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TABLE OF CONTENTS
1.0 INTRODUCTION ............................................................................................................................. 5
1.1 GENERAL ........................................................................................................................................................... 5 1.2 SCOPE ................................................................................................................................................................. 5 1.3 QUALITY ASSURANCE .................................................................................................................................. 5 1.4 QUALITY PLAN ................................................................................................................................................ 5 1.5 INSPECTION NOTICE .................................................................................................................................... 6 1.6 TERMS AND DEFINITIONS ......................................................................................................................... 6 1.7 ABBREVIATIONS ............................................................................................................................................. 7
2.0 REFERENCED CODES, STANDARDS AND SPECIFICATIONS .................................................... 8
2.1 CODES AND STANDARDS .......................................................................................................................... 8
3.0 GENERAL ....................................................................................................................................... 11
3.1 SCOPE ............................................................................................................................................................... 11 3.2 WELDING PROCESSES ................................................................................................................................ 11 3.3 WELDING CONSUMABLES ....................................................................................................................... 11 3.4 STORAGE AND HANDLING OF WELDING CONSUMABLES ........................................................ 12 3.5 EQUIPMENT ................................................................................................................................................... 13 3.6 PERSONNEL.................................................................................................................................................... 13
4.0 QUALIFICATION OF WELDING PROCEDURES ......................................................................... 14
4.1 WELDING PROCEDURE SPECIFICATIONS ........................................................................................... 14 4.2 WELDING PROCEDURES - ESSENTIAL VARIABLES ......................................................................... 15 4.3 PROCEDURE QUALIFICATION TEST WELDS ...................................................................................... 15 4.4 MECHANICAL TESTING OF WELDING PROCEDURE QUALIFICATION TEST WELDS ......... 19 4.5 PERMITTED WELDING PROCEDURE QUALIFICATION RETESTS ................................................ 21 4.6 FAILURE OF WELDING PROCEDURE QUALIFICATION TESTS ..................................................... 22 4.7 BRAZING AND ALUMINOTHERMIC WELDING OF ANODIC BONDING LEADS .................. 22 4.8 WELD PROCEDURE QUALIFICATION RECORD(S) ........................................................................... 23
5.0 QUALIFICATION OF WELDERS ................................................................................................... 24
5.1 GENERAL ......................................................................................................................................................... 24 5.2 WELDER CERTIFICATE ................................................................................................................................ 24 5.3 RE-QUALIFICATION OF WELDERS ......................................................................................................... 25 5.4 ANODE CABLE PIN BRAZERS .................................................................................................................. 25 5.5 WELDER QUALIFICATION: WELD INSPECTION AND TESTING .................................................. 26
6.0 PRODUCTION WELDING............................................................................................................. 27
6.1 GENERAL ......................................................................................................................................................... 27 6.2 (LINE) PIPE PREPARATION ........................................................................................................................ 27 6.3 ALIGNMENT ................................................................................................................................................... 28 6.4 WEATHER PROTECTION ............................................................................................................................ 28 6.5 TACK WELDS .................................................................................................................................................. 29 6.6 STRAY ARCS ................................................................................................................................................... 29 6.7 INTER-RUN CLEANING .............................................................................................................................. 29 6.8 PREHEAT AND INTERPASS TEMPERATURE ....................................................................................... 29 6.9 PARTIALLY COMPLETED WELDS ............................................................................................................ 30 6.10 POST-WELD HEAT TREATMENT ............................................................................................................. 30 6.11 MATERIAL TRACEABILITY AND WELD IDENTIFICATION .............................................................. 31
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6.12 PRODUCTION WELD TESTS ..................................................................................................................... 31
7.0 REPAIR WELDING ........................................................................................................................ 32
7.1 GENERAL ......................................................................................................................................................... 32 7.2 DEFECT REMOVAL ....................................................................................................................................... 32 7.3 INSPECTION OF WELD REPAIRS ............................................................................................................ 33 7.4 RECORD OF WELD REPAIR ....................................................................................................................... 33 7.5 WELD REPAIR RATE ..................................................................................................................................... 33
8.0 INSPECTION AND TESTING OF PRODUCTION WELDS .......................................................... 34
8.1 VISUAL INSPECTION ................................................................................................................................... 34 8.2 NON-DESTRUCTIVE TESTING ................................................................................................................. 34 8.3 ACCEPTANCE CRITERIA NDT ................................................................................................................... 34
9.0 RADIOGRAPHY ............................................................................................................................ 35
9.1 RADIOGRAPHIC PROCEDURES ............................................................................................................... 35 9.2 PROCEDURE RADIOGRAPHS ................................................................................................................... 35 9.3 PRODUCTION RADIOGRAPHY................................................................................................................ 36 9.4 RADIATION PROTECTION ........................................................................................................................ 36 9.5 QUALIFICATION OF RADIOGRAPHERS ............................................................................................... 36 9.6 FILM IDENTIFICATION ................................................................................................................................ 37 9.7 FILM PROCESSING ....................................................................................................................................... 37 9.8 STORAGE OF UNEXPOSED FILMS ......................................................................................................... 37 9.9 STORAGE OF RADIOGRAPHS .................................................................................................................. 37
10.0 MANUAL ULTRASONIC TESTING .............................................................................................. 38
11.0 AUTOMATED ULTRASONIC TESTING (AUT) ........................................................................... 39
11.1 APPROVAL OF CONTRACTOR, OPERATORS AND SYSTEM ........................................................ 39 11.2 AUT SYSTEM .................................................................................................................................................. 39 11.3 CALIBRATION BLOCK FOR PULSE-ECHO AND THROUGH-TRANSMISSION TECHNIQUE
40 11.4 CALIBRATION TIME OF FLIGHT DIFFRACTION TECHNIQUE: ...................................................... 41 11.5 PROCEDURE ................................................................................................................................................... 42 11.6 INSPECTION ................................................................................................................................................... 43 11.7 PULSE–ECHO AND THROUGH TRANSMISSION TECHNIQUE .................................................... 43 11.8 TIME OF FLIGHT DIFFRACTION .............................................................................................................. 43 11.9 REPEAT INSPECTION .................................................................................................................................. 43 11.10 SURFACE CONDITION AND TEMPERATURE ..................................................................................... 44 11.11 COUPLANT ..................................................................................................................................................... 44 11.12 ULTRASONIC EQUIPMENT PULSE-ECHO AND THROUGH TRANSMISSION ....................... 44 11.13 ULTRASONIC EQUIPMENT – TOFD ....................................................................................................... 45 11.14 PROBES ............................................................................................................................................................ 45 11.15 MONITOR/DISPLAY .................................................................................................................................... 45 11.16 STORAGE ......................................................................................................................................................... 45 11.17 QUALIFICATION OF AUT SYSTEM ......................................................................................................... 45 11.18 INSPECTION OF WELD REPAIRS ............................................................................................................ 45
12.0 SURFACE EXAMINATION............................................................................................................ 46
12.1 MAGNETIC PARTICLE INSPECTION (MPI) .......................................................................................... 46 12.2 DYE PENETRANT INSPECTION (DPI) .................................................................................................... 46
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13.0 INTERPRETATION AND ACCEPTANCE CRITERIA FOR N.D.T. ............................................... 47
13.1 ACCEPTANCE CRITERIA VISUAL ............................................................................................................. 47 13.2 ACCEPTANCE CRITERIA RADIOGRAPHY ............................................................................................. 47 13.3 ACCEPTANCE CRITERIA MANUAL ULTRASONIC TESTING .......................................................... 47 13.4 MECHANISED PULSE ECHO + TOFD: INTERPRETATION AND SIZING OF WELD DEFECTS
47 13.5 ACCEPTANCE CRITERIA MECHANISED PULSE ECHO + TOFD ................................................... 49 13.6 ACCEPTANCE CRITERIA MAGNETIC PARTICLE INSPECTION ...................................................... 49 13.7 ACCEPTANCE CRITERIA DYE PENETRANT INSPECTION ............................................................... 49
14.0 REPORTING OF N.D.T. ................................................................................................................. 50
14.1 GENERAL ......................................................................................................................................................... 50 14.2 SPECIFIC MPI.................................................................................................................................................. 50 14.3 SPECIFIC DYE PENETRANT ....................................................................................................................... 50 14.4 SPECIFIC ULTRASONIC .............................................................................................................................. 51 14.5 SPECIFIC AUT ................................................................................................................................................. 51 14.6 SPECIFIC RADIOGRAPHIC: ........................................................................................................................ 51
15.0 DOCUMENTATION ...................................................................................................................... 52
15.1 GENERAL ......................................................................................................................................................... 52 15.2 INITIAL SUBMISSIONS ............................................................................................................................... 52 15.3 FINAL DOCUMENTATION ........................................................................................................................ 53 15.4 STORAGE BY CONTRACTOR .................................................................................................................... 53 15.5 DELIVERY DOCUMENTATION ................................................................................................................. 53
APPENDIX 1: MECHANICAL TEST REQUIREMENTS PIPE WELDS ................................................. 54
APPENDIX 2: IMPACT TESTING DETAILS ......................................................................................... 56
APPENDIX 3: HARDNESS TESTING DETAILS ................................................................................... 57
APPENDIX 4: RADIOGRAPHIC ACCEPTANCE CRITERIA: ................................................................ 58
APPENDIX 5: MANUAL ULTRASONICS ACCEPTANCE CRITERIA .................................................. 59
APPENDIX 6: Mechanised Pulse Echo + TOFD Acceptance Criteria ............................................. 60
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1.0 INTRODUCTION
1.1 GENERAL
Neptune Energy Netherlands B.V. (NEPTUNE ENERGY) is a company producing hydrocarbons
in the Dutch sector of the North Sea. For this purpose several production and treatment facilities
have been installed along with connecting pipelines.
