates U-bolts U-straps Non metallic pads Sliding supports Low friction supports Spring supports Attachments to piping piping Material Clamped Attachment Welded Attachment Attachments to pipe with with inside lining lining Hanger rods Removable supports BOP elevations above pipe support structure.
30 30 30 30 30 31 31 31 31 31 31 32 32 32 32 32 32 32 32
12. 12.1 12.2 12.3 12.4 12.5 12.6
Special considerations considerations Adjustable supports supports Supporting of pressure relief valves (PSV) Supporting of small bore branches - vent & drain connections Hold-down supports Shock absorbers (Mechanical snubbers) Supporting from mechanical equipment equipment
34 34 34 34 35 35 35
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12.7 12.8 12.9 12.10 12.11 12.12 12.13 12.14
Control valve set Utility stations Tundishes Rodding out points Manifolds Mud–bulk-solid Heavy support loads Piping submerged in seawater
35 35 35 35 35 35 35 35
13.
Pipe penetrations
36
14. 14.1 14.2 14.3 14.4 14.5 14.6 14.7 14.8 14.9
Insulated pipes Heat conservation – Class 1 Cold conservation conservati on – Class 2 Personnel protection – Class 3 Frost protection – Class 4 Fire protection – Class 5 Acoustic insulation insulation – Class 6, 7 & 8 External condensation condensation and icing protection – Class 9 Fire protection on flanges Future insulation
36 36 36 36 36 36 36 36 36 37
15. 15.1
General supporting of small bore pipes Special considerations considerations for supporting of small bore piping
37 37
16.
Hook-up supports
38
17.
Starter bars
38
18. 18.1 18.2 18.2.1 18.2.2 18.2.3
Surface preparation and protection Colour / Coating Fireproofing Full fire protection Integrity protection Deck / beam deflection effects due to fire
39 39 39 39 39 39
19.
Tagging of pipe supports
39
20. 20.1
Filing system Documents to be filed internally
40 40
21. 21.1 21.2 21.3 21.4
MAINTENANCE & MODIFICATION PROJECTS. (V&M). Pipe Support Design Practice. Use of adhesive for pipe supports. Tapped and screwed bolted connections Planning / working methods / LIAISON with other disciplines disciplines
40 40 40 41 41
22. 22.1
Interface with structural discipline Loads
41 41
23. 23.1 23.2
Typical bolted frames and connections General rules for bolted connection Typical bolted frames
42 42 43
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23.3 STANDARD BACK-MARKS FOR DRILLED BOLT HOLES IN ROLLED STEEL ANGLES (Unless noted otherwise on the pipe support drawing): 23.4 STANDARD BACK-MARKS FOR DRILLED BOLT HOLES IN UNP profiles. (Unless noted otherwise on the pipe support drawing) 23.5 STANDARD BACK-MARKS FOR DRILLED BOLT HOLES IN IPE, HEA & HEB profiles. (Unless noted otherwise on the pipe support drawing) 23.6 Typical offshore connection to primary steelwork.
48 49 50 50
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1.
INTRODUCTION
1.1
REVISION HISTORY
01 Issued for review.
02 Issued for Acceptance:
Rev.02:
o
1.2:
Re-phrased.
o
1.7.1:
References added. Existing references updated.
o
1.7.2:
Updated and re-phrased.
2.1.3:
o
3:
Heading changed.
o
3.1:
Bullet point added (facilitate access for inspection). Reference to TCD4583 and NORSOK L-002 added.
o
3.6:
Heading changed and section re-phrased.
o
3.7.1:
Wave loads added.
3.7.4: 3.7.6:
Re-phrased. Note to be transferred to TCD 4583, next rev.
o
3.10:
Alternative methodology (EN-13480) added.
o
3.11:
“The effect of vibration….” and “Fatigue calculations….” added.
3.12:
Re-phrased.
o
3.12.1: Updated.
o
5.9:
Heading changed. “Such supports need to….” added.
o
6.2:
New section.
o
6.3:
Reference to section 2.1.3 added. One bullet point added.
7.2.1:
Re-phrased.
7.4.1:
Re-phrased.
o o
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o
o
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7.4.3:
Heading changed. Section re-phrased.
o
7.5:
Material table updated.
o
7.7:
LDSS added to table column “welded to reinf. plt.”. Note 1 added.
o
7.8:
Filler material re-phrased. Sketch added.
o
7.9: Sentence “The exceptions are…..” re-phrased. Table updated (Beams and 40mm thk plate deleted).
o
11.1.1: “If shoes are required….” added.
o
11.1.2: Re-phrased.
o
11.12: Note added.
o
12.13: Section replaced with reference to 2.1.3.
21.1:
Re-phrased.
21.4:
Re-phrased.
o o o
22.1:
Section replaced with reference to 2.1.3.
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1.2
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GENERAL
The purpose of this procedure is to outline the philosophy for supporting pipes, define activities to be performed and assign responsibilities to parties involved. This is to ensure that the scope of work pertaining to design of pipe supports and associated structures on ConocoPhillips installations is fully covered, taking into account all the applicable codes of practice, standards, guidelines and regulations that are relevant for detail engineering.
1.2.1
WORK INCLUDED
This Procedure is applicable for pipe supporting of all platform production and utility piping systems in the scope of work.
1.2.2
WORK EXCLUDED
All instrument control piping, risers and sub sea pipe work, all heating & ventilation systems, and air & water service systems within the living quarter.
1.3
DEFINITIONS
All terms, phrases and abbreviations within the entire scope of this procedure shall be interpreted as follows: Company:
ConocoPhillips
Company's representatives:
Any agent(s) appointed by the Company to specify, or conduct inspections, tests, verifications and expediting functions that assure the quality and performance of the work specified.
Engineering contractor:
Company responsible for detail engineering of pipe supports
The work specified:
The scope of work in all "agreements", which contractually obligate the "supplier" to Company's specified requirements
Vendor/fabricator:
The Company's contractor (whether a main contractor, subcontractor, supplier, agent or manufacturer) who is responsible for meeting all requirements of the work specified and liable for the result
"Unless Other":
The phrase used to indicate the precedence over this Procedure of special requirements in Company's associated documentation or in any mandatory regulations.
Will:
Is normally used in connection with an action by the Company, rather than by a Contractor.
May:
Is used where a provision is completely discretionary.
Should:
Is used where a provision is advisory only.
Shall:
Is used where a provision is mandatory.
If (When):
Requirement at the Company's option, beyond minimum specification requirement.
Alloy steel lines:
Mean lines made of 6MO, Duplex, Super Duplex or Titanium.
Lean Duplex Steel
LDSS
Stainless Steel:
316 / 316 L
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Abbreviations: NORSOK
Norsk sokkels konkurranseposisjon
ANSI:
American national standards institute
ASME:
American society of mechanical engineers
API:
American petroleum institute
BLAST:
Forces created by explosion
TOS
Top of steel
BOS
Bottom of steel
BOP:
Bottom of pipe (Elevation)
CL
Centreline
EL
Elevation
BS:
British standard
DN:
Nominal diameter (In mm)
GRP:
Glass fibre reinforced plastic
NS:
Norwegian standard
PS:
Pipe support
Sch:
Schedule
WA:
Welded attachment to pipe
WT:
Wall thickness
UNO
Unless noted otherwise
FB
Flatbar
SHS
Square hollow section
RHS
Rectangular hollow section
NDE
Non-destructive examination
MPI
Magnetic particle inspection
DPI
Dye penetrant inspection
1.4
LOCATION
Location is the site of final installation.
1.5
ENVIRONMENTAL DATA
The atmosphere is saline. Ref. Project document “Metocean Design Basis” or similar
1.6
COMPLIANCE WITH STATUTORY REGULATIONS
The vendor is responsible for compliance of the Work Specified within the relevant code for the piping system.
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1.7
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NORMATIVE AND INFORMATIVE REFERENCES
The following standards include provisions and guidelines which, through reference in this text, constitute provisions and guidelines. Latest issue of the references shall be used unless otherwise agreed. Other recognized standards may be used provided it can be shown that they meet the requirements of the referenced standards
1.7.1
NORMATIVE REFERENCES
NORSOK L-002, rev.3
Piping system layout, design and structural analysis.
NORSOK M-001, rev.4
Materials selection.
NORSOK M-101, rev.4
Structural steel fabrication.
NORSOK M-102, rev.1
Structural aluminium fabrication.
NORSOK M-120, rev.5
Material data sheets for structural steel.
NORSOK M-121, rev.1
Aluminium structural material.
NORSOK M-601, rev.5
Welding and inspection of piping.
NORSOK N-001, rev.7
Integrity of offshore structures.
NORSOK N-004, rev.2
Design of steel structures.
TCD 4583
Piping system design requirements for new installations, modifications and repair of existing facilities
TCD 4650
Material Selection
TCD 2169
ConocoPhillips engineering numbering system
TCD 4314
Documentation for operation (DFO)
TCD 6296
Structural Design
BD01-AK-K-05001
Material Selection Philosophy
BD01-AK-K-05002
Coating Specification
ASME B31.3 (2008)
Process piping
ISO 14692, rev.1
Glass-reinforced plastics (GRP) piping.
