media/files/e/engie-ep-v2/documents/500-pipin… · author: matherp created date: 20121126100147z

GDF SUEZ E&P Nederland B.V.Specification 580, Rev. 0 of 54

TABLE OF CONTENTS

1. INTRODUCTION .........................................................................................................................................51.1 General ............................................................................................................................................51.2 Scope ..............................................................................................................................................51.3 Quality Assurance.............................................................................................................................51.4 Quality Plan ......................................................................................................................................51.5 Inspection Notice .............................................................................................................................51.6 Terms and Definitions ......................................................................................................................61.7 Abbreviations ...................................................................................................................................6

2. REFERENCED CODES, STANDARDS AND SPECIFICATIONS .........................................................................72.1 Codes and Standards .......................................................................................................................7

3. GENERAL ..................................................................................................................................................93.1 Scope ..............................................................................................................................................93.2 Welding Processes ...........................................................................................................................9Table 1: Welding Processes and Consumables:............................................................................................. 93.3 Welding Consumables ......................................................................................................................93.4 Storage and Handling of Welding Consumables ..............................................................................103.5 Equipment .....................................................................................................................................103.6 Personnel.......................................................................................................................................11

4. QUALIFICATION OF WELDING PROCEDURES ............................................................................................124.1 Welding Procedure Specifications ...................................................................................................124.2 Welding Procedures - Essential Variables ........................................................................................134.3 Procedure Qualification Test Welds.................................................................................................13Table 2: Extent of testing complete butt weld: ............................................................................................. 14Table 3: Extent of testing for full penetration repair: ................................................................................... 15Table 4: Extent of testing for partial penetration repair: .............................................................................. 15Table 5: Extent of testing for single pass cap repair .................................................................................... 164.4 Mechanical Testing of Welding Procedure Qualification test welds ..................................................16Table 6: Charpy requirements weld testing: ................................................................................................. 17Table 7: Hardness value requirements: ........................................................................................................ 174.5 Permitted Welding Procedure Qualification retests ..........................................................................184.6 Failure Of Welding Procedure Qualification Tests ............................................................................184.7 Brazing and aluminothermic welding of anodic bonding leads .........................................................18Figure 1: Requirements for hardness traverse and impressions ................................................................. 194.8 Weld Procedure Qualification Record(s) ..........................................................................................20Table 8: Checklist WPQ Records.................................................................................................................... 20

5. QUALIFICATION OF WELDERS ..................................................................................................................215.1 General ..........................................................................................................................................215.2 Welder Certificate...........................................................................................................................215.3 Re-qualification of welders .............................................................................................................225.4 Anode cable pin brazers .................................................................................................................225.5 Welder qualification: weld inspection and testing ............................................................................22Table 9: Welder Qualification Tests Requirements per Welder ................................................................... 22

6. PRODUCTION WELDING...........................................................................................................................236.1 General ..........................................................................................................................................236.2 (Line) Pipe Preparation ...................................................................................................................236.3 Alignment.......................................................................................................................................23Table 10: Permitted misalignment of surfaces (EN 12732:2000 Table G1) ................................................... 246.4 Weather Protection ........................................................................................................................246.5 Tack Welds ....................................................................................................................................246.6 Stray Arcs.......................................................................................................................................246.7 Inter-Run Cleaning..........................................................................................................................246.8 Preheat and Interpass Temperature ...............................................................................................246.9 Partially completed welds ...............................................................................................................256.10 Post-Weld Heat Treatment ..............................................................................................................256.11 Material Traceability and Weld Identification ...................................................................................256.12 Production Weld Tests ....................................................................................................................26


7. REPAIR WELDING ....................................................................................................................................277.1 General ..........................................................................................................................................277.2 Defect Removal..............................................................................................................................277.3 Inspection of Weld Repairs .............................................................................................................277.4 Record of Weld Repair....................................................................................................................287.5 Weld Repair Rate ...........................................................................................................................28

8. INSPECTION AND TESTING OF PRODUCTION WELDS................................................................................298.1 Visual Inspection ............................................................................................................................298.2 Non-destructive Testing ..................................................................................................................298.3 Acceptance Criteria NDT .................................................................................................................29

9. RADIOGRAPHY ........................................................................................................................................309.1 Radiographic Procedures................................................................................................................309.2 Procedure Radiographs ..................................................................................................................309.3 Production Radiography .................................................................................................................309.4 Radiation Protection .......................................................................................................................319.5 Qualification of Radiographers........................................................................................................319.6 Film Identification...........................................................................................................................319.7 Film Processing ..............................................................................................................................319.8 Storage of Unexposed films ............................................................................................................319.9 Storage of Radiographs ..................................................................................................................32

10. MANUAL ULTRASONIC TESTING ................................................................................................................33

11. AUTOMATED ULTRASONIC TESTING (AUT) ................................................................................................3411.1 Approval of Contractor, Operators and System ................................................................................3411.2 AUT System ....................................................................................................................................3411.3 Calibration Block for pulse-echo and through-transmission technique .............................................35

Table 11: Tolerances of reflectors: .................................................................................................................. 3511.4 Calibration time of flight diffraction technique: ................................................................................36

Table 12: Tolerances of notches:..................................................................................................................... 3611.5 Procedure ......................................................................................................................................3611.6 Inspection ......................................................................................................................................3711.7 Pulse–echo and through transmission technique............................................................................3711.8 Time of flight diffraction..................................................................................................................3711.9 Repeat inspection ..........................................................................................................................3711.10 Surface condition and Temperature ...............................................................................................3711.11 Couplant .......................................................................................................................................3811.12 Ultrasonic equipment pulse-echo and through transmission...........................................................3811.13 Ultrasonic equipment – TOFD ........................................................................................................3811.14 Probes ..........................................................................................................................................3811.15 Monitor/display .............................................................................................................................3811.16 Storage .........................................................................................................................................3811.17 Qualification of AUT system ...........................................................................................................3911.18 Inspection of Weld Repairs ............................................................................................................39

12. SURFACE EXAMINATION ..........................................................................................................................4012.1 Magnetic Particle Inspection (MPI) .................................................................................................4012.2 Dye Penetrant Inspection (DPI) ......................................................................................................40


13. INTERPRETATION AND ACCEPTANCE CRITERIA FOR N.D.T. .......................................................................4113.1 Acceptance Criteria Visual .............................................................................................................41Figure 2: Angle of incidence between parent metal and weld ...................................................................... 4113.2 Acceptance Criteria Radiography ...................................................................................................4113.3 Acceptance Criteria Manual Ultrasonic Testing ...............................................................................4113.4 Mechanised Pulse Echo + TOFD: Interpretation and sizing of weld defects .....................................4113.5 Acceptance Criteria Mechanised Pulse Echo + TOFD ......................................................................4213.6 Acceptance Criteria Magnetic Particle Inspection ...........................................................................4213.7 Acceptance Criteria Dye Penetrant Inspection ................................................................................42

14. REPORTING OF N.D.T. .............................................................................................................................4314.1 General .........................................................................................................................................4314.2 Specific MPI 4314.3 Specific Dye Penetrant............................................................................................................................. 4314.4 Specific Ultrasonic.................................................................................................................................... 4314.5 Specific AUT 4314.6 Specific Radiographic: ............................................................................................................................. 44

15. DOCUMENTATION ...................................................................................................................................4515.1 General .........................................................................................................................................4515.2 Initial Submissions ........................................................................................................................4515.3 Final Documentation .....................................................................................................................4515.4 Storage by CONTRACTOR ...............................................................................................................4615.5 Delivery Documentation ................................................................................................................46

APPENDIX 1: MECHANICAL TEST REQUIREMENTS PIPE WELDS .................................................................47Appendix 1A Sample locations mainline weld .................................................................................. 47Appendix 1B Sample locations Full Penetration Repair ................................................................... 47Appendix 1C Sample locations Partial Penetration Repair .............................................................. 48Appendix 1D Sample locations Cap Repair....................................................................................... 48APPENDIX 2: IMPACT TESTING DETAILS ....................................................................................................49Appendix 2A Charpy details mainline weld and full penetration repair .......................................... 49Appendix 2B Charpy details partial penetration repair .................................................................... 49APPENDIX 3: HARDNESS TESTING DETAILS ..............................................................................................50APPENDIX 4: RADIOGRAPHIC ACCEPTANCE CRITERIA:...............................................................................51APPENDIX 5:MANUAL ULTRASONICS ACCEPTANCE CRITERIA ....................................................................52APPENDIX 6:Mechanised Pulse Echo + TOFD Acceptance Criteria .............................................................53Acceptance criteria based on good workmanship ............................................................................................. 53


1. INTRODUCTION

1.1 GENERAL

GDF SUEZ E&P Nederland B.V. (GDF SUEZ) is a company producing hydrocarbons in the Dutch sectorof the North Sea. For this purpose several production and treatment facilities have been installedalong with connecting pipelines.

1.2 SCOPE

1.2.1 The purpose of this document is to define the minimum requirements for the approval of weldingconsumables, welding processes, welding operators as well as production welding and weldinspection of carbon steel pipelines in compliance with and in addition to the requirements of EN12732:2000, NEN 3650-2:2003, and EN 288-9:1999.

1.2.2 A Scope of Work will be issued giving project specific requirements which shall include design detailsand the requirement (or not) for Nickel content and CTOD testing.

1.3 QUALITY ASSURANCE

1.3.1 CONTRACTOR shall have in operation an approved Quality System based on the requirements of EN-ISO 3834 Parts 1, 2 and 4: 2006 (see also table 2 in EN 12732:2000).

1.3.2 CONTRACTOR’s Quality Manual(s) shall be submitted for review, by GDF SUEZ, as part of his biddocuments.

1.4 QUALITY PLAN

1.4.1 CONTRACTOR shall submit a Quality Plan, based on his Quality Manual (s), covering all operations toGDF SUEZ for approval. CONTRACTOR's subsequent Quality Control of the work shall strictly adhereto the agreed Quality Plan.

1.4.2 Quality Plan shall show hold, witness, review, monitor and approve points for GDF SUEZ andCERTIFYING AUTHORITY. Regarding inspection, the Quality Control Plan shall include:• A flowchart illustrating each inspection point and its relative location in the procedure cycle,

where conformance of characteristics is verified.• The characteristics to be inspected at each inspection point, the procedures and acceptance

criteria to be used. The procedures shall be provided to GDF SUEZ, as requested.• Copies of specific forms used by CONTRACTOR to record the results of each inspection.

1.4.3 CONTRACTOR shall maintain quality records as documentary evidence of compliance with qualityrequirements. Quality records shall be available to GDF SUEZ for analysis and review.

1.4.4 All CONTRACTOR inspection systems shall be subject to evaluation and checks by GDF SUEZ toensure that the system is effectively applied and meets the requirements of this specification.

1.4.5 CONTRACTOR shall employ experienced and competent supervisors to ensure that both the standardof workmanship and the quality of materials used comply with the requirements of this specification.

1.5 INSPECTION NOTICE

1.5.1 CONTRACTOR shall give GDF SUEZ and CERTIFYING AUTHORITY inspectors at least five working daysnotice of the time and location of fabrication, inspection and testing work. All production shall besubject to inspection by GDF SUEZ and/or the CERTIFYING AUTHORITY.

1.5.2 Intermediate inspections and/or examinations carried out or stage approvals given by GDF SUEZ orthe CERTIFYING AUTHORITY do not absolve the CONTRACTOR from his responsibility that thematerial(s), welding and testing have to comply fully with all rules, regulations and specifications.


1.6 TERMS AND DEFINITIONS

The following terms and definitions apply in this Specification:

GDF SUEZ GDF SUEZ E&P Nederland B.V. or its nominatedrepresentative

CONTRACTOR Engineering and Installation Contractor appointed by GDFSUEZ

CERTIFYING AUTHORITY Any authority required by law and/or as nominated by GDFSUEZ in accordance with the Contract for which certificatesshall be obtained before the work shall be accepted by GDFSUEZ as well as those persons acting as its representatives.

shall indicates a mandatory requirement.

should indicates a preferred method.

1.7 ABBREVIATIONS

The following abbreviations have been used and apply in this Specification:

AUT Automatic Ultrasonic TestingCSWIP Certification Scheme for Welding & Inspection PersonnelCW Centre (line) of WeldCTOD Crack Tip Opening DisplacementDN Diameter NominalDPI Dye Penetrant InspectionFCAW Fluxed Core Arc WeldingFL Fusion LineGMAW Gas Metal Arc WeldingGTAW Gas Tungsten Arc WeldingHAZ Heat Affected Zone of Weld.IQI Image Quality IndicatorsLR Latest RevisionMAG Metal Active Gas (welding)MIG Metal Inert Gas (welding)MMAYS Material’s Maximum Allowable Yield StrengthMMATS Material’s Maximum Allowable Tensile StrengthMPI Magnetic Particle InspectionMRB Manufacturing Record BookNDT Non Destructive Testing.PAM Portable Arc MonitoringPO Purchase OrderPWT Production Weld TestSAW Submerged Arc WeldingSMAW Shielded Metal-Arc WeldingSMTS Specified Minimum Tensile StrengthSMYS Specified Minimum Yield StrengthSVGA Super Video Graphics ArrayTOFD Time of Flight DiffractionUT Ultrasonic TestingWPQ(R) Welding Procedure Qualification (Records)WPS Welding Procedure SpecificationWPT Welding Production Test


2. REFERENCED CODES, STANDARDS AND SPECIFICATIONS

2.1 CODES AND STANDARDS

2.1.1 All Work covered by this Specification shall be performed by CONTRACTOR, as a minimum, inaccordance with the requirements of the following referenced codes and standards;

NEN 3650-2:2003 Requirements for Steel Pipeline Transportation Systems.

