ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
Z0-TS-P-04010 Z0-TS-P-04010 REV. NO.: 1 DATE:. 12/11/2008 PAGE: 1 OF 53
SPECIFICATION FOR FABRICATION, FAB RICATION, ERECTION ERECTION & TESTING TESTING OF METAL METAL LIC PIPEWORK Z0-TS-P-04010 REVISION REVISION : 1 12th NOVEMBER 2008 ISSUED FOR IMPLEMENTATION
APPROVED SPECIFICATION ENDORSED BY THE FACILITIES ENGINEERING MANAGER NAJEM A. QAMBAR
Z0-TS-P-04010-Rev-1
ZADCO CORPORATE ENGINEERING SPECIFICATION
Z0-TS-P-04010 Z0-TS-P-04010
PIPING
REV. NO.: 1
FABRICATION & ERECTION OF METALLIC PIPEWORK
DATE:. 12/11/2008 PAGE: 2 OF 53
ISSUE RECORD Rev.
Date
Origin ator
Reviewer Reviewer
Appr oval
Revision Descript ion
A
29/03/ 05 A. Ratna
B
20/09/05 20/09/05
A. Ratna
David Galloway Galloway
Mahrous A Rabbou
Issued for Review/Comme Review/Comments nts
C
04/02/06 04/02/06
A. Ratna
David Galloway Galloway
Mahrous A Rabbou
Issued for Approval Approval
D
12/02/08
A. Ratna
A.Kumar
Mahrous A Rabbou
Updated & Re-issued for Approval
1
12/11/08
A. Ratna
A.Kumar
Mahrous A Rabbou
Issued for Implementation
Z0-TS-P-04010-Rev-1
Issued for IDC
ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
Z0-TS-P-04010 Z0-TS-P-04010 REV. NO.: 1 DATE:. 12/11/2008 PAGE: 3 OF 53
TABLE OF CONTENTS 1
SCOPE .................................................................... ............................................................. ............................. 6
2
CODES, STANDARDS, SPECIFICATIONS SPECIFICATIONS AND ABBREVIATIONS.................................................... 6
3
FABRICATION, ASSEMBLY AND ERECTION........................................................................................ 6 3.1 GENERAL REQUIREMENTS ....................................................... ........................................................... 6 3.2 CUTTING AND CUTTING AND BEVELLING................................................ ........................................................ ............ 6 3.3 ASSEMBLY OF PIPING COMPONENTS .............................................................................. .................. 7 3.4 THREADED AND THREADED AND SOCKET WELD PIPING ......................................................................... .................... 7 3.5 PIPE BENDING ............................................................................. .......................................................... 8 3.6 FLANGES ...................................................... ............................................................ .............................. 8 3.7 GASKETS..................................................... ........................................................... ................................ 9 3.8 DISSIMILAR MATERIALS INTERFACE (FLANGED JOINTS)...................................................... ................. 9 3.9 PIPING FOR ROTATING EQUIPMENT .......................................................... ......................................... 9 3.10 WELDED BRANCH CONNECTIONS ............................................................................................ .......... 9 3.11 SMALL BORE PIPING ............................................................................................. .............................. 10 10 3.12 PIPEWORK FOR SUBSEQUENT LINING ............................................................................................. 10 3.13 FIELD TIE-INS TO EXISTING FACILITIES ( ‘BROWN’ FIELDS): .............................................. ................. 10 3.14 DECK PENETRATIONS ..................................................... ........................................................... ........ 10
4
WELDING.................................................................... ................................................................. ................. 11 4.1 4.2
5
CLEANING .................................................................... ............................................................... ................. 12 5.1 5.2 5.3
6
GENERAL REQUIREMENTS ........................................................ ....................................................... . 11 QUALIFICATION ........................................................................................................ ........................... 11
SHOP FABRICATION................................................... ........................................................... .............. 12 FIELD INSTALLATION ................................................................................ .......................................... 12 INSTALLATION OF VALVES ................................................... ........................................................... ... 12
PIPE SUPPORTS........................................................................................................................................... SUPPORTS........................................................................................................................................... 13 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8
GENERAL.............................................................................................................................................. 13 SPRINGS............................................................................................................................................... 13 SPRING HANGERS .................................................................. ............................................................ 13 EXPANSION JOINTS .......................................................................... .................................................. 13 INSULATED PIPING........................................................ ............................................................ .......... 13 PIPE SHOE.................................................... ........................................................ ................................ 14 PIPE SUPPORT ATTACHMENT SUPPORT ATTACHMENT WELDS ..................................................... ......................................... 14 PIPE ELEVATIONS ......................................................................................... ...................................... 14
7
TOLERANCES ..................................................................... .................................................................. ....... 15
8
TEST & INSPECTION ............................................................................................. .................................... 15 8.1 8.2
GENERAL.............................................................................................................................................. 15 INSPECTION/TESTING OF HFI BENDS ...................................................... ......................................... 15
Z0-TS-P-04010-Rev-1
ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
Z0-TS-P-04010 Z0-TS-P-04010 REV. NO.: 1 DATE:. 12/11/2008 PAGE: 4 OF 53
TABLE OF CONTENTS(CONT'D) 9
PRESSURE TESTING ................................................................... ............................................................... 16 9.1 9.2 9.3 9.4 9.5 9.6 9.7 9.8 9.9 9.10
10
SCOPE ...................................................... ........................................................... ................................. 16 DEFINITION ...................................................................................... .................................................... 16 GENERAL REQUIREMENTS ........................................................ ....................................................... . 16 CONTRACTOR’S RESPONSIBILITIES..................................................... ............................................ 16 SYSTEMS.............................................................................................................................................. 17 EXTENT OF TESTING........................................................................................................................... TESTING........................................................................................................................... 17 TEST PRESSURES.................................................... ........................................................... ................ 18 TEST PROCEDURE ...................................................... ............................................................ ............ 18 TESTING MEDIUM ....................................................... ........................................................... .............. 20 TEST RECORDS ........................................................... ........................................................... ............. 20
LEAK / TIGHTNESS TEST ................................................................ ......................................................... 21 10.1 10.2 10.3 10.4
SCOPE ...................................................... ........................................................... ................................. 21 PREPARATION ........................................................ ........................................................................... .. 21 TEST ..................................................................................................................................................... 21 INERTING.............................................................................................................................................. 21
11
TESTING OF FIELD INSTALLED PIPEWORK & TIE-INS ................................................................. 21
12
WATER FLUSHING OF PIPING SYSTEMS................................................................ ............................ 22 12.1 12.2 12.3 12.4
13
SCOPE ...................................................... ........................................................... ................................. 22 DESIGN CRITERIA ................................................................... ............................................................ 22 EXCEPTIONS................................................. ........................................................ ............................... 22 GENERAL REQUIREMENTS ........................................................ ....................................................... . 22
INTERNAL CLEANING OF PIPEWORK BY PICKLING AND GRITBLASTING GRITBLASTING............................ 23 13.1 SCOPE ...................................................... ........................................................... ................................. 23 13.2 GENERAL.............................................................................................................................................. 23 13.3 DEGREASING...................................................... ........................................................ ......................... 24 13.4 GRIT BLASTING....................................................... ....................................................... ...................... 24 13.5 ACID CLEANING ...................................................... ....................................................... ...................... 24 13.6 PASSIVATION................................................... ............................................................ ........................ 25 13.7 DRYING.................................................. ............................................................ ................................... 25 13.8 INSPECTION............................................... ........................................................ .................................. 25 13.9 PROTECTIVE COATING ........................................................... ........................................................... . 25 13.10 TRANSPORTATION OF PICKLED & GRIT BLASTED PIPING.............................................................. 25 13.11 ERECTION .......................................................................................................... .................................. 25
14
MARKING ........................................................... ............................................................... ........................... 25
15
PAINTING ..................................................................................................................................................... 25
16
DOCUMENTATION............................................................ ................................................................... ...... 26 16.2 16.3
17
SHOP FABRICATION................................................... ........................................................... .............. 26 SITE WORK (ASSEMBLY/ ERECTION) ................................................................................................ 26
SHIPMENT ................................................................ .................................................................... ................ 26
Z0-TS-P-04010-Rev-1
ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
Z0-TS-P-04010 REV. NO.: 1 DATE:. 12/11/2008 PAGE: 5 OF 53
TABLE OF CONTENTS(CONT'D) ANNEXURE-I: I.1 I.2 I.3 I.4 I.5 I.6 I.7 I.8
SCOPE ...................................................... ........................................................... ................................. 28 PROCESS .................................................... ........................................................... .............................. 28 CONSUMABLES .................................................... ............................................................ ................... 28 PREPARATION ........................................................ ........................................................................... .. 28 QUALIFICATION REQUIREMENTS .................................................................................................... .. 29 WELDING ......................................................... ............................................................ ......................... 29 PRECAUTIONS FOR FABRICATION OF STAINLESS STEEL PIPEWORK ......................................... 29 INSPECTION & TESTING .................................................................. ................................................... 29
ANNEXURE –II: II.1 II.2 II.3 II.4 II.5 II.6
AUSTENITIC STAINLESS STEEL & 904L PIPEWORK.................................................... 27
COPPER-NICKEL PIPEWORK ......................................................................... ................. 30
SCOPE ...................................................... ........................................................... ................................. 31 FABRICATION PROCEDURE ........................................................... .................................................... 31 WELDING PROCESS........................................................ ........................................................... ......... 31 WELDING QUALIFICATION REQUIREMENTS .................................................................................... 32 PRECAUTIONS FOR FABRICATION OF COPPER NICKEL PIPEWORK ............................................ 32 BRAZING ............................................................ ................................................................................ ... 32
ANNEXURE III : III.1 III.2 III.3 III.4 III.5 III.6 III.7 III.8 III.9
TITANIUM PIPEWORK .................................................................. ................................... 34
SCOPE ...................................................... ........................................................... ................................. 35 WELDING PROCESS & EQUIPMENT............................................................................................... .... 35 WELD PREPARATION ........................................................ .................................................................. 35 PRECAUTIONS...................................................... ....................................................... ........................ 36 WELDING CONSUMABLES................................................. ........................................................ ......... 36 WELDING QUALIFICATION REQUIREMENTS .................................................................................... 36 WELDING & FABRICATION .......................................................... ........................................................ 37 CLEANING, REMOVAL OF DEFECTS & REPAIR WELDING ............................................................... 38 INSPECTION & TESTING .................................................................. ................................................... 38
TABLES ................................................................................................................................ ...................................... 39 TABLE 1: TABLE 2: TABLE 3: TABLE 4 :
TOLERANCE ........................................................................................... .................................... 40 HEAT TREATMENT OF FORMED BENDS .................................................................................. 41 NDE REQUIREMENTS (BUTT, BRANCH AND ATTACHMENT WELDS) ................................... 43 SET-ON BRANCHES .................................................... ............................................................ ... 44
APPENDIX- A ....................................................................................................................... ..................................... 45 A.1 A.2
CODES / STANDARDS / SPECIFICATIONS ............................................................ ............................. 46 ABBREVIATIONS USED ..................................................................................................... .................. 51
Z0-TS-P-04010-Rev-1
ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
Z0-TS-P-04010 REV. NO.: 1 DATE:. 12/11/2008 PAGE: 6 OF 53
1
SCOPE
1.1
This specification describes the minimum requirements for the fabrication, handling, erection and testing of metallic pipework, for projects executed at all ZADCO facilities.
1.2
In cases of conflict between this and individual specifications and/or drawings issued for the project, the more stringent requirement shall apply, unless directed otherwise by the Company.
1.3
Construction shall be as per ‘Approved for Construction’ issue of arrangement drawings or isometric drawings together with relevant pipe class documents issued for the project and shall comply with this specification, unless noted otherwise.
1.4
Unless specific dispensation is requested by contractor and granted by the Company in writing, it is understood that all fabricated & installed piping, complies with the specifications, drawings, pipe material specification and related documents.
2
CODES, STANDARDS, SPECIFICATIONS AND AB BREVIA TIONS
2.1
The codes, standards and specifications listed under section 1 of ‘Appendix-A’, shall be considered part of this specification. The list is provided as a guide and is not necessarily complete. Other codes etc. may be called as required by the Company.
2.2
Unless noted otherwise all construction shall, as a minimum, meet the requirements of the codes, standards and specifications listed in Appendix-A. The editions or revision of the referenced Codes, Standards & Specifications governing shall be that ruling at the date of contract, except as modified by this specification.
2.3
In the case of conflict between this specification and its associated specifications, data sheets and the Code declared above, the Contractor shall bring the matter to the Company’s attention for resolution and approval in writing. Should any requirements be in conflict the more stringent requirement shall prevail.
2.4
The abbreviations in the text of either this specification or project documentation shall be deemed to mean the description listed under section 2 of ‘Appendix-A’.
3
FABRICATION, ASSEMBLY AND ERECTION
3.1
GENERAL REQUIREMENTS
3.1.1
Piping fabrication, assembly & erection shall conform to the requirements of this specification and ASME B31.3.
3.1.2
The extent of fabrication will be as detailed on the piping drawings and/or isometrics and will include any attachments pipe supports, shown in the form of structural shapes for guides, anchors, etc.
3.1.3
The new facilities shall comply with the project drawings/documents. Alternative materials, thickness, design shall be acceptable only subsequent to written approval from Company.
3.1.4
The ‘Approved for Construction’ drawings / documents shall be physically verified at site prior to start of construction activities. Discrepancies, if any, shall be highlighted and resolved in writing with the Company.
3.1.5
In the event of simultaneous fabrication activities, steels requiring different welding electrodes/ procedures (e.g. CS, KCS, SS etc.) shall be welded in separate areas in order to avoid mixing of pipe materials and electrodes.
3.2
CUTTING AND BEVELLING
3.2.1
Cutting and bevelling of pipes may be done by mechanical means: flame cutting, plasma cutting or water cutting. The following shall apply:
3.2.2
For carbon steel, flame (or arc) cuts shall be reasonably smooth and all oxides shall be removed from the surface by grinding to bright metal.
Z0-TS-P-04010-Rev-1
ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
Z0-TS-P-04010 REV. NO.: 1 DATE:. 12/11/2008 PAGE: 7 OF 53
3.2.3
For low-alloy steel, after flame cutting a minimum of 2 mm of material shall be removed from the cut surface by grinding.