1.2 SCOPE
1.2.1 The purpose of this document is to define the minimum requirements for the approval of
welding consumables, welding processes, welding operators as well as production welding and
weld inspection of carbon steel pipelines in compliance with and in addition to the requirements
of EN 12732:2013, land pipelines NEN 3650-2:2012, offshore pipelines NEN 3656:2015 and EN
288-9:1999.
1.2.2 A Scope of Work will be issued giving project specific requirements which shall include design
details and 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 12732:2013).
1.3.2 CONTRACTOR’s Quality Manual(s) shall be submitted for review, by NEPTUNE ENERGY, as part
of his bid documents.
1.4 QUALITY PLAN
1.4.1 CONTRACTOR shall submit a Quality Plan, based on his Quality Manual (s), covering all
operations to NEPTUNE ENERGY for approval. CONTRACTOR's subsequent Quality Control of
the work shall strictly adhere to the agreed Quality Plan.
1.4.2 Quality Plan shall show hold, witness, review, monitor and approve points for NEPTUNE ENERGY
and CERTIFYING 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 NEPTUNE ENERGY, 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
quality requirements. Quality records shall be available to NEPTUNE ENERGY for analysis and
review.
1.4.4 All CONTRACTOR inspection systems shall be subject to evaluation and checks by NEPTUNE
ENERGY to ensure that the system is effectively applied and meets the requirements of this
specification.
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1.4.5 CONTRACTOR shall employ experienced and competent supervisors to ensure that both the
standard of workmanship and the quality of materials used comply with the requirements of
this specification.
1.5 INSPECTION NOTICE
1.5.1 CONTRACTOR shall give NEPTUNE ENERGY and CERTIFYING AUTHORITY inspectors at least five
working days notice of the time and location of fabrication, inspection and testing work. All
production shall be subject to inspection by NEPTUNE ENERGY and/or the CERTIFYING
AUTHORITY.
1.5.2 Intermediate inspections and/or examinations carried out or stage approvals given by NEPTUNE
ENERGY or the CERTIFYING AUTHORITY do not absolve the CONTRACTOR from his
responsibility that the material(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:
NEPTUNE ENERGY Neptune Energy Netherlands B.V. or its nominated
representative
CONTRACTOR Engineering and Installation Contractor appointed by
NEPTUNE ENERGY
CERTIFYING AUTHORITY Any authority required by law and/or as nominated by
NEPTUNE ENERGY in accordance with the Contract for which
certificates shall be obtained before the work shall be
accepted by NEPTUNE ENERGY as well as those persons
acting as its representatives.
shall indicates a mandatory requirement.
should indicates a preferred method.
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1.7 ABBREVIATIONS
The following abbreviations have been used and apply in this Specification:
AUT Automatic Ultrasonic Testing
CSWIP Certification Scheme for Welding & Inspection Personnel
CW Centre (line) of Weld
CTOD Crack Tip Opening Displacement
DN Diameter Nominal
DPI Dye Penetrant Inspection
FCAW Fluxed Core Arc Welding
FL Fusion Line
GMAW Gas Metal Arc Welding
GTAW Gas Tungsten Arc Welding
HAZ Heat Affected Zone of Weld
IQI Image Quality Indicators
LR Latest Revision
MAG Metal Active Gas (welding)
MIG Metal Inert Gas (welding)
MMAYS Material’s Maximum Allowable Yield Strength
MMATS Material’s Maximum Allowable Tensile Strength
MPI Magnetic Particle Inspection
MRB Manufacturing Record Book
NDT Non-Destructive Testing
PAM Portable Arc Monitoring
PO Purchase Order
PWT Production Weld Test
SAW Submerged Arc Welding
SMAW Shielded Metal-Arc Welding
SMTS Specified Minimum Tensile Strength
SMYS Specified Minimum Yield Strength
SVGA Super Video Graphics Array
TOFD Time of Flight Diffraction
UT Ultrasonic Testing
WPQ(R) Welding Procedure Qualification (Records)
WPS Welding Procedure Specification
WPT Welding Production Test
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2.0 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, in
accordance with the requirements of the following referenced codes and standards;
NEN 3650-2 2012 Requirements for Steel Pipeline Transportation Systems.
NEN 3653 2009 Methods for the determination of NDE acceptance criteria for defects in
pipeline girth welds.
NEN 3656 2015 Requirements for submarine pipeline systems in steel
EN 12732 Latest
Revision Gas supply systems-Welding Steel pipe work - Functional requirements.
API 1104: 2005
Errata 1
Latest
Revision
Welding of Pipelines and Related Facilities
Alternative Acceptance Standards for Girth Welds
ASME BPV 5
Latest
Revision
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)
BS 7448- 2. Latest
Revision Fracture mechanics toughness tests: CTOD.
EN 10045-1 Latest
Revision Metallic materials – Charpy impact test – Part 1: Test method.
EN 10204 Latest
Revision Metallic Products – Types of inspection documents.
EN 10208-2 Latest
Revision
Steel Pipes for pipelines in combustible fluids – Technical delivery
conditions – Part 2: Pipes of requirement class B.
EN 10246-17
Latest
Revision
Non-destructive testing of steel tubes – Part 17: Ultrasonic testing of
tube ends of seamless and welded steel tubes for the detection of
laminar imperfections.
EN 10246-18
Latest
Revision
Non-destructive testing of steel tubes – Part 18: Magnetic particle
testing of tube ends of seamless and welded steel tubes for the
detection of laminar imperfections.
NEN-EN-ISO 9015 Latest
Revision
Destructive test on weld in metallic materials-Hardness testing-Part 1:
Hardness test on arc welded joints.
EN 12668-2 Latest
Revision
Characterization and verification of ultrasonic examination equipment.
Part 2: Probes .
EN 12668-3 Latest
Revision
Characterization and verification of ultrasonic examination equipment.
Part 3: Combined equipment.
NEN-EN-ISO 17638 Latest
Revision
Non-destructive examination of welds – Magnetic particle examination
of welds.
NEN-EN-ISO 23278 Latest
Revision
Non-destructive examination of welds- Magnetic particle testing –
Acceptance levels.
NEN-EN-ISO 17639 Latest
Revision
Destructive tests on welds in metallic materials – Macroscopic and
microscopic examination of welds.
NEN-EN-ISO 14732
Latest
Revision
Welding personnel. Approval testing of welding operators for fusion
welding and resistance weld setters for fully mechanized and automatic
welding of metallic materials
NEN-EN-ISO 17636 Latest
Revision
Non-destructive examination of welds – Radiographic examination of
welded joints.
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NEN-EN-ISO 15609 Latest
Revision
Specification and qualification of welding procedures for metallic
materials –Welding procedure specification Part 1: Arc welding.
EN 1668 Latest
Revision
Welding consumables – Rods, wires and deposits for tungsten inert gas
welding of non-alloy and fine grain steels – Classification.
ISO 17640 Latest
Revision
Non-destructive examination of welds – Ultrasonic examination of
welded joints.
EN 24063
Latest
Revision
Welding, brazing, soldering and braze welding of metals – Nomenclature
of processes and reference numbers for symbolic representation on
drawings.
EN 25580 Latest
Revision
Specification for minimum requirements for industrial radiographic
illuminators for non-destructive testing
EN 287-1 A2 Latest
Revision Approval testing of welders – Fusion welding – Part 1: Steels.
EN 288-9
Latest
Revision
Specification and approval of welding procedures for metallic materials –
Part 9: Welding procedure test for pipeline welding on land and offshore
site butt welding of transmission pipelines.
EN- ISO 19232-1 Latest
Revision
Non-destructive testing – Image quality of radiographs – Part 1: Image
quality indicators (wire type) – Determination of image quality value
EN- ISO 9712 Latest
Revision Qualification and certification of NDT personnel. General principals.