NEN 3653:2009 Methods for the determination of NDE acceptance criteria for defects in pipeline girthwelds.

EN 12732:2000 Gas supply systems-Welding Steel pipe work - Functional requirements.

API 1104: 2005 Errata1 – 2007

Welding of Pipelines and Related FacilitiesAlternative Acceptance Standards for Girth Welds

ASME BPV 5 Boiler and pressure vessel code, section 5: article 4, mandatory appendices numbers Iand II and article 5 mandatory appendices numbers I and II (July 2001)

BS 7448:pt 2.:1997 Fracture mechanics toughness tests: CTOD.

EN 10045-1:1990 Metallic materials – Charpy impact test – Part 1: Test method.

EN 10204:2004 Metallic Products – Types of inspection documents.

EN 10208-2:2009 Steel Pipes for pipelines in combustible fluids – Technical delivery conditions – Part 2:Pipes of requirement class B.

EN 10246-17:2000 Non-destructive testing of steel tubes – Part 17: Ultrasonic testing of tube ends ofseamless and welded steel tubes for the detection of laminar imperfections.

EN 10246-18:2000 Non-destructive testing of steel tubes – Part 18: Magnetic particle testing of tube endsof seamless and welded steel tubes for the detection of laminar imperfections.

EN 1043-1:1995 Destructive test on weld in metallic materials-Hardness testing-Part 1: Hardness teston arc welded joints.

EN 12668-2:2001 Characterization and verification of ultrasonic examination equipment. Part 2: Probes .

EN 12668-3:2000 Characterization and verification of ultrasonic examination equipment. Part 3:Combined equipment.

EN 1290:1998A2:2003 Non-destructive examination of welds – Magnetic particle examination of welds.

EN 1291:1998A2:2003 Non-destructive examination of welds- Magnetic particle testing – Acceptance levels.

EN 1321:1997 Destructive tests on welds in metallic materials – Macroscopic and microscopicexamination of welds.

EN 1418:1998Welding personnel. Approval testing of welding operators for fusion welding andresistance weld setters for fully mechanized and automatic welding of metallicmaterials

EN 1435:1997A2:2003 Non-destructive examination of welds – Radiographic examination of welded joints.

EN 15609-1:2004 Specification and qualification of welding procedures for metallic materials –Weldingprocedure specification Part 1: Arc welding.

EN 1668:1997 Welding consumables – Rods, wires and deposits for tungsten inert gas welding of non-alloy and fine grain steels – Classification.

EN 1714:1998 Non-destructive examination of welds – Ultrasonic examination of welded joints.

EN 24063:1992 Welding, brazing, soldering and braze welding of metals – Nomenclature of processesand reference numbers for symbolic representation on drawings.

EN 25580:1992 Specification for minimum requirements for industrial radiographic illuminators for non-destructive testing

EN 287-1:2004A2:2006 Approval testing of welders – Fusion welding – Part 1: Steels.

EN 288-9:1999Specification and approval of welding procedures for metallic materials – Part 9:Welding procedure test for pipeline welding on land and offshore site butt welding oftransmission pipelines.

EN 462-1:1995 Non-destructive testing – Image quality of radiographs – Part 1: Image qualityindicators (wire type) – Determination of image quality value


EN 473:2008 Qualification and certification of NDT personnel. General principals.

EN 499:1995 Welding consumables – Covered electrodes for manual metal arc welding of non-alloyand fine grain steels – Classification.

EN 571-1:199 Non-destructive testing-Penetrant testing-Part 1: General principals.

EN 583-1:1999 Non-destructive testing-Ultrasonic examination -Part 1: General principals.

EN 583-6:2009 TOFD technique as a method for detection and sizing of discontinuities.

EN 756:2004Welding consumables. Solid wires, solid wire-flux and tubular cored electrode-fluxcombinations for submerged arc welding of non alloy and fine grain steels.Classification

EN 757:1997 Welding consumables – Covered electrodes for manual metal arc welding of highstrength steels – Classification.

EN 760:1996 Welding consumables – Fluxes for submerged arc welding – Classification.

EN 875:1995 Destructive tests on welds in metallic materials-Impact tests-Test specimen location,notch orientation and examination.

EN 895:1995 Destructive tests on welds in metallic materials – Transverse tensile test.

EN 910:1996 Destructive tests on welds in metallic materials – Bend tests.

EN 970:1997 Non destructive examination of fusion welds – visual examination.

EN-ISO 6892-1:2009 Metallic materials. Tensile testing Part 1:. Method of test at room temperature

EN-ISO 14175:2008 Welding consumables – Shielding gases for arc welding and cutting.

EN-ISO 14341:2008 Welding consumables – Wire electrodes and deposits for gas-shielded metal arcwelding of non-alloy and fine grain steels – Classification.

EN-ISO 17632:2004 Welding consumables – Tubular cored electrodes for gas shielded and non-gasshielded metal arc welding of non-alloy and fine grain steels – Classification.

EN-ISO 3834-1:2006 Quality requirements for welding – Fusion welding of metallic materials – Part 1:Criteria for the selection of the appropriate level of quality requirements.

EN-ISO 3834-2:2006 Quality requirements for welding – Fusion welding of metallic materials – Part 2:Comprehensive quality requirements.

EN-ISO 3834-4:2006 Quality requirements for welding – Fusion welding of metallic materials – Part 4:Elementary quality requirements.

ISO 17025:2005 General requirements for the competence of testing and calibration laboratories.

ISO 3690:2000 Welding and allied processes -- Determination of hydrogen content in ferritic steel arcweld metal

ISO 9001 Quality Management Systems : Requirements

2.1.2 The edition of each code and standard stated in this section shall apply; together with all publishedamendments. Where conflict occurs between the requirements of this Specification and referencedcodes and standards, the most stringent requirements shall apply. Where any of the documents arerevised and the revision affects the scope of supply, CONTRACTOR shall notify GDF SUEZ in writingimmediately.


3. GENERAL

3.1 SCOPE

3.1.1 All welding shall, be carried out in accordance with the requirements of EN 12732:2000 NEN 3650-2:2003, and EN 288-9:1999, augmented with the additional requirements detailed in thisspecification.

3.2 WELDING PROCESSES

3.2.1 All welding shall be by Manual, Semi-Automatic or Automatic Shielded Metal-Arc Welding (SMAW),Fluxed Core Arc Welding (FCAW), Gas Metal Arc Welding (GMAW), Gas Tungsten Arc Welding (GTAW)or Submerged Arc Welding (SAW). Other processes may be agreed by GDF SUEZ; however in suchcases the inspection and testing requirements may be varied as deemed necessary by GDF SUEZand/or CERTIFYING AUTHORITY.

Table 1: Welding Processes and Consumables:Type of Process Procedure no.

according to:EN 24063

Consumables shall be in accordancewith:

Shielded Metal Arc Welding 111 EN 499 & EN 757Gas Metal Arc Welding 135, 141 EN-ISO 14341 & EN 1668Flux-Cored Arc Welding 114, 136, 138 EN-ISO 17632Shielding gases EN-ISO 14175:Submerged Arc Welding 12 EN 756Fluxes for submerged arcwelding

12 EN 760

3.2.2 FCAW process shall be thoroughly controlled at all times by CONTRACTOR to avoid any excessivescatters in the mechanical properties (and specially impact properties) of weld deposits. In that view,mechanical test results of qualification test welds shall show sufficient safety margins against therequirements of this specification. The GDF SUEZ reserves the right to reject such a process when itsreliability is not satisfactory.

3.3 WELDING CONSUMABLES

3.3.1 Welding consumables shall be selected to ensure that they overmatch the maximum allowable yieldand tensile values of the project’s line pipe. The Material’s Maximum Allowable Yield Strength(MMAYS) shall be overmatched by at least 50 Mpa and the Material’s Maximum Allowable TensileStrength (MMATS) shall be overmatched by at least 30 Mpa. As such the minimum weld metal’s;

1) Yield Strength shall be the line pipe’s SMYS + 120 Mpa + 50 Mpa = 170 Mpa2) Tensile Strength shall be the line pipe’s SMTS + 120 Mpa + 30 Mpa.= 150 Mpa.

3.3.2 The deposited weld metal, shall exhibit mechanical properties greater than, and chemical analysissimilar to (taking into account any specific property requirements), those of the actual base material.For the welding of the carbon steel line pipe and parts, the nickel content of deposited weld metalshall not exceed 1%.

3.3.3 When specified in the Scope of Work the root pas shall be welded with a consumable which containsless than 0.25% Nickel.

3.3.4 All batch test certificates (according to EN 10204:2004, type 3.1) for welding filler materials showingall test results, including impact testing, all weld tensile testing and chemical analyses, shall beprovided by CONTRACTOR for each production batch of consumables in use.

3.3.5 Low hydrogen consumables shall give a maximum diffusible hydrogen content of 5 ml per 100 gramsof Weld Metal determined with the method specified by ISO 3690:2000. The electrodes shall besupplied in vacuum packing. Moreover, they shall be guaranteed against moisture absorption for 8hours after pack opening.


3.3.6 Cellulosic coated electrodes may be used provided that special weld procedures preventing hydrogeninduced cracking are established.

3.3.7 Special considerations are to be made when welding steels with a SMYS above 420MPa to ensuresafety against cold cracking in the HAZ and/or weld metal. Attention must also be paid to therequirements for overmatching yield and tensile strength.

3.3.8 Welding consumables for other processes than manual or mechanised arc welding may requirespecial consideration with respect to certification, handling and storage (see also 3.4 of thisSpecification).

3.4 STORAGE AND HANDLING OF WELDING CONSUMABLES

3.4.1 The minimum requirements for the care, storage, control and handling of consumables and flux (forSAW) shall be those of the relevant consumable manufacturer. CONTRACTOR shall provide a detailedstorage, control and handling procedure to GDF SUEZ. Any proposed re-cycling of flux is subject toGDF SUEZ approval.

3.4.2 Different grades and batches shall be individually identified and completely separated from eachother.

3.4.3 Low hydrogen welding consumables shall be supplied in sealed, dirt and moisture-resistantpackages. Damaged packages and any consumables showing signs of damage, deterioration,corrosion or any other contamination shall not be used.

3.4.4 Cellulosic consumables shall always be kept in their original container.

3.4.5 Consumables shall be stored and handled at all times in such a way as to avoid damage andcontamination to them and their containers. Consumables in open containers shall be protectedfrom environmental moisture changes.

3.5 EQUIPMENT

3.5.1 All welding shall be performed using equipment of a type that has proved to be reliable and suitablefor the work being performed. Equipment used for production welding shall be of the samespecification to that used to qualify the welding procedure. Cable lengths shall also reflect thoseused in production.

3.5.2 CONTRACTOR shall ensure and demonstrate that all welding machines are properly earthed to avoidthe occurrence of stray arcing. CONTRACTOR shall provide earth clamps of an approved design andshall ensure only insulated electrode holders are used.

3.5.3 Current certification/calibration certificates for all testing equipment shall be provided to GDF SUEZfor review prior to use. CONTRACTOR shall maintain a system for calibration control for all equipment.

3.5.4 Independent means shall be provided by CONTRACTOR for the accurate monitoring of all weldingparameters including current, voltage, welding speed, thermal input, preheat, interpass temperatureand, for fine wire and gas shielded welding, process-wire feed speed, gas flow rate and gascomposition (especially oxygen level) etc. These parameters shall be measured and recorded on asampling basis (to be agreed) during each shift.

3.5.5 Where (semi-) automatic welding systems are utilised the equipment shall be designed to providecurrent cut-off linked to wire feed speed in order to minimise the risk of copper contamination at stoppoints. This shall be proven during procedure qualification and also on production welding equipmentat start of production (using a sacrificial pipe sample).

3.5.6 Where copper tips are used, CONTRACTOR shall have a control procedure in place to ensure that nowelding shall be allowed to continue once a copper touch has been discovered. Further actions onthis subject shall be agreed by CONTRACTOR and GDF SUEZ prior to commencement of production.


3.6 PERSONNEL

3.6.1 CONTRACTOR's welding supervisors shall have full knowledge of all specification requirements andthe applicable standards and codes and shall be qualified according to EN 12732:2000 Section11.3

3.6.2 Current copies of all pertinent documentation, such as this Specification and approved WeldingProcedure Specifications, shall be in the English language and shall be at the disposal of the weldingcrews and inspection personnel during all operations.

3.6.3 All welders shall be qualified as set out in Section 5 of this Specification.

3.6.4 All CONTRACTOR’s welding inspection personnel shall be qualified according to a minimum of CSWIP3.1 Welding Inspector or a GDF SUEZ approved equivalent and be in possession of a current eyesightcertificate in accordance with EN 970 and EN 473:2008.

3.6.5 Non Destructive Examination personnel shall be qualified in accordance with EN 473:2008 and asdetailed in the NDT sections of this specification.


4. QUALIFICATION OF WELDING PROCEDURES

4.1 WELDING PROCEDURE SPECIFICATIONS

4.1.1 CONTRACTOR shall propose detailed Welding Procedure Specifications (WPS) for all production andproposed/anticipated repair welding. Proposed WPSs along with a matrix detailing all procedures andthe amount of tests to be carried out shall be submitted to GDF SUEZ and the CERTIFYINGAUTHORITY for review prior to welding of the test welds.