API RP14E
Recommended practice for design and installation of offshore production platform piping systems.
NS 1871, rev.1
ISO general purpose screw threads - Basic profile.
ISO 262, rev2
ISO general purpose metric screw threads - Selected sizes for screws, bolts and nuts.
ISO 1461, rev1
Hot dip galvanized coatings on fabricated iron and steel articles.
EN 1090-2, rev.1
Execution of Steel Structures and aluminium structures – Part 2: Technical requirements for steel structures.
EN 1993-1-1, rev.1
Eurocode 3: Design of steel structures - Part 1-1: General rules and rules for buildings
ASTM A153 (2009)
Standard specification for zinc coating (hot dip) on iron and steel hardware
EN 10025, rev.1
Hot rolled products of structural steels.
Greater Ekofisk Area Development Pipe support procedure
DIN 933
Hexagon head bolts
DIN 934
Hexagon head nuts
BD01-AK-P-06043
Pipe support detail standard
1.7.2
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INFORMATIVE REFERENCES
BD01-AK-F-05001
Safety strategy
BD01-AK-F-05006
Passive fire protection philosophy
ELDS-AK-F-00101
Design accidental load specification
BD01-AK-P-06016
Piping detail standard
Other informative references are: Pipe stress procedure, Comprehensive analyses, Metocean design basis, and Line list.
1.7.3
APPARENT CONFLICT IN REQUIREMENTS
The engineering contractor shall inform Company immediately if a significant doubt occurs about the specified requirements. The subject must be clarified and necessary confirmation given in writing from the Company before the work is executed. Company is the sole judge.
1.7.4
DEVIATION FROM SPECIFICATIONS
Deviations may only be made after Company approval, alternatives to the above referenced codes, standards, specifications and guidelines may be offered if considered equivalent or better. All deviations shall be approved by Company thru treatment of non conformance in SAP.
2.
SCOPE OF WORK
2.1
FOR ENGINEERING CONTRACTOR
2.1.1
PIPE SUPPORT MODELLING & DRAWING
Engineering contractor shall perform detail design of pipe supports for process and utility pipes. A volume model of calculated structural elements will be placed in the 3D model based on support details selected from the Pipe Support Detail Standard on lines specified as scope in point 1. Engineering contractor shall produce detail pipe support drawings for specified scope above, including annotation to complete the drawing with material list and references. Pipe support details, like springs, clamps, shoes, guides etc. (non-structural pipe supports on pipe items) will be located/indicated with reference to particular sheet in the Pipe Support Detail Standard.
2.1.2
PIPE SUPPORT ON ENGINEERING ISOMETRICS
Support location and number will be shown on the engineering isometric together with welded attachment information if applicable.
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2.1.3
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INTERFACE WITH STRUCTURAL DEPARTMENT
The Pipe Support Group shall at the start of a project agree on a clear and consistent format/routine for communicating pipe support layouts and reporting pipe support reactions (i.e. vertical, horizontal and moment force components at pipe support footings) to the Structural Department. Pipe supports with one or more reaction components (vertical/horizontal) exceeding 10KN shall be included in a list/ plot as well as those where the sum of several adjacent components exceeds 10KN on the same structural member. Reactions exceeding 10kN shall be approved by the Structural Department prior to commencing prefabrication. The overall layout and configuration of pipe supports with reactions less than 10KN shall also be agreed with the Structural Department. The Pipe Support Group shall calculate and design pipe support frames carrying total vertical or horizontal pipe loads to 35KN. Design and calculations of frames carrying more than 35KN vertical or horizontal pipe load shall be checked and approved by the Structural Department prior to commencing prefabrication. Pipe support frames shall be designed to avoid significant moment reactions.
2.1.4
INTERFACE WITH MECHANICAL DEPARTMENT
The pipe support group/designer shall coordinate with, and give input to Mechanical Department regarding load input and interface requirements such as attachment plates/lugs to vessel etc. Requirements shall be marked up on vendor drawings.
2.1.5
INTERFACE WITH PIPING STRESS GROUP
The pipe support group/designer shall coordinate with stress department to get all required information regarding critical pipes (i.e. load, function & spring information). Load information should be provided using reports from applicable 3D modelling tool (i.e. PDMS) used by engineering contractor for this purpose.
2.1.6
MULTIDISCIPLINE INTERFACE
The pipe support group/designer should seek to coordinate for common rack support locations for cable trays, HVAC ducts and piping.
2.1.7
PIPE SUPPORT INDEX
The pipe support group/designer shall enter support information into the pipe support index. This document shall be issued before project end. The index shall contain pipe support information such as pipe support number, function, line number reference etc. See TCD-4314 for required information to be included. Before issue to the Company, the pipe support index shall be updated with spring information where applicable.
2.1.8
SPRING INDEX
The pipe support group/designer shall enter spring information into the Spring Support Index. The index shall include information such as pipe support number, line number reference, spring type, spring size, preset load, operating load, travel, and stress isometric reference. This information need to be included in the pipe support index before the pipe support index is issued to the Company (ref. 2.1.7).
Greater Ekofisk Area Development Pipe support procedure
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2.2
FOR FABRICATION CONTRACTOR
2.2.1
FINAL PREPARATION, DRAWING, BRACING & MATERIAL TAKE OFF
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Final preparation of shop fabrication drawings based upon drawings delivered by Engineering Contractor. Install bracing in line with Piping Detail Standard Material take-off and procurement of pipe support items except for spring assembly.
2.2.2
TEMPORARY PIPE SUPPORTS
Locate and design temporary supports (Sea fastening, testing, interface) and Tow Out/Transport supports. Additional supports in follow on engineering at the fabrication yard.
2.2.3
PIPE SUPPORT LOCATION TOLERANCES
Pipe support locations given by Engineering Contractor are to be regarded as fixed, but Fabrication Contractor is allowed a certain location tolerance as long as all other requirements are met such as maximum allowable pipe span etc. Following location tolerances are acceptable without prior Company approval:
Pipes that require comprehensive analyses:
All other lines:
250
100
mm location tolerances
mm location tolerances
For location of welded attachments to a pipe, the isometric drawing is the governing document.
2.2.4
PIPE SUPPORT DESIGN REQUIREMENTS
The fabrication contractor shall design the pipe supports in his scope according to the requirements given in this procedure and in the pipe support detail standard and piping detail standard.
3.
DESIGN BASIS
3.1
GENERAL
The pipe supports function is to support the pipe from the surrounding structure. They shall:
Carry the weight of the pipe as well as that of any equipment connected to the pipe.
Control the movement of the pipe.
Direct and transfer the loads from the pipe to the surrounding structure, and generally remove or restrain one or more of the six degrees of freedom at particular points on the pipe.
The supports for piping shall be positioned and selected to:
Prevent piping stresses in excess of those permitted by the design code for the system.
Avoid the possibility of liquid pockets.
Prevent deflections in pipe supports beyond stated requirements.
Prevent leakage at joints.
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Prevent thrusts and moments on connected equipment in excess of those permitted by applicable requirements.
Prevent resonance with imposed wind forces or contained fluid induced vibrations.
Prevent resonance with imposed mechanical or acoustically induced vibrations from reciprocating machines.
Prevent interference with free thermal expansion or contraction as required by the pipe stress analysis.
Prevent unintentional disengagement of piping from its support.
Prevent deflections of piping greater than those, which the span selection tables in the Pipe Support Detail Standard, are based on.
Facilitate access for inspection
Piping requiring drainage slope shall be given special consideration.
Pipe supports shall be designed to fulfil requirements stated in TCD4583 sect. 2.2.17 and NORSOK L-002 sect. 6.17
3.2
LAYOUT CONSIDERATIONS
The pipe supports shall be considered an integral part of the pipe work and structural design and shall be considered from piping layout studies through to final support selection. Common supports for other services such as Electrical/Instrument Cables and HVAC ducting should be utilised whenever practical.
3.3
EXPANSION
Expansion calculations for piping shall be based on maximum/minimum design temperatures stated in the process line list.
3.4
DEFLECTIONS
The effect of deck deflections, platform sway and flexibility in structures and equipment such as storage tanks shall be considered in selection of supports and incorporated in design/calculation where relevant. Magnitude of deflection and sway shall be obtained from the Structural- and Marine Disciplines.
3.5
EXPLOSION DRAG/BLAST
The design of the pipe supports shall consider the effects of explosion drag/blast loads.
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3.6
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DESIGN FACTORS AND ACCEPTANCE CRITERIA
Pipe supports shall be proven to satisfy the limit states outlined in NORSOK Standard N-001, i.e.:
Ultimate Limit State, ULS
Serviceability Limit State, SLS (eg. deflections)
Accidental Limit State, ALS (eg. blast)
Fatigue Limit State, FLS where relevant (eg. acoustic induced vibrations)
Material factors (MF):
Material factors shall be applied as outlined in NORSOK Standard N-001, i.e.:
ULS: MF for the selected pipe support material (ref. section 7.5) shall according to NORSOK Standard N-001 be set to 1,15 for steel material and 1,2 for aluminium material. Material factors for welds and bolt connections shall be 1,3 according to NORSOK Standard N-004.