3.2.4
For stainless steel, flame cutting shall not be used but plasma or water cutting may be used. The surface shall be ground to bright metal after plasma cutting.
3.2.5
Weld bevels for butt welds of pipes and fittings shall be in accordance with ASME B16.25.
3.2.6
Shop bevelling of field welds is not required if a make-up length (extra length for field cutting to size) is provided. In these cases, bevels shall be prepared after cutting the relevant pipe spool to the required length. Cutting oil shall be removed.
3.2.7
Pipe cutting shall be accurate and smooth, true to template .
3.2.8
The dimensions shown on drawings and isometrics do not allow for weld prior to welding root gaps.
3.2.9
Pipes for socket weld joints shall be cut square and burrs removed.
3.3
ASSEMBLY OF PIPING COMPONENTS
3.3.1
For butt-welding of all piping components (e.g. pipe ends, fittings and welding neck flanges), a uniform root gap shall be provided as specified in the relevant Welding Procedure Specification.
3.3.2
Minimum spacing of circumferential welds shall be as follows: •
•
For Pipe NB > 2”: one diameter of pipe For Pipe NB < 1½": not less than four times the pipe wall thickness or 40mm (1 ½") whichever is the greater.
3.3.3
Longitudinal weld seams of adjacent sections of pipe shall be staggered by at least 60° and, where possible shall be located such that they do not obstruct openings and external attachments. However, these shall be separated by at least twice the wall thickness of the thicker pipe.
3.3.4
If the pipe contains a longitudinal weld, this weld shall not be located at the bottom of the pipe after installation; it should be located at least 60° from the bottom of the pipe i.e. the longitudinal weld seams shall not fall between 4 and 8 o'clock positions.
3.3.5
Where practical, weld seams made on site shall be located at least 300 mm away from adjacent pipe work, pipe supports, walkways, and other structural members.
3.3.6
Pipes that are required to be free of scale shall be blast cleaned before the welding shop accepts them for further handling.
3.3.7
The joining of short pieces of piping (less than 500 mm in length) to make up straight lengths of piping is prohibited, except if required for weld repair/rectification.
3.3.8
Welding of piping in sour service (including welded piping components), shall comply with NACE MR 01-75/ ISO 15156.
3.3.9
Flange bolt shall straddle the established horizontal and vertical centrelines of pipe except where connecting to equipment dictates otherwise.
3.4
THREADED AND SOCKET WELD PIPING
3.4.1
Threads shall be concentric with the axis of pipe as per ASME B 1.20.1 tapered and clean cut. Inside end shall be deburred by reaming.
3.4.2
Threaded connections shall be gauge checked or chased after welding or heat treatment.
3.4.3
In order to avoid excessive shrinkage stresses during weld solidification, a gap shall be left between the end of the pipe and the stop of the socket-welding component in accordance with ASME B16.11 (1.6mm or 1/16" minm.). Failure to include this gap can lead to premature piping failures.
3.4.4
Threaded joints shall be preferably seal welded to avoid crevice corrosion. Joints which are not to be seal welded shall be thoroughly cleaned, the male threads coated with sealant and made
Z0-TS-P-04010-Rev-1
ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
Z0-TS-P-04010 REV. NO.: 1 DATE:. 12/11/2008 PAGE: 8 OF 53
up sufficiently to cause threads to seize. Sealant shall be PTFE tape in services to 230°C (450°F).The threaded joints must be referred to the Company/ Engineer for the seal welding requirements. 3.4.5
Threaded joints to be seal welded shall not be coated with PTFE sealant tape.
3.5
PIPE BENDING
3.5.1
General
3.5.1.1
Pulled bends may be used only with the Company’s approval. Where the approval is granted, they shall be equal to at least four times the nominal pipe diameter, on sizes 1½" and below and ratings of 150# and 300#. Allowance must be made for expansion and steelwork clearances.
3.5.1.2
Mitred bends shall not be used without Company’s approval. Where this is granted, the weld contours shall merge smoothly with the pipe surfaces. Welds with sharp corners or undercutting are not acceptable.
3.5.1.3
For bends from welded pipe, the longitudinal weld seam should be located in the neutral zone of the bend. If the pipe will be installed horizontally, the longitudinal weld shall be located on the top of the pipe. If one spool is bent in various planes, the longitudinal weld shall be 45° from the top of the pipe.
3.5.1.4
Pipes may be bent using either a hot or cold bending as defined in ASME B-31.3, unless noted otherwise. Fabrication of bends by High Frequency Induction Bending (HFIB) is also permitted.
3.5.1.5
The temperature limitations shall be in accordance with ASME B31.3.
3.5.1.6
During hot bending, local heating by manually operated gas torches shall not be applied.
3.5.1.7
Water quenching or fine water spray quenching of hot-formed bends shall not be permitted, unless it is part of the process such as induction bending.
3.5.1.8
After bending, out-of-roundness shall not exceed 5% of the nominal diameter nor shall the wall thickness be reduced below 12½% of the nominal wall thickness of the pipe.
3.5.1.9
The completed bends shall conform to design drawings and be free from excessive surface scaling and wrinkles.
3.5.1.10 Wall thinning as a result of pipe bending shall be measured by an ultrasonic technique as applicable to an approved procedure. 3.5.1.11 Any final corrections after heat treatment should preferably be carried out cold. 3.5.1.12 Weld repairs of cracks in pipe bends is not permitted. 3.5.1.13 If sand is used in the bending process, on completion of bending the interior of the pipe shall be thoroughly cleaned using mechanically driven wire brushes, to remove all traces of sand. 3.5.2
Heat Treatment of Formed Bends
3.5.2.1
Heat treatment requirements on formed bends are stipulated in Table-2 and shall comply with ASME B-31.3.
3.5.2.2
Formed bends shall be heat treated in a furnace. The furnace cycle shall be automatically recorded using sufficient number of thermocouples to indicate uniform furnace temperature. A minimum of three thermocouples shall be used to record metal temperatures.
3.5.2.3
Heat treatment after cold bending is required when elongation of the outer tube fibres exceeds 5% of the elongation value of the material.
3.6
FLANGES
3.6.1
Flange faces shall be cleaned of oil, grease, dirt, inhibitors, etc and shall be checked to ensure freedom from gouges, nicks, etc.
3.6.2
Threads of all steel bolts and studs (except austenitic stainless steel) shall be doped in the field with a graphite-based grease before installation to prevent galling of the threads.
3.6.3
The brand and type of thread compound intended for use on threaded joints shall be approved prior to use.
Z0-TS-P-04010-Rev-1
ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
Z0-TS-P-04010 REV. NO.: 1 DATE:. 12/11/2008 PAGE: 9 OF 53
3.6.4
Flanges indicated on the drawings to be supplied loose for field welding, shall be wired on by the fabricator.
3.6.5
The bevel end on the mating pipe shall be prepared for welding after site verification of the dimensions, incorporating cutting allowance as required.
3.6.6
Flanges shall be edge hard-marked with their line identity.
3.6.7
Flanges shall be protected against damage to gasket face
3.7
GASKETS
3.7.1
Gaskets for high temperature service and all steam services shall be dusted with graphite prior to installation.
3.7.2
Temporary gaskets shall be used for connections that have to be opened before or after pressure testing, such as equipment connections, orifice flanges, etc. Spiral wound metal nonasbestos gaskets shall not be re-used without approval.
3.8
DISSIMILAR MATERIALS INTERFACE (Flanged Joints)
3.8.1
Wherever dissimilar materials are coupled together in piping systems, a corrosivity evaluation shall be made.
3.8.2
Copper-based materials shall always be isolated from more corrosion resistant materials including 25 Cr Duplex, Titanium and 6 Mo alloys.
3.8.3
If the interface (dissimilar materials) is in corrosive service, galvanic corrosion shall be mitigated by one of the following methods: i.
Internally coating the more noble material to approx. 10 D (ten pipe diameters) from the junction. Compatibility of coatings and fluid shall be verified.
ii.
Use of thick walled CS-flanged section at the junction, which is designed for replacement at scheduled intervals.
iii.
Use of a spool piece of non-conducting material (e.g. FRP or Rubber-lined CS) about 10 D (ten pipe diameters) long.
iv.
The use of Flanged Electrical Isolation Kits (Insulating Gasket Kits) in offshore facilities is generally not recommended in non-seawater systems . Flanges involving insulating gasket kits shall be assembled & tested before being welded on the pipe. A voltage of 1500VDC shall be applied across the flange assembly for one minute without causing breakdown of the insulation or flash over.
3.8.4
The mitigation measure adopted and procedure for the same shall be developed on case to case basis and shall be subject to review & approval by Company.
3.9
PIPING FOR ROTATING EQUIPMENT
3.9.1
Piping alignment at pumps, turbines and compressors shall be carefully controlled and checked to minimise stresses. Flange and/or pipe alignment, bolthole orientations and centreline elevations shall be such that the connecting pipe may be ‘floated’ into place.
3.9.2
Piping connections to pumps, turbines and compressors shall not be made until shims have been installed and until all anchor bolts have been tightened.
3.9.3
Piping to equipment shall be supported independently of the equipment.
3.10
WELDED BRANCH CONNECTIONS
3.10.1
Branch connections shall be as per the piping isometric drawing in conformance with the Piping Material Specification and shall comply with ASME B31.3.
3.10.2
Welded- type branch connections should as far as practicable, be made preferably in the fabrication shop and avoided in field. However, if making at site is unavoidable, the welding must comply with all requirements of this specification.
Z0-TS-P-04010-Rev-1
ZADCO CORPORATE ENGINEERING SPECIFICATION
Z0-TS-P-04010
PIPING
REV. NO.: 1 DATE:. 12/11/2008
FABRICATION & ERECTION OF METALLIC PIPEWORK
PAGE: 10 OF 53
3.10.3
Branch connections shall be joined to the header with full penetration welds. No crevices are allowed and the bore side shall be smooth and free from any cracks.
3.10.4
The post-weld heat treatment of branch connections shall be in accordance with ASME B31.3, except that heat treatment is required when the nominal thickness of the thickest part is > 25 mm.
3.10.5
Welding & inspection for “Set-on Branches” shall be as per Table-4.
3.11
SMALL BORE PIPING
3.11.1
Field layout and routing of small bore piping 1½” N.B & below, shall comply with the specified minimum overhead clearances as per Company specifications.
3.11.2
Recommended maximum spans between hangers or supports for small bore carbon steel piping for service temperatures up to 200°F (93°C), are as follows: Pipe NB (inch)
½
Pipe Condition
¾
1
1½
2
Maximum Span (*), mm
Bare
2100
2700
3700
4600
5500
Insulated
1800
2400
3300
4300
5200
*
3.11.3
Valid for uniform loading conditions only. Concentrated loads, such as valves, orifice flanges, strainers or other specialities, shall be supported close to the load point. The above span shall apply to: •
All wall thickness for a given diameter
•
All conditions of service, ie corrosive, non-corrosive, liquid, vapour and gas.
3.11.4
Installation of support span shall be based on the smallest pipe diameter on that pipe rack.
3.12
PIPEWORK FOR SUBSEQUENT LINING
3.12.1
Pipework which is to be subsequently lined to protect against corrosion, erosion, etc., shall have all internal weld seams ground smooth and flush with the parent material.
3.12.2
All weld spatter and flux shall be removed.
3.12.3
All sharp edges and corners should be ground to a minimum radius of 3/16" (4.8mm)
3.13
FIELD TIE-INS TO EXISTING FACILITIES ( ‘Brown’ Fields):
3.13.1
As far as practical, the design should facilitate maximum fabrication at Contractor’s yard onshore with only tie-ins (hook-ups) to existing systems at site
3.13.2
During Brown field welding, Mechanical or Pneumatic test plug should be provided to the existing oil and gas lines with venting connection as a positive isolation. The upstream pressure of the plug can be monitored during welding in order to avoid sudden release of the plug. The vent line should be extended up to the non hazard area.
3.13.3
To optimize on loss of production and facilitate ‘Hydrotest’ of new facilities subsequent to installation, Tie-ins to existing facilities (‘Brown’ Field) should preferably be ‘Flanged’ and not ‘Butt welded’ type, unless warranted by other considerations. For running plant/hazardous areas, field welds shall be minimized in a.
3.13.4
Filed Tie in welds shall be treated as ‘Golden Joints’ Procedure for the same shall be developed by .Contractor and shall be subject to Company’s approval.
3.14
DECK PENETRATIONS
3.14.1
Deck penetrations shall generally be furnished with a ‘sleeve’ as per Company approved ‘Structural Standard Details’, developed for the project. The sleeve shall have a minimum clearance of one inch all around the ‘Pipe OR Insulation’ (as the case may be) to avoid crevice corrosion.
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ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
Z0-TS-P-04010 REV. NO.: 1 DATE:. 12/11/2008 PAGE: 11 OF 53
3.14.2
If after erection at site, the pipe is observed to have off-centered and has lesser clearance, then contractor shall modify The deck penetration to achieve the desired clearance
4
WELDING
4.1
GENERAL REQUIREMENTS
4.1.1
Welding shall comply with ASME B-31.3 & ASME Sec-IX and this specification.
4.1.2
For seamless pipes upto NPS 16”, root pass & hot pass shall be made using Gas Tungsten Arc Welding (GTAW) process. For larger diameter pipes, root & hot passes by Shielded Metal Arc Welding (SMAW) are acceptable.
4.1.3
Welding of pipes, branch fittings and flanges in sizes DN 50 and smaller shall be carried out using GTAW.
4.1.4
In addition to ASME B31.3 requirements, for carbon steel and duplex stainless steel process piping operating at design temperatures below 0 °C, the welding procedure qualification shall incorporate Impact test requirements for parent metal, weld metal and HAZ also. Average impact values & temperatures shall not be less than those permitted by code for the parent metal.
4.1.5
If the ambient temperature is below -10°C no welding shall be permitted. For ambient temperature between 0°C and -10°C: The metal shall be heated to 20°C even if pre-heating is not specified on the welding procedure. Precautions such as local heating and lagging shall be taken to avoid rapid cooling after welding. Irrespective of the class of steel, root runs shall be made without interruption other than for changing electrodes or to allow the welder to re-position himself. •
•
4.1.6 4.1.7
Butt welds shall not be allowed to cool to ambient temperature until the thickness of the weld deposited exceeds one-third of the final weld thickness or 5 mm, whichever is less. Wherever possible, all welds shall be completed without interruption.