4.1.2 The weld procedure shall be proven, if required, to be suitable for reeling and, if deemed necessaryby GDF SUEZ and/or CERTIFYING AUTHORITY, extra tests may be required to prove such suitability.

4.1.3 Any change(s) to any of the proposed WPS's shall be proposed/discussed with GDF SUEZ and theCERTIFYING AUTHORITY before being implemented.

4.1.4 Welding Procedure Specifications (WPS) shall be prepared on forms in accordance with EN 15609-1:2004 and shall contain, as a minimum, the following information:a) Material specification of base materials.b) Welding process and whether manual or automatic.c) Qualified Wall thickness and diameter range (see Section 4.2).d) Geometry of weld groove including dimensional tolerances.e) Root gap (if any) showing allowable tolerances.f) Welding position and direction.g) Filler metal name/type/classification/diameter per pass/layer.h) Name/type/specification/classification/composition of flux and/or flows.i) Gas shielding flow and gas backing (purging) flow (if any).j) Backing strips (permanent backing strips are not allowed).k) Number and sequence of all passes (indicate stringer or weave beads and maximum weave

width).l) Welding current* and voltage range* and polarity. If pulse welding is used, the pulse range.m) Travel speed and electrode run-out length for each pass and permitted range.n) Heat input range*.o) Minimum preheat and maximum inter-pass temperatures and where measured.p) Post-weld heat treatment (if any).q) Method of cleaning and cutting.r) Method of joint set-up including clamp type.s) (Repairs) method of defect removal and preparation of weld area.t) (Repairs) pre-heat prior to gouging.u) (Repairs) minimum and maximum opening sizes.

* Note: Recorded ranges shall be included in the WPS, these shall not include % allowances,these must be noted separately in the WPS.

4.1.5 All WPS's, including all procedures for repair welding, shall be welded/qualified in accordance withthe requirements of EN 288-9:1999 and this specification.

4.1.6 All welding and testing required to qualify a procedure shall be performed in the presence of GDFSUEZ, who shall receive ten (10) days minimum advance notice of the date qualification welding is tostart.

4.1.7 GDF SUEZ shall witness all non-destructive examinations and destructive testing and shall reviewand approve all related results. All mechanical testing shall be carried out by a certified (see ISO/IEC17025:1999) testing facility subject to prior approval of GDF SUEZ.

4.1.8 Production welding shall not commence until all Welding Procedure Qualifications (WPQ) have beenaccepted/approved by GDF SUEZ and the CERTIFYING AUTHORITY.


4.2 WELDING PROCEDURES - ESSENTIAL VARIABLES

4.2.1 An approval of a WPS obtained by a manufacturer is valid in workshops or sites under the sametechnical and quality control of that manufacturer (EN 288-9:1999 – 8.2).

Essential variables shall be as defined in EN 288-9:1999 with the addition of those detailed in thisspecification. Any changes outside the permissible limits of the essential variables shall necessitatere-qualification of the welding procedure.

4.2.2 Additional requirements for essential variables:1. Filler metal: clause 3.3.3 of this specification replaces clauses 8.4.4 and 8.4.5 of EN 288-

9:1999.2. Heat input: clause 4.3.5 of this specification replaces clause 8.4.7 of EN 288-9:1999.3. Any change in size/diameter of welding consumable: replaces clause 8.5.1 of EN 288-9:1999.4. The use of water quenching/cooling (for a rapid reduction of the material temperature for NDT

or any other reason).5. The use of “hot-starts”.

4.3 PROCEDURE QUALIFICATION TEST WELDS

4.3.1 CONTRACTOR shall perform all procedure qualification test welds in accordance with EN 288-9:1999and the relevant sections of this specification

4.3.2 Test welds shall be identified with a unique number, which shall be hard-stamped in the pipe. All testsamples shall be hard-stamped with the GDF SUEZ inspector’s mark prior to removal from the testpipe. All marking shall be recorded by CONTRACTOR and witnessed by GDF SUEZ and theCERTIFYING AUTHORITY.

4.3.3 All pipe for qualification test welds shall be line pipe selected from production pipe manufactured forthis project and from each steel manufacturer or source of supply. Contractor shall check this pipefor identification and conformity to the line pipe specifications and relevant certificates (EN 10208-2and EN 10204). The pipe selected for procedure welding should be supplied from the heat or lotexhibiting one of the highest carbon equivalents as proven by the product analysis during line pipeproduction.

4.3.4 At least one complete weld shall be made and tested to qualify each pipe to pipe welding procedureand one weld for pipe to fitting welding procedure. For small diameter pipe, additional welds shall bemade where necessary to provide sufficient material for testing. When manual welding is to be used,a minimum of one complete test joint is to be made for each Welding Procedure. For semi-automaticor automatic welding equipment, a minimum of three consecutive complete test joints shall to bemade (all of which must be acceptable for NDT).

4.3.5 Procedure qualification test welds, and all repair test welds, shall be carried out between two piecesof pipe (each with a minimum length of 500mm), which shall be restrained. Weld ProcedureQualifications shall be completely monitored and recorded by CONTRACTOR’s QC department usingcalibrated Portable Arc Monitoring (PAMs or ALX unit) equipment. All “as-runs” recording, forexample, voltage, amperage, pre-heat and inter-pass temperature (refer to 6.8 for the requirements),travel speed, electrodes, position, welder, polarity, gas composition etc. shall be included in thedocumentation package submitted along with the NDT and Mechanical Test Results, prior toapproval of the WPQ and final WPS.

4.3.6 For qualification of delays between runs refer to 6.9 of this specification.

4.3.7 Where the use of water quenching/cooling is proposed (for a rapid reduction of the materialtemperature to allow Automated Ultrasonic Testing), this shall be qualified during procedurequalifications and noted on the ultimate WPS.

4.3.8 The test welds shall be non-destructively inspected in accordance with the relevant NDT sections ofthis Specification. Should the test weld not meet the stated acceptance criteria it shall not besubmitted for mechanical testing.

4.3.9 NDT of procedures shall take place a minimum of 24 hours after completion of welding.


4.3.10 Welds, which pass non-destructive testing shall be tested in full accordance with EN 288-9:1999 andthis specification. Samples shall be removed from the locations described in Appendix 1.

4.3.11 The following tables show the minimum amount of procedures to be qualified as well as theinspection and testing requirements that are in compliance with or in addition to EN 288-9:1999.Consideration should be taken with EN 288-9:1999 Section 8 with regards to qualification ranges.Typical examples are given for repair excavation requirements.

Table 2: Extent of testing complete butt weld:

Test Piece Type of inspection Extent of inspection NoteVisual examination 100% Section 8Radiographic examination 100% Section 9Ultrasonic examination 100% Section 10/11MPI examination 100% Section 12

Type of test Extent of testing NoteTransverse tensile test 2 specimens See 4.4.1All weld tensile test 4 specimens See 4.4.2Impact test 4 sets cap &

4sets root (>20mm)See 4.4.3

Macro examination 2 test specimens See 4.4.4Hardness test 2 test specimens See 4.4.5Bend test 2 root & 2 face See 4.4.6

Butt-weld

At least 1 completeweld per process(see 4.3.4)

Note: For Doublesided SAW sidebends may be usedto replace root andface bends.

CTOD (if required in the Scope ofWork)

9 (3x CW + 6x FL) See 4.4.7

CW

Th

CWRoot Pass

Fill(s)

Cap

Hot Pass

Th

External Cap

Internal Cap

Root Area

Typical examples of mainline and double joint welds are shown here.


Table 3: Extent of testing for full penetration repair:


Type of test Extent of testing NoteTransverse tensile test 1 specimens See 4.4.1Impact test 4 sets cap &

4 sets root(>20mm)See 4.4.3

Macro examination 1 test specimens See 4.4.4Hardness test 1 test specimens See 4.4.5

Full PenetrationRepair weld

1 off

Bend test 2 root & 2 face See 4.4.6CW

Th

CW

Root Pass

Fill(s)

Cap

Hot Pass

Original Weld HAZ

Table 4: Extent of testing for partial penetration repair:


Type of test Extent of testing NoteTransverse tensile test 1 specimens See 4.4.1Impact test 4 sets cap See 4.4.3Macro examination 1 test specimens See 4.4.4Hardness test 1 test specimens See 4.4.5

PartialPenetrationRepair to leave aminimum of3mm parentmetal.

1 off

Bend test 2 face See 4.4.6

CW

CW

To Be Qualified =3 mm

30º ± 10ºTo Be Qualified

Original Weld Metal

Original Weld HAZExcavation Boundary


Table 5: Extent of testing for single pass cap repair

Test Piece Type of inspection Extent of inspection NoteVisual examination 100% Section 8Radiographic examination 100% Section 9MPI examination 100% Section 12

Type of test Extent of testing NoteMacro examination 1 test specimens See 4.4.4Hardness test 1 test specimens See 4.4.5

Single Pass CapRepair

1 off

Bend test 1 face See 4.4.6CW

Th

CW

Single Pass Cap Repair

Original Weld Metal

4.3.12 Repairs shall be carried out centred at the 6 o’clock position. All stages of the repair weldingqualification (including gouging {note-gouging pre-heat to be qualified} and grinding of repairexcavation – see Section 7.2.3) shall be carried out with the test pipe in its required fixed position.The ends of the pipe shall be closed off and no access to the inside shall be allowed.

4.3.13 Results of procedure qualification testing shall be recorded on WPQ record forms in accordance withEN 288-9:1999 and this specification (see also Section 4.1.4).

4.3.14 Test samples shall be removed from the locations shown in Appendix 1.

4.3.15 Welders who weld the procedure(s) may be qualified on acceptance of the procedure(s). However,where two welders are used on one weld extra samples may be required to comply with therequirements stated in Table 9.

4.4 MECHANICAL TESTING OF WELDING PROCEDURE QUALIFICATION TEST WELDS

4.4.1 Transverse Tensile TestingTwo transverse (cross weld) tensile tests shall be performed according to EN 895.

If the specimen breaks in the weld metal or HAZ, it shall be considered unacceptable unless it can beproven that the achieved values for Yield Strength and Ultimate Tensile strength are in excess ofthose required for All Weld Tensile Tests as specified in 4.4.2.

4.4.2 All Weld Tensile TestingActual weld properties shall be demonstrated by the performance of All Weld Metal Tensile Tests,parallel to the weld axis. The actual type and size of test specimen is dependent on thediameter/wall thickness of the involved line pipe and the applied type/number of consumables in theinvolved weld.

From each procedure 4 round bar test specimens, of the largest possible size, will be tested. Twospecimens shall be taken as close as possible to the weld root area and two specimens as close aspossible to the weld cap area.

After testing, a macro shall be prepared from the broken test specimen. If the sample demonstratesthat the test included any FL/HAZ or pipe material then the test will be considered invalid and shallbe re-done.

The resulting Yield Strength shall be greater than the highest recorded yield strength of the basematerial (see Section 3.3) and as a minimum this shall exceed the SMYS by at least 100 Mpa.


The resulting Tensile Strength shall be greater than the highest recorded tensile strength of the basematerial (see Section 3.3) and as a minimum this shall exceed the SMTS by at least 80Mpa.

. With GDF SUEZ approval, these tests may be substituted with cross weld tensile tests with fullstress/strain curves.

4.4.3 Charpy V-Notch impact testingTest specimens shall be taken and prepared in accordance with EN-10045-1 in such a way that theaxis of the notch is perpendicular to the pipe surface. Test specimens and testing for impact testshall be in accordance with this specification for position and temperature of testing and with EN875 for dimensions and testing (see also Appendix 2).

Each set shall comprise of three full size specimens taken with the notch (The notch line shall be cutthrough the pipe thickness) in the following locations, (see Appendix 2A):a) weld centre lineb) weld fusion linec) weld fusion line + 2mmd) weld fusion line + 5mmFor partial penetration repairs the following samples shall be taken, (see Appendix 2B):a) weld fusion line to existing weldb) weld centre linec) weld fusion lined) weld fusion line + 2mm

Test specimens with Charpy V-notch shall be used and sampled from 2 mm below the outer surfaceof the pipe and transverse to the weld. When the pipe wall thickness exceeds 20 mm, four more setsare required, in the same circumferential locations, but taken within 2 mm of the inside surface ofthe pipe. The minimum absorbed energy values shall be as stated in Table 6:

Table 6: Charpy requirements weld testing:

Specified minimum yieldstrength of steel:

Average of3 specimens

Single Specimen* TestTemperature

All 50 Joule (J) 40 Joule (J) –20°C**

*Note 1: only one single value may be below the average requirement.**Note 2: Unless Design Temperature is lower in which case Design Temperature applies.The percentage [%] shear at the fracture surface shall be recorded and be a minimum of 50%.Refer to the Scope of Work for details.

4.4.4 MacrographyTwo macro sections of the welds shall be prepared and examined in accordance with EN 1321. Thetest pieces shall be polished and etched for macrographic examination of the weld. The weldcross-section shall be examined for good weld profile and sufficient penetration free of significantinclusions or other defects. It shall also serve to confirm the amount of weld passes that have beendeposited and their compliance with the pWPS.

4.4.5 Hardness TestingHardness surveys shall be carried out on both macro sections, in accordance with EN 1043-1. TheVickers method HV10 shall be used, as detailed in Appendix 3. Results of hardness tests shall bebelow the maximum values specified in Table 7. Permanent records of macro sections shall be keptby means of photo-macrographs showing all hardness indentations.