EN- ISO 2560 Latest
Revision
Welding consumables – Covered electrodes for manual metal arc
welding of non-alloy and fine grain steels – Classification.
EN- ISO 3452-1 Latest
Revision Non-destructive testing-Penetrant testing-Part 1: General principals.
EN- ISO 16810 Latest
Revision
Non-destructive testing-Ultrasonic examination -Part 1: General
principals.
EN- ISO 16828 Latest
Revision TOFD technique as a method for detection and sizing of discontinuities.
EN- ISO 14171
Latest
Revision
Welding consumables. Solid wires, solid wire-flux and tubular cored
electrode-flux combinations for submerged arc welding of non alloy and
fine grain steels. Classification
EN- ISO 18275 Latest
Revision
Welding consumables – Covered electrodes for manual metal arc
welding of high strength steels – Classification.
EN- ISO 14174 Latest
Revision
Welding consumables – Fluxes for submerged arc welding –
Classification.
EN 875 Latest
Revision
Destructive tests on welds in metallic materials-Impact tests-Test
specimen location, notch orientation and examination.
EN- ISO 4136 Latest
Revision Destructive tests on welds in metallic materials – Transverse tensile test.
EN- ISO 5173 Latest
Revision Destructive tests on welds in metallic materials – Bend tests.
EN- ISO 17637 Latest
Revision Non destructive examination of fusion welds – visual examination.
EN-ISO 6892-1 Latest
Revision
Metallic materials. Tensile testing Part 1:. Method of test at room
temperature
EN-ISO 14175 Latest
Revision Welding consumables – Shielding gases for arc welding and cutting.
EN-ISO 14341 Latest
Revision
Welding consumables – Wire electrodes and deposits for gas-shielded
metal arc welding of non-alloy and fine grain steels – Classification.
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EN-ISO 17632
Latest
Revision
Welding consumables – Tubular cored electrodes for gas shielded and
non-gas shielded metal arc welding of non-alloy and fine grain steels –
Classification.
EN-ISO 3834-1
Latest
Revision
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 Latest
Revision
Quality requirements for welding – Fusion welding of metallic materials –
Part 2: Comprehensive quality requirements.
EN-ISO 3834-4 Latest
Revision
Quality requirements for welding – Fusion welding of metallic materials –
Part 4: Elementary quality requirements.
ISO 17025 Latest
Revision
General requirements for the competence of testing and calibration
laboratories.
ISO 3690 Latest
Revision
Welding and allied processes -- Determination of hydrogen content in
ferritic steel arc weld metal
ISO 9001 Latest
Revision Quality Management Systems : Requirements
2.1.2 The edition of each code and standard stated in this section shall apply; together with all
published amendments. Where conflict occurs between the requirements of this Specification
and referenced codes and standards, the most stringent requirements shall apply. Where any
of the documents are revised and the revision affects the scope of supply, CONTRACTOR shall
notify NEPTUNE ENERGY in writing immediately.
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3.0 GENERAL
3.1 SCOPE
3.1.1 All welding shall, be carried out in accordance with the requirements of EN 12732, NEN 3650-
2, NEN 3665 and EN 288-9, augmented with the additional requirements detailed in this
specification.
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
NEPTUNE ENERGY; however in such cases the inspection and testing requirements may be
varied as deemed necessary by NEPTUNE ENERGY and/or CERTIFYING AUTHORITY.
Table 1: Welding Processes and Consumables:
Type of Process Procedure no.
according to:
EN 24063
Consumables shall be in
accordance with:
Shielded Metal Arc Welding 111 EN- ISO 2560 & EN-ISO 18275
Gas Metal Arc Welding 135, 141 EN-ISO 14341 & EN 1668
Flux-Cored Arc Welding 114, 136, 138 EN-ISO 17632
Shielding gases EN-ISO 14175:
Submerged Arc Welding 12 EN-ISO 14171
Fluxes for submerged arc
welding
12 EN-ISO 14174
3.2.2 FCAW process shall be thoroughly controlled at all times by CONTRACTOR to avoid any
excessive scatters 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 the requirements of this specification. The NEPTUNE ENERGY reserves
the right to reject such a process when its reliability is not satisfactory.
3.3 WELDING CONSUMABLES
3.3.1 Welding consumables shall be selected to ensure that they overmatch the maximum
allowable yield and 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 Tensile Strength (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 Mpa
2) 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
analysis similar 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 metal shall not exceed 1%.
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3.3.3 When specified in the Scope of Work the root pas shall be welded with a consumable which
contains less than 0.25% Nickel.
3.3.4 All batch test certificates (according to EN 10204:2004, type 3.1) for welding filler materials
showing all test results, including impact testing, all weld tensile testing and chemical analyses,
shall be provided 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
grams of Weld Metal determined with the method specified by EN-ISO 3690. The electrodes
shall be supplied in vacuum packing. Moreover, they shall be guaranteed against moisture
absorption for 8 hours after pack opening.
3.3.6 Cellulosic coated electrodes may be used provided that special weld procedures preventing
hydrogen induced cracking are established.
3.3.7 Special considerations are to be made when welding steels with a SMYS above 420MPa to
ensure safety against cold cracking in the HAZ and/or weld metal. Attention must also be paid
to the requirements for overmatching yield and tensile strength.
3.3.8 Welding consumables for other processes than manual or mechanised arc welding may require
special consideration with respect to certification, handling and storage (see also 3.4 of this
Specification).
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
(for SAW) shall be those of the relevant consumable manufacturer. CONTRACTOR shall provide
a detailed storage, control and handling procedure to Neptune Energy. Any proposed re-cycling
of flux is subject to Neptune Energy approval.
3.4.2 Different grades and batches shall be individually identified and completely separated from
each other.
3.4.3 Low hydrogen welding consumables shall be supplied in sealed, dirt and moisture-resistant
packages. 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 and
contamination to them and their containers. Consumables in open containers shall be protected
from environmental moisture changes.
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3.5 EQUIPMENT
3.5.1 All welding shall be performed using equipment of a type that has proved to be reliable and
suitable for the work being performed. Equipment used for production welding shall be of the
same specification to that used to qualify the welding procedure. Cable lengths shall also reflect
those used in production.
3.5.2 CONTRACTOR shall ensure and demonstrate that all welding machines are properly earthed to
avoid the occurrence of stray arcing. CONTRACTOR shall provide earth clamps of an approved
design and shall ensure only insulated electrode holders are used.
3.5.3 Current certification/calibration certificates for all testing equipment shall be provided to
NEPTUNE ENERGY for 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
welding parameters including current, voltage, welding speed, thermal input, preheat, interpass
temperature and, for fine wire and gas shielded welding, process-wire feed speed, gas flow rate
and gas composition (especially oxygen level) etc. These parameters shall be measured and
recorded on a sampling basis (to be agreed) during each shift.
3.5.5 Where (semi-) automatic welding systems are utilised the equipment shall be designed to
provide current cut-off linked to wire feed speed in order to minimise the risk of copper
contamination at stop points. This shall be proven during procedure qualification and also on
production welding equipment at 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 no welding shall be allowed to continue once a copper touch has been discovered. Further
actions on this subject shall be agreed by CONTRACTOR and NEPTUNE ENERGY prior to
commencement of production.
3.6 PERSONNEL
3.6.1 CONTRACTOR's welding supervisors shall have full knowledge of all specification requirements
and the applicable standards and codes and shall be qualified according to EN 12732 Section
11.3
3.6.2 Current copies of all pertinent documentation, such as this Specification and approved Welding
Procedure Specifications, shall be in the English language and shall be at the disposal of the
welding crews 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
CSWIP 3.1 Welding Inspector or a NEPTUNE ENERGY approved equivalent and be in possession
of a current eyesight certificate in accordance with EN 970 and EN-ISO 9712.
3.6.5 Non Destructive Examination personnel shall be qualified in accordance with EN- ISO 9712 and
as detailed in the NDT sections of this specification.
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4.0 QUALIFICATION OF WELDING PROCEDURES
4.1 WELDING PROCEDURE SPECIFICATIONS
4.1.1 CONTRACTOR shall propose detailed Welding Procedure Specifications (WPS) for all production
and proposed/anticipated repair welding. Proposed WPSs along with a matrix detailing all
procedures and the amount of tests to be carried out shall be submitted to NEPTUNE ENERGY
and the CERTIFYING AUTHORITY 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
necessary by NEPTUNE ENERGY 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 NEPTUNE
ENERGY and the CERTIFYING 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
with the requirements of EN 288-9 and this specification.
4.1.6 All welding and testing required to qualify a procedure shall be performed in the presence of
NEPTUNE ENERGY, who shall receive ten (10) days minimum advance notice of the date
qualification welding is to start.
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Specification 580 rev. 1 Page 15 of 61
4.1.7 NEPTUNE ENERGY shall witness all non-destructive examinations and destructive testing and
shall review and approve all related results. All mechanical testing shall be carried out by a
certified (see ISO 17025) testing facility subject to prior approval of NEPTUNE ENERGY.