4.1.8
Any bevelled edge of pipe that has been damaged shall be restored to minimum tolerances. All bevels shall be cleaned to give bright metal.
4.1.9
All sections of tacked or welded pipe shall be closed at night to prevent animals or foreign matter from entering such sections.
4.1.10
The deposited filler material shall match the chemistry and minimum properties of the metal to be welded and shall not exceed the parent metal strength by more than 20%.
4.1.11
Exposed machined and threaded surfaces shall be protected from oxidation during heat treatment.
4.1.12
The use of backing rings is not permitted.
4.1.13
Baking of low hydrogen electrodes shall be followed as per manufacture’s data and maintaining the same temp for welding by providing portable heater.
4.1.14
Contractor’s ITP (Inspection and Test plan) shall define the QC activities for welding.
4.2
QUALIFICATION
4.2.1
Welding shall be as per the qualified welding procedure for each type of base metal
4.2.2
The fabricator shall provide the following certificates and records a) b) c) d) e) f)
Weld Procedure Specification (WPS) Welding Procedure Qualifications Records (WPQR) Welders Qualifications and Test Results (WQT) Pyrometer Charts or Records of Heat Treatment Radiography Reports and other Non-Destructive Test Results Certifying Authority Release Notes
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g) Weld Location Map h) Fabrication tolerance inspection reports/Dimensional Checks. i) Pressure Test reports j) Calibration Certificate Welders and welding procedure shall be qualified and requalified, if necessary, in accordance with ASME B31.3 and ASME Boiler and Pressure Vessel Code, Section IX. Additionally, extra hardness traverses shall be made across the heat-affected zone of the weld and base metal within 2 mm of the internal and external pipe surfaces. Hardness values shall not exceed the values stipulated in NACE MR01 75. Qualification certificates shall be made available.
4.2.4
The WPS shall clearly specify the root penetration thickness and the tolerance permissible on the same.
4.2.5
Welding qualification tests shall be witnessed by the Engineer. Each welder shall carry on his person evidence of his qualifications. Each welding operator shall mark his identification symbol adjacent to each weld or in weld map, together with the planned Q.C. weld number.
5
CLEANING
5.1
SHOP FABRICATION
5.1.1
On completion of all fabricated piping, the Fabrication Vendor shall ensure that all loose foreign material such as scale, sand, weld spatter particles, cutting chips, etc., shall be removed from both inside and the outside of the piping assembly by any suitable means, such as mechanically driven rotary cleaning tools, wire brush, etc.
5.1.2
All piping assemblies shall be blown out with compressed air as an initial cleaning operation and inspected internally for cleanliness.
5.1.3
On completion of cleaning, all open ends shall be protected against damage.
5.1.4
The completed fabrications shall be inspected to ensure the absence of any foreign bodies and the end caps checked to ensure a tight fit and taped on before transportation.
5.2
FIELD INSTALLATION
5.2.1
Prior to erection, the Contractor shall ensure that any grease, oils, inhibitors or any anticorrosion coating, has been thoroughly cleaned and removed, and that all pipe sections or fabricated pieces are free from internal obstructions and foreign matter. Following erection, the Erection Contractor shall flush all piping systems with water or other approved fluid until free of foreign matter.
5.2.2
After erection, the ends of vertical pipes which are left open temporarily and openings in the top 270° of horizontal piping shall be suitably protected against the introduction of dirt, debris, tools, rags, etc.
5.2.3
Prior to connecting adjacent pieces of horizontal piping, the open ends shall be examined to ensure that all water, dirt, tools, rags, bottles and other foreign materials have been removed.
5.3
INSTALLATION OF VALVES
5.3.1
Contractor shall exercise special care to ensure cleanliness of both upstream and downstream piping spools prior to installation of valves (especially soft seated valves e.g. Ball valves).
5.3.2
The piping spools shall be thoroughly cleaned by any suitable means, such as mechanically driven rotary cleaning tools, wire brush, etc. to ensure that the internal surfaces are free from any remnant foreign matter e.g scale, sand or any foreign particle(s) likely to damage the valve seating surfaces during pre-commissioning & commissioning, before installing the valves.
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6
PIPE SUPPORTS
6.1
GENERAL
6.1.1
Pipe supports shall generally be as per Company standards
6.1.2
Sliding surfaces shall be cleaned of dirt, paint, rust or foreign matter and coated with graphite grease, unless noted otherwise.
6.1.3
Guides shall be assembled to permit free sliding under operating conditions, minimum guide clearance to be 3mm unless otherwise stated.
6.1.4
For proprietary pipe supports, the manufacturer’s instructions shall be followed during erection and hydrostatic test, no un-authorised welding shall take place.
6.1.5
P.T.F.E. sliding units and TICO pads shall be free from slough and other defects through all stages of fabrication and erection.
6.1.6
Straight runs of small bore piping on pipe racks for which pipe supports are determined on site shall be suitably guided at not more than 12m centres. Unless otherwise specified on piping drawings, guides shall be kept to a minimum of 40 pipe diameters clear of pipe bends or loops.
6.1.7
Piping specified as subject to cold spring, shall not be pulled into position until pipe anchors have been installed and pipe shoes fitted.
6.1.8
No welding shall be conducted on any cast iron or malleable iron pipe support.
6.1.9
Where U clamp is required, rubber/ coated U clamp should be used.
6.1.10
Use of doubler plates on pipes shall be avoided. It is recommended to use pipe shoes instead.
6.2
SPRINGS
6.2.1
Variable and constant support springs are to be supplied as complete assemblies. At time of installation spring load indicator shall be checked for cold load position in accordance with values given on spring data sheets; also the spring scale shall be checked that it shows the correct position for the load indicator under its working conditions.
6.2.2
When springs are supplied with pre-set pins, the pins must not be removed until after completion of final hydrostatic testing of pipe at site. After removal, the pins shall be wired to spring casing for future use. A record shall be maintained for the removal of each pre-set pin.
6.3
SPRING HANGERS
6.3.1
At the time of installation, spring hangers or supports shall be checked for accurate cold position loading.
6.3.2
All temporary hangers and supports shall be designed to ensure that they are adequate for the purpose.
6.4
EXPANSION JOINTS
6.4.1
Expansion joints shall be installed without removing cold position restraints and these restraints shall not be removed without prior approval of the ENGINEER.
6.4.2
If permanent supports or hangers immediately adjacent to expansion joints are not available for immediate erection, suitable temporary supports shall be provided to prevent overloading the expansion joints.
6.4.3
Expansion joint shipping bars shall be left in place until pipe supports have been installed and final hydrostatic or pneumatic testing of line completed in accordance with the agreed system testing procedure.
6.5
INSULATED PIPING
6.5.1
Insulated pipes shall be on shoes (except the classification covering “Personnel Protection” which shall bear BOP on TOS).
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6.5.2
Any small bore piping running parallel to adjacent steel is to have sufficient clearance to allow for fittings and the support cleats, and shall be suitably packed.
6.5.3
Shoes for supporting insulated piping on structural steel shall be attached prior to erecting the pipe.
6.5.4
Onshore pipe racks shall have a 25mm dia bar welded onto the steelwork to form a rubbing bar. Pipes not requiring a shoe will be supported off the steelwork by a 125mm angle flat at top with toe welded to the top of the steelwork, unless noted otherwise in the design drawings/ documents.
6.6
PIPE SHOE
6.6.1
Standard pipe shoes shall be 100mm high and 300 mm long, unless noted otherwise.
6.6.2
Pipe shoe lengths shall be located so that the base of the shoe is always fully in contact with the supporting steelwork.
6.6.3
Pipe shoes shall not be welded to support steel, unless noted otherwise. However, shoe guides shall be welded to support steel only.
6.6.4
Pipe shoes for P.T.F.E. Slide Units shall have heights and lengths to suit the application.
6.6.5
All pipe shoes and corrosion plates shall be positioned to be central on pipe support steelwork when pipe is in a non-operating condition.
6.7
PIPE SUPPORT ATTACHMENT WELDS
6.7.1
All pipe support attachment welds to process or utility piping shall be continuous fillet-weld as per ASME B31.3, unless otherwise noted on the drawings or data sheet.
6.7.2
Eyes of all eye rods are to be welded closed.
6.8
PIPE ELEVATIONS
6.8.1
Pipe elevations relative to supporting steelwork shall be as listed below, for offshore & onshore where applicable, unless otherwise indicated in the design drawings/documents. PIPE MATERIAL
BOTTOM OF PIPE (BOP) ELEVATION
Un-insulated Carbon Steel- Offshore Platforms NB < 1½”
:
BOP = TOS + Support Cleat
NB > 2”
:
BOP = TOS + 6 mm (for wear pad)
Un-insulated Carbon Steel (- Onshore pipe Rack) All sizes
:
BOP = TOS + 125 mm
NB < 1½”
:
BOP = TOS + Support Cleat
NB > 2”
:
BOP = TOS + 100mm for shoe
NB < 1½”
:
BOP = TOS + Support Cleat
NB > 2”
:
BOP = TOS + 100mm for shoe
Copper Nickel
Galvanized & SS
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Titanium All Sizes
:
BOP = TOS + Support Cleat
7
TOLERANCES
7.1
Tolerance on fabrication, assembly & erection of pipe work shall comply with ASME B-31.3, with minimum values as per Table-1, unless noted otherwise.
7.2
Weld spacing, shrinkage and fitting tolerances shall be accounted for in fabricating piping assemblies involving multiple fittings. The specified overall dimensions shall be maintained.
8
TEST & INSPECTION
8.1
GENERAL
8.1.1
Contractor shall be responsible for all inspection and testing.
8.1.2
An approved ITT plan shall be in place prior to commencement of inspection and testing.
8.1.3
All dimensions shall be checked to ensure that fabrication meets the requirements of the isometric drawings within the specified tolerances.
8.1.4
Inspection shall be carried out before any paint, coating, or lining is applied.
8.1.5
NDE on welding shall be carried out before heat treatment as well as after heat treatment to the extent defined in Table-3.
8.1.6
The methods to be employed for inspection, acceptance criteria for welds and the progressive examination shall be in accordance with ASME B31.3. As part of welding procedure qualification, these shall include the following as a minimum: • •
Impact Test at Minimum Design Metal Temperature (MDMT) Hardness Tests, to demonstrate that the weld metal as well as the HAZ complies with NACE MR 01-75/ ISO 15156 requirements.
8.1.7
Stress relieved weld joints shall be hardness tested as specified by ASME B31.3
8.1.8
NDE Technicians shall be qualified to ASNT/ PCN Level II. They may be assisted by Level I Technicians.
8.1.9
Contractor shall keep the Inspection Authority notified of progress of the work and give reasonable advance notice of required tests or inspections. Additionally, he shall also arrange for the Inspector’s free access to the fabrication shop throughout the period.
8.2
INSPECTION/TESTING OF HFI BENDS
8.2.1
Each production bend shall be subjected to the following inspection and testing after bending and heat treatment: • •
8.2.2
Dimensional checking for ovality, angle, etc. in accordance with ASME B16.9. Visual inspection of the external surface including bevels and, where possible, the internal surface. The surface of bends shall be free of any crack/ suspected crack, any lap/ dent or excessive wrinkles.
For one bend of each production run, i.e., bending machine operating with same pipe size, wall thickness and material, and with all bending parameters within specified limits, the following tests shall be performed: •
•
An ultrasonic wall thickness measurement on the complete outer and inner radius of each bend shall be carried out to ensure that the wall thicknesses are within the required tolerances. Minimum and maximum values shall be recorded. Complete outside and (where accessible) inside magnetic particle examination to ASTM E709 for carbon steel and low alloy steel. There shall be no linear indications. The method used and the results shall be shown on the material certificate.
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•
•
•
8.2.3
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Complete outside and (where accessible) inside liquid penetrant surface examination to ASTM E165 for stainless steel bends. There shall be no linear indications longer than 2 mm. The method used and the results shall be shown on the material certificate. Hardness tests shall be performed at 1/6, 1/2 and 5/6 of the bend angle on the outside surface with four measurements at each location, including the inner and outer radius and the neutral axis. Where possible, the same measurements shall also be taken on the inside surface of the bend. The hardness values shall be as specified in ‘Table-2 Heat Treatment of Formed Bends’. The results shall be shown on the material certificate.
Hydrostatic Testing of Pipe Bends Hydrostatic pressure testing is not required prior to installation. The Contractor shall, however, certify that each delivered bend is capable of passing a hydrostatic test at the test pressure at which the original pipe has already been tested in the pipe mill. Hydrostatic testing of piping systems or spools including bends shall be carried out after installation at site.
9
PRESSURE TESTING
9.1
SCOPE This section defines the pressure testing prior to commissioning of piping systems. Its intent is to lay down a framework in which a systems testing procedure can be implemented.
9.2
DEFINITION A system, within the context of this specification, is a ne twork of piping and equipment subjected to a test pressure, the only restrictions to flow being, blinds or any other blocking devices.
9.3
GENERAL REQUIREMENTS
9.3.1
This section sets practical limitations within which piping systems as defined above may be tested with safety and in accordance with the requirements of the applicable codes and standards.
9.3.2
The procedures under this section are to enable the strength and tightness of welded, flanged and screwed joints to be safely and thoroughly tested.
9.3.3
As far as possible, hydrostatic testing of fabricated spools shall be completed at contractor’s yard, prior to offshore mobilisation.
9.3.4
All stress relieving and other heat treatments of pipe and equipment, together with full Q.C. release shall be completed before testing.
9.3.5
No insulation, paint or other covering shall be applied over any welded, seam or joint before completion of the pressure testing.
9.3.6
Pressure testing shall be to Company’s procedure PEMS/HTPT/033 as laid out in this specification and shall comply with ASME B31.3 latest edition, 'Process Piping'.
9.3.7
Pressure recorders shall be used to monitor and record pressure test results.
9.3.8
All gauges to be used for tests shall be tested, calibrated and approved by the ENGINEER. A minimum of two gauges shall be used, positioned at the highest and lowest points in the system. The range of the gauges shall be 1.5 times the hydrostatic test pressure.