Table 7: Hardness value requirements:

Hardness location Hardness HV10

Weld metal and HAZ: root 250

Weld metal and HAZ: cap 275


4.4.6 Bend Testing,Specimens and testing for butt joints shall be in accordance with EN 910.

The diameter of the former or inner roller shall be 4t and the bending angle shall be 180° for parentmetal with elongation A ≥ 20%. For parent metal with elongation < 20% the following formula shall beapplied:

(100 x ts )d = A - ts

whered is the diameter of the former or the inner rollerts is the thickness of the bend test specimenA is the minimum tensile elongation required by the material specification

During testing, the test specimens shall not reveal any one single flaw > 3 mm in any direction. Flawsappearing at the corners of a test specimen shall be ignored in the evaluation.

4.4.7 Chemical AnalysisQuantitative chemical analyse of the weld cross-section shall be made in the root zone and fillerpasses to verify the chemical elements as per the chemistry requirement of the applicableconsumable specification.

4.4.8 CTOD TestingIf required in the Scope of Work, CTOD testing shall be carried out according to BS 7448:part2.:1997. 3 (three) Centre of Weld samples shall be taken and 6 (six) Fusion Line samples (of which 3may be used). Testing shall be carried out at 0°C.

4.5 PERMITTED WELDING PROCEDURE QUALIFICATION RETESTS

4.5.1 Welding Procedure Qualification re-tests are not permitted without the approval of GDF SUEZ.

4.5.2 Where re-tests are permitted, they shall be limited to:a) Tensile Tests - if one test fails to comply with the specified mechanical requirements, two further

test specimens shall be taken.b) All Weld Tensile - if one test fails to meet the minimum specified requirements for the base

material, two more tests shall be taken.c) Hardness Tests - if one test fails to comply with the specified mechanical requirements, two

further test specimens shall be taken for each one that failed.d) Bend Tests - if one test fails to comply with the specified requirements, two further test

specimens shall be taken.e) Charpy-V Notch Impact Tests - if one Charpy value from a set of three test specimens falls below

the minimum individual value specified in 4.4.3, then three further tests shall be carried out. Allthree re-test specimens shall meet the requirements of 4.4.3 and the mean value of all six testsshall be calculated and shall meet the specified minimum average value.

4.5.3 If any single (permitted) re-test subsequently fails, no further re-testing shall be allowed and the testshall be deemed to have failed (see clause 4.6).

4.6 FAILURE OF WELDING PROCEDURE QUALIFICATION TESTS

4.6.1 Should a procedure qualification test fail any of the required visual, non-destructive and/ormechanical tests or permitted re-tests, it shall be regarded as not complying with the requirements ofthis specification. The cause of failure shall be established, rectified and the WPS revised asappropriate, before the qualification test is repeated.

4.7 BRAZING AND ALUMINOTHERMIC WELDING OF ANODIC BONDING LEADS

4.7.1 Full details of the joining technique, proposed procedure and associated equipment shall besubmitted to GDF SUEZ prior to use and be in conformance with the manufacturer’srecommendations.


4.7.2 The procedure shall be qualified (in accordance with EN 12732:2000 Annex H) by making threeconsecutive test joints in the presence of GDF SUEZ on materials to be used in production andrepresenting the upper quartile of the carbon equivalent range.

4.7.3 The electrical resistance shall be measured and should not exceed 0.1Ω. The mechanical strength ofthe joint shall be tested by means of a sharp blow from a 1kg. Hammer.

4.7.4 All three joints shall be sectioned and prepared for metallographic examination. The following testsshould be performed on the sections:a) Copper contamination measurement: The depth of copper contamination below the surface of

the pipe material shall be measured metallographically. The fusion line of the weld or brazeshould not be more than 1mm below the pipe surface. Intergranular copper penetration of thepipe material shall not exceed 0.5mm beyond the fusion line when a micro-section isexamined at a magnification not exceeding x50.

b) Hardness survey: Each section shall be tested using a 10kg load. A transverse should bemade across the weld zone as shown below and should consist of at least 6 impressions; twoin the heat affected zone each side of the weld/braze and one in the parent metal each side ofthe weld/braze. The hardness value shall not exceed 325HV 10. See the figure 1:

Note: Hardness impressions 2, 3, 4 and 5 should be entirely within theheat-affected zone and located as close as possible to the fusion boundary

Weld heat affected zone (visible after etching)

1 2

3 4

65

Weld/Braze metal Parent Metal Surface

Figure 1: Requirements for hardness traverse and impressionsfor brazing and aluminothermic welding.


4.8 WELD PROCEDURE QUALIFICATION RECORD(S)

The Weld Procedure Qualification Record(s) shall contain the following documentation and beprecluded with a check list sheet (see example below) showing the contents of each package:

Table 8: Checklist WPQ Records

WPQ: 010-013168.3mm x 18.3mm (L450QO PSL2) Pipe to Pipe

Designation: Mainline WeldingWPQ □(Pre) WPS □As Runs □Weld Visual Inspection Report □Weld Radiographic Inspection Report □Weld Ultrasonic Inspection Report □Weld M.P.I Report □Mechanical Test Results □Material Certificate(s) □Consumable Certificate(s) □Material Cutting List □Welders Details □NDT Technician Qualifications □

Following a final review of the packages, each checklist shall be signed off by GDF SUEZ,CONTRACTOR and the CERTIFYING AUTHORITY.


5. QUALIFICATION OF WELDERS

5.1 GENERAL

5.1.1 The use of pre-qualified welders is not allowed. Each welder or welding machine operator shallbe qualified in accordance with EN 287-1:2004 or EN 1418:1998 and this specification prior tothe start of production welding by making a test weld using the qualified welding procedure. Thiswill comprise of a minimum of one half-circumference weld for welder qualifications and forrepair welders sufficient weld to allow for removal of all mechanical test samples (note that“defect” removal by gouging and grinding forms part of repair welder qualification). The testwelds shall be performed with the pipe in the same position as will be found in productionwelding. Each welding machine operator (for submerged arc welding) shall produce onecomplete weld.

5.1.2 CONTRACTOR shall ensure that only qualified welders and welding operators are employed duringconstruction, welding within the permissible range, position and process for which they are qualified.

5.1.3 The following applications shall be qualified: Welding Process Welding Position Filler Material (including combinations). The welder is only allowed to use the type of filler

material for which he has been approved (i.e. cellulosic only qualifies cellulosic) Pipe Material Girth weld or weldolet

5.1.4 The following ranges can be qualified in accordance with EN 12732: DN 50 qualifies all diameters up to and including DN 100 (category small diameter) DN 150 qualifies all diameters between DN 100 and DN 250 (category medium diameter) DN 400 qualifies equal to or greater than DN 250 (category large diameter)

5.1.5 If a welder fails a qualification test, the result shall be provided to GDF SUEZ. The welder or weldingoperator may carry out a retest (new test joints of the same type as the rejected one), provided thecause of failure is determined and not attributed to inadequate training. If the retest meets thespecification requirements, the test will be considered satisfactory. Any welder failing a qualificationtest shall not be permitted further testing without prior GDF SUEZ approval and without a period ofappropriate training.

5.2 WELDER CERTIFICATE

5.2.1 CONTRACTOR shall operate a scheme for welder qualification certification certificates and welderidentification, which shall be provided to GDF SUEZ for approval prior to the qualification programmecommencing.

5.2.2 The pipeline welder certificate shall be similar to that proposed in EN 287-1. The certificate shallclearly indicate the standard to which the welders’ certification has been performed, i.e. ThisSpecification/EN12732/EN 287-1.

5.2.3 The duration of validity for the certificate is 6 months. NDT records shall be maintained for thepurpose of extending the validity of the welder certificates.

5.2.4 The original certificate is non-transferable and shall be in the possession of the welder orCONTRACTOR (at the production location) during execution of the work

5.2.5 The original certificates shall be signed by GDF SUEZ.


5.3 RE-QUALIFICATION OF WELDERS

5.3.1 Re-qualification of welders or operators is required if any change is made to the welding procedure,which necessitates re-qualification of said welding procedure.

5.3.2 GDF SUEZ reserves the right to require the re-qualification of welders or welding machine operators ifrepair rates are encountered in production welding by any one or more operators, which in GDFSUEZ's opinion are excessive (refer also to Section 7.5)

5.4 ANODE CABLE PIN BRAZERS

Prior to carrying out production work, each operator shall complete three test joints, witnessed byGDF SUEZ, which should pass the tests for electrical continuity and mechanical strength described inSection 4.5. A list shall be produced identifying all “qualified” pin brazers and this shall be approvedby GDF SUEZ and displayed at the work location.

5.5 WELDER QUALIFICATION: WELD INSPECTION AND TESTING

Each test weld shall undergo visual inspection, non-destructive testing, and destructive testing inaccordance with the following table. Non-acceptable results shall constitute the rejection of the test.

Table 9: Welder Qualification Tests Requirements per Welder

Test Piece Type of inspection Extent of inspection NoteVisual examination 100% Section 8Radiographic examination* 100% Section 9MPI examination 100% Section 12

Type of test Extent of testing NoteMacro examination 1 test specimen See 4.4.4

Butt Weld orHalf ButtWeld

Bend test 2 root & 2 face See 4.4.6Test Piece Type of inspection Extent of inspection Note

Visual examination 100% Section 8Radiographic examination 100% Section 9MPI examination 100% Section 12


Full andPartialPenetrationRepair

Bend test 2 root & 2 face (FP)2 face (PP)

See 4.4.6

Test Piece Type of inspection Extent of inspection NoteVisual examination 100% Section 8Radiographic examination 100% Section 9MPI examination 100% Section 12


Cap Repair

Bend test 2 face See 4.4.6Test Piece Type of inspection Extent of inspection Note

Visual examination 100% Section 8MPI examination 100% Section 12

Type of test Extent of testing Note

Weldolet

Macro examination 4 test specimen See 4.4.4

*Note: For Automatic Processes (MAG/MIG) when the wall thickness exceeds 8mm UltrasonicExamination shall be carried out in accordance with Section 10 or 11 (in accordance with EN12732).


6. PRODUCTION WELDING

6.1 GENERAL

6.1.1 Production welding shall not commence until the qualified welding procedures, qualified welders andqualified inspection personnel lists have been reviewed and approved by GDF SUEZ.

6.1.2 At every welding station / location the relevant approved welding procedure specifications (W.P.S.)and approved welder’s lists shall be clearly displayed.

6.1.3 If the requirements specified in the approved WPS’s are not being complied with then this shall because for rejection of the weld or welds in question.

6.2 (LINE) PIPE PREPARATION

6.2.1 The weld bevels and adjacent surfaces for a distance of 100 mm shall be free from surface defects,coating, moisture, grease, paint or rust immediately prior to welding.

6.2.2 Line pipe will be supplied by GDF SUEZ with the end preparation as specified in the line pipe’smaterial specification. Should CONTRACTOR elect to use a different bevel approval shall be obtainedfrom GDF SUEZ, and the bevel design shall be incorporated in the weld procedure specifications.

6.2.3 For pipe-to-fitting welds where wall thickness changes are involved, the joint design in accordancewith EN 12732:2000 Annex C shall be provided by CONTRACTOR for GDF SUEZ's review. All changesof section shall have a smooth and uniform finish.

6.2.4 Any pipe bevel showing evidence of end area lamination shall be immediately reported to GDF SUEZin writing and then cut back until the laminated section is removed, and re-bevelled. After re-bevellingthe pipe end shall be wet magnetic particle inspected and ultrasonically inspected over a distance of100 mm from the bevel, in accordance with EN 10246-18 and EN 10246-17, to ensure that nofurther laminations are present. Any linear indication greater than 10 mm in any direction shall because for rejection.

6.2.5 Field bevels shall be made by machine tool (automatic or hand controlled). Thermal cutting is notacceptable. The bevel ends shall be smooth and uniform and dimensions shall be in accordance withthe qualified welding procedure specification.

6.2.6 Burrs, small score marks, indentations or other small defects within the joint preparation shall, at thediscretion of GDF SUEZ be ground out, otherwise the joint shall be re-prepared. Any damage to linepipe by field welding machines shall be reported to GDF SUEZ prior to repair in accordance with theline pipe specification.

6.2.7 Bevels and the pipe's external surface within 50 mm of the bevel shall be cleaned by power tools to abright finish prior to lining up the pipe.

6.3 ALIGNMENT

6.3.1 Internal line-up clamps shall be used when possible and shall not be removed until 100% of the rootrun and hot pass are completed. When external line-up clamps are used the equipment shall besubject to review by GDF SUEZ prior to welding.

6.3.2 For the welding of fittings and flanges the line-up procedure shall be provided for GDF SUEZ review.

6.3.3 Welding shall be continuous as far as possible and no joint shall be accepted when subjected tointerruptions not covered by the Welding Procedure Qualification. Strong-backs shall not be used.

6.3.4 Hammering or heating shall not be used for correction of misalignment. Spacer tools shall be used tocheck final fit-up.


6.3.5 The alignment of abutting pipe ends shall be such as to minimise the internal offset betweensurfaces. Any offset greater than 1.5 mm, provided it is carried by dimensional variations within thespecified permitted tolerances (see Table 10), shall be equally distributed around the circumferenceof the pipe or fittings.

Table 10: Permitted misalignment of surfaces (EN 12732:2000 Table G1)

Wall Thickness (T) Permissibleexternal misalignment

Permissibleinternal misalignment

T ≤ 10 mm 0.3 x T 1 mm on entire circumference10mm < T ≤ 25.4 mm 20% of T or 3 mm whichever

is less10% of T or 2 mm whichever

is less

6.3.6 Any misalignment shall be reduced to a minimum by rotation of the pipes to obtain the best fit. Whena pipe with a longitudinal weld is used, the seams on adjacent pipes shall be spaced a minimum of30° apart and preferably in the 10 to 2 o'clock position.