4.1.8 Production welding shall not commence until all Welding Procedure Qualifications (WPQ) have
been accepted/approved by NEPTUNE ENERGY 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 same
technical and quality control of that manufacturer (EN 288-9– 8.2).
Essential variables shall be as defined in EN 288-9 with the addition of those detailed in this
specification. Any changes outside the permissible limits of the essential variables shall
necessitate re-qualification of the welding procedure.
4.2.2 Additional requirements for essential variables:
Filler metal: clause 3.3.3 of this specification replaces clauses 8.4.4 and 8.4.5 of EN 288-9.
Heat input: clause 4.3.5 of this specification replaces clause 8.4.7 of EN 288-9.
Any change in size/diameter of welding consumable: replaces clause 8.5.1 of EN 288-9.
The use of water quenching/cooling (for a rapid reduction of the material temperature for
NDT or any other reason).
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 and 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 test samples shall be hard-stamped with the NEPTUNE ENERGY inspector’s mark prior to
removal from the test pipe. All marking shall be recorded by CONTRACTOR and witnessed by
NEPTUNE ENERGY and the CERTIFYING AUTHORITY.
4.3.3 All pipe for qualification test welds shall be line pipe selected from production pipe
manufactured for this project and from each steel manufacturer or source of supply. Contractor
shall check this pipe for identification and conformity to the line pipe specifications and relevant
certificates (EN 10208-2 and EN 10204). The pipe selected for procedure welding should be
supplied from the heat or lot exhibiting one of the highest carbon equivalents as proven by the
product analysis during line pipe production.
4.3.4 At least one complete weld shall be made and tested to qualify each pipe to pipe welding
procedure and one weld for pipe to fitting welding procedure. For small diameter pipe,
additional welds shall be made 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-automatic or automatic welding equipment, a minimum of three
consecutive complete test joints shall to be made (all of which must be acceptable for NDT).
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Specification 580 rev. 1 Page 16 of 61
4.3.5 Procedure qualification test welds, and all repair test welds, shall be carried out between two
pieces of pipe (each with a minimum length of 500mm), which shall be restrained. Weld
Procedure Qualifications shall be completely monitored and recorded by CONTRACTOR’s QC
department using calibrated Portable Arc Monitoring (PAMs or ALX unit) equipment. All “as-
runs” recording, for example, 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 the documentation package submitted along with the NDT and
Mechanical Test Results, prior to approval 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 material
temperature to allow Automated Ultrasonic Testing), this shall be qualified during procedure
qualifications and noted on the ultimate WPS.
4.3.8 The test welds shall be non-destructively inspected in accordance with the relevant NDT
sections of this Specification. Should the test weld not meet the stated acceptance criteria it
shall not be submitted 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
and this 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 the
inspection and testing requirements that are in compliance with or in addition to EN 288-9.
Consideration should be taken with EN 288-9 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 Note
Butt-weld
At least 1 complete
weld per process
(see 4.3.4)
Note: For Double
sided SAW side
bends may be used
to replace root and
face bends.
Visual examination 100% Section 8
Radiographic examination 100% Section 9
Ultrasonic examination 100% Section 10/11
MPI examination 100% Section 12
Type of test Extent of testing Note
Transverse tensile test 2 specimens See 4.4.1
All weld tensile test 4 specimens See 4.4.2
Impact test 4 sets cap &
4sets root (>20mm)
See 4.4.3
Macro examination 2 test specimens See 4.4.4
Hardness test 2 test specimens See 4.4.5
Bend test 2 root & 2 face See 4.4.6
CTOD (if required in the
Scope of Work)
9 (3x CW + 6x FL) See 4.4.7
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Specification 580 rev. 1 Page 17 of 61
Typical examples of mainline and double joint welds are shown here.
Table 3: Extent of testing for full penetration repair:
Test Piece Type of inspection Extent of inspection Note
Full Penetration
Repair weld
1 off
Visual examination 100% Section 8
Radiographic examination 100% Section 9
Ultrasonic examination 100% Section 10/11
MPI examination 100% Section 12
Type of test Extent of testing Note
Transverse tensile test 1 specimens See 4.4.1
Impact test 4 sets cap &
4 sets root(>20mm)
See 4.4.3
Macro examination 1 test specimens See 4.4.4
Hardness test 1 test specimens See 4.4.5
Bend test 2 root & 2 face See 4.4.6
CW
Th
CWRoot Pass
Fill(s)
Cap
Hot Pass
Th
External Cap
Internal Cap
Root Area
CW
Th
CW
Root Pass
Fill(s)
Cap
Hot Pass
Original Weld HAZ
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Specification 580 rev. 1 Page 18 of 61
Table 4: Extent of testing for partial penetration repair:
Test Piece Type of inspection Extent of inspection Note
Partial
Penetration
Repair to leave a
minimum of
3mm parent
metal.
1 off
Visual examination 100% Section 8
Radiographic examination 100% Section 9
Ultrasonic examination 100% Section 10/11
MPI examination 100% Section 12
Type of test Extent of testing Note
Transverse tensile test 1 specimens See 4.4.1
Impact test 4 sets cap See 4.4.3
Macro examination 1 test specimens See 4.4.4
Hardness test 1 test specimens See 4.4.5
Bend test 2 face See 4.4.6
Table 5: Extent of testing for single pass cap repair
Test Piece Type of inspection Extent of inspection Note
Single Pass Cap
Repair
1 off
Visual examination 100% Section 8
Radiographic examination 100% Section 9
MPI examination 100% Section 12
Type of test Extent of testing Note
Macro examination 1 test specimens See 4.4.4
Hardness test 1 test specimens See 4.4.5
Bend test 1 face See 4.4.6
CW
CW
To Be Qualified =3 mm
30º ± 10º
To Be Qualified
Original Weld Metal
Original Weld HAZExcavation Boundary
CW
Th
CW
Single Pass Cap Repair
Original Weld Metal
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Specification 580 rev. 1 Page 19 of 61
4.3.12 Repairs shall be carried out centred at the 6 o’clock position. All stages of the repair welding
qualification (including gouging {note-gouging pre-heat to be qualified} and grinding of repair
excavation – 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
with EN 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 the requirements stated in Table 9.
4.4 MECHANICAL TESTING OF WELDING PROCEDURE QUALIFICATION TEST WELDS
4.4.1 Transverse Tensile Testing
Two 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 be proven that the achieved values for Yield Strength and Ultimate Tensile strength are in
excess of those required for All Weld Tensile Tests as specified in 4.4.2.
4.4.2 All Weld Tensile Testing
Actual 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 the
diameter/wall thickness of the involved line pipe and the applied type/number of consumables
in the involved weld.
From each procedure 4 round bar test specimens, of the largest possible size, will be tested.
Two specimens shall be taken as close as possible to the weld root area and two specimens as
close as possible to the weld cap area.
After testing, a macro shall be prepared from the broken test specimen. If the sample
demonstrates that the test included any FL/HAZ or pipe material then the test will be considered
invalid and shall be re-done.
The resulting Yield Strength shall be greater than the highest recorded yield strength of the
base material (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
base material (see Section 3.3) and as a minimum this shall exceed the SMTS by at least 80Mpa.
With NEPTUNE ENERGY approval, these tests may be substituted with cross weld tensile tests
with full stress/strain curves.
4.4.3 Charpy V-Notch impact testing
Test specimens shall be taken and prepared in accordance with EN-10045-1 in such a way that
the axis of the notch is perpendicular to the pipe surface. Test specimens and testing for impact
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Specification 580 rev. 1 Page 20 of 61
test shall be in accordance with this specification for position and temperature of testing and
with EN 875 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 cut through the pipe thickness) in the following locations, (see Appendix 2A):
a) weld centre line
b) weld fusion line
c) weld fusion line + 2mm
d) weld fusion line + 5mm
For partial penetration repairs the following samples shall be taken, (see Appendix 2B):
a) weld fusion line to existing weld
b) weld centre line
c) weld fusion line
d) weld fusion line + 2mm
Test specimens with Charpy V-notch shall be used and sampled from 2 mm below the outer
surface of the pipe and transverse to the weld. When the pipe wall thickness exceeds 20 mm,
four more sets are required, in the same circumferential locations, but taken within 2 mm of the
inside surface of the pipe. The minimum absorbed energy values shall be as stated in Table 6:
Table 6: Charpy requirements weld testing:
Specified minimum yield
strength of steel:
Average of
3 specimens
Single Specimen* Test
Temperature
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 Macrography
Two macro sections of the welds shall be prepared and examined in accordance with NEN-EN-
ISO 17639. The test pieces shall be polished and etched for macrographic examination of the
weld. The weld cross-section shall be examined for good weld profile and sufficient penetration
free of significant inclusions or other defects. It shall also serve to confirm the amount of weld
passes that have been deposited and their compliance with the pWPS.