9.3.9
Contractor shall supply and install all test materials, e.g.. Blind Flanges, Spades, Links or Spools, Vents and Drains, as required for the test.
9.4
CONTRACTOR’S RESPONSIBILITIES
9.4.1
Contractor shall thoroughly review the requirements Company’s procedure PEMS/HTPT/033 and this specification and any conflicts/ambiguities shall be resolved with Company before implementation.
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9.4.2
Contractor shall carry out all inspection and testing required of them by this specification and shall correct all deficiencies evidenced by inspection and/or tests. They will also advise the Company of any major repairs required and submit proposed repair procedure for the Company's approval.
9.4.3
Contractor shall advise the Company of his schedule of hydrostatic testing and also give 24 hours notice of his intention to hydrostatically test specific lines and/or equipment.
9.4.4
Contractor shall furnish a detailed test procedure for Company’s approval.
9.4.5
Contractor shall supply all necessary facilities to perform the work, these shall include, but not be limited to, the supply of all pumps, equipment, tools, materials, (including temporary pipe pups, blinds and supports), scaffolding, labour and other services to satisfactorily complete the work according to schedule. All materials supplied by the contractor which are temporarily added to the lines for pressure testing shall be painted yellow for ease of identification when removal is required after completion of the pressure test.
9.4.6
After successful completion of the tests, contractor shall drain and dry the piping systems and remove all temporary material used for testing, e.g. blanks, pups, supports, scaffolding, etc, and reinstate check valves and all other equipment isolated for the purpose of hydrotesting.
9.5
SYSTEMS
9.5.1
Pressure Test Flow Diagrams shall be prepared by the contractor showing systems to be tested, valves to be opened and equipment to be blinded. It should also be a record of systems tested. A suitable marked up reproducible of the P & ID's shall be de veloped for this purpose.
9.5.2
The Test Flow Diagram shall clearly show the demarcation limits of each test circuit and shall be identifiable with the hydro or pneumatic test certificates.
9.5.3
It is economically desirable to test at one time as much of the piping and equipment as possible without exceeding the allowable test pressure of the weakest element in the system, i.e. the test pressure on any line shall not exceed the design pressure of any vessel, exchanger or other appurtenances installed in the system and included in the test.
9.5.4
Equipment with test shall be isolated from the system undergoing the test.
9.5.5
Equipment, pressure relieving devices, expansion joints, instruments, filters etc. and equipment with test pressures lower than that for piping, shall be isolated from the system undergoing the test i.e. blanked off or removed from the system prior to testing. Such equipment shall be inspected during the commissioning test.
9.5.6
The sequence of systems to be tested at any one time shall be determined by the Company based upon erection progress and the pressure test flow sheets.
9.6
EXTENT OF TESTING
9.6.1
Orifice plates, strainers, filter elements, instrument valves, metering equipment, turbines, pumps, compressors, heat exchangers, safety valves, rupture discs or ejectors shall not be subject to piping pressure test. These shall be blocked out of the test system. Expansion joints must be tested with the piping in order to check restraining devices.
9.6.2
Blind flanges required shall be indicated on the Pressure Test Flow Diagrams and shall be installed prior to testing. Only rated blinds and spades shall be used. Non-standard spades & blinds are not acceptable.
9.6.3
Instrument piping at orifice flanges and equipment, up to and including the first block valve, shall be tested with their respective piping systems by the piping contractor. The balance of the instrument piping shall be tested pneumatically and separately by the instrument contractor, to avoid introducing foreign matter.
9.6.4
Pneumatic transmission lines shall be air tested at pressures & procedures as per this specification. Reference must be made to the Company’s Instrument Installation and Testing Specification.
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9.6.5
Where Hydrostatic testing is considered impracticable, Pneumatic testing may be substituted but only with specific approval from Company’s. This may require providing special supports or special arrangement to facilitate the same, specially on large diameter low pressure vapour lines. Such testing shall comply with Company’s procedure (ref. Appendix-A2).
9.6.6
Where full hydrostatic tests are uneconomical, impracticable or piping, refractory or attached equipment are liable to damage by water, pneumatic testing may be substituted, but only subsequent to Company’s approval. Such testing shall comply with Company’s procedure (ref. Appendix-A2).
9.6.7
Company maintains the right to have each reinforcing pad (or each segment thereof) tested to a pressure of at least 15 psig (0.20 MPa) with air, utilising soap solution to detect air leaks.
9.7
TEST PRESSURES
9.7.1
The piping test pressure shall be as listed on the Line Designation List and the Pressure Test Flow Diagrams.
9.7.2
The hydrostatic test pressure to be used on each line in internal pressure service shall normally be not less than 1.5 times the design pressure in accordance with ASME B 31.3. However, if the test spool involves sections of existing piping, the test pressure shall be governed as set out in company’s procedure (ref. Appendix-A2), unless otherwise noted.
9.7.3
The maximum test pressure for any metallic piping system comprising flanged joints, shall not exceed the limits set as per ASME B16.5
9.7.4
The minimum hydrostatic test pressure to be considered shall be 100 psig (0.79 MPa), except for the following; •
Lines normally open to atmosphere
•
Large diameter lines for which the test pressure will be specially calculated.
•
Lines subject to pneumatic testing as qualified by this specification
9.7.5
For pneumatic testing, it is advisable to carry out a preliminary test at not more than 20 psig. The pressure should be increased gradually in small increments allowing sufficient time at each step for the system to stabilise. Pneumatic test pressure shall be governed as set out in company’s procedure (ref. Appendix-A2), unless noted otherwise.
9.7.6
The actual test pressure shall be modified if required to conform with any requirements of the ASME Boiler and Pressure Vessel Code, or to national or local regulations. Requirements of the ASME Boiler and Pressure Vessel Code will apply only to the small amounts of piping at such units which come within the jurisdiction of that Code.
9.8
TEST PROCEDURE
9.8.1
Necessary steps shall be taken to ensure hydrostatic tests do not result in damage to equipment and that all portions of systems are in fact, tested. The requirements of the Pressure Test Flow diagrams shall be closely adhered to. Contractor shall ensure no damage to instrumentation during pressure test.
9.8.2
All joints and welds (except those previously tested) shall be left un-insulated and exposed for examination during the test. Equipment which is not to be included in the test shall be isolated from the system (using blinds). Compressor suction and discharge lines shall be drained and nozzles blinded to prevent water entering the compressor. All lines shall be cleared of debris by flushing with water.
9.8.3
To ensure complete exclusion of air, the system shall be slowly filled from the bottom (if possible) and vents shall be placed and opened at the highest points.
9.8.4
Soft seated valves, particularly Ball valves, shall be installed in open position and not operated until the lines have been thoroughly flushed.
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9.8.5
Control valves shall be set in the open position or removed and spool pieces substituted. For control valves, in specific case if some valve cannot be isolated and has to remain in the line during testing, close cooperation with the instrument engineer shall be maintained in order to open valves that are normally closed. These valves shall not be jacked open or forced open. On completion of the test, the valve seat must be physically inspected for cleanliness prior to operation.
9.8.6
For joints that are to be broken for hydro testing or after testing, as far as practical, temporary gaskets shall be used. This is of particular importance on lines where spiral wound gaskets are used.
9.8.7
All restrictions that interfere with filling, venting or draining such as orifice plates and flow nozzles, shall not be installed until testing and flushing are complete.
9.8.8
For hydrostatic testing, all piping in other than liquid service shall be adequately supported (using temporary supports if necessary) particularly on lines using spring or counterweight supports. Spring gagging devices shall not be removed until the completion of testing. Adjacent large lines are not to be tested simultaneously where the weight of the combined test water load may overload the structure or supports.
9.8.9
Lines containing check valves should have the pressure source located on the upstream side. If this is not possible, the valve obturator is to be removed from the line, or jacked open prior to testing.
9.8.10
Vents (and other connections which can serve as vents) shall be open during filling so that all air is vented prior to applying test pressure to the system.
9.8.11
Test pressure shall be maintained for sufficient time to permit inspection of the system under test and to determine small seepage type leaks. The minimum time allowed for system undergoing a pressure test is one hour plus the time actually required to allow for inspection.
9.8.12
The pressure gauge shall be located at the highest and lowest point of the main pipe run.
9.8.13
Submerged lines shall be tested prior to installation. However, if installation is essential prior to testing, the test pressure shall be applied for a minimum of 2 hours and checked for pressure drop.
9.8.14
Any leaks shall be repaired and the lines retested.
9.8.15
On completion of satisfactory hydro test, all lines and equipment shall be completely drained of the test fluid. Vents in the system shall be open while draining, to avoid a vacuum. Also, in the event of a pipe failing during pressure testing, the system under test shall be vented to avoid a vacuum. Special attention shall be given to points where water may be trapped, such as valve bodies or low points.
9.8.16
If the residual moisture left in the system after draining is considered detrimental, steps shall be taken to dry out the system. Consideration shall be given to drying or replacing valve packings to be used at low temperatures and for corrosive service.
9.8.17
When conditions require a test pressure to be maintained for a period of time, during which the system might be subject to thermal expansion, provision shall be made for relieving the resultant excess pressure.
9.8.18
Pneumatic testing, if warranted, shall be conducted only after receipt of written consent from Company. Such test shall be carried out in accordance with ASME B 31.3.
9.8.19
If a test performed in accordance with this specification requires a joint (flanged, screwed or welded) to be used for blocking purposes, then the adequacy of the remade joints shall be checked as part of plant start-up procedure. On satisfactory completion and acceptance of the hydrostatic test all test materials shall be removed and connections plugged and or sealed as required by Company.
9.8.20
Any welds or portions of welds that leak on hydrostatic test and which have not been radiographed prior to the test, shall be radiographed at the affected areas before they are cut out and re-made. Such radiography, repair and retesting shall be at the Contractor's expense.
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9.8.21
Furnace tubing should be hydrotested with the piping system. Furnace coils, if shop fabricated should first be hydrotested and then air tested in the Vendor's shop. If the coils are field fabricated, hydrotesting shall be carried out after all heat treatment has been completed, to be followed by pneumatic test.
9.8.22
Where called for by the site circuit testing programme, temporary end spades shall be used to isolate equipment from the line continuity test. (The Contractor shall supply these end spades).
9.9
TESTING MEDIUM
9.9.1
Unless noted otherwise, Hydrostatic testing shall be performed with clean fresh water having a minimum of pH 8. ‘Treated Seawater’ used at ZADCO Wellhead Towers for Firewater/ Injection Water service is considered satisfactory.
9.9.2
Seawater will preferably not be used but, with specific approval, inhibited seawater may be used on the installation and the system subsequently flushed with fresh water.
9.9.3
The temperature of the test water shall in no instance be allowed to fall below 7°C.
9.9.4
The testing medium may be changed by specific agreement if testing conditions imposed by water are considered deleterious to the pipe system, eg possibility of freezing. If the water temperature is likely to fall to 0°C or below, glycol or alcohol with a corrosion inhibitor, or other approved anti- freeze shall be used. It should be noted that special gaskets may be required for alternative test media.
9.9.5
For testing of austenitic stainless steel piping and equipment, the hydrotest water shall have a chloride content < 30 ppm. Piping must be thoroughly drained and dried on completion of testing.
9.9.6
Kerosene is an acceptable alternative testing medium for austenitic stainless steel piping
9.9.7
For Pneumatic Testing the medium shall be oil free air or inert gas subject to Company’s approval. The minimum metal temperature for all components during a test should be 16°C.
9.10
TEST RECORDS
9.10.1
Valid calibration test certificate and sketch showing the system limits to be tested shall be submitted to Company.
9.10.2
The Contractor shall maintain records of all hydrostatic tests conducted, indicating: •
Date of test.
•
Equipment and/or line number (s).
•
Design pressure and temperature.
•
Operating pressure and temperature
•
Test Pressure (Gauge No. Pressure Recorder Charts).
•
Test Duration
•
Water temperature and chloride content (where applicable)
•
Testing medium (if not water).
•
Applicable remarks concerning defects.
•
•
9.10.3
Approving Authority’s signature certifying that all piping has been tested as required by the code. Any other data required.
Test procedures, reports and test results shall be submitted to the Company.
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ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
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10
LEAK / TIGHTNESS TEST
10.1
SCOPE
10.1.1
The tightness test, also called Leak Test, will be done after hydrostatic pressure test on all gas/vapour lines, upto the last block valve on each system. This test shall be carried out for whole sketches corresponding to each system on one P&ID.
10.1.2
These tests shall be conducted as pre-operational leak tests on the following : •
All insulated lines irrespective of service (Test carried out prior to insulating)
•
All HC lines for both gas & liquid lines including fuel lines
•
All lines in corrosive/ chemical service.
10.1.3
Operational leak tests shall be carried out on all utility lines (e.g. Firewater, Instrument/ Plant Air, Potable Water etc.), utilising normal operational fluid as a service test.
10.2
PREPARATION
10.2.1
Each system shall include equipment (tanks, exchangers, filters etc..except mechanical equipment):
10.2.2
Each blind flange or spade before equipment shall be removed EXCEPT for those installed between end of circuit and mechanical equipment (or isolating two systems on one P&ID), which shall remain in the system.
10.2.3
Soapy water or soapy solution shall be put around each valve and equipment flange to check flanges and valve gland
10.2.4
A check shall be carried out of the whole network listed on the check-list.
10.2.5
The whole network shall be marked out to ensure no use by anyone other than the test team
10.2.6
All flanges shall be taped and a pinhole made in each tape.
10.3
TEST
10.3.1
The system shall be pressurised with air to a pressure of 60 psi or 15% of maximum allowable design pressure (whichever is less).
10.3.2
Soapy water shall be applied to detect leakage.
10.4
INERTING
10.4.1
Subsequent to the leak test, the piping system shall be inerted with Nitrogen, prior to charging the line for production start-up.