6.3.7 The minimum distance between two circumferential welds shall be 3 times the pipe diameter orminimum 500 mm, whichever is greatest.

6.4 WEATHER PROTECTION

6.4.1 Welding shall not be performed when the weather conditions and/or lack of weather protection donot permit satisfactory workmanship or adequate inspections.

6.4.2 Shelters/tents shall be provided/used giving adequate protection, from wind, rain, draft and cold, tothe area of welding.

6.5 TACK WELDS

6.5.1 The works shall be set-up, properly spaced and supported and tack welded in accordance with thewelding procedure that is to be employed for the root run. Where preheat is required for the root run,this shall be applied prior to tack welding and maintained until the joint is completed.

6.5.2 Tack welds shall be a minimum of 25 mm long and spaced evenly around the joint circumference.

6.5.3 Tack welds may be incorporated into the final joint provided they are ground to a suitable featheredge at each end to ensure adequate fusion with the root run.

6.5.4 Tack welding shall only be carried out by qualified welders.

6.6 STRAY ARCS

6.6.1 Arcs shall only be struck on fusion faces. Precautions shall be taken to prevent stray arcs, especiallyon the pipe where the earth clamp is fitted.

6.6.2 Positions where stray arcs have accidentally occurred shall be repaired. Repairs shall be carried outto an agreed procedure. The procedure shall include the removal of defective material by grinding,checking by Magnetic Particle examination for cracks and checking that wall thickness is withinpermitted tolerances.

6.7 INTER-RUN CLEANING

6.7.1 Each run of weld metal shall be cleaned of slag and flux deposits by either hand or power toolsbefore the next run is applied, as required.

6.8 PREHEAT AND INTERPASS TEMPERATURE

6.8.1 The minimum required preheat temperature shall be 100°C.


6.8.2 At no time shall the pre-heat exceed that of the qualified welding procedure by more than 50 °Cexcept where required in 6.8.3

6.8.3 For welding of flanges to pipe the pre-heat shall be increased to a temperature 50 °C higher than thequalified pipe to pipe W.P.Q.

6.8.4 The interpass temperature shall never exceed the maximum temperature specified in the qualifiedwelding procedure, and at no time shall the temperature become high enough to damage the pipe'sprotective coating. The interpass temperature measured immediately before the start of thesubsequent weld run shall not be less than the minimum preheat temperature. In principal, anddependant on material selection, the maximum allowable interpass temperature is 250°C.

6.8.5 Preheat shall be applied using electrical or gas methods such that the required temperature is evenlydistributed around the entire circumference of the joint and extending at least 75 mm on either sideof the joint area.

6.8.6 Preheat temperatures shall be checked using thermal indicating crayons, digital thermometers,thermocouples or contact pyrometers.

6.8.7 Preheat temperatures shall be measured approximately 75mm from both sides of the weld / bevel,around the pipe’s circumference. Interpass temperature shall be measured adjacent to the weld.

6.8.8 Preheat for repair welds shall be applied uniformly around the whole circumferential weld.

6.8.9 Maximum interpass temperature shall be monitored on a regular basis to ensure adherence to theproject specific approved WPS. If interpass temperature is seen to be exceeded the regularity ofmonitoring shall be increased so as to satisfy GDF SUEZ that the specified parameters are being met.

6.9 PARTIALLY COMPLETED WELDS

6.9.1 Whenever possible, joints shall not be left partially completed. The welding of fittings shall becompleted in one cycle.

6.9.2 When production conditions are such that pipe to pipe joints have to be left partially completed thefollowing conditions shall apply:a) The minimum number of runs deposited before cooling shall be as qualified in the approved

welding procedure.b) When vertical-down welding is used, the second run (hot pass) shall be deposited immediately

after completion of the root run (stringer bead), and the time lapse shall not be greater than thatused in the procedure qualification test, with a maximum of 15 minutes.

c) Upon discontinuation of welding the joint shall be wrapped in dry insulation, heat resistantmaterial with a waterproof backing and shall be cooled in a slow and uniform manner.

d) Prior to recommencement of welding the joint shall be reheated to within the specifiedpreheat/interpass temperature range.

e) No welds shall be left partially completed overnight.

6.10 POST-WELD HEAT TREATMENT

Not required unless by the approved WPQ.

6.11 MATERIAL TRACEABILITY AND WELD IDENTIFICATION

6.11.1 CONTRACTOR shall employ a procedure for material traceability and weld identification (See also therequirements of section 10.3). Welder’s foreman shall track welders’ performance and identifyproblems regarding individual welders. GDF SUEZ shall be advised of specific problems.

6.11.2 Identification marks adjacent to welds shall be by crayon, weather proof chalk or by some otherappropriate means. The use of hard stamps is not permitted. Identification marks shall not beremoved until after the welds have been visually and non-destructively inspected.


6.11.3 CONTRACTOR's material traceability and weld identification procedure shall be submitted to GDFSUEZ for approval prior to commencement of work.

6.12 PRODUCTION WELD TESTS

6.12.1 When specified in the Scope of Work, CONTRACTOR shall allow for and carry out Production WeldTests (PWT) as detailed in EN 12732, GDF SUEZ may request, at any time, a weld to be removed bycutting the pipeline, leaving sufficient material on both sides of the weld to accommodate therequired mechanical testing. CONTRACTOR shall re-join and re-weld the pipeline.

6.12.2 The removed weld shall be mechanically tested as required for WPQ test welds (see section 4.)

6.12.3 If the weld fails to meet the minimum specified requirements, detailed in section 4., all productionwelds produced before the date of testing shall be regarded as not meeting specificationrequirements and are subsequently rejected until CONTRACTOR can demonstrate, to the satisfactionof GDF SUEZ and the CERTIFYING AUTHORITY, that all production welds do have the minimumrequired mechanical properties.


7. REPAIR WELDING

7.1 GENERAL

7.1.1 CONTRACTOR shall notify GDF SUEZ of CONTRACTOR's intention to repair a weld before commencingthe repair. Weld repairs are permitted for defects located in the filling and cover passes (i.e. partialpenetration repairs) and shall be at least 50 mm long. Repairs at root or including the root shall beminimized and such repairs shall be subject to special approval of GDF SUEZ on a case to case basis.

7.1.2 Only one attempt at a weld root repair shall be performed. If it is still unacceptable, the entire weldmust be replaced. Should the weld be removed (cut-out) the re-bevelling, by machining, shall be suchthat the entire prior heat affected zone is removed.

7.1.3 Weld repairs shall only be carried out by qualified welders working to written, qualified and GDF SUEZapproved procedures.

7.1.4 Only one attempt at any repair in the weld body shall be allowed unless express GDF SUEZ andCERTIFYING AUTHORITY approval is given to attempt a second repair. Should this second repair alsobe un-acceptable according to the Acceptance Criteria agreed for the project, the complete weld shallbe removed.

7.1.5 Repairs shall be limited to a maximum of 20% of the weld circumference (EN 12732:2000 Section6.7). If more than 20% of the weld exhibits defects requiring repair, or if several defective weldsections amount to this length overall, the weld joint in question shall be cut out and re-weldedunless otherwise agreed by GDF SUEZ.

7.2 DEFECT REMOVAL

7.2.1 Weld defects shall be removed by grinding, machining or air-arc gouging (followed by grinding).

7.2.2 If air-arc gouging is used then the defect area shall be subsequently cleaned by grinding and wirebrushing to a bright metal finish to remove all contaminated material. The cut-out portion shall besufficiently deep and long to remove the defect. At the ends and side of the cut there shall be agradual taper from the base of the cut to the surface of the weld metal. The width and profile of thecut shall be such that adequate access for re-welding is provided. The excavation shall be cleared bymagnetic particle inspection prior to re-welding to ensure complete removal of the defect.

7.2.3 In the event that the defect is close to the weld root and the whole thickness of the weld seam is tobe removed, the new gap opening at the weld root shall remain within the qualified root gaptolerances defined in the WPS. Gouging is only allowed up to 3mm from the internal surface of thepipe after which grinding shall be used to remove the remaining area.

7.2.4 Welds found with cracks shall be repaired by complete removal of the weld i.e. by cutting out asection of pipe containing the weld.

7.2.5 External defects such as undercuts and pin-holes shall be repaired by re-capping the weld for aminimum distance of 38 mm past both ends of the defect. This distance shall be measured parallelto the length of the weld. The re-capped area shall be dressed to a smooth profile. Re-capping shallonly be permitted if the maximum hardness has been shown to be within the acceptance limits ofthis Specification by previous qualification or in-situ portable hardness testing. The in-situ testingprocedure and equipment shall be subject to GDF SUEZ's review and shall be calibrated andcertified.

7.3 INSPECTION OF WELD REPAIRS

Each repair weld shall be subjected, as a minimum, to the same inspection and documentationrequirements as the original weld.


7.4 RECORD OF WELD REPAIR

A full record of all repairs shall be maintained by CONTRACTOR. The record shall include thefollowing:• Weld number• Type and size of defect• Circumferential location (defined to an approved system)• Estimate of the depth (assessed by ultrasonic test where possible)• Where possible, the name of the welder who produced the defect• Repair welding procedure number• Name of repair welder• Copy of the inspection reports for the repair• Date of repair.

7.5 WELD REPAIR RATE

If the weld repair rate during production reaches a level that is unacceptable to GDF SUEZ (above 5%of weld numbers but taking into consideration initial welding during start-up) and there appears to bea consistent re-occurrence of a specific defect, CONTRACTOR should halt production and carry out aninvestigation into the cause. CONTRACTOR shall inform GDF SUEZ of any reasons for high repair ratesand issue his proposals to alleviate such problems. Any such proposed changes must be within theessential variable range already qualified. If this is not the case a re-assessment shall be maderelating to the suitability and continued acceptability of the qualified welding procedure(s).

If the cause of repairs is traced to lack of good workmanship, GDF SUEZ may request the removal ofthe responsible welder(s) from the production line.


8. INSPECTION AND TESTING OF PRODUCTION WELDS

8.1 VISUAL INSPECTION

8.1.1 CONTRACTOR shall visually inspect every weld to a GDF SUEZ approved procedure and forcompliance with EN12732. All visual inspection shall be documented by CONTRACTOR.

8.1.2 Visual inspection shall be carried out at all stages of fabrication and shall include:a) inspection of weld preparations and set-up prior to start of welding;b) after tack-up (where applicable)c) completed weld.

8.2 NON-DESTRUCTIVE TESTING

8.2.1 All welds and repaired welds shall be non-destructively tested (NDT) in accordance with NEN 3650-2:2003, EN 12732:2000 and EN 288-9:1999 and as required by this specification. NDT shall becarried out according to written procedures, which shall be submitted to GDF SUEZ for approval priorto the commencement of work.

8.2.2 All NDT procedures shall be approved by CONTRACTOR’s Level 3 specialist.

8.2.3 In principal all production girth welds shall be inspected 100% by an automatic ultrasonic system(AUT) as outlined in Section 11, supplemented where appropriate by other inspection methods.

Other welds such as flange welds may be inspected by radiography (see Section 9) subject to GDFSUEZ approval.

8.2.4 In specific cases GDF SUEZ may agree to the application of (X-) radiography (see Section 9) tomainline production welds.

8.2.5 Magnetic Particle Inspection shall be carried out on;a) welds with suspected defects in the root area, when accessible;b) welds in which defects have been detected by radiography, UT or AUT and where additional

inspection is necessary to confirm removal of the defects.

Both wet and dry methods may be used, depending on the temperature of the object to be examined.The wet method based on water or oil shall be used when the temperature is below 50ºC and the drymethod is applicable above temperatures of 50ºC.

8.3 ACCEPTANCE CRITERIA NDT

8.3.1 For the Acceptance Criteria of NDT refer to Section 13 of this Specification.


9. RADIOGRAPHY

9.1 RADIOGRAPHIC PROCEDURES

9.1.1 Prior to the start of production radiography CONTRACTOR shall provide to the GDF SUEZ a detailedRadiographic Procedure in compliance with EN 1435:1997, EN 12732:2000 and this specification.As a minimum the procedure shall include the following:a) Project name and job numberb) Procedure number and revisionc) Techniqued) type of equipment and kilo Volt (kV) ratinge) type of filmf) intensifying screensg) shieldingh) source sizei) geometric relationship defined by sketchj) limit of film coveragek) tube voltage or source strength and exposure timel) material thickness rangem) type of image quality indicatorn) processing

9.1.2 The radiation source shall be x-ray unless otherwise agreed by GDF SUEZ. The single wall, singleimage technique shall always be used, unless otherwise agreed with GDF SUEZ.

9.1.3 Wire type image quality indicators, in accordance with EN 462-1 shall be used.

9.1.4 Film type and screens shall comply with the requirements of EN 1435:1997. For Weld ProcedureQualification only very fine grain (Agfa D4 or equivalent) film with lead screens should be used.

9.2 PROCEDURE RADIOGRAPHS

9.2.1 Three radiographs shall be taken to qualify each radiographic procedure qualification test, prior touse on production or qualification welds. These radiographs shall establish the minimumradiographic quality level for all production radiography. Subject to GDF SUEZ agreement, theadequate quality of these radiographs shall result in qualification of the radiographic procedure.Should any variables in the procedure specification change, the radiographic procedure shall be re-qualified. Fogging shall be reported, see 9.8.2.