4.4.5 Hardness Testing
Hardness surveys shall be carried out on both macro sections, in accordance with NEN-EN-ISO
9015. The Vickers method HV10 shall be used, as detailed in Appendix 3. Results of hardness
tests shall be below the maximum values specified in Table 7. Permanent records of macro
sections shall be kept by means of photo-macrographs showing all hardness indentations.
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Specification 580 rev. 1 Page 21 of 61
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 NEN-EN-ISO 5173.
The diameter of the former or inner roller shall be 4t and the bending angle shall be 180° for
parent metal with elongation A ≥ 20%. For parent metal with elongation < 20% the following
formula shall be applied:
d = (100 x ts )
- ts A
where
d is the diameter of the former or the inner roller
ts is the thickness of the bend test specimen
A 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.
Flaws appearing at the corners of a test specimen shall be ignored in the evaluation.
4.4.7 Chemical Analysis
Quantitative chemical analyse of the weld cross-section shall be made in the root zone and filler
passes to verify the chemical elements as per the chemistry requirement of the applicable
consumable specification.
4.4.8 CTOD Testing
If required in the Scope of Work, CTOD testing shall be carried out according to BS 7448:part 2.
3 (three) Centre of Weld samples shall be taken and 6 (six) Fusion Line samples (of which 3 may
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 NEPTUNE
ENERGY.
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.
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Specification 580 rev. 1 Page 22 of 61
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. All three re-test specimens shall meet the requirements of 4.4.3 and the mean value of all
six tests shall 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 test shall 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/or
mechanical tests or permitted re-tests, it shall be regarded as not complying with the
requirements of this specification. The cause of failure shall be established, rectified and the
WPS revised as appropriate, 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 be
submitted to NEPTUNE ENERGY prior to use and be in conformance with the manufacturer’s
recommendations.
4.7.2 The procedure shall be qualified (in accordance with EN 12732 Annex H) by making three
consecutive test joints in the presence of NEPTUNE ENERGY on materials to be used in
production and representing 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 of the 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
tests should 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 braze
should not be more than 1mm below the pipe surface. Intergranular copper penetration of
the pipe material shall not exceed 0.5mm beyond the fusion line when a micro-section is
examined at a magnification not exceeding x50.
b) Hardness survey: Each section shall be tested using a 10kg load. A transverse should be made
across the weld zone as shown below and should consist of at least 6 impressions; two in the
heat affected zone each side of the weld/braze and one in the parent metal each side of the
weld/braze. The hardness value shall not exceed 325HV 10. See the figure 1:
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Specification 580 rev. 1 Page 23 of 61
Figure 1: Requirements for hardness traverse and impressions
for brazing and aluminothermic welding.
4.8 WELD PROCEDURE QUALIFICATION RECORD(S)
The Weld Procedure Qualification Record(s) shall contain the following documentation and be
precluded with a check list sheet (see example below) showing the contents of each package:
Table 8: Checklist WPQ Records
WPQ: 010-013
168.3mm x 18.3mm (L450QO PSL2) Pipe to Pipe
Designation: Mainline Welding
WPQ □
(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 NEPTUNE ENERGY,
CONTRACTOR and the CERTIFYING AUTHORITY.
Note: Hardness impressions 2, 3, 4 and 5 should be entirely within the
heat-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
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Specification 580 rev. 1 Page 24 of 61
5.0 QUALIFICATION OF WELDERS
5.1 GENERAL
5.1.1 The use of pre-qualified welders is not allowed. Each welder or welding machine operator shall
be qualified in accordance with EN 287-1 or NEN-EN-ISO 14732 and this specification prior to
the start of production welding by making a test weld using the qualified welding procedure.
This will comprise of a minimum of one half-circumference weld for welder qualifications and
for repair 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 test
welds shall be performed with the pipe in the same position as will be found in production
welding. Each welding machine operator (for submerged arc welding) shall produce one
complete weld.
5.1.2 CONTRACTOR shall ensure that only qualified welders and welding operators are employed
during construction, 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 NEPTUNE ENERGY. The welder
or welding operator may carry out a retest (new test joints of the same type as the rejected
one), provided the cause of failure is determined and not attributed to inadequate training. If
the retest meets the specification requirements, the test will be considered satisfactory. Any
welder failing a qualification test shall not be permitted further testing without prior NEPTUNE
ENERGY approval and without a period of appropriate training.
5.2 WELDER CERTIFICATE
5.2.1 CONTRACTOR shall operate a scheme for welder qualification certification certificates and
welder identification, which shall be provided to NEPTUNE ENERGY for approval prior to the
qualification programme commencing.
5.2.2 The pipeline welder certificate shall be similar to that proposed in EN 287-1. The certificate shall
clearly indicate the standard to which the welders’ certification has been performed, i.e. This
Specification/EN12732/EN 287-1.
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Specification 580 rev. 1 Page 25 of 61
5.2.3 The duration of validity for the certificate is 6 months. NDT records shall be maintained for the
purpose 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 or
CONTRACTOR (at the production location) during execution of the work
5.2.5 The original certificates shall be signed by NEPTUNE ENERGY.
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 NEPTUNE ENERGY reserves the right to require the re-qualification of welders or welding
machine operators if repair rates are encountered in production welding by any one or more
operators, which in NEPTUNE ENERGY'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
by NEPTUNE ENERGY, which should pass the tests for electrical continuity and mechanical
strength described in Section 4.5. A list shall be produced identifying all “qualified” pin brazers
and this shall be approved by NEPTUNE ENERGY and displayed at the work location.
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Specification 580 rev. 1 Page 26 of 61
5.5 WELDER QUALIFICATION: WELD INSPECTION AND TESTING
Each test weld shall undergo visual inspection, non-destructive testing, and destructive testing
in accordance 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 Note
Butt Weld or
Half Butt Weld
Visual examination 100% Section 8
Radiographic examination* 100% Section 9
MPI examination 100% Section 12
Type of test Extent of testing Note
Macro examination 1 test specimen See 4.4.4
Bend test 2 root & 2 face See 4.4.6
Test Piece Type of inspection Extent of inspection Note
Full and Partial
Penetration
Repair
Visual examination 100% Section 8
Radiographic examination 100% Section 9
MPI examination 100% Section 12
Type of test Extent of testing Note
Macro examination 1 test specimen See 4.4.4
Bend test 2 root & 2 face (FP)
2 face (PP)
See 4.4.6
Test Piece Type of inspection Extent of inspection Note
Cap Repair Visual examination 100% Section 8
Radiographic examination 100% Section 9
MPI examination 100% Section 12
Type of test Extent of testing Note
Macro examination 1 test specimen See 4.4.4
Bend test 2 face See 4.4.6
Test Piece Type of inspection Extent of inspection Note
Weldolet
Visual examination 100% Section 8
MPI examination 100% Section 12
Type of test Extent of testing Note
Macro examination 4 test specimen See 4.4.4
*Note: For Automatic Processes (MAG/MIG) when the wall thickness exceeds
8mm Ultrasonic Examination shall be carried out in accordance with
Section 10 or 11 (in accordance with EN 12732).
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Specification 580 rev. 1 Page 27 of 61
6.0 PRODUCTION WELDING
6.1 GENERAL
6.1.1 Production welding shall not commence until the qualified welding procedures, qualified
welders and qualified inspection personnel lists have been reviewed and approved by NEPTUNE
ENERGY.
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
be cause 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 NEPTUNE ENERGY with the end preparation as specified in the line
pipe’s material specification. Should CONTRACTOR elect to use a different bevel approval shall
be obtained from NEPTUNE ENERGY, 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
accordance with EN 12732 Annex C shall be provided by CONTRACTOR for NEPTUNE ENERGY's
review. All changes of 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
NEPTUNE ENERGY in writing and then cut back until the laminated section is removed, and re-
bevelled. After re-bevelling the pipe end shall be wet magnetic particle inspected and
ultrasonically inspected over a distance of 100 mm from the bevel, in accordance with EN
10246-18 and EN 10246-17, to ensure that no further laminations are present. Any linear
indication greater than 10 mm in any direction shall be cause for rejection.
6.2.5 Field bevels shall be made by machine tool (automatic or hand controlled). Thermal cutting is
not acceptable. The bevel ends shall be smooth and uniform and dimensions shall be in
accordance with the qualified welding procedure specification.
6.2.6 Burrs, small score marks, indentations or other small defects within the joint preparation shall,
at the discretion of NEPTUNE ENERGY be ground out, otherwise the joint shall be re-prepared.
Any damage to line pipe by field welding machines shall be reported to NEPTUNE ENERGY prior
to repair in accordance with the line 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 a bright finish prior to lining up the pipe.