11
TESTING OF FIELD INSTALL ED PIPEWORK & TIE-INS Field tie-ins shall be subject to the following test/ inspection: Tie-in Joint Welded : (Golden Weld)
Type of Test / Inspection When it is not practical to perform a pressure test of a final closure weld that joins a new or replacement section of piping to an existing system (‘Field Tie-in’), all the following requirements shall be satisfied: • • • •
Z0-TS-P-04010-Rev-1
New or replacement piping is pressure tested Closure weld is full penetration butt weld Final closure butt weld shall be 100% radiographic quality MT or PT shall be performed on the root pass and the completed weld
ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
Z0-TS-P-04010 REV. NO.: 1 DATE:. 12/11/2008 PAGE: 22 OF 53
These joint(s) shall be as per API 570 and as a minimum, shall undergo: I. Fit-up check for misalignment & root gap etc II. 100% MT/PT on ‘Root’ pass III. 100% RT + 100% MT/PT on finished joint. A ‘Methods Statement’ shall be developed for ‘Golden’ joints, incorporating the above which shall be subject to Company’s review/approval prior to implementation. Flanged :
Hydrotest in yard prior to load out. If not, then hydrotest offshore prior to installation.
12
WATER FLUSHING OF PIPING SYSTEMS
12.1
SCOPE This section defines the water flushing operations in connection with hydro-testing. Deviations from this procedure must be approved by the Engineer.
12.2
DESIGN CRITERIA
12.2.1
Media Stainless steel lines
:
potable, with chloride below 30 ppm, and pH less than 8
Carbon steel and alloy lines
:
fresh water, and pH less than 8.
Piping in salt water service
:
use freshwater or saltwater
Once through flushing
:
until flush water is clear
Circulation loop flushing
:
until circulating pump strainer is free of foreign materials and circulating water is clear
:
Velocities to be the maximum possible with the available equipment and test pressures, or with the site water supply. Minimum requirement being that full bore discharge from the open pipe end shall be achieved by the contractor
• • •
12.2.2
Duration • •
12.2.3
Velocities All lines filled with water and drained per hydro - or system test
12.3
EXCEPTIONS The following systems and/or lines do not require flushing with water: •
• •
Lines and/or systems that are to be chemically cleaned and flushed with other than fresh water or seawater. Lines in which the presence of water would cause operational difficulties. All instrument air lines – lines will be tested with air, soap tested and blown out with air. All air must be 100% oil free.
12.4
GENERAL REQUIREMENTS
12.4.1
General
12.4.2
Contractor shall fill piping and systems with clear water and conduct all flushing as per this specification and as directed by the ENGINEER.
12.4.3
Flushing operations shall be carried out after hydrostatic testing.
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ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
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12.4.4
Contractor shall notify the ENGINEER of flushing schedule and provide all necessary drawings required.
12.4.5
Contractor shall maintain log of lines and systems flushed.
12.4.6
If necessary the Contractor shall provide suitable circulation and/or flushing pumps, and header tanks.
12.4.7
Contractor shall provide suitable temporary pipe connections, hose connections, blind flanges, temporary gaskets, temporary strainers and dummy spools as required for flushing.
12.4.8
Flushing procedures for units or sections of units where moisture cannot be tolerated due to process considerations shall be as agreed to with the Company.
12.4.9
Contractor shall flush all lines to limits established by the Company.
12.4.10
Piping
12.4.10.1 Contractor shall clean temporary strainers, if necessary, during flushing operation. 12.4.10.2 Contractor shall isolate or remove in-line components such as control valves, positive displacement meters, turbine meters, rotameters, orifice plates etc. for flushing. 12.4.10.3 Contractor shall ensure no damage to any instrument during flushing. If necessary the Contractor shall provide spool pieces for temporary replacement of items requiring removal during flushing. 12.4.10.4 The Contractor must ensure that all traces of water are removed before exposing the systems to sour gas. 12.4.11
Vessels & Equipment
12.4.11.1 Vessels and equipment which are not included in hydro-test shall only be flushed under instructions from the Engineer. 12.4.11.2 Flushing into tanks is allowed providing tank is thoroughly cleaned after flushing. 12.4.11.3 Contractor shall not flush through exchangers or rotating equipment. 12.4.11.4 Contractor shall isolate th e equipment and blind if necessary, and re-instat e the same when flushing is complete. 13
INTERNAL CLEANING OF PIPEWORK BY PICKLING AND GRIT BLASTING
13.1
SCOPE This section covers the requirements for the internal cleaning of pipe work by pickling and grit blasting. It is essentially for stainless steel piping and compressor piping, seal and lube oil systems but the extent of such cleaning shall be specified by project instructions and indicated on line designation lists and the piping isometrics
13.2
GENERAL
13.2.1
Reasonable and statutory safety precautions shall be taken by the Contractor in connection with the work and as may be determined by site conditions.
13.2.2
The pickling operation shall include the following stages: Degreasing, Acid Wash, Rinsing, Passivating, Drying and Application of a Protective Coating.
13.2.3
The pickling operations shall be performed in a continuous manner, particularly the rinsing and passivating stage following the acid cleaning cycle. (Carbon steel is highly susceptible to corrosion during this critical stage.)
13.2.4
Before commencement of work the Contractor shall state whether the materials and/or sequence of operations differ from those stated in his quotation.
13.2.5
The cleanliness required shall be such that the treated piping shall be free from dirt, grease, oil moisture, mill scale, fluff or any other form of contamination.
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ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
Z0-TS-P-04010 REV. NO.: 1 DATE:. 12/11/2008 PAGE: 24 OF 53
13.2.6
Where the ENGINEER considers necessary, machined surfaces and non-ferrous components are to be protected against the harmful action of the cleaning solutions; protection shall take the form of plastic caps, sheet, tape or acid resisting compounds.
13.3
DEGREASING
13.3.1
Large quantities of loosely held scale and foreign material may be removed by hand or power tool prior to cleaning.
13.3.2
Degreasing of the piping surfaces shall be performed to remove all traces of oil or grease adhering to pipe surfaces prior to pickling.
13.3.3
Degreasing shall be performed by the use of suitable heavy duty alkaline or detergent cleaning solutions maintained at temperatures between 80°C (176°F) and 90°C (194°F) for one or more hours depending on the degree of contamination.
13.3.4
As an alternative, tri-chloro ethylene may be used as a solvent. In such cases care should be exercised that the area is adequately ventilated to clear toxic vapours. This solvent may not be used in connection with Titanium Pipework (see Appendix III).
13.3.5
The piping surfaces should be thoroughly rinsed or flushed with potable water for at least 15 minutes to remove all traces of the degreasing solution from the piping surfaces.
13.4
GRIT BLASTING
13.4.1
Surface preparation by blast cleaning must be carried out prior to installation of any equipment, piping, etc, in the modules. After equipment has been installed, blast cleaning will only be allowed if the area to be cleaned can be sealed off and maintained at an air pressure below atmospheric.
13.4.2
Blast cleaning shall not be conducted when ambient conditions are such that visible rusting occurs.
13.4.3
Inside of pipes shall be grit blasted to a near white metal finish using a metallic grit as defined in SSPC-SP10/ NACE No.2.
13.4.4
All grit blasted pipes shall be thoroughly purged of grit by sweeping and using high pressure air (100 psi), the piping shall be rotated axially and circumferentially during this operation. The air used shall be free of oil and moisture. Adequate traps and separators shall be provided.
13.4.5
Protective coating should be carried out as rapidly as possible after grit blasting and purging.
13.5
ACID CLEANING
13.5.1
The pipework should be sprayed, circulated or immersed in a 10% solution of inhibited hydrochloric acid at a temperature not exceeding 66°C (150°F) for one hour or longer until the oxide scale is completely removed.
13.5.2
The inhibitor concentrations shall be in accordance with the supplier recommendations.
13.5.3
Certain proprietary brands of de-scaling solution are available. Use of any one of these is acceptable provided proof, i.e. laboratory tests, can be furnished, that such solvents will perform an efficient pickling job.
13.5.4
The piping shall be dipped with vents open at all high points to prevent the trapping of any air and to allow for the escape of hydrogen during the pickling operation.
13.5.5
The acid shall be made fresh for each pickling operation. The strength of the acid shall be monitored to maintain required concentration.
13.5.6
The acid solution shall be replaced if the ferric iron (FE+++) content exceeds 0.4% by weight, in order to avoid excessive metal loss.
13.5.7
The piping shall be thoroughly rinsed/ flushed with potable water as rapidly as possible after the acid cleaning operations to rid the surfaces of all traces of excess acid or iron salts and prevent the formation of after rust. (High pressure water and adequate drainage are required to facilitate rapid rinse/flush operation.)
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ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
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13.5.8
All dead ends should be opened long enough to flush out all entrapped acid.
13.5.9
Rinsing shall continue for at least 10 minutes after the pH of the effluent water equals the pH of the influent water. (Thorough rinsing eliminates necessity for subsequent neutralising stages.)
13.6
PASSIVATION
13.6.1
Passivation cycle.
13.6.2
Passivating solutions containing 3% phosphoric acid shall be flushed through a temperature between 60°C(140°F) and 80°C(176°F) for one or more hours.
13.6.3
Certain proprietory brands of pickling solution are claimed to passivate the metal in the same reaction as the pickling. If this claim can be substantiated by laboratory reports a separate passivation cycle will not be necessary.
13.7
DRYING
of tubing surfaces shall be performed as rapidly as possible after the rinsing the pipework at
Drying shall be done by purging the pipe with commercial nitrogen gas or dry filtered air at a temperature maintained between 65°C (150°F) and 80°C (170°F). 13.8
INSPECTION
13.8.1
A visual inspection shall be performed by the Contractor, in accordance with SSPC:VIS 1, to ensure that the piping faces are free from all traces of foreign contamination.
13.9
PROTECTIVE COATING
13.9.1
Cleaned piping internal surfaces are to be coated with a rust preventative which will not require removal before start up. Acceptable preventatives are Mobil.Mobilarma 522 and 524 or approved equivalents
13.10
TRANSPORTATION OF PICKLED & GRIT BLASTED PIPING
13.10.1
All treated pipework shall be protected prior to shipment/transportation to prevent damage in transit and during storage.
13.10.2
Ends of piping shall be securely plugged and sealed with plastic caps. Flange gasket surfaces shall be protected with bolt-on wooden blanks. In addition a corrosion preventative shall be applied to the gasket surfaces. When wood blanks are used, a plastic sheet shall be placed between the flange and blank to prevent the compound soaking into the wood.
13.11
ERECTION
13.11.1
Every precaution shall be taken during erection to prevent foreign matter from entering into the piping system. Protective covers shall not be removed until final assembly is imminent.
14
MARKING
14.1
After satisfactory inspection and after shop painting or galvanising, each pipe detail shall be suitably tagged using metal tag plates marked with the identifying piece mark number as indicated on the isometric fabrication drawing.
14.2
Additionally, piping spools involving pipes NPS > 6” shall also be stencilled with these identity numbers.
14.3
Marking by die-stamp is prohibited on carbon steel piping less than 0.25" (6mm) wall thickness.
15
PAINTING
15.1
Painting of pipework shall be in accordance with Company specifications.
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ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
16
DOCUMENTATION
16.1
REQUIRED DOCUMENTS
Z0-TS-P-04010 REV. NO.: 1 DATE:. 12/11/2008 PAGE: 26 OF 53
Contractor shall keep the following documents ready at all times, for Company’s inspection: •
Welding Procedures and Inspection Documents
•
Welder Performance Qualification Records;
•
Weld Map
•
Magnetic Particle Examination/ Dye Penetrant Test Records;
•
Ultrasonic Examination Records.
•
Radiographic and Heat Treatment Records
•
Hydrostatic Test Records/ Pneumatic Test Records
•
Coating Records
•
Visual examination and hardness test records
•
Inspection & Test Plan (ITP)
16.2
SHOP FABRICATION
16.2.1
The fabricator shall ensure that comprehensive records are kept in his factory sufficient to enable rapid tracing of the appropriate NDT records against any spool piece.
16.2.2
Additionally, upon shipment of spools, two copies of each shop spool drawing shall be given to the inspector. These copies shall clearly indicate where NDT have been taken, the record reference number(s) of the NDT records, and shall state if post weld heat treatment has been carried out.
16.2.3
Each copy will be signed by the inspector when he is satisfied that all NDT records and heat treatment charts have been reviewed and passed. One copy shall be sent to the site and one copy retained by the Inspector.
16.2.4
Original NDT records and heat treatment charts shall be submitted to the Company for retention.
16.3
SITE WORK (ASSEMBLY/ ERECTION)
16.3.1
The methods employed above for shop fabrication shall also be applied at site, and compiled by the radiographic inspector. Additional control may be required by the Company’s inspectors and these shall be mutually agreed at the appropriate time.
17
SHIPMENT
17.1
All flange faces, threaded ends, and other machined surfaces of all piping of all materials shall be coated with grease type rust preventative applied as recommended by the manufacturer. The make and brand of grease used shall first be approved by the Inspector.
17.2
All flange faces shall be protected against damage in shipment by suitable covers of wood or plastic. The covers shall be securely and tightly attached by at least three bolts or by wiring through at least four bolt holes.
17.3
Threaded ends shall be provided with thread protection. Ends prepared for butt welding in the field shall be protected by a tapped on tight fitting cap.
17.4
No piping shall be released for shipment until it has been approved by the Inspector and until all the shipping documents and invoices, required by the applicable purchase order, have been furnished.
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ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
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ANNEXURE-I: AUSTENITIC STAINL ESS STEEL & 904L PIPEWORK
Z0-TS-P-04010-Rev-1
ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
I.1
Z0-TS-P-04010 REV. NO.: 1 DATE:. 12/11/2008 PAGE: 28 OF 53
SCOPE This appendix describes the minimum requirements for the welding and inspection of austenitic stainless steel piping to (ASTM A-312) including 904L (UNS N08904) pipework, for use in ZADCO facilities.
I.2
PROCESS
I.2.1
The welding process shall be Gas Tungsten Arc Welding (GTAW), Gas Metal Arc Welding (GMAW) both with an inert shielding gas such as Argon or Shielded Metal Arc Welding (SMAW).
I.2.2
Precautions should be taken during GTAW welding to ensure adequate supply of high purity argon shielding gas. (Oxygen content should not exceed 0.05%.) Inner surfaces of the pipes in the vicinity of the weld should be provided with additional protection by purging with basking gas.
I.3
CONSUMABLES
I.3.1
For the GTAW process, non-consumable thoriated tungsten electrodes (AWS A5.12 Classification EW Th-2) shall be used. The tips of the electrodes shall be tapered to a sharp point using grinding wheels reserved specifically for this work.