9.2.2 For procedure qualification Image Quality Indicators shall be placed on both the source side and thefilm side of the weld. Minimum IQI sensitivity shall be as stated in EN1435:1997.

9.2.3 A Radiographic Qualification Technique Sheet shall be produced showing all required and achievedvalues. This must be approved by GDF SUEZ prior to commencement of any production activities.This may be qualified on WPQ material but nipples must not be sent for mechanical testing prior toapproval of the technique(s).

9.2.4 One of the radiographic procedure qualification films shall be available in the production linedarkroom along with the approved technique sheet, for reference purposes, to prove that productionradiographs are being produced to the same quality as that qualified.

9.3 PRODUCTION RADIOGRAPHY

9.3..1 Production Radiography (if agreed) shall be carried out on completion of welding and in accordancewith the qualified radiographic procedure.

9.3.2 Facilities and viewing conditions shall be in accordance with ISO 25580. Radiographs shall beviewed dry.

9.3.3 Where possible, the IQI shall be placed on the source side of the weld being examined. Where this isnot possible, film side IQI may be used and marked as “F”.


9.3.4 Film density shall lie in the range 2.0 - 3.6 in the weld area. The density measurement shall be madein the area of the weld image. A minimum of 5cm overlap shall be required to prove coverage of thediagnostic film length. CONTRACTOR shall have a calibrated densitometer available for GDF SUEZuse in the event of disputes.

9.3.5 A continuous number tape shall be used and lead letters shall be affixed to each section of the weldbeing Radiographed. The images of these letters shall appear on the Radiograph to ensureunequivocal identification of the section.

9.3.6 The zero data shall be at the top of the pipe and the direction in which the film numbering systemhas been applied shall be defined alongside the weld using weather proof paint, chalk, crayon or feltpen. The zero data and numbering direction for both Double Joint and Firing Line welds shall be inthe same direction.

9.3.7 To determine the absence of backscatter a letter "B" shall be affixed to the unexposed side of thefilm.

9.3.8 Films of weld repairs shall be marked with the original number with the suffix R. The completecircumference of the weld shall be examined.

9.4 RADIATION PROTECTION

CONTRACTOR shall be responsible for the protection and monitoring of Radiographic personnel andshall ensure that all work is performed in accordance with the relevant Health and Safety Regulationsand in accordance with the Contract for the safety of all personnel. CONTRACTOR shall beresponsible for notification of the use of Radiography as required by Statutory Regulations. Breachesof Radiographic safety shall not be permitted and may result in removal of the offending party(ies)from the work-site, at GDF SUEZ's sole discretion.

9.5 QUALIFICATION OF RADIOGRAPHERS

9.5.1 Radiographic Interpreters shall be qualified to a minimum of Level 2 according to the requirementsof EN-473 and shall have at least 2 years proven experience in pipeline welding film interpretationand be specifically trained to identify indications of copper contamination in welds made byautomatic systems, where these are utilised.

9.5.2 Radiographic examination shall be performed by personnel qualified as a minimum to Level 2according to EN-473.

9.5.3 GDF SUEZ’s Representative retains the right to reject any NDT personnel who, in his opinion, do notconform and/or perform to the required standards.

9.6 FILM IDENTIFICATION

As a minimum, the identification on the film shall include:

GDFS-Project-Material-Diam. x w.t. - Weld Number; {R (Repair) or RW (Re-weld)} - Date

9.7 FILM PROCESSING

Film shall be processed on site in such a way as to allow storage for a minimum of 7 years withoutdeterioration. CONTRACTOR shall submit a procedure for ensuring processing chemicals have beenremoved to GDF SUEZ for approval.

9.8 STORAGE OF UNEXPOSED FILMS

9.8.1 All unexposed film shall be stored in a clean dry place where surrounding conditions will not bedetrimental to the emulsion.


9.8.2 When requested by GDF SUEZ, CONTRACTOR shall develop a sample of unexposed film, which shallhave a fogging density of less than 0.3.

9.9 STORAGE OF RADIOGRAPHS

On completion of the Work, CONTRACTOR shall submit all the documentation detailed in section15.3. CONTRACTOR shall store all radiographs for a period of 7 years in a controlled environment. Onrequest of GDF SUEZ, CONTRACTOR shall make Radiographs/films available, together with viewingfacilities, for re-checking.


10. MANUAL ULTRASONIC TESTING

10.1 The Manual Ultrasonic Testing procedure shall be in accordance with NEN 3650-2:2003 and EN12732:2000 (EN 583-1 and EN 1714:1997). CONTRACTOR shall submit detailed procedure andtechnique sheets for ultrasonic testing to GDF SUEZ for approval prior to the start of production.

10.2 GDF SUEZ shall be invited to witness all technique qualifications, which result in the production ofthe relevant technique sheets. Should any of the variables of the technique(s) change, followingapproval, the ultrasonic procedure shall be re-qualified.

10.3 Manual Ultrasonic Testing shall be carried out by personnel qualified as a minimum to Level 2according to EN-473.

10.4 Manual Ultrasonic Testing may only be used in lieu of radiographic examination with prior, writtenapproval of GDF SUEZ.


11. AUTOMATED ULTRASONIC TESTING (AUT)

11.1 APPROVAL OF CONTRACTOR, OPERATORS AND SYSTEM

11.1.1 The NDT contractor shall be an independent and accredited by GDF SUEZ. Proven historical datashowing the validity of the AUT system shall be submitted to GDF SUEZ for approval.

11.1.2 When an automatic ultrasonic system is deemed acceptable to GDF SUEZ, the operator responsiblefor the final interpretation and sentencing of the welds shall, besides being in possession of an EN473 level 2 Ultrasonic qualification and further independent or GDF SUEZ qualification(s) inAUT/TOFD, prove to GDF SUEZ that he has sufficient knowledge and experience of Lay bargeinterpretation and welding technology in order to be able to identify weld defects inherent to thewelding system(s) being used.

11.1.3 As long as the Good Workmanship Acceptance Criteria described in this specification is used there isno requirement for the NDT contractor to carry out a qualification test using blind tests to prove theconventional pulse-echo/ through transmission technique system and the time of flight diffractiontechnique.

11.2 AUT SYSTEM

11.2.1 Time of flight diffraction shall be included to improve interpretation of ultrasonic pulse-echoresponses and accurate sizing in through-thickness dimension. In principal all sizing will be executedby means of pulse-echo technique.

11.2.2 A mechanised manipulator shall rotate the ultrasonic transducer-array, including the time of flightunit, around the girth weld while signals are processed, recorded and available for immediateinterpretation in one single rotation.

11.2.3 The NDT contractor shall design an ultrasonic inspection system specific to the typical weldconfiguration and material acoustics used for the project. CONTRACTOR will deliver relevant data oftypical weld bevel preparation, dimensions and actual (test) material. In case phased arrayequipment is used along with a combination of various pipe manufacturers/suppliers, a specialcalibration block will be manufactured from pipe delivered by each supplier.

11.2.4 As a minimum the following attributes shall be implemented in the design of the ultrasonic system:a) The weld volume shall be proportionally divided into through-thickness inspection zones,

depending on the weld geometry, the weld process (layer height) and the pipe wall thickness,between 2.5 mm and 4.0 mm (the actual zone height shall be determined from macrosproduced during weld procedure qualification).

b) Each inspection zone shall represent, by gate setting a proportional weld volume, a fusion lineand at least a 2 mm heat affected zone.

c) Detection of weld defects according to the requirements of EN 12732:2000 and NEN 3650-2:2003 and identification in terms of sizing through-thickness and length.

d) Discrimination between embedded and surface breaking defects.e) Detection of transverse and longitudinal weld defects.f) Detection of stacked defects.

11.2.5 Probes for each zone shall be designed to produce optimum detection, sizing and determination("through-thickness" and length) of weld defects, therefore:a) probe characteristics of reference reflector shall prove at least 12 dB echo response above noise

level of the target path, without interference by adjacent (reflected) signals of mode conversiondisturbances by (weld cap, pipe surface or weld root) geometry reflectors

b) depending on weld geometry (focussed) probes of various angles shall be necessaryc) through-thickness discrimination between zones shall be between 6 dB and 12 dBd) Transit distance measurements in the root zone shall visualise the root pattern.e) Probe data sheets shall be made available to GDF SUEZ.


11.2.6 Time of flight diffraction (longitudinal scan with respect to the weld centre line), in accordance withEN 583-6 shall be implemented to improve:a) detection of volumetric defectsb) discrimination of weld defects and weld geometryc) accurate sizing of weld defects in through-thickness directiond) detection of unfavourably oriented defects for impulse-echo techniquese) detection of transverse weld defects.

11.2.7 The maximum allowable circumferential scanning velocity shall be determined according to Vc ≤ Wc •PRF/3.

11.2.8 Wc is the narrowest –6dB beam width of the appropriate probes and PRF is the effective pulserepetition frequency per probe.

11.2.9 The mechanised manipulation system shall be designed and interfaced with the GDF SUEZ specifiedrequirement for bare pipe ends:

11.3 CALIBRATION BLOCK FOR PULSE-ECHO AND THROUGH-TRANSMISSION TECHNIQUE

11.3.1 Calibration shall be carried out by using a specially machined block mounted in a representative pipesegment so that the complete mechanised manipulation system shall form a part of the calibration.

11.3.2 The calibration block shall be manufactured from project pipe. In case a phased array transducer isused for the inspection, a special calibration block shall be manufactured using material from eachpipe supplier.

11.3.3 A calibration scan shall always be carried out after a rejected weld. The print out of the calibrationruns shall become part of the repair record.

11.3.4 The calibration block shall contain reference reflectors (see table 11 for tolerances) simulating welddefects which, at least:a) Simulate fusion defects using 2 mm flat bottom holes and 1 and 2 mm deep surface notches

including a notch perpendicular to the scan directionb) Check measuring point density and weld volume coverage using 2mm through-thickness drilled

holes located at the weld centre line.

Table 11: Tolerances of reflectors:

Tolerance of machined reflectorsHole diameters ± 0,1 mmFBH ± 0,25 mmAll pertinent angles ± 1ºNotch depth ± 0,1 mmNotch length ± 0,5 mmCentral position of all reference reflectors per weld zone ± 0,1 mm

GDF SUEZ shall have the opportunity to witness the dimensional control checks of the calibrationblocks.

11.3.5 The frequency of calibration shall be agreed between CONTRACTOR and GDF SUEZ, however, shouldCONTRACTOR establish, during calibration, that the equipment has a sensitivity of less than theagreed lower tolerance, all welds examined since the previous calibration shall be re-examined.

11.3.6 As a minimum recalibration is required:a) After a weld repair has been called and prior to scanning the repaired weldb) When differences of material acoustics might occurc) If calibration results amplitudes vary more than ± 2dB from 80% FSHd) Wall thickness change.e) After equipment breakdown.f) If the gate settings need to be adjusted by more than 1mm.g) If required by GDF SUEZ.


11.4 CALIBRATION TIME OF FLIGHT DIFFRACTION TECHNIQUE:

11.4.1 The time of flight system shall be calibrated at the actual pipe by gain setting using grain noise andregistered and set for the project (EN 583-6).

Settings are only allowed to be changed after GDF SUEZ approval.

11.4.2 The ability of the system to produce diffraction signals shall be proved by means of machinednotches (see table 12 for tolerances of notch sizes) positioned through the weld centre line (internaland external surface) with a length of 10 mm, a depth of 2,5 mm and a width of 0,5 mm. Additional anotch with a depth of 1.0mm shall be machined in order to prove the systems capability to detect 1.5mm embedded defects in the root or cap zone.

Table 12: Tolerances of notches:

Tolerance of machined notchesNotch depth ± 0,1 mmNotch length ± 0,5 mmNotch width ± 0,1 mm

Note: The top angle shall be a maximum of 60º.

11.4.3 A calibration check is required on actual data (material acoustics, distance between transducers andwall thickness) via calculated difference of time of flight between creeping wave and longitudinalback wall / root reflection or mode converted back wall signals.

11.5 PROCEDURE

11.5.1 The procedure shall contain at least the following information:a) name of projectb) project and job numberc) procedure number and revision numberd) specific to pulse echo:

i. equipment: mechanized scanner, transducers, monitor/display, multi channel ultrasonicprocessor

ii. method of reporting (shall be one A4 format per weld)iii. system set up; sketch weld volume, inspection zones, probe array, probe positioning,

probe angles, probe identification, target paths and gate settingsiv. programming and recording per inspection zone; channel and probe setting,

amplification, gate setting, go-no-go setting, analogue setting, transit distance setting,minimum and maximum over trace.

v. description examination/execution; positioning manipulator ("zero point setting"), weldand scan identification, scan velocity, coupling, process checks (coupling, probepositioning, surface conditions, registration, hard copy)

vi. recalibrationvii. sizing technique and anticipated accuracyviii. monitor display setting.ix. the calculations made regarding the interaction rules.

e) specific to TOFDi. see pulse echo d) i, ii, iii, iv, vi, vii and viii.ii. programming and recording, sample frequency, amplification (A-scan)iii. calibration on actual pipe (B-scan); visualize creeping wave signal and longitudinal back

wall/root reflection and mode converted back wall signals, averaging (signal/noise ratioverses acceptable scan velocity), amount of A-scans per mm, calibration check bycalculation

iv. interpretation guidef) acceptance criteria (may be a separate procedure), as per Section 13g) couplant usedh) surface temperature limits


11.6 INSPECTION

11.6.1 Pulse echo and TOFD shall be combined to form part of the inspection and shall be executed in onesingle rotation around the pipe.