SLS/ ALS: MF for the selected pipe support material (ref. section 7.5) shall according to NORSOK Standard N-001 be set to 1.0
Load combinations and -factors (LF):
Loads acting on the pipe support shall be factored and combined in the limit states listed above and as outlined in NORSOK Standard N-001.
ULS: In most cases this means that the loads on the pipe support coming from the pipe stress analysis shall be factored by 1,3 in ULS and 1,0 otherwise, unless the pipe support receive environmental loads such as wind and/ or waves (typically for pipe supports under or at the periphery of platform cellar decks, ref. section 3.7.6). Also a surplus load factor of 1.2 may be used in addition to 1.3 when the exact loads are not known.
SLS/ALS/FLS: All combinations shall apply a load factor of 1,0.
Acceptance criteria:
The design stresses calculated from the applied (factored) loads shall not exceed the yield stress of the material, all limit states included.
Deflections shall not exceed the most conservative of L/360 or 3mm (where L is the span of the pipe support member) in the restrained directions (i.e. RS, LG, HD, LS). Structural deflection in tie in point also to be included.
Greater Ekofisk Area Development Pipe support procedure
3.7
LOADS
3.7.1
ACTING LOADS
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The design of pipe support elements and supporting structures shall be based on all concurrently acting loads. This may include the following:
Weight of pipe, fluid, insulation etc.
Hydrostatic test loads
Loads introduced by service pressure and temperature
Variable operating loads
Friction effects
Loads due to liquid slugs
Pulsation forces caused by reciprocating equipment
Wind forces
Blast loads
Heat loads
Acceleration
Wave loads /Run-up & spray
3.7.2
H YDROSTATIC LOAD
For piping containing gas or vapour subject to hydro test, support design shall take account of hydrostatic test load.
3.7.3
WIND
The effect of wind on exposed piping shall be calculated in accordance with the design code and wind speeds applicable to the project
3.7.4
BLAST
The project safety discipline shall specify which pipes and pipe supports require to be designed to withstand the pressure/blast from an explosion. The pipe stress group shall calculate the pipeline blast loads. The calculated blast loads shall be shown on the stress isometric and reported to the pipe support group for design of pipe supports. Blast loads on the pipe support structure shall be added to the pipeline blast loads. Ref. NORSOK L-002. When calculating the pipe support frame for blast, the drag pressure effect acting directly on the pipe support itself, shall also be accounted for. Allowable stress is to be set to 1.0 x yield stress for the support material. Pipe support deflection limit is 200mm. Use load factor = 1, and material factor = 1. When designing / checking pipe supports for blast, possible shielding from another pipe, equipment etc. should be taken into account. Less conservative blast calculations (but more complex) are possible if the above mentioned procedure is found to cause unwanted effects on the pipe support design. In these cases, the structural department is to be consulted for optimizations/new calculations.
Greater Ekofisk Area Development Pipe support procedure
3.7.5
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ACCELERATION
Gravity factors applicable to the project shall be added to design loads for pipe supports.
3.7.6
RUN-UP & SPRAY LOAD
Pipes that are exposed to wave run-up and spray must be designed to withstand these loads. Run-up & spray loads are to be regarded as design loads. NOTE: Due to subsidence (present and/or future) the location of new or modified pipe runs under or at the periphery of platform cellar decks shall preferably be avoided. If this is not possible the locations and supporting of such pipes shall be approved by ConocoPhillips' Asset Integrity Department. The reason for this is:
To confirm future freeboard and design wave (local/global) criteria.
Design wave kinematics can be complex (eg. under deck jetting) and require third party input.
The additional wave loading may not be acceptable for the platform (jacket) as a whole.
THIS NOTE TO BE TRANSFERRED TO NEXT REVISION OF TCD 4583
3.8
DESIGN LOADS
The pipe support loads should be based on the following:
Vertical load:
The weight of the pipe span carried by the actual support.
Horizontal load:
For rest supports, the horizontal load may be assumed equal to the friction force. The following coefficient of friction should be used to determine forces at sliding surfaces. Surfaces Steel to steel (Corroded) Stainless Steel to Stainless Steel Stainless Steel to Teflon
Friction coefficient
0.3 0.15 0.1
For anchors, line stops and in some cases guides, the vertical load may be used as design load in horizontal direction.
Load effects listed above shall be considered. Loads given on stress sketches shall also be reflected.
3.9
WELDED PIPE SUPPORT FRAMEWORK
Standard pipe support weld is (UNO):
a = 1 x WT for SHS & RHS profiles with WT up to and including 6.3mm. For wall thickness >6.3mm part pen weld is to be used
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a = 0.7 x WT CFW for all other profiles.
Should the weld size differ from the above mentioned, the weld shall be specified according to applicable fabrication standards (EN-1090-2).
3.10
WELDED ATTACHMENT TO PIPE (WA)
Pipe wall stresses caused by loading on WA shall be less than requirements stated in ASME B31.3 and guidelines stated in Kellogg’s: Design of piping systems (Alternatively the methodology outlined in EN-13480, part 3). Welding of field welded shear lugs shall comply with valid welding specifications and procedures. Maximum stress level on these welds must not exceed limits stated in ASME B31.3. Minimum distance between two welds on a pipe shall not normally be less than 50 mm (toe to toe). No welded attachment, including trunnions, shall be welded to Cold Pulled Bends. Wear plates or doubler plates shall under no circumstances be used on elbows.
3.11
ACOUSTIC FATIGUE
Special attention shall be paid to welded attachment / doubler plates on lines subject to acoustic fatigue conditions. A full circumferential reinforcement ring shall be welded to the pipe when welded attachment is required. The effect of vibration on pipe support and structure fatigue shall also be considered. Fatigue calculations of the pipe support (FLS) may be required.
3.12
BOLTED PIPE SUPPORT FRAME CONNECTIONS
With the exception of temporary, hook-up or removable supports, and supports towards aluminium sections/plates, bolted connections shall (due to inspection/corrosion considerations) be avoided in pipe support structures and their connections to existing structures (Unless welding is not possible due to offshore hot-work restrictions). Any bolts used shall have hardened washers and be tensioned and secured according to applicable standards in the project. Corrosion between carbon steel and stainless steel must be avoided using an isolation barrier.
3.12.1
BOLT HOLES
Holes for bolts attached to structural steel members shall be according to EN1090-2/ EN1993-1-1: Bolts ≤ M14 = 1mm larger. Bolts M16-M24 = 2mm larger Bolts ≥ M27 = 3mm larger.
3.13
TEMPORARY SUPPORTS
The Fabrication Contractor shall design and supply all temporary supports needed for, but not limited to the following cases:
3.13.1
INTERFACES
Temporary supports on pipes at interfaces where the ends of the pipes are insufficiently supported.
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H YDRO TEST
On piping systems to be hydro tested where an optimised pipe and support system would be overstressed.
3.13.3
FASTENING FOR TRANSPORT
Pipe supports for fastening during tow out/transport.
3.13.4
TAGGING
Temporary supports shall be painted according to Platform Colour Coding Schedule for the project. "TEMPORARY SUPPORT, REMOVE BEFORE START-UP AND COMMISSIONING", shall be hard stamped onto the support together with the support number in a rectangular white painted area visual after erection. The numbering digits shall be minimum 12 mm high. The instruction for removal shall also be noted on the support drawings if any. Wherever possible, bolted connections shall be used for easy removal.
4.
PIPE SPANS
The determination of basic pipe spans, overhangs and guide spacing, for piping systems not covered by detailed stress analysis, shall be in accordance with data in the tables and graphs in project Pipe Support Detail Standard. These table values must not be exceeded without approval from the Stress department. These tables are based on straight pipe runs. If the pipe has one or more directional changes, the span in the design must be decreased by the pipe support designer. Piping systems covered by a detailed stress analysis shall be supported strictly in accordance with the requirements shown on relevant stress isometric. No alteration exceeding specified tolerances shall be made except by written approval from the stress department. Standard pipe spans do not apply where concentrated weights such as valves or heavy fittings. Supports shall be placed as close as possible to these loads in order to keep pipe bending stresses within code allowable.
4.1
GUIDE SPANS
The piping system shall also be sufficiently guided. Include hold-down function if not in conflict with the function of the pipe. Following guidelines should be followed (based on straight pipe run):
metal piping DN40 and less: every support
metal piping DN50 – DN100: every second support
metal piping larger than DN100: every third support
GRP piping: according to Vendor Requirement.
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5.
PIPE SUPPORT LOCATIONS
5.1
PERSONNEL HAZARD
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No pipe supports shall, including springs, shock absorbers etc., be placed in a location likely to be a safety hazard to personnel e.g., tripping hazard, restricted headroom, blocking escape routes.