I.3.2
The filler metals used shall be of matching composition to the base materials and comply with AWS 5.4 or 5.9 as appropriate and suitable for the weld ing process used.
I.3.3
For base material in SS 904 L, the filler metal for welding to different materials shall be : For welding to:
Filler Material
Carbon steels
:
AWS ER 309 Mo
Other Stainless Steels
:
904 L
I.3.4
MIG welding of 904L should be carried out using a shielding gas consisting of 30% Argon and 70% Helium or 69% Argon, 30% Helium and 1% Oxygen.
I.3.5
The use of nitrogen if proposed as the shielding gas for the backing run, shall form part of the welding procedure submitted for approval by the ENGINEER.
I.4
PREPARATION
I.4.1
Edge Preparation
I.4.1.1
Preparation of ends of pipe and fittings to be welded shall be made by plasma arc cutting, machining or grinding. The end faces shall be prepared by grinding or with a file.
I.4.1.2
Grinding wheels shall be of a type suitable for stainless steel and must not have been previously used on carbon steel.
I.4.1.3
Edge preparations for butt-welds and branch connections shall be as per ASME B31.3.
I.4.1.4
Weld-o-lets and bevelled branch connections shall be suitably prepared to fit the contours of the pipe surface to which they are to be welded.
I.4.1.5
All joint preparations shall be designed so as to ensure full penetration welding.
I.4.2
Pre-weld and Inter-Run Cleaning
I.4.2.1
The ends to be welded shall be cleaned to remove all traces of paint, dirt and grease etc. Wire brushing to remove loose debris should be carried out ONLY with stainless steel brush that has not been used previously on carbon steel surfaces.
I.4.3
Jigging and Assembly
I.4.3.1
The assembly of the pipe sections prior to welding shall be as indicated earlier in this specification.
I.4.3.2
The bores of pipes of differing internal diameters shall be machined as per ASME B31.3.
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I.4.3.3
Tack welding may be carried out to provide a uniform root gap of 1.5mm along the joint faces. The tack welds of appropriate lengths and spacing for stainless steel should be made with normal gas shielding.
I.4.4
Pre-heating and Inter-pass Temperatures
I.4.4.1
If the ambient temperature is below 0°C, the austenitic stainless steel pipe work should be preheated to 50°C maximum prior to commencement of welding. The inter-pass temperature should not exceed 100°C. Post weld heat treatment is not required.
I.5
QUALIFICATION REQUIREMENTS
I.5.1
WPS/ PQR/ Welders Qualification etc. shall be as stipulated earlier in this specification, in compliance with ASME Section IX.
I.6
WELDING
I.6.1
Tack welds on pipes with wall thicknesses < 4mm must be removed during the root pass. To avoid cracks in the root pass of thicker material, the tack welds should be made shorter by grinding the start and finish of the tack prior to starting the root pass.
I.6.2
Tacks, if used for positioning the fillet welds, shall be free from defects and be cleaned of oxide and slag to permit complete fusion with the first weld run.
I.6.3
In order to preserve the corrosion resistance and minimise hot cracking of 904L weldments, low heat input welding procedures should be used. This can be achieved using small diameter electrodes, low welding current and high welding speed. Incidence of hot cracking is also minimised by keeping the joint faces clean and free from oil and grease etc, as well as maintaining the shielding gas flowing for a few seconds before and completion of welding.
I.6.4
The maximum bead width produced by weaving should be no more than twice the electrode diameter.
I.6.5
For thinner walled material (< 3mm), maintain short arc length to avoid loss of alloying elements from the arc.
I.6.6
Particular attention should be paid to weld starts and craters to ensure complete removal of slag from sharp corners and cavities.
I.7
PRECAUTIONS FOR FABRICATION OF STAINLESS STEEL PIPEWORK
I.7.1
During fabrication, caution shall be exercised to ensure that stainless steels do not come in contact with unalloyed or low alloy steels.
I.7.2
Stainless steel shall be fabricated in a separate work area, on wooden work-benches and with tools to be used only for the fabrication of SS.
I.7.3
It shall be ensured that stainless steel parts do not come in direct contact with zinc or zinccontaining parts (e.g. galvanised shackles, clamps and rollers) to prevent possible liquid metal embrittlement in the event of a fire. In case of any doubt, the stainless steel shall be chemically cleaned before any further work is carried out.
I.7.4
Stainless steel piping (particularly elbows, reducers and tees) coming from unconditioned storage shall be checked for surface contamination with chlorides caused by condensation, or covering caps. Stainless steel piping shall be cleaned by rinsing with low chloride water before painting and welding.
I.8
INSPECTION & TESTING
I.8.1
Visual Inspection, NDE & Pressure Test shall be carried out as per this specification.
I.8.2
Under RT, no tungsten inclusions are permitted within the weld metal area or the parent material.
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ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
ANNEXURE –II:
Z0-TS-P-04010-Rev-1
COPPER-NICKEL PIPEWORK
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ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
Z0-TS-P-04010 REV. NO.: 1 DATE:. 12/11/2008 PAGE: 31 OF 53
II.1
SCOPE
II.1.1
This appendix describes the minimum requirements for the welding and inspection of 90/10 and 70/30 copper-nickel seamless (ASTM B-466-85) and welded (ASTM B-608-82) pipework, for use in ZADCO facilities.
II.2
FABRICATION PROCEDURE
II.2.1
Procedures used for fabricating Cu-Ni pipework shall be as follows: •
NB > 3”: Welded using BW fittings.
•
NB < 2”: ‘Brazed’ using capillary type fittings.
II.2.2
Prior to start of welding or Brazing, contractor shall submit detailed welding, brazing and repair procedures (including cleaning procedures) covering all fabrication activity, for Company’s approval.
II.2.3
Welding/ Brazing shall be as per ASME section IX, unless noted otherwise.
II.2.4
Regardless of the welding/brazing process employed, all procedures shall be qualified under ASME IX and shall account for the pipe manufacturer’s recommended procedures, to meet ASME IX.
II.2.5
Brazing shall be by oxy-gas, oxy-acetylene or oxy-propane torch.
II.3
WELDING PROCESS
II.3.1
General
II.3.1.1
The welding process shall be Gas Tungsten Arc Welding (GTAW) incorporating Argon, Helium or their mixture as the shielding gas and non-consumable electrodes of Tungsten containing 2% Thoria (known as Thoriated Tungsten electrode) with a pointed tip.
II.3.1.2
Precautions should be taken during welding to ensure adequate supply of the shielding gas. Additional protection for the inner surfaces of the pipes in the vicinity of the weld should be provided.
II.3.2
Weld Preparation
II.3.2.1
Edge Preparation
II.3.2.1.1
Preparation of ends of pipe to be welded shall be made by machining or grinding.
II.3.2.1.2
Grinding wheels shall be low ferrite type, suitable for 90/10 or 70/30 copper-nickel alloy and must not have been previously used on carbon steel.
II.3.2.1.3
Wire brushes used shall be made of stainless steel or bronze.
II.3.2.1.4
Backing rings shall not be used, unless authorised by the Company.
II.3.2.1.5
Joint preparations for intersections and branch connections shall ensure full penetration welding
II.3.2.2
Pre-weld and Inter-Run Cleaning
II.3.2.2.1
The pre-weld cleaning procedure used must ensure removal of all traces of oxide, dirt and grease. Wire brushing should be carried out ONLY with stainless steel or bronze wire brushes to remove the slag and oxide film formed during welding.
II.3.2.3
Jigging and Assembly
II.3.2.3.1
The assembly of the pipe sections prior to welding shall be as per this specification.
II.3.2.3.2
Tack welds may be made as per this specification to give a uniform root gap of 1.5mm along the joint faces.
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ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
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II.3.2.3.3
The tack welds must be cleaned with a wire brush to permit complete fusion with the first weld run.
II.3.2.4
Pre-heating and Inter-pass Temperatures
II.3.2.4.1
If the ambient temperature is below 0°C copper-nickel pipework should be pre-heated to 50°C maximum prior to welding.
II.3.2.4.2
The inter-pass temperature should not exceed 150°C. Post weld heat treatment is not required.
II.3.2.5
Welding Consumables
II.3.2.5.1
For the GTAW process, non-consumable thoriated tungsten electrodes (AWS A5.12 Classification EW Th-2) shall be used. The electrode tips shall be tapered to a sharp point using grinding wheels reserved specifically for this work.
II.3.2.5.2
The filler metals used shall be of matching composition to the parent materials and contain titanium as deoxidant such as in C-17 of BS 2901 or similar.
II.3.2.5.3
Precautions should be taken during GTAW welding to ensure adequate supply of high purity Argon(99.995% pure) shielding gas. Inner surfaces of the pipes in the vicinity of the weld should be provided with additional protection by purging with shielding gas
II.4
WELDING QUALIFICATION REQUIREMENTS
II.4.1.1
WPS/ PQR/ Welders Qualification etc. shall be as stipulated earlier in this specification, in compliance with ASME Section IX.
II.4.1.2
Inspection & Testing
II.4.1.2.1
Visual Inspection, NDE & Pressure Test shall be carried out as per this specification.
II.5
PRECAUTIONS FOR FABRICATION OF COPPER NICKEL PIPEWORK
II.5.1.1
During fabrication, caution shall be exercised to ensure that Cu-Ni does not come in contact with ferrous material.
II.5.1.2
Fabrication shall be carried out in a separate work area, on wooden work-benches/pallets and with tools to be used only for the fabrication of Cu-Ni.
II.5.1.3
For shifting/lifting of Cu-Ni materials use of wire slings, chain blocks etc. is not permitted. Only fibrous webbings shall be used
II.5.1.4
During welding, welders shall use uncontaminated gloves.
II.6
BRAZING
II.6.1
Filler Metal
II.6.1.1
The filler metal used in brazing shall be a non-ferrous metal or alloy having a melting point above 427°C and below that of the metal being joined.
II.6.1.2
The filler metal shall melt and flow freely within the desired temperature range and in conjunction with a suitable flux of controlled atmosphere, shall wet and adhere to the surface to be joined.
II.6.2
Flux
II.6.2.1
Fluxes that are fluid and chemically active at the brazing temperature shall be used when necessary to prevent oxidation of the filler metal and the surfaces to be joined and to promote free flowing of the filler metal.
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II.6.3
Surface Preparation
II.6.3.1
The surfaces to be brazed shall be clear and free from grease, oxides, paint scale and dirt of any kind. Any suitable chemical or mechanical cleaning method may be used to provide a clean, wettable surface for brazing.
II.6.4
Joint Clearance
II.6.4.1
The clearance between surfaces to be joined shall be no larger than is necessary to allow complete capillary distribution of the filler metal.
II.6.5
Heating
II.6.5.1
The joint shall be brought to brazing temperature in as short a time as possible to minimise oxidation without localised underheating or overheating.
II.6.6
Qualifications
II.6.6.1
The qualification of brazing, brazers and brazing operators shall be in accordance with the requirements of Part C, Section IX, ASME Boiler and Pressure Vessel Code.
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ANNEXURE III :
Z0-TS-P-04010-Rev-1
Z0-TS-P-04010
TITANIUM PIPEWORK
DATE:. 12/11/2008 PAGE: 34 OF 53
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III.1
SCOPE
III.1.1
This appendix describes the minimum requirements for the welding and inspection of Titanium pipework and fittings 2" NB and below to ASTM B 381 GR.2 and ASTM B 363 Gr. WPT2 respectively, for use in ZADCO facilities.
III.1.2
Titanium pipework systems shall be fabricated out of threaded pipework and fittings. Where it is found necessary to weld, this section also defines the inert gas arc welding (TIG) of socket and/or butt weld unalloyed. Design shall be to ASME B31.3 Petroleum Refinery Piping, and welding procedure and welder performance qualification tests to ASME Boiler and Pressure Vessel Code, Section IX. The latest editions of the above codes shall apply. The completed pipework shall satisfy the requirements of ASME B 31.3.
III.2
WELDING PROCESS & EQUIPMENT
III.2.1
The welding process shall be Gas Tungsten Arc Welding (GTAW) with an inert shielding gas such as Argon [Tungsten-arc inert gas shielded process - T.I.G]. No other welding process shall be permitted.
III.2.2
Precautions should be taken during GTAW welding to ensure adequate supply of high purity Argon (99.995% pure) shielding gas. Inner surfaces of the pipes in the vicinity of the weld should be provided with additional protection by purging with shielding gas.
III.2.3
The recommended power supply for T.I.G. welding Titanium is D.C Straight Polarity (DCSP). The equipment shall incorporate high frequency arc initiation with a 'Crater Filling' facility.
III.3
WELD PREPARATION
III.3.1
Base Metal and Weld Preparation
III.3.1.1
The bore of the pipes to be joined shall be matched by selection.
III.3.1.2
The edges of the parts to be joined shall be prepared to the shape and dimensions previously qualified and shall be uniform and smooth and cleaned to bright metal.
III.3.1.3
Deburring of edges, if necessary, should be done with a clean sharp file. The use of sandpaper or steel wool to deburr or clean surfaces and edges is not permitted.
III.3.1.4
All scale, slag, oxide or any other foreign material shall be removed from the weld metal contact area and the adjacent surfaces to be cleaned of all foreign matter such as oil, grease paint, etc., for a distance of not less than 100mm from the edges of the weld preparation. If there is major evidence of scale, slag or oxide which is evidently of original titanium production origin, the material is to be rejected.
III.3.1.5
If the base material is in a scale-free condition, it will be necessary only to clean the surfaces by wire brushing the joint areas with a stainless steel brush or with a solvent such as alcohol or acetone. The solvent shall leave no residue. All chlorinated solvents such as Trichlorethylene and Methanol are expressly forbidden.
III.3.1.6
Once the surfaces are cleaned they should be kept entirely free of fingerprints by the use of clean linen gloves.
III.3.1.7
Cleaning of surfaces prior to welding must extend to a distance of 100mm from the edges of the weld preparations.
III.3.1.8
Edge preparations for butt-welds and branch connections shall be as per ASME B31.3.
III.3.1.9
Weld-o-lets and bevelled branch connections shall be suitably prepared to fit the contours of the pipe surface to which they are to be welded.
III.3.1.10
All joint preparations shall be designed so as to ensure full penetration welding.