11.6.2 The mechanised manipulator and recording system shall be capable of locating weld defects withinan accuracy of 1,0 mm.

11.6.3 A check on the accuracy of the encoding system shall be automatically performed on every scan.

11.6.4 Real time inspection of the weld and weld defects shall take place on a monitor/display includingcharacterizing, sizing and assessment.

11.6.5 As a summary, inspection results shall be recorded on one A4-format per weld.

11.7 PULSE–ECHO AND THROUGH TRANSMISSION TECHNIQUE

11.7.1 Prior to the commencement of weld inspection, the sensitivity setting shall be calibrated to 80% FSHof all separate reference reflectors.

11.7.2 During weld inspection, all indications with an echo response > 40% FSH shall be recorded

11.7.3 All indications with an echo response > 40% FSH shall be evaluated on length and position(inspection zone) according to the GDF SUEZ approved acceptance criteria.

11.7.4 The length of a weld defect shall be determined by the point at which the reflected pulse amplitudeamounts to less than 40% FSH. Beam width effects shall be compensated for.

11.7.5 Through thickness of a weld defect shall be assumed as the height of the inspection zone(s).Accurate sizing of through thickness shall be conducted by TOFD.

11.7.6 Transit distance threshold shall be set between 5% FSH and 40% FSH to discriminate weld flawsfrom geometry.

11.8 TIME OF FLIGHT DIFFRACTION

11.8.1 Before commencing weld inspection, TOFD shall be calibrated on the stamped calibration block andactual pipe.

11.8.2 TOFD shall be used as additional interpretation to pulse–echo responses and/or accurate throughthickness sizing (≤ 2.5 mm) shall be conducted by straightening and/or linearizing.

11.9 REPEAT INSPECTION

11.9.1 GDF SUEZ reserves the right to have any inspection repeated or confirmed, possibly by radiographicexamination of the ultrasonically inspected areas.

11.9.2 If any doubt is raised as to the calibration/accuracy and/or integrity of the system, GDF SUEZreserves the right to require CONTRACTOR to prove the system. If the performance is found to beincorrect, the NDT contractor will be required to repeat the inspection of welds examined since thelast proven acceptable calibration, at his own expense.

11.10 SURFACE CONDITION AND TEMPERATURE

11.10.1 The weld and adjacent pipe surface shall be cleaned by the welding contractor over a sufficient(ultrasonic inspection) width, in order to remove any surface defects such as weld spatters, flux, slagetc. which may impede the movement and coupling of the transducers over the pipe surface.

11.10.2 The inspection may only take place when the temperature of the metal is in the range 0ºC – 60ºC. Incase phased array is used, the calibration block temperature shall be within 5ºC of the surface underexamination.


11.11 COUPLANT

11.11.1 To provide an acoustic coupling between the probes and the object to be inspected, water or a non-greasy liquid or paste, which can be washed off by water, shall be used.

11.11.2 Continuity of coupling shall be assured (and recorded) by through-transmission measurements.

11.12 ULTRASONIC EQUIPMENT PULSE-ECHO AND THROUGH TRANSMISSION

11.12.1 The ultrasonic equipment shall provide an adequate number of separate channels to assureseparate presentations in one single rotation around the weld.

11.12.2 The ultrasonic instrument linearity (horizontally and vertically) shall not exceed ± 5% from ideal, to bedetermined according to the procedures detailed in:a) ASME Boiler and pressure vessel code, section 5: article 4, mandatory appendices numbers I

and II and article 5 mandatory appendices numbers I and II (July 2001)b) EN 12668-3

11.12.3 At GDF SUEZ request, (re)calibration certificates shall be made available.

11.12.4 Each separate channel shall provide:a) The amplitude and the transit distance informationb) An adjustable gate setting (start, length)c) The gain adjustmentd) The FSH threshold setting and recording (5% - 100%)e) A signal delay to provide coherent presentationf) A recording output per gate:

exceeded preset threshold amplitude, andanalogue amplitude presentation, andtransit distance presentation.

11.13 ULTRASONIC EQUIPMENT – TOFD

The ultrasonic instrument shall meet the requirements of EN 583-6 for automated TOFD inspection,including:a) minimum signal digitising with a sample rate of 100 MHzb) at least one A-scan per 2 mm circumferential length.

11.14 PROBES

All probes shall comply with the requirements of EN 12668-2.

11.15 MONITOR/DISPLAY

Real time inspection shall take place on a 20 inch (diagonal) monitor/display with a resolution(SVGA) of at least 800 x 600. The maximum scan resolution shall be 2 mm/scan.

11.16 STORAGE

NDT contractor shall store all the relevant digitised data in a safe place for at least 10 years(according to EN ISO 9001). Within this period the NDT contractor shall assure the availability ofdigital copies of the original ultrasonic results (along with viewing software) at GDF SUEZ’s request.


11.17 QUALIFICATION OF AUT SYSTEM

11.17.1 The NDT equipment and procedure(s) shall be qualified by calibration and technical justification.

11.17.2 Calibration blocks shall be made from each steel manufacturer or source of supply and calibrationscans shall be carried out before and after each weld scan (call-in and call-out) using the calibrationblock of the pipe joint(s) supplier(s) making up the weld.

11.18 INSPECTION OF WELD REPAIRS

11.18.1 Each repair weld shall be subjected, as a minimum, to the same inspection and documentationrequirements as the original weld.

11.18.2 In the case of a weld repair, special attention shall be given to the positioning of the scanner band.Due to the fact that the resulting width of the repaired area of the weld is usually greater than that ofthe original weld, it is possible that the repaired area will be outside the gate settings. This can beavoided by scanning the weld with the band in an “offset” position compared with its originalposition. The AUT operator shall measure the centreline and the angle of the new gap prior tocommencement of the repair welding. After the repair welding is finished, the first scan shall bemade with the band on the original position to confirm that the defect has been removed. A secondscan shall then be made with the band positioned on the centreline of the repaired area.

11.18.3 If the TOFD scan shows any relevant indications in the repaired area, a manual ultrasonicexamination shall be carried out which shall be completely witnessed by GDF SUEZ.


12. SURFACE EXAMINATION

12.1 MAGNETIC PARTICLE INSPECTION (MPI)

12.1.1 CONTRACTOR shall submit a detailed MPI procedure to GDF SUEZ for approval.

12.1.2 CONTRACTOR's procedure shall be in accordance with EN 1290:1998 for wet (or dry for excavations)Magnetic Particle Inspection. The yoke method shall be used for all MPI. The use of permanentmagnets is not allowed. The use of any other method shall be subject to GDF SUEZ approval.

12.2.3 Magnetic particle operators shall be qualified to Level 2 according to EN-473.

12.2 DYE PENETRANT INSPECTION (DPI)

12.2.1 CONTRACTOR shall submit a detailed DPI procedure to GDF SUEZ for approval.

12.2.2 Dye Penetrant Inspection shall be carried out in accordance with EN 571-1:1997 using Chloride-freedye.

12.2.3 Dye Penetrant Inspectors shall be qualified to Level 2 according to EN-473


13. INTERPRETATION AND ACCEPTANCE CRITERIA FOR N.D.T.

13.1 ACCEPTANCE CRITERIA VISUAL

a) Surface breaking defects are not acceptable. Excess weld metal should be uniform and not morethan 3mm in height. It should merge smoothly and gradually into the parent metal and notextend beyond the original joint preparation by more than 2mm. No area should have the weldface lower than the adjacent pipe surface.

b) The root bead or any concavity shall merge smoothly into the adjacent surface but at no pointshall the weld be thinner than the pipe thickness.

c) Any undercut shall not exceed 0.5mm in depth and 50mm in lengthd) The angle of incidence between the parent metal and weld shall be a minimum of120 (see

figure below taken from EN 12732:2000 Annex E)

≥120º

Figure 2: Angle of incidence between parent metal and weld

13.2 ACCEPTANCE CRITERIA RADIOGRAPHY

Acceptance criteria for Radiographic examination shall be in accordance with Appendix 4 of thisspecification.

13.3 ACCEPTANCE CRITERIA MANUAL ULTRASONIC TESTING

Acceptance criteria for Manual Ultrasonic Testing shall be in accordance with Appendix 5 of thisspecification.

13.4 MECHANISED PULSE ECHO + TOFD: INTERPRETATION AND SIZING OF WELD DEFECTS

13.4.1 Relevant weld defects

Indications are deemed to represent relevant weld defects when:a) a pulse echo response of > 40 % FSH is obtained; based on a reference reflector size of

3.0mm flat bottom hole.b) TOFD diffraction signals are measurably differentiated by having height “in the thickness

direction” in combination with phase reflection;c) TOFD diffraction signals are detected in combination with a local interference of the lateral

wave, typical to the pipe outer surface;d) TOFD diffraction signals are differentiated from the bottom reflection signals typical to the

normal pattern of the penetration, or the pipe inner surface;e) single TOFD diffraction signals occur in clusters or in evenly spread patterns.

13.4.2 Identification of weld defects

The identification of weld defects shall take place in terminology of h x lmax, where:a) h is the maximum allowable height dimension of a weld defect in mm;b) lmax is the maximum allowable length of a weld defect in mm in a circumferential direction.


13.4.3 Definition of surface breaking and embedded weld defects

A difference is made between “surface breaking” and “embedded” weld defects, where weld defectsnear to the surface in the zones adjacent to the pipe inner and outer surfaces are deemed surfacebreaking in case of insufficient resolution of the ultrasonic system or when the distance between thesurface and the defect is less than the maximum height of the defect. Defects in all other zoneslocated between the inner and outer zones are classed as being embedded.

13.4.4 Misalignment

Pulse-echo response near the noise level (0 % FSH) in combination with TOFD (see paragraph13.4.1), where diffraction signals fade in and fade out gradually to the normal root pattern and runparallel to it, are deemed misalignments.

13.4.5 Determination of “through thickness” weld defect height

The primary means of defining the height of a weld defect in the “through thickness” direction shallbe examination of the pulse-echo response, where after TOFD assisted correction/confirmation andvisual examination shall take place. The following methodology shall be applied to the aforesaid:

a) Weld defects detected by means of pulse-echo response are expected to have a “throughthickness” height equal to the number of inspected zones where the defect has been observed.

b) The observed values shall be corrected and/or confirmed by means of TOFD in the followingmanner:1) A weld defect in the root zone (= root penetration + zone height) shall principally be a

surface breaking defect, where the “through thickness” measurements (h) from the pipeinner surface shall be rounded of at 1,5 mm, 2,0 mm or 2,5 mm.

2) A detected weld defect in the zones between the root zone and the zone adjacent to theouter pipe surface shall be deemed to have a height of at least the inspected zone, unlessan alternate value is confirmed by means of TOFD.

3) A weld defect detected in the zone adjacent to the outer pipe surface shall principally bedeemed to be surface breaking, with a minimum height of at least the height of theinspected zone, unless an alternate value is confirmed by means of TOFD.

c) Where defects manifest on the pipe outer surface or in case of misalignment, defect heightsshall be corrected on the basis of visual examination but only after confirmation by GDF SUEZ

13.5 ACCEPTANCE CRITERIA MECHANISED PULSE ECHO + TOFD

Acceptance criteria for Automated Ultrasonic Testing shall be in accordance with Appendix 6 of thisspecification.

13.6 ACCEPTANCE CRITERIA MAGNETIC PARTICLE INSPECTION

13.6.1 Any weld or area tested by means of MPI shall be unacceptable if:a) any crack or crack like indication, regardless of size, is revealed;b) any linear indication is found;c) any rounded indication >2 mm is found;d) more than 3 rounded indications > 1.5mm, in line and with a distance between the indications of

less then 1.5mm measured from edge to edge, are found.

13.7 ACCEPTANCE CRITERIA DYE PENETRANT INSPECTION

13.7.1 Any weld or area tested by means of DPI shall be unacceptable if any defects as specified for MPI arerevealed.


14. REPORTING OF N.D.T.

14.1 GENERAL

CONTRACTOR should use standard NDT reports/forms giving all relevant details to the NDTtechnician in order to facilitate correct inspection methods and reporting standards.

NDT reports refer to those for Visual Inspection, Radiography, Ultrasonic Inspection(s), Dye PenetrantInspection and Magnetic Particle Inspection.

In principal the following information, but not limited to, SHALL be clearly shown on reports:a) GDF SUEZ nameb) GDF SUEZ project numberc) GDF SUEZ platform number or locationd) Unique report numbere) Specific details as to the weld numbers examined.f) Drawing number and revision numberg) Certifying Authority (and Registration number where applicable)h) Standard or Procedure Number (Approved) and Revisioni) Acceptance Criteriaj) Technicians name, qualification, level and certificate numberk) Shift being worked ( day, night or 0.00-12.00, 12.00-24.00)l) Material typem) Pre or post heat treatment (where applicable)n) Material thicknesso) Surface condition and temperaturep) Welding preparation and technique used (i.e V – SMAW)

14.2 SPECIFIC MPI

a) Method usedb) Yoke or magnet IDc) Current usedd) Field strengthe) Lighting used and light strengthf) Consumables used, contrast paint, ink etc

14.3 SPECIFIC DYE PENETRANT

a) Consumables usedb) Times used during application for penetration, cleaning and development.