5.2
MAINTENANCE
Supports should wherever possible be located such that equipment and control valves etc. can be removed for maintenance without the necessity of temporary supports for remaining piping.
5.3
EQUIPMENT REQUIREMENTS
Pipe supports shall be located dependent upon equipment requirements, e.g. removable spools for maintenance etc., pipe size and configuration, location of heavy valves, strainers etc. and the structure that is available to support the same.
5.4
SPRING LOCATION
The location of spring support shall ensure that load adjusters, load flanges, fixing bolts etc. are accessible for adjustment or removal.
5.5
PIPE SUPPORTS ON EQUIPMENT
The support of piping from mechanical equipment, vessels and exchangers shall be avoided wherever possible. When such locations have to be used, full details of clips, loads etc. shall be advised and agreed with relevant department.
5.6
USE OF EXISTING STRUCTURE
Location of supports shall maximise the use of existing structure with additional structure members being kept to a minimum.
5.7
PIPE SUPPORTS FROM ANOTHER PIPE
Supporting one pipe from another pipe should only be considered when all other possibilities have been investigated and is only applicable for pipes less than DN50. On no account shall any lines be supported from a copper-nickel or GRP pipe.
5.8
PIPE SUPPORT IN MODULE / AREA VOLUMES
Supports shall always be located within the confines of each module/area. They shall not protrude beyond their perimeters, with the exception of pipe supports classed as hook-up.
5.9
PIPE FLANGE SUPPORTS
Flange supports should be avoided. Flange supports should only be considered if all other possibilities have been investigated and found not sufficient. It will then be regarded as a special pipe support. Such supports need to be approved by company for each case.
Greater Ekofisk Area Development Pipe support procedure
6.
STRUCTURAL STEEL INTERFACE
6.1
NO-GO AREAS
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Structural areas with restrictions regarding pipe support attachments, No Go Areas, must be defined. This is being done by the structural department. Generally pipe supports welded to these areas are not allowed. If no other solution is possible, the pipe support has to be accepted by the structural department in each case.
6.2
BOLTED SUPPORTS ON STRUCTURAL FLANGES
Also, bolted support from structure member flange as shown in figure section 23.6 shall be avoided as far as practically possible. Such a support configuration shall be approved by the project structural department in each case before commencing prefabrication (to ensure documentation of the addition of local stresses to the global stress usage of the structure member ).
6.3
HEAVY PIPE SUPPORT LOADS TO STRUCTURAL STEELWORK
The Pipe Support Group shall coordinate, report and agree pipe support design and configurations with the Structural Department as outlined in Section 2.1.3. Point loads above 10 KN (also collective loads from 2 or more pipes, which locally give a load exceeding 10 KN) shall be reported to Structural Department. On pipe supports with collective loads exceeding 35 KN, the design and calculation of the pipe support structural frame shall be transferred to structural scope. All pipe supports which transmit individual or collective loads above the agreed limits set by Structural Department for the given project to a structural member or deck plate shall be closely co-ordinated with, and approved by the Structural Department. Generally, the following is not allowed:
7.
Un-braced cantilever supports from webs of beams or girders.
Pipe supports attached to truss diagonals should in general be avoided. In cases where other possibilities are inconvenient, the structural department shall be informed for eventual approval.
Pipe supports attached to horizontal bracings.
Pipe support attachments that will cause torsion in structural members.
Pipe supports attached to structures subjected to fatigue, e.g. crane pedestal and support structures, flare stack structures.
Pipe supports attached to deck plate which has insufficient capacity, stiffness or weld to transfer the reaction loads into supporting structural steel.
MATERIAL SPECIFICATION
All materials shall be according to this procedure, the pipe support detail standard, the pipe support detail drawing and referenced standards.
7.1
FABRICATION
Fabrication of pipe supports shall comply with project specification for structural steel fabrication.
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7.2
WELDING
7.2.1
GENERAL
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All welding shall be performed in accordance with company approved welding procedures.
7.2.2
FABRICATION WELDING
Fabrication welding of the pipe supports shall be performed in accordance with specification: NORSOK M-101 Structural Steel Fabrication.
7.2.3
WELDED ATTACHMENT TO PIPING
All welding of "Welded Attachments" onto piping shall be in accordance with specification: NORSOK M-601 Welding and Inspection of Piping System.
7.3
PAINTING
Structural steel parts shall be painted after fabrication according to the project’s “surface protection specification” and “platform colour coding schedule”.
7.4
INSPECTION AND NON DESTRUCTIVE EXAMINATION (NDE)
7.4.1
INSPECTION / NDE OF PIPE SUPPORT STRUCTURE
Welds within the pipe support shall be subject to NDE in accordance with NORSOK M-101/N-004 and applicable structural documents, specifying design classes and inspection categories for structural steel.
7.4.2
INSPECTION / NDE OF WELDED ATTACHMENT TO PIPING
NDE of welded attachments onto the pipe shall be in accordance with specification NORSOK M-601: Welding and Inspection of Piping System.
7.4.3
INSPECTION / NDE OF WELDED ATTACHMENT TO STRUCTURE
NDE of welded attachments onto structural steel shall be in accordance with NORSOK M-101/N004 and applicable structural documents, specifying design classes and inspection categories for structural steel. Inspection category for the weld between the pipe support and the structural steel shall be set according to the design class for the structural steel.
7.5
SELECTION OF MATERIALS
Pipe supports materials shall be according to Corporate Requirements; Use of materials in pipe support structures and material types and temperature limitations for pipe support details. First choice material for pipe support structural sections is lean duplex stainless steel (LDSS). First choice material for pipe support standard details is stainless steel (316L).
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PRODUCT FORM
MATERIAL
GRADE
MDS (Norsok std)
Plates:
LDSS
ASTM A 240 UNS S32304 (With PRE>28)
HOLD
ASTM A 240 UNS S32003
HOLD
SS 316L
ASTM A 240 grade 316L
S01 (M-630)
CS
EN 10025 S355J2 / S355K2
Y05 (M-120)
Aluminium
5083-H2
M01 (M-121)
Titanium
ASTM B 265 gr. 2
T01 (M-630)
SDSS (25Cr)
ASTM A 240 UNS S32750
D55 (M-630)
ASTM A 240 UNS S32760 ASTM A 240 UNS S32550 Profiles:
LDSS
ASTM A 240 UNS S32304 (With PRE>28) ASTM A 240 UNS S32003
Hanger Rods:
Forgings:
7.5.1
HOLD HOLD
SS 316L
ASTM A 240 grade 316L
S01 (M-630)
CS
EN 10025 S355J2 / S355K2
Y05 (M-120)
CS
EN 10210 S355J2H
Y04 (M-120)
Aluminium
6082-T6
M01/M02/M03/M04/M05 (M-121)
SS 316L
ASTM A 276 grade 316L
S01 (M-630)
CS
EN 10025 S355J2 / S355K2
Y05 (M-120)
SS 316L
ASTM A 182 grade F 316
S01 (M-630)
LTCS
ASTM A 350 grade LF2
C11 (M-630)
TEMPERATURE LIMITATIONS
Special consideration shall be taken for pipes with design temperature below –46 °C. A barrier (cold trap) might be required between pipe support and steelwork to avoid cold transportation in to the main steel through the support. Special consideration shall also be taken for lines with high design temperature (i.e. exhaust pipes). High temp barrier may be required in order to avoid high temperature being transferred into pipe support structural framework.
7.6
BOLTS AND NUTS (U-BOLTS AND U-STRAPS INCLUSIVE)
U-Bolts and U-straps
316L
Alloy steel bolts Semi-finished heavy hex. nuts
DIN 933 GRADE 8.8 (full threaded) DIN 934 GRADE 8
Bolts and Nuts to be Hot Dip Galvanised to
ASTM A153 or ISO 1461
Bolts with a diameter 10 mm shall be stainless steel Type 316 for metal temperature below 60 C based upon maximum operating temperature. All threads for bolts, rods, nuts etc. shall be metric. The threads shall be according to NS 1871 and ISO 262.
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7.7
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MATERIAL FOR ATTACHMENTS CLAMPED OR WELDED TO THE PIPE
The material for attachments to pipes shall be selected to suit the mechanical and chemical properties and design temperature of parent pipe. The material shall be selected from guidelines below. The rule for selection of material in reinforcement plates and shoes/brackets are as follow:
Reinforcement plates and brackets welded directly to pipe: As pipe class material, alternatively materials compatible with the pipe material (i.e. mechanical properties, chemical composition and design temperature of the pipe material)
Pipe support welded to reinforcement plates: Stainless steel type 316L is acceptable, also for temperatures above 60 C.
Clamped shoes: Stainless steel type 316L is acceptable, also for temperatures above 60C.
Guidelines for Selection of Materials for Brackets, Reinforcing Plates and Shoes. PIPE MATERIAL
REINF. PLATES Welded to pipe
BRACKETS Welded to Welded to pipe Reinf. plt.