III.3.1.11 The
need for severe cleaning techniques (eg. acid pickling) is an indication of sub-standard material and must not be used without prior approval of the Company.
III.3.1.12
The cleaned and prepared joint areas shall be welded with the minimum of delay and within the same working period or shift.
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III.3.1.13
If an appreciable delay is inevitable then the cleaned area shall be suitably covered to prevent contamination.
III.3.2
Pre-weld and Inter-Run Cleaning
III.3.2.1
The ends to be welded shall be cleaned to remove all traces of paint, dirt and grease etc. To remove loose debris, only wire-brushing should be carried out. The brush used shall be in stainless steel material, which has not been used previously on ferrous surfaces.
III.3.2.2
It is essential that 'Clean Area' facilities be provided, including clean overalls for the operators. Steps must be taken to guard any contamination of the titanium from ferrous materials.
III.3.2.3
In particular no fabrication or grinding of ferrous materials must be allowed near the titanium welding area.
III.3.3
Jigging and Assembly
III.3.3.1
The assembly of the pipe sections prior to welding shall be as indicated earlier in this specification.
III.3.3.2
The bores of pipes of differing internal diameters shall be machined as per ASME B31.3.
III.3.3.3
Tack welding may be carried out to provide a uniform root gap of 1.5mm along the joint faces. The tack welds of appropriate lengths and spacing for titanium should be made with gas shielding.
III.4
PRECAUTIONS
III.4.1
Titanium and its alloys are subject to severe embrittlement by relatively small amounts of hydrogen, oxygen and nitrogen. Titanium has an extreme affinity for these elements at welding temperatures. Hot Titanium will readily absorb oxygen and nitrogen from the atmosphere. Accordingly Titanium must be shielded from the normal atmosphere prior to, during, and after the welding process by blanketing the complete weld zone including the root weld and underside, with an inert atmosphere. The inert gas used for shielding shall be Argon with high purity level (99.995%).
III.4.2
Molten Titanium is highly reactive with most materials, including all the common refractories. This requires that the weld area be completely free from dust, grease and contact with ceramic blocks or other foreign material during welding. The use of coated arc-welding electrodes or other fluxing compounds is not permitted, since they cause contamination and embrittlement.
III.5
WELDING CONSUMABLES
III.5.1
For the GTAW process, non-consumable thoriated tungsten electrodes (AWS A5.12 Classification EW Th-2) shall be used. The electrode tips shall be tapered to a sharp point using grinding wheels reserved specifically for this work. The vertex angle at the electrode tip should be between 30 to 60 degrees for full penetration butt welds.
III.5.2
The filler wire shall be in accordance with AWS 5. 16-70 GR. ER TL-1, and suitable for the welding process. These shall be stored under consistently clean, warm and dry conditions.
III.5.3
The filler wire size is to be based on the smallest diameter that can carry the required current for the relevant welded joint.
III.6
WELDING QUALIFICATION REQUIREMENTS
III.6.1
WPS/ PQR/ Welders Qualification etc. shall be as stipulated earlier in this specification, in compliance with ASME Section IX.
III.6.2
The qualification documents shall include full details of the proposed mandatory back purging methods with respect to gas flow, gas pressure, dams etc. A minimum gas preflow of six times the volume of air being purged, i.e. 6xV, shall be used maintaining a slight measured positive pressure, subsequently.
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III.6.3
The weld procedure qualification tests shall be carried out under comparable field conditions, which will necessitate the use of a suitable chamber to ensure the maintenance of acceptable argon gas shielding.
III.6.4
Procedures shall be prepared as per ASME Section IX. No production welding shall be permitted prior to Company’s approval of these procedures.
III.6.5
The procedure test piece shall be examined in accordance with the ASME Section IX. Radiographic examination shall be in accordance with Paragraph UW-51 of ASME Section VIII.
III.7
WELDING & FABRICATION
III.7.1
Use of pulled bends is not permitted in titanium pipework.
III.7.2
Surfaces to be welded shall be dry, clean and at a temperature of 15°C minimum.
III.7.3
Preheating shall be carried out, as required, using hot air. Use of flames or torches is not permitted for this purpose.
III.7.4
Pre and post weld gas purging shall be incorporated, preferably controlled by timing devices. Alternatively the gas flow shall be left on continuously.
III.7.5
The inert gas shielding shall not be removed until the weld area has cooled to below 300°C. Each weld pass, root area, and under bead of the finished weld shall be visually examined. The visual examination shall pay particular attention to the colour of the weld and adjacent areas. A silver or light straw finish shall be acceptable. A dark straw, light blue, dark blue or powdery grey shall be unacceptable as evidence of unsatisfactory shielding.
III.7.6
Remelting of welding onto material that has been discoloured by heating is not allowed until the cleaning measures stipulated earlier for base metal and weld preparation are complied with.
III.7.7
If the shielding gas is supplied from cylinders the cylinder shall be changed when the pressure. drops to 25bar.
III.7.8
Tack welds on pipes with wall thickness < 4mm must be removed during the root pass. To avoid cracks in the root pass of thicker material, the tack welds should be made shorter by grinding the start and finish of the tack prior to starting the root pass.
III.7.9
Tacks, if used for positioning the fillet welds, shall be free from defects and be cleaned of oxide and slag to permit complete fusion with the first weld run.
III.7.10
In order to preserve the corrosion resistance and minimise hot cracking of weldments, low heat input welding procedures should be sued. This can be achieved using small diameter filler wire, low welding current and high speed. Incidence of hot cracking is also minimised by keeping the joint faces clean and free from oil and grease etc, as well as maintaining the shielding gas flowing for a few seconds before and completion of welding.
III.7.11
The maximum bead width produced by weaving should be no more than twice the electrode diameter.
III.7.12
For thinner walled material (< 3mm), maintain short arc length to avoid loss of alloying elements from the arc.
III.7.13
Particular attention should be paid to weld starts and craters to ensure complete removal of slag from sharp corners and cavities.
III.7.14
The technique, consumables, joint geometry etc., shall be in accordance with the procedure previously qualified. The manner of depositing the weld metal shall be such as to ensure complete fusion and full penetration where applicable with no undercutting on the sidewalls of the welding groove and that individual beads of deposited weld metal are not excessively convex.
III.7.15
When welding has stopped for any reason, care should be taken in restarting to ensure that the required penetration and fusion are obtained and that the weld is not contaminated. Any cracked tack welds must be completely removed and no attempts made to incorporate them into the finished weld.
III.7.16
At all times the root of the weld and adjacent heat affected zones must be protected from contamination as stipulated earlier.
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ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
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III.7.17
The ENGINEER reserves the option to request production hardness tests.
III.7.18
Welding and weld inspection shall meet the requirements of ASME B 31.3.
III.8
CLEANING, REMOVAL OF DEFECTS & REPAIR WELDING
III.8.1
Prior to cleaning each weld bead shall be visually examined for evidence of unsatisfactory shielding (ref sec.III.6.4).
III.8.2
Further visual examination shall also be carried out after thorough cleaning. Any cracks, porosity or other unacceptable defects that appear of the surface of any bead shall be removed before depositing the following bead.
III.8.3
Any section of titanium pipework, which receives a ferrous arc strike, must be cut out and replaced.
III.8.4
Repair welding shall not be permitted. Welds containing unacceptable defects shall be completely cut out.
III.9
INSPECTION & TESTING
III.9.1
Visual Inspection, NDE & Pressure Test shall be carried out as per this specification.
III.9.2
Under RT, no tungsten inclusions are permitted within the weld metal area or the parent material.
III.9.3
A Vickers' hardness survey using a 5 or 10 kg load shall be carried out on a prepared macrosection. The maximum individual hardness reading on the weld metal shall not exceed that of either of the parent metals by more than 30 points.
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ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
TABLES
Z0-TS-P-04010-Rev-1
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REV. NO.: 1
FABRICATION & ERECTION OF METALLIC PIPEWORK
TABLE 1:
Parameter
Z0-TS-P-04010
DATE:. 12/11/2008 PAGE: 40 OF 53
TOLERANCE
Applicability
Tolerance Limits
Linear Dimensions
Straight Pipe and Headers(face to face and end to end);
NB<10”(250mm) : ± 3.0mm (1/8 in)
(intermediate or overall)
Nozzles, Branches or other attachments(centre to centre, centre to end or centre to face);
These values shall not be accumulative
NB>12”(300 mm): ± 4.7mm (3/16 in)
Bends(end to end, end to face, face to face, centre to end or centre to face) Straightness Alignment (Squareness)
Flanged straight or any one length of pipe Flanges or other attachments with respect to Pipe Axis (measured across any diameter)
< 1:1000 < 3/64 in (1.2 mm) per Foot (305 mm)
Pipe Joint
Pipe joint offset misalignment
< 1/16" or (1.6mm)
Pipe Joint
Machined Weld Bevels: Deviation of weld-bevel from true position (across the land)
< 1/32" or (0.8 mm)
Valves Alignment
Vertical Lines
Plumb to 3mm per 3m ( < 25 mm) out of plumb
Valves Alignment
Horizontal lines
Level within ± 3mm
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REV. NO.: 1
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TABLE 2:
Base Material
Process
Carbon steel, fine grain C.S., 0.3 Mo steels and 0.5 Mo steel
Cold Bending
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HEAT TREATMENT OF FORMED BENDS
Parameter
Hardness < 248 HV10 or
Recommended Heat Treatment
No Heat treatment
Bend Radius > 1.3 x Dn. Hardness > 248 HV10 or
Normalised steels; Addl. Normalising treatment
Bend Radius < 1.3 x Dn.
Q+T steels: Austenising quench (oil, water) and temper treatment
(NOTE: The above heat treatments may be replaced by a stress relieving at a temp. above the PWHT temperature if it can be shown that there has been no deterioration of the mechanical and physical properties e.g. grain growth). Hot Bending
Normalized steels
Bending temp. 780 °C- 980 °C: No additional heat treatment. Bending temp. outside 780°C- 980 °C: Additional normalizing treatment
HFIB
Z0-TS-P-04010-Rev-1
Quenched+Tempered steels
Quench (oil, water) from the austenising temperature plus a temper heat treatment (in accordance with the Pipe Matl. Spec.)
Normalized steel
No heat treatment if testing on the finished bend indicates a normalised structure (grain size < 6 per ASTM E112) and hardness below 248 HV10. In case of non compliance with the above, the formed bend shall be subject to a normalising heat treatment.
Quenched+Tempered steel
A quench (oil, water) from the austenising temperature plus a temper heat treatment (in accordance with the pipe material specification).
ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING
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TABLE 2 (Cont’d):
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HEAT TREATMENT OF FORMED BENDS
Base Material
Process
Parameter
Chromiummolybdenum steel
Cold bending
Hardness < 248 HV10 or Bend Radius > 1.3 x Dn
No additional heat treatment
Hardness > 248 HV10 or Bend Radius < 1.3 x Dn.
Austenising quench (air) and temper treatment. Tempering temperatu re selected such that the specified mechanical values are met. (Applicable for both ‘Normalized’ as well as ‘Q+T’ steels)
Normalised Steels (Bending temp. 850 °C- 900 °C)
Normalising and cooling in still air. The specified mechanical values of the original material specification shall be met.
Quenched+Tempered Steels (Bending temp. 850 °C- 900 °C)
Air quench from austenising temperature and a tempering treatment. ( The specified mechanical values of the original material specification shall be met.)
All
Solution annealing followed by rapid quench
Hot bending/ HFIB
Austenitic SS
Duplex SS
Z0-TS-P-04010-Rev-1
Cold Bending
Recommended Heat Treatment
Hot bending
(For grade 316/316L)
Hot bending to be carried out between 1050°C - 1100°C (solution annealing) followed by rapid water quench
HFIB
All grades
Solution annealing (1050°C - 1100°C) followed by rapid water quench
Cold Bending
All
Solution annealing followed by rapid quench
Hot bending
All grades
Hot bending to be carried out between 1050°C - 1150°C (solution annealing) followed by rapid water quench
HFIB
All grades
Solution annealing (1050°C - 1150°C) followed by rapid water quench
ZADCO CORPORATE ENGINEERING SPECIFICATION
Z0-TS-P-04010
PIPING
REV. NO.: 1 DATE:. 12/11/2008
FABRICATION & ERECTION OF METALLIC PIPEWORK
TABLE 3:
PAGE: 43 OF 53
NDE REQUIREMENTS (BUTT, BRANCH AND ATTACHMENT WELDS)
Type/ Rating
Descript ion
NDE % (2) RT (1,3,4)
MT
PT
Carbon Steel/ CS Epoxy Lined/ CS -RJ/ CS Cement Lined
10
10
N/A
Stainless Steel
10
N/A
100
Copper Nickel/ Titanium
100
N/A
100
Carbon Steel / CS Epoxy Lined
10
10
N/A
Stainless Steel (including 904L)
10
N/A
100
Copper Nickel / Titanium
100
N/A
100
Carbon Steel / CS Epoxy Lined
10
10
N/A
Stainless Steel (including 904L)
100
N/A
100
900
Carbon Steel
100
100
N/A
1500/5000 /10000
Carbon Steel
100
100
N/A
150
300
600
Branch Welds : All Ratings Branch Welds : > 300 Field Welds
Branch Welds: Butt-end branches subject to severe cyclic service Carbon Steel
100
100
N/A
Stainless Steel/Copper Nickel/ Titanium
100
N/A
100
Other Branch-welds, Nozzles & Attachment-welds Carbon Steel
N/A
100
N/A
Stainless Steel/ Copper Nickel/ Titanium
N/A
N/A
100
Lines in any of the following services:
100
100 (for CS)
100 (for SS, Ti & Cu-Ni)
•
Low temperature ( < -20° F)
•
Non-sour Service( > 300# Rating)
•
Sour Service (All Ratings)
•
Hydrogen Service (All Ratings)
•
Lethal / Toxic Service (All Ratings)
NOTES
1 2 3
Radiography shall be carried out on Butt welds only unless otherwise noted or requested specially by Company.
4
For the following cases, RT may be substituted with UT:
10% radiography or magnetic particle examination implies that one weld in 10 will be fully examined. The first three production welds produced by each welder shall be 100% radio graphed. The above Table depicts the extent of radiography on the remaining welds.