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Specification 580 rev. 1 Page 28 of 61
6.3 ALIGNMENT
6.3.1 Internal line-up clamps shall be used when possible and shall not be removed until 100% of the
root run and hot pass are completed. When external line-up clamps are used the equipment
shall be subject to review by NEPTUNE ENERGY prior to welding.
6.3.2 For the welding of fittings and flanges the line-up procedure shall be provided for NEPTUNE
ENERGY review.
6.3.3 Welding shall be continuous as far as possible and no joint shall be accepted when subjected
to interruptions 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 to check final fit-up.
6.3.5 The alignment of abutting pipe ends shall be such as to minimise the internal offset between
surfaces. Any offset greater than 1.5 mm, provided it is carried by dimensional variations within
the specified permitted tolerances (see Table 10), shall be equally distributed around the
circumference of the pipe or fittings.
Table 10: Permitted misalignment of surfaces (EN 12732 Table G1)
Wall Thickness (T) Permissible
external misalignment
Permissible
internal misalignment
T ≤ 10 mm 0.3 x T 1 mm on entire
circumference
10mm < T ≤ 25.4 mm 20% of T or 3 mm whichever
is less
10% 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. When a pipe with a longitudinal weld is used, the seams on adjacent pipes shall be spaced
a minimum of 30° 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
or minimum 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
do not permit satisfactory workmanship or adequate inspections.
6.4.2 Shelters/tents shall be provided/used giving adequate protection, from wind, rain, draft and
cold, to the area of welding.
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Specification 580 rev. 1 Page 29 of 61
6.5 TACK WELDS
6.5.1 The works shall be set-up, properly spaced and supported and tack welded in accordance with
the welding 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
feather edge 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,
especially on 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
out to 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 within permitted 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 tools
before 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
°C except 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 the qualified pipe to pipe W.P.Q.
6.8.4 The interpass temperature shall never exceed the maximum temperature specified in the
qualified welding procedure, and at no time shall the temperature become high enough to
damage the pipe's protective coating. The interpass temperature measured immediately before
the start of the subsequent weld run shall not be less than the minimum preheat temperature.
In principal, and dependant on material selection, the maximum allowable interpass
temperature is 250°C.
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Specification 580 rev. 1 Page 30 of 61
6.8.5 Preheat shall be applied using electrical or gas methods such that the required temperature is
evenly distributed around the entire circumference of the joint and extending at least 75 mm
on either side of 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
the project specific approved WPS. If interpass temperature is seen to be exceeded the
regularity of monitoring shall be increased so as to satisfy NEPTUNE ENERGY 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 be
completed in one cycle.
6.9.2 When production conditions are such that pipe to pipe joints have to be left partially completed
the following 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 that used 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 resistant
material 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 specified
preheat/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.
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Specification 580 rev. 1 Page 31 of 61
6.11 MATERIAL TRACEABILITY AND WELD IDENTIFICATION
6.11.1 CONTRACTOR shall employ a procedure for material traceability and weld identification (See
also the requirements of section 10.3). Welder’s foreman shall track welders’ performance and
identify problems regarding individual welders. NEPTUNE ENERGY shall be advised of specific
problems.
6.11.2 Identification marks adjacent to welds shall be by crayon, weather proof chalk or by some other
appropriate means. The use of hard stamps is not permitted. Identification marks shall not be
removed 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
NEPTUNE ENERGY 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
Weld Tests (PWT) as detailed in EN 12732, NEPTUNE ENERGY may request, at any time, a weld
to be removed by cutting the pipeline, leaving sufficient material on both sides of the weld to
accommodate the required 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
production welds produced before the date of testing shall be regarded as not meeting
specification requirements and are subsequently rejected until CONTRACTOR can demonstrate,
to the satisfaction of NEPTUNE ENERGY and the CERTIFYING AUTHORITY, that all production
welds do have the minimum required mechanical properties.
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Specification 580 rev. 1 Page 32 of 61
7.0 REPAIR WELDING
7.1 GENERAL
7.1.1 CONTRACTOR shall notify NEPTUNE ENERGY of CONTRACTOR's intention to repair a weld
before commencing the repair. Weld repairs are permitted for defects located in the filling and
cover passes (i.e. partial penetration repairs) and shall be at least 50 mm long. Repairs at root
or including the root shall be minimized and such repairs shall be subject to special approval of
NEPTUNE ENERGY 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
weld must be replaced. Should the weld be removed (cut-out) the re-bevelling, by machining,
shall be such that 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
NEPTUNE ENERGY approved procedures.
7.1.4 Only one attempt at any repair in the weld body shall be allowed unless express NEPTUNE
ENERGY and CERTIFYING AUTHORITY approval is given to attempt a second repair. Should this
second repair also be un-acceptable according to the Acceptance Criteria agreed for the project,
the complete weld shall be removed.
7.1.5 Repairs shall be limited to a maximum of 20% of the weld circumference (EN 12732 Section 6.7).
If more than 20% of the weld exhibits defects requiring repair, or if several defective weld
sections amount to this length overall, the weld joint in question shall be cut out and re-welded
unless otherwise agreed by NEPTUNE ENERGY.
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
wire brushing to a bright metal finish to remove all contaminated material. The cut-out portion
shall be sufficiently deep and long to remove the defect. At the ends and side of the cut there
shall be a gradual taper from the base of the cut to the surface of the weld metal. The width
and profile of the cut shall be such that adequate access for re-welding is provided. The
excavation shall be cleared by magnetic 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 to be removed, the new gap opening at the weld root shall remain within the qualified root
gap tolerances defined in the WPS. Gouging is only allowed up to 3mm from the internal surface
of the pipe 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 a
section 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 a
minimum distance of 38 mm past both ends of the defect. This distance shall be measured
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Specification 580 rev. 1 Page 33 of 61
parallel to the length of the weld. The re-capped area shall be dressed to a smooth profile. Re-
capping shall only be permitted if the maximum hardness has been shown to be within the
acceptance limits of this Specification by previous qualification or in-situ portable hardness
testing. The in-situ testing procedure and equipment shall be subject to NEPTUNE ENERGY's
review and shall be calibrated and certified.
7.3 INSPECTION OF WELD REPAIRS
Each repair weld shall be subjected, as a minimum, to the same inspection and documentation
requirements 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 the
following:
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 NEPTUNE
ENERGY (above 5% of weld numbers but taking into consideration initial welding during start-
up) and there appears to be a consistent re-occurrence of a specific defect, CONTRACTOR
should halt production and carry out an investigation into the cause. CONTRACTOR shall inform
NEPTUNE ENERGY of any reasons for high repair rates and issue his proposals to alleviate such
problems. Any such proposed changes must be within the essential variable range already
qualified. If this is not the case a re-assessment shall be made relating to the suitability and
continued acceptability of the qualified welding procedure(s).
If the cause of repairs is traced to lack of good workmanship, NEPTUNE ENERGY may request
the removal of the responsible welder(s) from the production line.
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Specification 580 rev. 1 Page 34 of 61
8.0 INSPECTION AND TESTING OF PRODUCTION WELDS
8.1 VISUAL INSPECTION
8.1.1 CONTRACTOR shall visually inspect every weld to a NEPTUNE ENERGY approved procedure and
for compliance 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,NEN 3656, EN 12732 and EN 288-9 and as required by this specification. NDT shall be
carried out according to written procedures, which shall be submitted to NEPTUNE ENERGY for
approval prior to 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 NEPTUNE
ENERGY approval.
8.2.4 In specific cases NEPTUNE ENERGY may agree to the application of (X-) radiography (see
Section 9) to mainline 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 dry method 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.
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Specification 580 rev. 1 Page 35 of 61
9.0 RADIOGRAPHY
9.1 RADIOGRAPHIC PROCEDURES
9.1.1 Prior to the start of production radiography CONTRACTOR shall provide to the NEPTUNE
ENERGY a detailed Radiographic 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 number
b) Procedure number and revision
c) Technique
d) type of equipment and kilo Volt (kV) rating
e) type of film
f) intensifying screens
g) shielding
h) source size
i) geometric relationship defined by sketch
j) limit of film coverage
k) tube voltage or source strength and exposure time
l) material thickness range
m) type of image quality indicator
n) processing
9.1.2 The radiation source shall be x-ray unless otherwise agreed by NEPTUNE ENERGY. The single
wall, single image technique shall always be used, unless otherwise agreed with NEPTUNE
ENERGY.
9.1.3 Wire type image quality indicators, in accordance with EN- ISO 19232-1shall be used.
9.1.4 Film type and screens shall comply with the requirements of NEN- EN-ISO 17636-1-2. For Weld
Procedure Qualification 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
to use on production or qualification welds. These radiographs shall establish the minimum
radiographic quality level for all production radiography. Subject to NEPTUNE ENERGY
agreement, the adequate 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 the film side of the weld. Minimum IQI sensitivity shall be as stated in NEN- EN-ISO 17636-
1-2
9.2.3 A Radiographic Qualification Technique Sheet shall be produced showing all required and
achieved values. This must be approved by NEPTUNE ENERGY prior to commencement of any
production activities. This may be qualified on WPQ material but nipples must not be sent for
mechanical testing prior to approval of the technique(s).