WELDED SHOES Welded to Welded to pipe Reinf. plt.
Carbon Steel
As pipe class material As pipe class material As pipe class material As pipe class material
As pipe class material As pipe class material As pipe class material As pipe class material
LDSS/316L
NA
316L
316L
LDSS/316L
NA
316L
316L
LDSS/316L
NA
316L
316L
LDSS/316L
NA
316L (Note 1)
316L
Austenitic Stainless (AISI 316) Super Austenitic Stainless Duplex
Titanium 6Mo Stainless Steel GRP (ISO 14692)
1.
Titanium B265 Gr. 2 As pipe class material
As pipe class material
LDSS/316L
NA
As pipe class material
CLAMPED SHOES
316L 316L
316L
316L
When pipe support is subject to seawater (submerged or in spray zone) 25 Cr Duplex shall be used.
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7.8
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WELDING BETWEEN STAINLESS/ALLOY STEEL AND CARBON STEEL
Welding between stainless steel and carbon steel is acceptable when the distance between carbon steel attachment and pipe, is at least 50 mm. A stainless filler material shall be used for welded connections between stainless steel and carbon steel. The weld and the attachment shall be painted.
7.9
PREFERRED ROLLED SECTIONS
Material for pipe support steel profiles and plates shall be lean duplex stainless steel (UNS S32304). The exceptions are where SHS larger than SHS150 is needed, and where pipe support frames are submerged in seawater or subject to frequent splash/run-up/sea spray. In these cases, carbon steel frame with suitable flatbar on top shall be used. The selection of steel sections and qualities should be done as early as possible, in order to simplify design and keep the stock as small as possible. The following sections may be used as guidance:
Profile type Angle
Material: LDSS
Material: Al
L50 x 50 x 5 (Smallbore) L60 x 60 x 6 L80 x 80 x 8 L100 x 100x 10
(L50 x 50 x 5) (L75 x 75 x 9) (L100 x 100 x 10)
Square:
SHS50x50x5 (Smallbore) SHS 60 x 60 x 5 SHS 80 x 80 x 6 SHS 100 x 100 x 6 SHS 120 x 120 x 6 SHS 150 x 150 x 6 Rectangular:
(RHS 150 x 100 x 6) Plates:
6 THK 10 THK 15THK
(SHS 80 x 80 x 5) (SHS 100 x 100 x 5) (SHS 120 x 120 x 9)
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20 THK Flat bars:
FB 80 x 20 FB 100 x 20 FB 150 x 20 FB 175 x 20 FB 200 x 20 FB 250 x 20 * (See Note) FB 300 x 20 * (See Note) FB 400 x 20 * (See Note) FB 500 x 20 * (See Note)
Note:
(FB 75 x 10) (FB 100 x 10) (FB 150 x 10) (FB 150 x 15)
Profiles enclosed in parentheses shall be second choice. Flat bars marked with * to be cut from plate by Fabricator.
8.
PIPE SUPPORT IDENTIFICATION AND DOCUMENTATION
8.1
OUTLINE DESCRIPTION OF PIPE SUPPORT SYSTEM
8.1.1
DOCUMENTS FOR IDENTIFICATION AND DOCUMENTATION OF PIPE SUPPORTS
The following documents and drawings are used to locate, identify, list or detail all pipe supports:
Structural steel drawings
Engineering Isometrics
Stress Isometrics
Pipe Support Index
Vessel Clip Data Sheet
Pipe Support Standard Details
Spring index
8.1.2
ENGINEERING ISOMETRICS
Pipe support location and number shall be shown on the Engineering Isometric by using a symbol and dimensions to nearest reference point. Standard welded attachment on pipe details and materials shall be included on the Engineering Isometric.
8.1.3
PIPE SUPPORT INDEX
All Pipe Supports shall be listed by unique number in sequential order on an appropriate index.
The index shall contain pipe support number, line number, line size, stress isometric number, support functions, welded attachments, support status and welded attachments Y/N.
8.2
PIPE SUPPORT NUMBERING
8.2.1
PIPE SUPPORT NUMBERING
Each support shall be identified by a unique sequential number within each area. Pipe support area code should be the same as the area code for the supported pipe.
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PS-P543-0101
Where: PS
is Pipe Support.
P543
is Area.
0101
is Sequence number.
The following numbering system shall be used: 0001-2999 shall be for general pipe supports. 3000-3499 shall be for spring supports. 3500-3999 shall be for hook-up. 4000-4999 shall be for small bore pipe supports. 5000-5999 shall be used for Pipe rack / Bridge supports. 6000-6999 shall be for Vendor Package Pipe Supports. 7000-7499 shall be used for Pipe bracings 8000-8999 shall be used for site, yard use only. 9000-9499 welded Penetration. 9500-9999 shall be used for training purposes.
All supports shall be identified in this manner.
8.2.2
PIPE SUPPORT NUMBERING IN AREA BORDERS
A pipe support located on the north and east match line of an area shall be numbered in the adjacent areas.
8.3
DOCUMENT NUMBERING SYSTEM
Document numbers for pipe support detail drawings and index, will be specified in the specification project Engineering Numbering System.
9.
PIPE SUPPORT DETAIL DRAWING
The pipe support detail drawing shall contain all the necessary information for the construction and installation of the pipe support.
9.1
DRAWING LAYOUT
Generally, the detail drawings shall be drawn in scale. The standard drawing size is A3. The support should normally be drawn using 2 elevation views and supplemented with an iso view. If necessary, additional supplementary views and details shall be drawn.
9.2
POSITIONING INFORMATION ON PIPE SUPPORT DRAWING
All necessary positional information i.e. co-ordinates and angles shall be shown. Top of steel (TOS) or bottom of steel (BOS) as well as centre line elevations (CL EL) for the support point shall be given on the drawing.
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9.3
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MATERIAL LIST
The material list shall give a detailed description of all erection items, sufficient for purchasing and fabrication of the pipe supports. Welded attachments will appear on the piping iso.
9.4
ISO/STRESS ISO NUMBERS ON PIPE SUPPORT DRAWING
All line numbers and stress iso numbers shall be shown on the pipe support drawing.
9.5
LOCATION REFERENCES
A location reference (Datum Point) shall be located on the drawing. The support shall also have reference to existing steel structure that the pipe support is connected to.
10.
DETAIL DESIGN
10.1
GENERAL
For all supports within Engineering Contractor scope of work, the main structural elements will be designed and placed in the 3D model as a basis for further detailing, clash check etc. All detail design such as gussets, stiffeners, clamps, shoes, and other necessary information to construct the support is requested on the pipe support detail drawing and piping isometric. Pipe support design should be optimised to ensure sufficient stiffness to resist all currently acting loads, without impairing efficiency. However, weight must be held to a minimum
10.2
STANDARD PIPE SUPPORT COMPONENTS / FRAMING
Wherever possible, the maximum use of standard pipe support components, commercially available (clamps, beam attachments etc.), shall be used. Special components shall not be utilised unless absolutely essential to the support design integrity.
10.3
SPECIAL SUPPORTS
A special support shall be designed at any location where requirements fall outside the standard, whether in type, size, temperature or load.
10.4
SURFACE OF CONTACT BETWEEN PIPE/PS DETAIL AND PS STRUCTURE
Non-insulated piping DN50-DN250 shall rest directly on isolating pad on top of the support member, except in the following circumstances:
Wear plates shall be introduced at support points subject to repeated line movement.
Where required to limit local pipe wall stresses, a reinforcing pad shall be welded to the pipe wall.
For large bore piping (DN300 →) or where a reinforcing pad is inadequate to reduce local stresses sufficiently, saddles/shoes shall be provided.
GRP lines.
Carbon steel piping
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10.5
SUPPORTING OF CARBON STEEL PIPES
10.5.1
NON INSULATED CARBON STEEL PIPES
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All non-insulated carbon steel pipes shall generally be supported on clamped shoes with isolating material between the clamps and the pipe. The design temperature for the isolation material shall cover the design temperatures for the piping system.
10.5.2
INSULATED CARBON STEEL PIPES
DN50 and above. Insulated Carbon steel lines shall generally be supported on clamped shoes with isolating material between the shoe and the pipe. Carbon steel lines with personnel-protection shall have the insulation cut away locally and be supported as non-insulated pipe. Special consideration shall be taken for lines with design temperature below -46°C. A barrier (cold trap) might be required between pipe support and steelwork to avoid cold transportation in to the main steel through the support
10.6
SUPPORTING OF STAINLESS AND ALLOY STEEL PIPES
10.6.1
NON INSULATED STAINLESS AND ALLOY STEEL PIPES
DN50 – DN250 shall rest on an isolation pad, providing that both indentation checks and load bearing capacities of the insulating pad are sufficient. The design temperature for the isolation material shall cover the design temperatures for the piping system. DN300 and above shall generally be supported on clamped shoes with isolating material between the clamps and the pipe. The design temperature for the isolation material shall cover the design temperatures for the piping system.