•
•
Joints on pipe thickness > 10mm Use of Semi-automatic welding processes (GMAW) where one or more of the weld passes have been made with gas shielded filler wire.
The extent will be 5% of each weld length, giving particular attention to the weld junctions. Defect acceptance levels shall be the same as for RT.
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FABRICATION & ERECTION OF METALLIC PIPEWORK
TABLE 4 :
T-4.1
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SET-ON BRANCHES
WELDING
Root Run
GTAW
First 1/3 of overall thickness
GTAW
Final Run
MMAW (employing Low-Hydrogen Electrodes) or GTAW
T-4.2:
INSPECTION REQUIREMENTS - "SET-ON" BRANCHES
Description
Pre-Welding
Post-Weld & PWHT
Accept.
150
Criteria
150
300
> 600
Dye penetrant inspection of the edges of the hole bored in the header prior to welding (PT)
10%
100%
100%
Note 1
Ultrasonic examination of the header adjacent to the proposed branch opening prior to cutting (UT)
100%
100%
100%
Note 1
Hardness Test (Vickers)
100%
300
100%
> 600
100%
NOTES 1.
No Laminar Defects. No Linear Defects.
2.
Weld deposit shall not exceed the hardness of the parent material by more than 50 VPN
Z0-TS-P-04010-Rev-1
Note 2
ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
APPENDIX- A
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CODES / STANDARDS / SPECIFICATIONS
A.1
Note: The edition or revision of the referenced Codes, Standards & Specifications governing, shall be that ruling on the date of order, unless noted otherwise. A.1.1
INTERNATIONAL CODES/ STANDARDS/ SPECIFICATIONS
General ISO 9001
Quality Management Systems - Requirements
ISO 8501
Preparation of Steel Substrates before Application of Paints and Related Products – Visual Assessment of Surface Cleanliness
Am erican National St andar d (ANSI/ASME) B1.1
Unified Inch Screw threads (UN and UNR Thread form)
B1.20.1
Pipe Threads General Purpose (Inch)
B16.5
Steel Pipe Flanges and Flanged Fittings
B16.9
Factory –made Wrought Steel Buttwelding Fittings
B16.10
Face to Face and End to End - Dimensions of Valves
B16.11
Forged Fittings, Socket-Welding and Threaded
B16.20
Metallic Gaskets for Pipe Flanges, Ring-Joint, Spiral Wound and Jacketed.
B16.21
Non-Metallic Flat Gaskets for Pipe Flanges
B16.24
Cast Copper Alloy Pipe Flanges & Flanged Fittings
B16.25
Butt welding Ends
B16.28
Wrought Steel Butt welding Short Radius Elbows and Returns
B16.34
Valves - Flanged, Threaded and Welding Ends
B16.36
Orifice Flanges
B16.47
Large Diameter Steel Flanges
B16.48
Steel Line Blanks
B18.2.1
Square and Hex. Bolts and Screws (Inch Series)
B18.2.2
Square and Hex. Nuts (Inch Series)
B31.3
Process Piping
B31.4
Pipeline Transportation Systems for Liquid Hydrocarbons and Other Liquids
B31.5
Refrigeration Piping
B31.8
Gas Transmission and Distribution Piping System
B36.10M
Welded and Seamless Wrought Steel Pipe
B36.19M
Stainless Steel Pipe
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ASTM / ASME CODES ASME Section II
Materials
ASME Section II (Part D)
Properties
ASME Section V
Non-destructive Examination
ASME Section VIII
Pressure Vessels
ASME Section IX
Qualification Standard for Welding and Brazing Procedures, Welders, Brazers and Welding & Brazing Operators
ASTM D5162
Discontinuity (Holiday) Testing of Nonconductive Protective Coating on Metallic Substrates
ASTM Standards for Forgings, Castings, Plates and materials for various piping components British Standard Institute (BSI) BS EN 593
Industrial Valves - Metallic Butterfly Valves
BS EN ISO 10434
Bolted Bonnet Steel Gate Valves for the Petroleum, Petrochemical and Allied Industries
BS EN 1452-1
Plastics piping Systems for water supply - Unplasticised Polyvinyle Chloride (PVC-U) : Part 1: General
BS EN 1452-2
Plastics Piping Systems for Water Supply - Unplasticized Poly (Vinyl Chloride) (PVC-U) - Part 2: Pipes
BS EN 1452-3
Plastics Piping Systems for Water Supply - Unplasticized Poly (Vinyl Chloride) (PVC-U) - Part 3: Fittings
BS EN 1452-4
Plastics Piping Systems for Water Supply - Unplasticized Poly (Vinyl Chloride) (PVC-U) - Part 4: Valves
BS EN 1452-5
Plastics Piping Systems for Water Supply - Unplasticized Poly (Vinyl Chloride) (PVC-U) - Part 5: Fitness for Purpose of the System
BS 1868
Steel Check Valves (Flanged and Butt-Welding Ends) for the Petroleum, Petrochemical and Allied Industries.
BS 1873
Steel Globe and Globe Stop and Check Valves (Flanged and butt-welding ends) for the Petroleum, Petrochemical and Allied Industries.
BS 5154
Copper Alloy Globe, Globe Stop and Check, Check and Gate Valves.
BS EN ISO 17292
Metal Ball Valves for Petroleum, Petrochemical and Allied Industries.
BS EN ISO 15761
el Gate, Globe And Check Valves for Sizes DN 100 and Smaller, for the Petroleum and Natural Gas Industries
BS 6364
Valves for Cryogenic Service
BS EN 12266-1
Industrial valves Testing of valves Part 1: Pressure Tests, Test Procedures and Acceptance Criteria - Mandatory Requirements
BS EN 12266-2
Industrial valves Testing of valves Part 1: Pressure Tests, Test Procedures and Acceptance Criteria – Suppl. Requirements
BS EN ISO 10497
Testing of Valves: Fire Type Testing Requirements
BS 7531
Specification for Compressed Non-Asbestos Fibre Jointing.
Z0-TS-P-04010-Rev-1
ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
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American Petroleum Ins ti tute (A PI) API Spec 5L
Specification for Line Pipe
API Spec 6A
Specification for Wellhead & Christmas Tree Equipment
API Spec 6D
Specification for Pipeline Valves (Gate, Ball and Check Valves)
API Spec 6FA
Specification for Fire Test for Valves
API 594
Check Valves: Wafer, Wafer Lug and Double Flanged type.
API 598
Valve Inspection and Testing
API 599
Metal Plug Valves – Flanged and Welding Ends
API 600
Bolted Bonnet Steel Gate Valves for Petroleum and Natural Gas Industries
API 602
Steel Gate, Globe and Check Valves for Sizes DN 100 and Smaller for the Petroleum and Natural Gas Industries
API 607
Fire Test for Soft-Seated Quarter Turn Valves
API 609
Butterfly Valves: Double Flanged, Lug-Type and Wafer-Type
API RP 14E
Recommended Practice for Design and Installation of Offshore Production Platform Piping Systems
Manufacturers Standardisation Society (MSS) MSS-SP-6
Standard Finishes for Contact Faces of Pipe Flanges and Connecting EndFlanges of Valves and Fittings
MSS-SP-9
Spot Facing for Bronze, Iron and Steel Flanges
MSS-SP-25
Standard Marking System for Valves, Fittings, Flanges and Unions
MSS-SP-44
Steel Pipe Line Flanges
MSS-SP-45
By-pass & Drain Connections
MSS-SP-54
Quality Standard for Steel Castings for Valves, Flanges & Fittings and other Piping Components: Radiographic Examination Method
MSS-SP-55
Quality Standard for Steel Castings for Valves, Flanges & fittings and other Piping Components: Visual Method for Evaluation of Surface Irregularities
MSS-SP-67
Butterfly Valves
MSS-SP-75
Spec. for High test Wrought Butt Welding Fittings
MSS-SP-97
Integrally Reinforced Branch Outlet Fittings (Socket-Welding, Threaded and Butt-Welding Ends)
Z0-TS-P-04010-Rev-1
ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
Z0-TS-P-04010 REV. NO.: 1 DATE:. 12/11/2008 PAGE: 49 OF 53
National Association of Corrosion Engineers (NACE) TM-01-77
Laboratory Testing of Metals for Residence to specific forms of Environmental Cracking in H2S Environments.
TM-02-84
Evaluation of Pipeline and Pressure Vessel Steels for Resistance to Hydrogen Induced Cracking.
MR-01-75 /
Petroleum and Natural Gas Industries - Materials For Use In H2S containing Environments in Oil & Gas Production:
ISO 15156
Part-1: General principles for selection of cracking-resistant materials Part-2: Cracking-resistant Carbon and Low Alloy Steels Part-3: Cracking-resistant CRAs (Corrosion Resistant Alloys) and other Alloys RP-04-72
Method and Controls to prevent In-service Environmental cracking of Carbon Steel Weldments in Corrosive Refining Environments.
European Normes EN 10204
Inspection Documents for the Delivery of Metallic Products
EN 12163
Copper and Copper Alloys – Rods for General Purposes.
EN 12167
Copper and Copper Alloys – Profiles & Rectangular Bar for General Purposes.
Engineering Equipment and Materials Users Association (EEMUA) Publications EP 144
90/10 Copper-Nickel Alloy Piping for Offshore Applications Specification: Tubes Seamless and Welded
EP 145
90/10 Copper-Nickel Alloy Piping for Offshore Applications Specification: Flange Composite and Solid
EP 146
90/10 Copper-Nickel Alloy Piping for Offshore Applications Specification: Fittings
EP 192
Guide for the Procurement of Valves for Low Temperature (Non-Cryogenic) Service
The Soci ety for Protecti ve Coatings (SSPC) SSPC: SP10/ NACE No.2
Joint Surface Preparation Standard: Near-White Metal Blast Cleaning
SSPC: VIS 1
Visual Standard for Abrasive Blast Cleaned Steel
SSPC: PA2
Measurement of Dry Coating Thickness with Magnetic Gages
SSPC: QP3
Standard Procedure for Evaluating Qualifications of Shop Painting Applicators
Z0-TS-P-04010-Rev-1
ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
A.1.2
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COMPANY'S SPECIFICATIONS/ DATA SHEETS/ PROCEDURES ZO-TS-P-02010 ZO-TS-P-02020
Specification for Purchase Bulk Piping Materials: Pipes, Fittings & Flanges Specification for Purchase of Bolts & Gaskets
ZO-TS-P-02030
Specification for Purchase of Ball valves
ZO-TS-P-02040
Specification for Purchase of Butterfly Valves
ZO-TS-P-02050
Specification for Purchase of Gate, Globe, Needle & Check Valves
ZO-TS-P-02060
Specification for Purchase of Plug Valves
ZO-DS-P-01010
Valve Data sheets : Ball Valves
ZO-DS-P-01020
Valve Data sheets : Gate Valves
ZO-DS-P-01030
Valve Data sheets : Globe Valves
ZO-DS-P-01040
Valve Data sheets : Check Valves
ZO-DS-P-01050
Valve Data sheets : Wafer Check Valves
ZO-DS-P-01060
Valve Data sheets : Nozzle Check Valves
ZO-DS-P-01070
Valve Data sheets : Needle Valves
ZO-DS-P-01080
Valve Data sheets : Butterfly Valves
ZO-DS-P-01090
Valve Data sheets : Plug Valves
ZO-TS-Y-02040
Coating System for External Surfaces of Valves
ZO-TS-Y-02020
Specification for Fluoropolymer Coated Bolting and Threaded Fasteners
ZO-TS-Y-02010
Specification for Protective Coating Systems
ZO-TS-Z-01010 A3-STD-M-006
Specification for General Data on Environmental and Climatic Conditions at ZADCO Facilities Pipe Supports Standard
PEMS/HTPT/033
Pressure Testing for Plant Equipment
Z0-TS-P-04010-Rev-1
ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
A.2
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ABBREVIATIONS USED
The Abbreviations in the text of this Specification shall be deemed to mean as follows: AED AISI Al-Brnz ANSI AS API ASME ASTM ASNT
Anti-Explosive Decompression American Iron and Steel Institute Aluminium Bronze American National Standard Institute Alloy Steel American Petroleum Institute American Society of Mechanical Engineers American Society for Testing Materials American Society for Non Destructive Testing
BB BC BE BL BOP BRNZ BS BSI BV BW
Bolted Bonnet Bolted Cover Bevelled Ends Blind Bottom of pipe Bronze British Standards British Standards Institute Bureau Veritas Butt Weld
CA CB CNAF CONC CP CS CSWIP
Corrosion Allowance Capillary Silver Brazing Compressed Non-Asbestos fiber Concentric Code of practice. Carbon Steel Certification Scheme for Welding & Inspection Personnel
DI DRG DWG DN DNV DSS
Ductile Iron Drawing Drawing Nominal Diameter Det Norse Veritas Duplex Stainless Steel
ECC EEMUA EN EP EPDM
Eccentric Engineering Equipment & Material Users Association European Norms EEMUA Publication Ethylene – Propylene – Diene - Terpolymers
Z0-TS-P-04010-Rev-1
ZADCO CORPORATE ENGINEERING SPECIFICATION PIPING FABRICATION & ERECTION OF METALLIC PIPEWORK
FB FC FF FLG
Full Bore Fail Close Flat Face Flange
GTAW GMAW
Gas Tungsten Arc Welding Gas Metal Arc Welding
HAZ HC HFIB HOR
Heat Affected Zone Hydro-carbon High Frequency Induction Bending Horizontal
ID IN IS & Y ITCS
Internal Diameter Inches Inside Screw & Yoke Impact Tested Carbon Steel
KCS
Killed Carbon Steel
LO LC
Locked Open Locked Closed
MAX MIN MM MSS MT
Maximum Minimum Millimeter Manufacturer's Standardization Society Magnetic Particle Testing
NACE NB NDT NDE NO NPS
National Association of Corrosion Engineers Nominal Bore Non Destructive Testing Non Destructive Examination Number Nominal Pipe Size
ORIF OS & Y OD
Orifice Outside Screw and Yoke Outside Diameter
PCN PE P & ID PRESS PT PVDC PWHT
Personnel Certification in Non-destructive Testing Plain Ends Piping and Instrumentation Diagram Pressure Penetrant Testing Poly-Vinyledene Chloride Post Weld Heat Treatment
Z0-TS-P-04010-Rev-1
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