14.4 SPECIFIC ULTRASONIC

a) Equipment type and IDb) Probes used (including frequency, diameters, angles etc.)c) Couplant usedd) Calibration and reference blocke) Sensitivityf) Transfer correctiong) Range

14.5 SPECIFIC AUT

a) Equipment usedb) Location of defects (zone, upstream, downstream, depth)c) Details of defect (height, start, end and length)d) A written note shall be generated for the marking up of defects.e) Print outs of scans shall contain the time and date of examination


14.6 SPECIFIC RADIOGRAPHIC:

a) Radiation source, size and IDb) Type and size of filmc) Exposure time in kV and mA minutesd) Technique usede) Thickness of material and weld reinforcement.f) Films shall be identified separately (i.e Weld FL (DJ) 01 film 1, 2, 3 and 4 if applicable)g) Interpretation and sentencing per film according to the Approved Acceptance Criteriah) Qualification type and level of Interpreteri) Acceptance of interpretation by CONTRACTOR


15 DOCUMENTATION

15.1 GENERAL

15.1.1 CONTRACTOR shall provide all documentation, in the English language, to GDF SUEZ for review asrequired by the Purchase Order, this Specification and other referenced Specifications.

15.1.2 CONTRACTOR's documentation procedures shall be subject to review and approval by GDF SUEZ.

15.2 INITIAL SUBMISSIONS

15.2.1 Prior to the commencement of procedure qualification and production CONTRACTOR shall providethe following documentation for review by GDF SUEZ. Documentation shall include but not be limitedto the following:

a) Quality Plan;b) Test and Inspection Plan;c) Quality Assurance Manual;d) Proposed Welding Procedure Specifications including repairs;e) Welding Procedure Qualification Matrix;f) Joint Designs;g) Line-up procedure;h) Welding Consumable Technical Information (Manufacturer's);i) Welding Consumable Batch Test Certificates;j) Line-up Clamp Detailsk) Test Equipment Calibration Certificates;l) Film Processing Procedure;m) Radiographic Safety Procedures;n) N.D.T. Procedures and Procedure Qualification Reports;o) N.D.T. Operator Qualification Certificates.p) Evidence of quality reviews, of internal systems audits and corrective action requests;q) Details of CONTRACTOR's Q.C. personnel and equipment;

15.3 FINAL DOCUMENTATION

15.3.1 Within 4 weeks of completion of the order, CONTRACTOR shall deliver to GDF SUEZ a ManufacturingRecord Book (MRB) containing, as a minimum, the following documentation:

a) Purchase Order (PO) and variations to PO.b) CONTRACTOR's daily/weekly/monthly reports issued to GDF SUEZ.c) all approved queries and concessionsd) manufacturing procedures.e) quality control/inspection procedures.f) non-destructive testing procedures and qualification records.g) welding procedure(s) and qualification test results.h) copies, in sequential order, of all GDF SUEZ issued approvals.i) all inspection and test reports and certification recording the results of inspection and testing

as specified in this specification;j) visual inspection and N.D.T. Reportsk) welder qualification recordsl) approved list of qualified weldersm) dimensional control reportsn) hydrostatic test recordso) heat treatment recordsp) pipe fabrication certificates (see 15.3.2)q) weld tracking sheets (see 15.3.3)

15.3.2 Pipe fabrication certificates are supplied to the CONTRACTOR with/for each length of pipe.CONTRACTOR shall maintain a material traceability system locating the correct position/place ofeach length of pipe.


15.3.3 The Weld Tracking Sheet or As Laid Record shall contain the following minimum information:

a) pipe number and lengthb) weld numberc) pipe number and lengthd) material heat numbere) material certificate number (see 15.3.2)f) date weldedg) shift (day/night)h) welding procedure usedi) name/type and batch no(s) of weld consumablesj) report numbers of all applicable test and inspection reports

15.4 STORAGE BY CONTRACTOR

15.4.1 After approval of the MRB, CONTRACTOR shall make 3 electronic (pdf) copies. The original plus 2electronic copies shall be submitted to GDF SUEZ. CONTRACTOR shall store 1 copy of the MRB,together with all Radiographs, for a period of 7 years (see 9.9).

15.5 DELIVERY DOCUMENTATION

15.5.1 During the fabrication/construction phase, extra copies of the in 15.3.1 listed documentation shallbe furnished by CONTRACTOR upon the request of GDF SUEZ and/or the CERTIFYING AUTHORITY,e.g. NDT reports and Weld tracking sheets.


APPENDIX 1: MECHANICAL TEST REQUIREMENTS PIPE WELDS

Appendix 1A Sample locations mainline weld

Note: In case of welded pipe the welds may be located directly across from each other in the 12 o’clockposition.

Appendix 1B Sample locations Full Penetration Repair


Appendix 1C Sample locations Partial Penetration Repair

Appendix 1D Sample locations Cap Repair


APPENDIX 2: IMPACT TESTING DETAILS

Appendix 2A Charpy details mainline weld and full penetration repair

Appendix 2B Charpy details partial penetration repair


APPENDIX 3: HARDNESS TESTING DETAILS

CW

CW

Mid weld

Weld MetalHAZ

2 mm APPROX

2 mm APPROX

H.A.Z.:

From Fusion Line and into unaffected Base Metal at Fusion Line, Fusion Line +2mm, Fusion Line +5mm for eachtransverse location. Spacing between tests in H.A.Z. shall be 0,5mm.

WELD METAL:

At least 5 indentations for each transverse location, the outer two shall be 2mm from the fusion lines and theremainder equally spaced.


APPENDIX 4: RADIOGRAPHIC ACCEPTANCE CRITERIA:

The following Acceptance Levels for radiography are based on Table G.2.2 (Tier 1) of EN 12732:2000.DEFECT DEFECT ACCEPTANCE LEVELS

External Profile Weld reinforcement shall be uniform and not less than 1 mm. Maximum Height shall be3mm.The cap shall merge smoothly with the parent metal and not extend beyond the originaljoint preparation by more than 3mm each side. Surface breaking defects are notacceptable.

Internal Profile The root bead or any concavity shall merge smoothly into the adjacent surface but at no pointshould the weld be thinner than the pipe thickness.

Root Concavity Root concavity is acceptable if the density of the image is no greater than that of theadjacent parent material. If the defect image is darker than the adjacent parent metal, itshall be classed as incomplete root penetration. Root concavity shall not exceed 25% of theweld circumference.

Cap Undercut Length: 50mmTotal: 50mm in 300mm or 15% of circumference (if less)Depth: 1mm or 0.1 x T if less

Root Undercut Length: 25mmTotal: 25mm in 300mm or 8% of circumference (if less)Depth: 1mm or 0.1 x T if less

Crack Any form of crack or suspected crack shall be considered unacceptable regardless of its sizeor its location and the weld cut out.

Crater Cracks 4mmExcessive RootPenetration

Excess penetration: 2mm maximum with localised 3mm.

Incomplete RootPenetration orLack of Root orCap Fusion

Any individual imperfection due to incomplete root penetration or lack of fusion at weld rootand cap shall not exceed 25mm in length.The total length of such imperfections shall not exceed 25mm in any 300mm or 8% ofcircumference (if less).

Incomplete Fusiondue to cold lap,Lack of Sidewalland Lack of Inter-run Fusion(not in root orcapping beads)

Any individual imperfection due to incomplete fusion due to cold lap between two adjacentweld beads or between the weld metal and the base metal that is not open to the surface,shall not exceed 50mm in length. The total length of such imperfections in any continuous300mm length of weld shall not exceed 50mm. For any weld less than 300mm in length, theaggregate length of indications of incomplete fusion due to cold lap shall not exceed 15% ofthe weld length (if less).

Worm Holes Not AcceptableHollow Bead Length: 50mm

Total: 50mm in 300mm or 15% of circumference (if less)Inclusions 12mm in 300mm and 4 in 300mm

Slag Length: 50mmTotal: 50mm in 300mm or 15% of circumference (if less)

Burn Through Any Burn Through shall not be acceptable if the image is darker than that of the parentadjacent metal.Burn through producing a darker image than that of the adjacent parent metal is notacceptable if its length exceeds 0.33WT, with a maximum of 6mm.Only two burn throughs are allowed in any 300mm of weld.

Porosity Porosity shall not exceed a total area when projected radially through the weld, of 2% of theprojected weld area in the radiograph, calculated by multiplying the length of the weldaffected by porosity, with a minimum of 150mm, by the maximum width of the weld. An isolated pore greater than 0.25WT(max.3mm) in any direction shall be consideredunacceptable.

High DensityIndications

GDF SUEZ has the right to reject any indication on (excessive) density alone even if the lengthor dimensions of that defect appear to be within the acceptance limits. CONTRACTOR shallnotify GDF SUEZ of any indications having a high density.

Copper Inducedindications

Any indication showing suspected copper or copper crack like indications shall be rejectedand the weld removed.

DefectAccumulation

100mm in 300mm or 15% of pipe circumference (if less), excluding porosity.Note: Root Concavity is not included in accumulation calculations unless is causes the weldthickness to be less than that of the pipe.

Defect Interaction Inherent in defect accumulation criteria.


APPENDIX 5:MANUAL ULTRASONICS ACCEPTANCE CRITERIA

The following Acceptance levels for manual ultrasonic testing are in accordance with EN 12732:2000 TablesG.3.1 and G.3.2

Recording of indicationsCalibration standards and fault reflection lengths using the Distance Gain Size method

Wall thickness (T)In mm

Calibration level –circular disc reflector

diameter, in mm

Sensitivity settingamplitude below

calibration level by dB

Fault reflection lengthsto be recorded above

this length (mm)6 < T ≤ 15 1.0 6 10

15 < T ≤ 20 1.5 6 1020 < T ≤ 40 2.0 6 10

Assessment of indications using the Distance Gain Size methodMaximum allowable numbers and sizes of reflectors

Wall thickness T*In mm

Number of indicationsper m of seam

Maximum allowablelengths of reflectors per

echo**mm

Echo level abovecalibration level

dB

-6 ≤ T ≤ 10 5and 2

1020

≤ 6≤ 6

10 < T ≤ 20 10and 3and 1

102010

≤ 6≤ 6

≤ 12***20 < T ≤ 40 10

and 4and 1

102510

≤ 6≤ 6

≤ 12***40 < T ≤ 60 10

and 4and 1

103010

≤ 6≤ 6

≤ 12***NOTES:

* If wall thicknesses differ, the lower wall thickness shall be decisive

** For confirmed volume defects (not in vicinity of the surface), fault lengths exceeding thecalibration levels by up to 6dB can be allowed up to 1.5 times the allowable length.Confirmation may take the form of a radiographic examination.

*** The acceptability of single, large defects shall be confirmed on the basis of random samples, e.g.by means of radiographic examination.


APPENDIX 6: Mechanised Pulse Echo + TOFD Acceptance Criteria

General

All relevant indications shall be examined in accordance with this section. In the case of two unequal wallthicknesses, the thinnest dimension shall be applied.

A group of indications in which the individual defect lengths are deemed acceptable, shall be accepted only whenthe group is found to comply with all of the conditions stated for interaction.

In the event that the AUT contractor applies a software program utilising the above mentioned interaction rules,the software shall be made available to GDF SUEZ for validation prior to the commencement of pipelineinstallation.

Indications which do not comply with conditions of the aforesaid shall be treated as one single indication.Furthermore, the defective dimensions (“h” and “l”) shall be measured, including the distance between theindications and the table below shall be applied for evaluation of the defects.

Sizing (In-)Accuracy

1. If no validation testing to NEN 3653 is performed, the Sizing (In-)Accuracy to be applied shall be 1.5mmfor the root and fill and 2mm for the cap. These values may be adjusted after validation testing hasproven a better sizing accuracy.

2. If no validation to NEN 3653 is carried out, the acceptance of the proposed defects shall be confirmed byCurved Wide Plate Testing, using proposed Surface Breaking Defects only.

Acceptance criteria based on good workmanship

Maximum allowable defect length (“l”) in mm

Wall thickness (mm) Surface breaking Embedded Defect Height (“h”)20 30 1.5 – 2.510 15 2.5 – 3.06 ≤ Wt ≤10

Not acceptable 10 3.0 – 3.525 50 1.5 – 2.520 40 2.5 – 3.010 < Wt ≤ 250 25 3.0 – 3.5

20 25 1.5 – 2.510 10 2.5 – 3.0WQT / repairs

Not acceptable 10 3.0 – 3.5

1- Only 1 defect, or summation / interaction of smaller defects, as agreed is allowed in any 12.5%of Weld Circumference Length;

1- Maximum Allowable Defect Square Area is 7.0 %, including Threshold and Sizing (In)Accuracy, inany 12.5% of Weld Circumference Length.

2- Threshold Root / Cap 40% of 2mm Notch3- Threshold Embedded 40% of 3mm FBH.4- Indications in ROOT below threshold, may be full circumference, 360°.5- Maximum Misalignment (Hi-Low) 10% of Wall Thickness, if greater then the value (mm) over 10%

to be added to the actual defect height for evaluation.6- No weld flaws are allowed in the weld area where longitudinal/spiral weld crosses with

circumferential weld7- CONTRACTOR shall also have data and information available to identify (suspected) copper

induced cracking. Welds containing (suspected) copper induced cracking shall be cut out.


Interaction Rules

Interaction Rules shall be applied as per API 1104 – 2005 Errata 1 – 2007, modified as follows:

Interaction exists if;

a- S < ((2c1+ 2c2) / 2) + sizing (in)accuracy)b- S1 < ((2c1+ 2c2) / 2) + sizing (in)accuracy), or

S2 < ((2a1+ 2a2) / 2) + sizing (in)accuracy)

Embedded = when ligament (d) > than flaw height + Sizing (In)Accuracy, (2a).

media/files/e/engie-ep-v2/documents/500-pipin… · author: matherp created date: 20121126100147z

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