10.6.2
INSULATED STAINLESS AND ALLOY STEEL PIPES
DN50 and above. Insulated Stainless and Alloy steel lines shall rest on clamped shoes. However lines with personnel-protection shall have the insulation cut away locally and be supported as non-insulated pipe. Special consideration shall be taken for lines with design temperature below -46°C. A barrier (cold trap) might be required between pipe and pipe support to avoid cold transportation in to the main steel through the support
10.7
SUPPORTING OF GRE/GRP PIPES
Supporting of glass fibre reinforced epoxy / plastic piping should be performed according to Company standard and vendor requirements. For GRP systems generally ancillary items such as valves, flanges, expansion joints and the like must be independently supported. GRP-lines shall be guided according to vendor requirements to avoid the pipe "snaking", but always taking into account special considerations where the pipe changes direction, connects to equipment-nozzles, valves etc. For suitable pipe support items, see Pipe Support Detail Standard.
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10.7.1
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NON INSULATED AND INSULATED GRE/GRP PIPES
Insulated and non-insulated GRP-lines shall be supported on clamped shoes with a rubber-clip strip between the clamps and the pipe to avoid damage on the pipe wall. In vertical pipe runs U-Strap can be used as a guide.
11.
STANDARD PIPE SUPPORT DETAILS
11.1
SHOES
Shoe heights shall generally be according to the table in 11.12 of this procedure.
11.1.1
WELDED SHOES AND TRUNNIONS
Welded shoes and trunnion shall be used for all lines above DN600. For smaller line sizes welded shoes shall only be used for line stops, anchors and guides with lateral forces. Where welded attachments are required on titanium pipes, only trunnions shall be used as WA. If shoes are required on bridges or in flarestacks, welded shoes/trunnions shall be used
11.1.2
CLAMPED SHOES
Company has experienced that clamped shoes has become loose. This standard type must be used with care, since there is limited friction capacity between the shoe clamp and the pipe. Clamped shoes shall not be used on bridges, in expansion loops, flare towers or other locations where the pipe can be exposed to big linear movement. If shoes are required in these areas, welded shoes/trunnions shall be used. Clamped shoes shall not be used on:
Lines that experiences slug-loads i.e.: o
Production flow lines.
o
Production and test lines from manifolds to the separators.
o
Lines from sub sea installations.
Lines that experiences excessive pipe movements and high rate of deflection changes.
Lines with large vibrations i.e. lines close to large rotating or reciprocating equipment/machines. At least, the three first pipe supports from inlet/outlet shall be of welded type.
Clamped shoes can be used for insulated lines up to and including DN600, and for all noninsulated horizontal lines from DN300 up to and including DN600. For non-insulated vertical lines between DN300 and DN600, U-strap can be used as guide.
11.2
WEAR PLATES
Wear plates shall be used in cases where reinforcement of the pipe wall is required. For example:
Supports subject to repeated line movements.
Where required to limit local pipe wall stresses especially on thin walled pipe.
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11.3
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U-BOLTS
U-Bolts may be used to hold the pipe in position, either as guide or hold-down support. For pipe sizes DN50-DN200. U-Strap is preferred to U-Bolt, use U-Bolt when space is limited.
11.4
U-STRAPS
U-straps may be used as guides for horizontal and vertical lines and 3-way restraint for light duty purposes. Use lined u-straps for all pipe classes. Size range DN50-DN600.
11.5
NON METALLIC PADS
Pads are used for purposes as:
Erosion (wear).
Galvanic insulation.
Low friction.
Acoustic insulation.
Cold transport trap.
Make up unforeseen differences in elevations on installed supports.
11.6
SLIDING SUPPORTS
Sliding supports for lines subjected to excessive movement, thermal or otherwise, shall be of a size to cater for the maximum movement in either direction. These supports or attachments shall be positioned centrally over the supporting member during erection.
11.7
LOW FRICTION SUPPORTS
Pipe supports requiring a low coefficient of friction shall have a slide unit installed between the surfaces of the support and pipe saddle/attachment. The units shall be commercially available components. Any bonding of low friction material to steel backing plates shall be by vendor.
11.8
SPRING SUPPORTS
Springs shall only be used when there is no other method of satisfactorily supporting the line. These locations will be defined by the pipe stress department on the stress sketches. Spring design criteria will be listed on the stress isometrics. Variable springs shall be selected where movements are not excessive and where load variation is below 20%. Spring units will be of the present type. Constant springs shall be selected where large movements occur or where heavy loads will give prohibitive out of loads if variable springs were used. Constant springs shall only be used where stated on the stress isometric. Springs shall be supplied suitably protected against a saline environment e.g. Plastic coated or SS 316L springs. Spring support housing shall be SS 316L. Welding to spring housing is not allowed. Base flanges shall be bolted to the structure. The spring load scale and springinformation sign shall be in SS (Permanent marking). Spring information shall be listed in the project spring Index / pipe support index.
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11.9
ATTACHMENTS TO PIPING
11.9.1
MATERIAL
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The materials for all attachment to piping shall be selected according to material specification and chart in section 7.7., or according to piping material specification. Wear- / doubler plates on elbows are not allowed.
11.9.2
CLAMPED ATTACHMENT
Where possible, attachments to piping shall be clamped.
11.9.3
WELDED ATTACHMENT
Supports requiring a welded attachment shall be marked on the piping isometrics with a note "WELDED ATTACHMENT".
11.9.4
ATTACHMENTS TO PIPE WITH INSIDE LINING
Lined Pipe - Welding of supports can be performed in the fabrication shop and only prior to lining of pipe. No site welding allowed
11.10
HANGER RODS
Use of hanger rods shall be kept to a minimum. When no other alternative is left hanger rods can be used for supports required to carry vertical loads only.
11.11
REMOVABLE SUPPORTS
Bolted connections shall only be provided as an integral part of the design for supports that will need to be removed for maintenance purposes, or part of load out/transport.
11.12
BOP ELEVATIONS ABOVE PIPE SUPPORT STRUCTURE. Pipe Material
Nominal Diameter
Pipe Size
Insulation
Carbon steel
Stainless st.
Duplex
Titan
6Mo
GRP
DN 15
½“
No Yes
+6 +150
+6 +150
+6 +150
+6 +150
+6 +150
+6 +150
DN 20
¾“
DN 25
1“
No Yes No Yes
+6 +150 +6 +150
+6 +150 +6 +150
+6 +150 +6 +150
+6 +150 +6 +150
+6 +150 +6 +150
+6 +150 +6 +150
DN 32
1¼“
DN 40
1 ½”
No Yes No Yes
+6 +150 +6 +150
+6 +150 +6 +150
+6 +150 +6 +150
+6 +150 +6 +150
+6 +150 +6 +150
+6 +150 +6 +150
DN 50
2”
DN 80
3”
No Yes No Yes
+150 +150 +150 +150
+6 +150 +6 +150
+6 +150 +6 +150
+6 +150 +6 +150
+6 +150 +6 +150
+6 +150 +6 +150
DN 100
4”
DN 125
5”
No Yes No Yes
+150 +150 +150 +150
+6 +150 +6 +150
+6 +150 +6 +150
+6 +150 +6 +150
+6 +150 +6 +150
+6 +150 +6 +150
DN 150
6”
No Yes
+150 +150
+6 +150
+6 +150
+6 +150
+6 +150
+6 +150
DN 200
8”
DN 250
10”
No Yes No
+150 +150 +150
+6 +150 +6
+6 +150 +6
+6 +150 +6
+6 +150 +6
+6 +150 +6
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Yes
+150
+150
+150
+150
+150
+150
No Yes No Yes No Yes No Yes
+150 +150 +150 +150 +150 +150 +150 +150
+150 +150 +150 +150 +150 +150 +150 +150
+150 +150 +150 +150 +150 +150 +150 +150
+150 +150 +150 +150 +150 +150 +150 +150
+150 +150 +150 +150 +150 +150 +150 +150
+150 +150 +150 +150 +150 +150 +150 +150
No Yes No Yes
+150 +150 +150 +150
+150 +150 +150 +150
+150 +150 +150 +150
+150 +150 +150 +150
+150 +150 +150 +150
+150 +150 +150 +150
24”
No Yes
+150 +150
+150 +150
+150 +150
+150 +150
+150 +150
+150 +150
DN 650
26”
DN 700
28”
No Yes No Yes
+150 +150 +150 +150
+150 +150 +150 +150
+150 +150 +150 +150
+150 +150 +150 +150
+150 +150 +150 +150
+150 +150 +150 +150
DN 750
30”
DN 800
32”
DN 850
34”
DN 900
36”
No Yes No Yes No Yes No Yes
+150 +150 +150 +150 +150 +150 +150 +150
+150 +150 +150 +150 +150 +150 +150 +150
+150 +150 +150 +150 +150 +150 +150 +150
+150 +150 +150 +150 +150 +150 +150 +150
+150 +150 +150 +150 +150 +150 +150 +150
+150 +150 +150 +150 +150 +150 +150 +150
DN 950
38”
No Yes
+150 +150
+150 +150
+150 +150
+150 +150
+150 +150
+150 +150
DN 1000
40”
No Yes
+150 +150
+150 +150
+150 +150
+150 +150
+150 +150
+150 +150
DN 300
12”
DN 350
14”
DN 400
16”
DN 450
18”
DN 500
20”
DN 550
22”
DN 600
Note: On M&M projects 100mm high shoes can be used.