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Specification 580 rev. 1 Page 36 of 61
9.2.4 One of the radiographic procedure qualification films shall be available in the production line
darkroom along with the approved technique sheet, for reference purposes, to prove that
production radiographs 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
accordance with the qualified radiographic procedure.
9.3.2 Facilities and viewing conditions shall be in accordance with ISO 25580. Radiographs shall be
viewed dry.
9.3.3 Where possible, the IQI shall be placed on the source side of the weld being examined. Where
this is not 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
made in the area of the weld image. A minimum of 5cm overlap shall be required to prove
coverage of the diagnostic film length. CONTRACTOR shall have a calibrated densitometer
available for NEPTUNE ENERGY use 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
weld being Radiographed. The images of these letters shall appear on the Radiograph to ensure
unequivocal 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
system has been applied shall be defined alongside the weld using weather proof paint, chalk,
crayon or felt pen. The zero data and numbering direction for both Double Joint and Firing Line
welds shall be in the same direction.
9.3.7 To determine the absence of backscatter a letter "B" shall be affixed to the unexposed side of
the film.
9.3.8 Films of weld repairs shall be marked with the original number with the suffix R. The complete
circumference of the weld shall be examined.
9.4 RADIATION PROTECTION
CONTRACTOR shall be responsible for the protection and monitoring of Radiographic
personnel and shall ensure that all work is performed in accordance with the relevant Health
and Safety Regulations and in accordance with the Contract for the safety of all personnel.
CONTRACTOR shall be responsible for notification of the use of Radiography as required by
Statutory Regulations. Breaches of Radiographic safety shall not be permitted and may result in
removal of the offending party(ies) from the work-site, at NEPTUNE ENERGY'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
requirements of EN-ISO 9712 and shall have at least 2 years proven experience in pipeline
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Specification 580 rev. 1 Page 37 of 61
welding film interpretation and be specifically trained to identify indications of copper
contamination in welds made by automatic systems, where these are utilised.
9.5.2 Radiographic examination shall be performed by personnel qualified as a minimum to Level 2
according to EN-ISO 9712.
9.5.3 NEPTUNE ENERGY’s Representative retains the right to reject any NDT personnel who, in his
opinion, do not conform and/or perform to the required standards.
9.6 FILM IDENTIFICATION
As a minimum, the identification on the film shall include:
NEPTUNE ENERGY-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
without deterioration. CONTRACTOR shall submit a procedure for ensuring processing
chemicals have been removed to NEPTUNE ENERGY 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 be
detrimental to the emulsion.
9.8.2 When requested by NEPTUNE ENERGY, CONTRACTOR shall develop a sample of unexposed
film, which shall have 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
section 15.3. CONTRACTOR shall store all radiographs for a period of 7 years in a controlled
environment. On request of NEPTUNE ENERGY, CONTRACTOR shall make Radiographs/films
available, together with viewing facilities, for re-checking.
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10.0 MANUAL ULTRASONIC TESTING
10.1 The Manual Ultrasonic Testing procedure shall be in accordance with NEN 3665, NEN 3650-2
and EN 12732 (EN-ISO 16810 and ISO 17640). CONTRACTOR shall submit detailed procedure
and technique sheets for ultrasonic testing to NEPTUNE ENERGY for approval prior to the start
of production.
10.2 NEPTUNE ENERGY shall be invited to witness all technique qualifications, which result in the
production of the relevant technique sheets. Should any of the variables of the technique(s)
change, following approval, the ultrasonic procedure shall be re-qualified.
10.3 Manual Ultrasonic Testing shall be carried out by personnel qualified as a minimum to Level 2
according to EN-ISO 9712.
10.4 Manual Ultrasonic Testing may only be used in lieu of radiographic examination with prior,
written approval of NEPTUNE ENERGY.
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11.0 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 NEPTUNE ENERGY. Proven
historical data showing the validity of the AUT system shall be submitted to NEPTUNE ENERGY
for approval.
11.1.2 When an automatic ultrasonic system is deemed acceptable to NEPTUNE ENERGY, the operator
responsible for the final interpretation and sentencing of the welds shall, besides being in
possession of an EN-ISO 9712 level 2 Ultrasonic qualification and further independent or
NEPTUNE ENERGY qualification(s) in AUT/TOFD, prove to NEPTUNE ENERGY that he has
sufficient knowledge and experience of Lay barge interpretation and welding technology in
order to be able to identify weld defects inherent to the welding system(s) being used.
11.1.3 As long as the Good Workmanship Acceptance Criteria described in this specification is used
there is no requirement for the NDT contractor to carry out a qualification test using blind tests
to prove the conventional pulse-echo/ through transmission technique system and the time of
flight diffraction technique.
11.2 AUT SYSTEM
11.2.1 Time of flight diffraction shall be included to improve interpretation of ultrasonic pulse-echo
responses and accurate sizing in through-thickness dimension. In principal all sizing will be
executed by means of pulse-echo technique.
11.2.2 A mechanised manipulator shall rotate the ultrasonic transducer-array, including the time of
flight unit, around the girth weld while signals are processed, recorded and available for
immediate interpretation in one single rotation.
11.2.3 The NDT contractor shall design an ultrasonic inspection system specific to the typical weld
configuration and material acoustics used for the project. CONTRACTOR will deliver relevant
data of typical weld bevel preparation, dimensions and actual (test) material. In case phased
array equipment is used along with a combination of various pipe manufacturers/suppliers, a
special calibration 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 macros
produced during weld procedure qualification).
b) Each inspection zone shall represent, by gate setting a proportional weld volume, a fusion line
and at least a 2 mm heat affected zone.
c) Detection of weld defects according to the requirements of EN 12732 and NEN 3650-2, NEN
3656 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.
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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
conversion disturbances by (weld cap, pipe surface or weld root) geometry reflectors
b) depending on weld geometry (focussed) probes of various angles shall be necessary
c) through-thickness discrimination between zones shall be between 6 dB and 12 dB
d) Transit distance measurements in the root zone shall visualise the root pattern.
e) Probe data sheets shall be made available to NEPTUNE ENERGY.
11.2.6 Time of flight diffraction (longitudinal scan with respect to the weld centre line), in accordance
with EN-ISO 16810 shall be implemented to improve:
a) detection of volumetric defects
b) discrimination of weld defects and weld geometry
c) accurate sizing of weld defects in through-thickness direction
d) detection of unfavourably oriented defects for impulse-echo techniques
e) 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 pulse
repetition frequency per probe.
11.2.9 The mechanised manipulation system shall be designed and interfaced with the
NEPTUNE ENERGY specified requirement 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
pipe segment 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
is used for the inspection, a special calibration block shall be manufactured using material from
each pipe supplier.
11.3.3 A calibration scan shall always be carried out after a rejected weld. The print out of the
calibration runs shall become part of the repair record.
11.3.4 The calibration block shall contain reference reflectors (see table 11 for tolerances) simulating
weld defects 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 direction
b) Check measuring point density and weld volume coverage using 2mm through-thickness
drilled holes located at the weld centre line.
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Specification 580 rev. 1 Page 41 of 61
Table 11: Tolerances of reflectors:
Tolerance of machined reflectors
Hole diameters ± 0,1 mm
FBH ± 0,25 mm
All pertinent angles ± 1º
Notch depth ± 0,1 mm
Notch length ± 0,5 mm
Central position of all reference reflectors per weld zone ± 0,1 mm
NEPTUNE ENERGY shall have the opportunity to witness the dimensional control checks of the
calibration blocks.
11.3.5 The frequency of calibration shall be agreed between CONTRACTOR and NEPTUNE ENERGY,
however, should CONTRACTOR establish, during calibration, that the equipment has a
sensitivity of less than the agreed 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 weld
b) When differences of material acoustics might occur
c) If calibration results amplitudes vary more than ± 2dB from 80% FSH
d) Wall thickness change.
e) After equipment breakdown.
f) If the gate settings need to be adjusted by more than 1mm.
g) If required by NEPTUNE ENERGY
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
and registered and set for the project (EN-ISO 16810).
Settings are only allowed to be changed after NEPTUNE ENERGY approval.
11.4.2 The ability of the system to produce diffraction signals shall be proved by means of machined
notches (see table 12 for tolerances of notch sizes) positioned through the weld centre line
(internal and external surface) with a length of 10 mm, a depth of 2,5 mm and a width of 0,5
mm. Additional a notch with a depth of 1.0mm shall be machined in order to prove the systems
capability to detect 1.5 mm embedded defects in the root or cap zone.