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Notes: 1.
All lines with insulation shall be elevated according to this table.
2.
Hydraulic lines, high-pressure supply and return lines including DN50 and above shall be supported as normal lines. Hydraulic tubing up to and including 38 mm or pipes smaller than DN 50 shall be supported by special “Hydraulic Clamps” according to the following BOP table: Pipe size Tubing size BOP el. BOP el.
No insulation. Insulation
DN15 16 mm +21 +121
DN20 20 mm +19 +119
DN25 25 mm +21 +121
DN40 38 mm +31 +131
3.
Lines, which require acoustic damping on pipe support needs a minimum BOP elevation of 188 mm.
4.
Lines with personnel protection insulation shall be supported like non-insulated lines and have the insulation cut away locally
12.
SPECIAL CONSIDERATIONS
12.1
ADJUSTABLE SUPPORTS
Supports for pipes at strain sensitive equipment shall be designed to allow for adjustment during the life of the plant. Adjustable supports shall be located adjacent to equipment nozzles unless otherwise specified by stress section.
12.2
SUPPORTING OF PRESSURE RELIEF VALVES (PSV)
Special consideration shall be made to supporting of piping around PSV’s. It must be supported in such a way that PSV removal is possible without temporary supports. Inlet and outlet piping shall stay in position while the PSV is dismantled for maintenance.
12.3
SUPPORTING OF SMALL BORE BRANCHES - VENT & DRAIN CONNECTIONS
All small bore branch connections, both critical and non critical, shall be checked for flexibility prior to the IDC Phase of the project. Branch connections at high bending stress locations are included in the stress analysis model of the main pipe. In fatigue exposed areas of piping systems, all small bore branch outlets shall be added into the Stress calculation model. Where applicable, branch connections shall be braced from the main pipe in accordance project approved Piping Detail Standard. Welded bracing is the preferred option, and where practical all bracing supports are to be installed in prefabrication. Where unsupported branch outlets occur with concentrated loads such as vent/drain valves, the branch shall be braced against the parent pipe. Reference should be made to project approved Piping Detail Standard.
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HOLD-DOWN SUPPORTS
Hold down supports is normally used in combination with guides on non-critical lines. Be aware of design criteria in sect. 3. Hold down supports shall only be used on critical lines when specified on stress isometric.
12.5
SHOCK ABSORBERS (MECHANICAL SNUBBERS)
Shock absorbers, struts etc. shall be used only when specified on stress isometric.
12.6
SUPPORTING FROM MECHANICAL EQUIPMENT
Supporting of piping from mechanical equipment or vessels can be done if all other possibilities investigated are impractical. In such cases all necessary documentation including a pipe support detail drawing must be transmitted to the Mechanical or Vessel section for approval by the Vendor and the Company if required. These supports must be designed as early as possible to be included on the vendor’s fabrication drawing.
12.7
CONTROL VALVE SET
Unless dictated otherwise by the stress isometric, all control valve sets shall be anchored up stream and guided down stream.
12.8
UTILITY STATIONS
The free pipe ends shall be securely fixed, supported by U-clamps either as guides or anchors.
12.9
TUNDISHES
Generally tundishes are located in floor level and welded to the floor plate, but if not e.g. located in grating, the tundishes may be guides or anchored to keep them in position.
12.10
RODDING OUT POINTS
The rodding out points in the drain system shall normally be anchored to withstand the rodding forces.
12.11
MANIFOLDS
Manifolds may have an anchor in the middle and guides at both ends to allow free expansion in both directions. The friction forces must be considered.
12.12
MUD–BULK-SOLID
Each pipe spool to be separately supported for easy dismantle and removal.
12.13
HEAVY SUPPORT LOADS
See section 2.1.3
12.14
PIPING SUBMERGED IN SEAWATER
When supporting pipes submerged in seawater, special material selection suitable for seawater service must be provided.
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PIPE PENETRATIONS
Pipes penetrating beams and decks may be supported at or close to penetration sleeve unless it will interfere with sealing or fireproofing. In welded (water tight) pipe penetrations, a pipe support point shall be provided. Pipe support point shall have sequence number from the 9000-9500 series. No 2D-drawings shall be issued for this series.
14.
INSULATED PIPES
All insulated pipes including DN50 and above shall be supported on shoes except for lines with Personal Protection Insulation. Class 3.
14.1
HEAT CONSERVATION – CLASS 1
Lines with Hot Service Insulation shall be supported on shoes.
14.2
COLD CONSERVATION – CLASS 2
Lines with cold conservation insulation shall generally be supported on “normal” shoes, but lines which may cool the supporting steel below design temperature -46°C might be installed with insulating barrier (cold trap).
14.3
PERSONNEL PROTECTION – CLASS 3
Lines with Personnel Protection Insulation shall be supported like non-insulated lines and have the insulation cut away locally.
14.4
FROST PROTECTION – CLASS 4
Lines with Frost Proofing and electrically traced lines shall rest on shoes.
14.5
FIRE PROTECTION – CLASS 5
Lines with Fire Proofing Insulation shall rest on shoes.
14.6
ACOUSTIC INSULATION – CLASS 6, 7 & 8
Lines with potential need for Acoustic Insulation shall be supported on a sound-absorbing arrangement if required by the mechanical department. Shoes may be used in combination with a sound-absorbing material.
14.7
EXTERNAL CONDENSATION AND ICING PROTECTION – CLASS 9
Lines with External Condensation and Icing Protection Insulation shall generally be supported on “normal” shoes, but lines which may cool the supporting steel below design temperature -46°C might be installed with insulating barrier (cold trap).
14.8
FIRE PROTECTION ON FLANGES
Supporting of flanges shall under no circumstances be allowed for Lines with Fire protection on Flanges.
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FUTURE INSULATION
Lines with Future Insulation shall rest on shoes.
15.
GENERAL SUPPORTING OF SMALL BORE PIPES
All non-insulated small bore piping shall be supported with U-bolt, grip type. The exceptions are:
Critical lines were other function is defined, e.g. non-grip clamp or rest only.
Hydraulic lines less than DN50, where hydraulic clamps shall be utilised.
Lines with high temperatures and long straight runs, use of non-grip clamps shall be used on part of the line.
All insulated small bore piping shall be supported with 100 mm high weld bracket, grip type, which shall be welded to support structure. The exceptions are:
Critical lines where other function is defined, e.g. non-grip clamp or rest only.
Hydraulic lines less than DN50, where hydraulic clamps shall be utilised.
Lines with high temperatures and long straight runs, use of non-grip clamps shall be used on part of the line.
On utility stations, use U-bolt instead of weld bracket and cut the insulation locally.
15.1
SPECIAL CONSIDERATIONS FOR SUPPORTING OF SMALL BORE PIPING
a) For supporting of firewater lines, the length between the end of the sprinkler and the last pipe support shall not be more than 600 mm for DN25 and DN40 pipe. In cases where this is not sufficient to avoid vibration at deluge releases the distance shall be reduced. b) When positioning the first support on lines away from equipment or branches from larger bore pipe, allowance should be made for sufficient flexibility in the pipe. It is important to make sure the small bore pipe routing near connections to equipment/large bore pipe is in such a way that griptype pipe support can be used without introducing stress problems to the connection. This means that the pipe designer may need to apply several elevation and/or directional changes of the small bore pipe to get enough flexibility before the first small bore pipe support (See fig. next page for an illustrated example).
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c) Use of double U-bolt/brackets shall always be provided on all “free-end pipe supports” and both side of a valve shall be provided with a pipe support (See fig.).
d) When supporting lines with design temperature above 150°C, pipe clamps for high temperature service shall be utilised. e) Pipe support drawings shall always be issued for critical small bore lines. If nothing else is agreed, pipe support drawings shall be issued for non-critical small bore piping defined in piping scope. f) Critical small-bore pipe support drawings shall be checked as all other pipe support drawings. Non critical small-bore pipe support drawings only require self check by the pipe support designer and disc. approval before issue. g) Human activity (handling of valves, step etc.) shall be taken in consideration when designing small bore pipe supports.
16.
HOOK-UP SUPPORTS
Hook-Up lines are lines to be erected during the hook-up phase. These are lines between areas or modules, or for connecting late installed equipment. Hook-up Supports are supports for these types of lines or supports that for some legitimate reason has to be installed in the Hook-Up phase. The detail drawing shall have HOOK-UP SUPPORT highlighted in a rectangular frame at the top.
17.
STARTER BARS
In areas where the structures will have sprayed on fireproofing it may be necessary to install starter bars for later installation of supports. Starter bars must not protrude below main girders or outside modules to interfere with transportation. The fabricator, who is requesting for starter bars on a structure within another fabricator scope, shall document it on a structural drawing for the area with necessary references to pipe supports, and the information issued to the respective module fabricator.
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18.
SURFACE PREPARATION AND PROTECTION
18.1
COLOUR / COATING
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Stainless or Alloy Steel materials shall in general not be painted. All carbon steel pipe support structures and details shall be surface protected according to Surface protection specification for the project. Colours shall be according to the colour scheme for the project.
18.2
FIREPROOFING
All requirements/criteria regarding fireproofing of pipes will be specified by the safety department (Which piping systems, sizes or pipes that need fireproofed pipe supports). Safety will also specify requirements for protection of critical inline equipment or valves (i.e. EV’s). Pipe support department will then decide which pipe supports to be fireproofed to meet the criteria for the pipe stated by safety. Usually every second pipe support needs fireproofing but this needs to be verified for each case. Special attention should be made to deflection effects stated in 18.2.3.
18.2.1
FULL FIRE PROTECTION
A fully fireproofed pipe support shall be modelled as NORMAL/FP or BLAST/FP in applicable 3D modelling tool (i.e. PDMS), and marked with a note on the 2D pipe support drawing.
18.2.2
INTEGRITY PROTECTION
Integrity fire-protection of deck etc. by partly fireproofing the pipe support connected to the structure will be the Fabricator’s scope.
18.2.3
DECK / BEAM DEFLECTION EFFECTS DUE TO FIRE
When deciding which pipe supports to be fireproofed, special attention should be made to deck deflections due to fire. Because a structural deck/beam is not fireproofed on top, a major deflection upwards may occur in the middle of the deck/beam-span. Fireproofed pipe supports shall not be placed in the middle of a deck/beam-span. These pipe supports shall be placed near bulkheads, walls etc. to avoid large upward movement that could cause damage to the pipe that needs to be intact in the initial stage of a fire. The pipe support dept., along with the safety- and layout dept., are all responsible for making a piping/pipe support-design that meet the above mentioned requirement.
19.
TAGGING OF PIPE SUPPORTS
Every pipe support shall be tagged with its unique Pipe Support Tag Number hard stamped onto the support in a rectangular white painted area visual after erection. The numbering digits shall be minimum 12 mm high. Parts of a future support assembly may be strapped together and be given a common Tag Number. Special notes shall be stamped onto the support together with Pipe Support Tag Number e.g. HOOK-UP SUPPORT and TEMPORARY SUPPORT.
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FILING SYSTEM
The Piping Layout Group shall keep a well documented and up to date filing system showing all correspondence in and out of the group and ensure that only the latest issue of any drawing is being worked on.
20.1
DOCUMENTS TO BE FILED INTERNALLY
Pipe Support Detail Standard and Procedure.
Piping Detail Standard.
Structural Drawings.
Plot Plans.
Stress Isometrics.
Line List.
Piping and Valve Material Specification.
Insulation Specification.
Pipe Support Index.
All correspondence and documents produced within the section.
Engineering Isometrics.
Trunnion calculations.
Structural pipe support calculations.
21.
MAINTENANCE & MODIFICATION PROJECTS. (V&M).
21.1
PIPE SUPPORT DESIGN PRACTICE.
Generally, pipe support design principles are the same for both Maintenance & Modification and for New-Build projects. Pipe supports shall be designed for economy and “fitness for purpose” and the use of welded connections to existing structure. However, if “hot work” is not possible, bolted connections shall be designed according to typical examples shown in section 23.2. These examples also apply to welded connections taking due consideration of including backing plates in transitions/corners of members (to ensure proper transfer of bending moments). Where practical, pipe support design shall incorporate the use of stainless steel to minimise the need for costly offshore painting. However, due regard should be paid to the isolation of any dissimilar metals. During installation, any bolted connections shall be sealed by an insulation barrier approved by Company. The typical frames and details in Section 23.2 are shown for the purpose of standardisation and shall be used to the extent possible. The design of these typical frames shall be documented by calculations confirming that the stresses in joints/flanges are acceptable for the worst load conditions and combinations, both for bolted and welded connections. This also applies to any other "off the shelf" design solutions. The details shown in Section 23.6 shall only be used as a "last resort" and shall be approved and documented by the project structural department before commencement of prefabrication.
21.2
USE OF ADHESIVE FOR PIPE SUPPORTS.
The use and type of Adhesive to secure Pipe Support Frames shall be kept to a minimum and is subject to Client Approval. Adhesive connections shall only be used where welding is not allowed
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or impractical such as some In-deck tanks. Adhesive connections shall not be used where large moments are lightly to occur about the connection. The Type of adhesive used should have full Vendor documentation governing it use and strength limitations. Surface preparation and Full HMS and Instructions for use should be supplied Offshore before commencement of Installation of any Pipe Supports using adhesive
21.3
TAPPED AND SCREWED BOLTED CONNECTIONS
Tapped and Screwed Bolted Connections shall be kept to a minimum and only used where welding or normal bolted connections are not allowed. All Tapped connections shall use a suitable thread lock compound such as ‘Loctite’ or similar Project approved
21.4
PLANNING / WORKING METHODS / LIAISON WITH OTHER DISCIPLINES
Plans, procedures and communication will vary between each M&M contract and sometimes even between each project (AFE) and/or work order (PM02). It will also depend on time schedules and the criticality of the lines to be supported. Prioritized action plans should be agreed upon at the earliest opportunity and coordinated/followed-up continuously throughout execution (engineering, prefabrication and installation) of the project/work order. The Pipe support designer shall locate and design the pipe supports with assistance from the piping layout engineer and the piping stress engineer. Information to assist design can come from existing drawings and or measurements from offshore surveys. In cases where loads are above 10kN; either from one support or compounded from several pipe supports acting together, or where torsion loads are unavoidably transferred through to the existing steel structure from the pipe support, reference should be made to section 2.1.3.
22.
INTERFACE WITH STRUCTURAL DISCIPLINE
22.1
LOADS
See section 2.1.3.
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23.
TYPICAL BOLTED FRAMES AND CONNECTIONS
23.1
GENERAL RULES FOR BOLTED CONNECTION
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The positioning of holes for bolts shall be such as to prevent corrosion and local bending, and facilitate good installation of the bolts. Minimum spacing of bolts: Where D is the diameter of the hole, the spacing between the centres of bolts in the direction of load transfer should not be less than 2,2D. The spacing between rows of bolts perpendicular to the direction of load should normally not be less than 3,0D. This may be reduced to 2,4D provided that the design bearing resistance is reduced accordingly. Reference should be made to the Structural code. Maximum spacing of bolts: Where t is the thickness of the thinnest plate, the maximum spacing between bolts in each row and the spacing at right between rows of bolts should not exceed the lesser of 14t or 200mm. Adjacent rows may be symmetrically staggered. Where large centres are used the connection should be checked for local buckling. Minimum edge distance for bolts: Where D is the diameter of the hole, the minimum edge distance from the centre of bolt to the adjacent edge of any part measured at right angles to the direction of load transfer should not normally be less than 1,5D. The edge distance may be reduced to a minimum of 1,2D provided that the design bearing resistance is reduced accordingly. Reference should be made to the latest Structural Design Code. Minimum end distance for bolts: where D is the diameter of the hole, the minimum end distance from the centre of bolt to the adjacent end of any part measured in the direction of load transfer should not normally be less than 1,2D. The end distance should be increased if necessary to provide adequate bearing resistance. Reference should be made to the latest Structural Design Code.
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23.2
TYPICAL BOLTED FRAMES
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23.3
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STANDARD BACK-MARKS FOR DRILLED BOLT HOLES IN ROLLED STEEL ANGLES (Unless noted otherwise on the pipe support drawing):
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L (≥)
S1
S2
S3
Maximum Dia. Bolt (mm)
60
35
-
-
16
80
45
-
-
20
100
55
-
-
24
120
-
45
50
16
150
-
55
55
20
23.4
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STANDARD BACK-MARKS FOR DRILLED BOLT HOLES IN UNP profiles. (Unless noted otherwise on the pipe support drawing)
B (≥)
S1
Maximum Dia. Bolt (mm)
50
30
10
55
30
10
60
35
12
65
35
16
75
45
20
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STANDARD BACK-MARKS FOR DRILLED BOLT HOLES IN IPE, HEA & HEB PROFILES. (UNLESS NOTED OTHERWISE ON THE PIPE SUPPORT DRAWING)
B (≥)
S1
S2
S3
S4
Maximum Dia. Bolt (mm)
55
30
-
-
-
10
64
34
-
-
-
10
73
40
-
-
-
10
82
44
-
-
-
10
100
54
-
-
-
12
110/120
60
-
-
-
12
140
70
-
-
-
20
150
90
-
-
-
20
170/200
90
-
-
-
24
220/260
140
-
-
-
24
300
(140)
120
60
240
20/24
23.6
TYPICAL OFFSHORE CONNECTION TO PRIMARY STEELWORK.