Table 12: Tolerances of notches:
Tolerance of machined notches
Notch depth ± 0,1 mm
Notch length ± 0,5 mm
Notch width ± 0,1 mm
Note: The top angle shall be a maximum of 60º.
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Specification 580 rev. 1 Page 42 of 61
11.4.3 A calibration check is required on actual data (material acoustics, distance between transducers
and wall thickness) via calculated difference of time of flight between creeping wave and
longitudinal back 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 project
b) project and job number
c) procedure number and revision number
d) specific to pulse echo:
i. equipment: mechanized scanner, transducers, monitor/display, multi channel ultrasonic
processor
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 settings
iv. 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"), weld
and scan identification, scan velocity, coupling, process checks (coupling, probe
positioning, surface conditions, registration, hard copy)
vi. recalibration
vii. sizing technique and anticipated accuracy
viii. monitor display setting.
ix. the calculations made regarding the interaction rules.
e) specific to TOFD
i. 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 ratio
verses acceptable scan velocity), amount of A-scans per mm, calibration check by
calculation
iv. interpretation guide
f) acceptance criteria (may be a separate procedure), as per Section 13
g) couplant used
h) surface temperature limits
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Specification 580 rev. 1 Page 43 of 61
11.6 INSPECTION
11.6.1 Pulse echo and TOFD shall be combined to form part of the inspection and shall be executed
in one single rotation around the pipe.
11.6.2 The mechanised manipulator and recording system shall be capable of locating weld defects
within an 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
including characterizing, 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%
FSH of 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 NEPTUNE ENERGY approved acceptance criteria.
11.7.4 The length of a weld defect shall be determined by the point at which the reflected pulse
amplitude amounts 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 flaws
from geometry.
11.8 TIME OF FLIGHT DIFFRACTION
11.8.1 Before commencing weld inspection, TOFD shall be calibrated on the stamped calibration block
and actual pipe.
11.8.2 TOFD shall be used as additional interpretation to pulse–echo responses and/or accurate
through thickness sizing (≤ 2.5 mm) shall be conducted by straightening and/or linearizing.
11.9 REPEAT INSPECTION
11.9.1 NEPTUNE ENERGY reserves the right to have any inspection repeated or confirmed, possibly by
radiographic examination of the ultrasonically inspected areas.
11.9.2 If any doubt is raised as to the calibration/accuracy and/or integrity of the system, NEPTUNE
ENERGY reserves the right to require CONTRACTOR to prove the system. If the performance is
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Specification 580 rev. 1 Page 44 of 61
found to be incorrect, the NDT contractor will be required to repeat the inspection of welds
examined since the last 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,
slag etc. 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. In case phased array is used, the calibration block temperature shall be within 5ºC of the
surface under examination.
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 assure
separate 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 be determined 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 NEPTUNE ENERGY request, (re)calibration certificates shall be made available.
11.12.4 Each separate channel shall provide:
a) The amplitude and the transit distance information
b) An adjustable gate setting (start, length)
c) The gain adjustment
d) The FSH threshold setting and recording (5% - 100%)
e) A signal delay to provide coherent presentation
f) A recording output per gate:
exceeded pre-set threshold amplitude, and analogue amplitude presentation, and transit
distance presentation.
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Specification 580 rev. 1 Page 45 of 61
11.13 ULTRASONIC EQUIPMENT – TOFD
The ultrasonic instrument shall meet the requirements of EN-ISO 16828 for automated TOFD
inspection, including:
a) minimum signal digitising with a sample rate of 100 MHz
b) 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
of digital copies of the original ultrasonic results (along with viewing software) at NEPTUNE
ENERGY’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
calibration scans shall be carried out before and after each weld scan (call-in and call-out) using
the calibration block 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 documentation
requirements 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 of the original weld, it is possible that the repaired area will be outside the gate
settings. This can be avoided by scanning the weld with the band in an “offset” position
compared with its original position. The AUT operator shall measure the centreline and the
angle of the new gap prior to commencement of the repair welding. After the repair welding is
finished, the first scan shall be made with the band on the original position to confirm that the
defect has been removed. A second scan 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 ultrasonic
examination shall be carried out which shall be completely witnessed by NEPTUNE ENERGY.
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Specification 580 rev. 1 Page 46 of 61
12.0 SURFACE EXAMINATION
12.1 MAGNETIC PARTICLE INSPECTION (MPI)
12.1.1 CONTRACTOR shall submit a detailed MPI procedure to NEPTUNE ENERGY for approval.
12.1.2 CONTRACTOR's procedure shall be in accordance with NEN-EN-ISO 17638 for wet (or dry for
excavations) Magnetic Particle Inspection. The yoke method shall be used for all MPI. The use
of permanent magnets is not allowed. The use of any other method shall be subject to NEPTUNE
ENERGY approval.
12.2.3 Magnetic particle operators shall be qualified to Level 2 according to EN-ISO 9712.
12.2 DYE PENETRANT INSPECTION (DPI)
12.2.1 CONTRACTOR shall submit a detailed DPI procedure to NEPTUNE ENERGY for approval.
12.2.2 Dye Penetrant Inspection shall be carried out in accordance with EN-ISO 3452-1 using Chloride-
free dye.
12.2.3 Dye Penetrant Inspectors shall be qualified to Level 2 according to EN-ISO 9712
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Specification 580 rev. 1 Page 47 of 61
13.0 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
more than 3mm in height. It should merge smoothly and gradually into the parent metal and
not extend beyond the original joint preparation by more than 2mm. No area should have the
weld face lower than the adjacent pipe surface.
b) The root bead or any concavity shall merge smoothly into the adjacent surface but at no point
shall the weld be thinner than the pipe thickness.
c) Any undercut shall not exceed 0.5mm in depth and 50mm in length
d) The angle of incidence between the parent metal and weld shall be a minimum of120 (see
figure below taken from EN 12732 Annex E)
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 this
specification.
13.3 ACCEPTANCE CRITERIA MANUAL ULTRASONIC TESTING
Acceptance criteria for Manual Ultrasonic Testing shall be in accordance with Appendix 5 of this
specification.
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.
≥120º
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Specification 580 rev. 1 Page 48 of 61
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
defects near to the surface in the zones adjacent to the pipe inner and outer surfaces are
deemed surface breaking in case of insufficient resolution of the ultrasonic system or when the
distance between the surface and the defect is less than the maximum height of the defect.
Defects in all other zones located 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 paragraph
13.4.1), where diffraction signals fade in and fade out gradually to the normal root pattern and
run parallel 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
shall be examination of the pulse-echo response, where after TOFD assisted
correction/confirmation and visual 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 “through
thickness” 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 following
manner:
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 pipe
inner 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 the
outer pipe surface shall be deemed to have a height of at least the inspected zone, unless
an alternate value is confirmed by means of TOFD.
3) A weld defect detected in the zone adjacent to the outer pipe surface shall principally be
deemed to be surface breaking, with a minimum height of at least the height of the
inspected 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 heights
shall be corrected on the basis of visual examination but only after confirmation by NEPTUNE
ENERGY
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Specification 580 rev. 1 Page 49 of 61
13.5 ACCEPTANCE CRITERIA MECHANISED PULSE ECHO + TOFD
Acceptance criteria for Automated Ultrasonic Testing shall be in accordance with Appendix 6 of
this specification.
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 are revealed.
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Specification 580 rev. 1 Page 50 of 61
14.0 REPORTING OF N.D.T.
14.1 GENERAL
CONTRACTOR should use standard NDT reports/forms giving all relevant details to the NDT
technician in order to facilitate correct inspection methods and reporting standards.
NDT reports refer to those for Visual Inspection, Radiography, Ultrasonic Inspection(s), Dye
Penetrant Inspection and Magnetic Particle Inspection.
In principal the following information, but not limited to, SHALL be clearly shown on reports:
a) NEPTUNE ENERGY name
b) NEPTUNE ENERGY project number
c) NEPTUNE ENERGY platform number or location
d) Unique report number
e) Specific details as to the weld numbers examined
f) Drawing number and revision number
g) Certifying Authority (and Registration number where applicable)
h) Standard or Procedure Number (Approved) and Revision
i) Acceptance Criteria
j) Technicians name, qualification, level and certificate number
k) Shift being worked ( day, night or 0.00-12.00, 12.00-24.00)
l) Material type
m) Pre or post heat treatment (where applicable)
n) Material thickness
o) Surface condition and temperature
p) Welding preparation and technique used (i.e V – SMAW)
14.2 SPECIFIC MPI
a) Method used
b) Yoke or magnet ID
c) Current used
d) Field strength
e) Lighting used and light strength
f) Consumables used, contrast paint, ink etc
14.3 SPECIFIC DYE PENETRANT
a) Consumables used
b) Times used during application for penetration, cleaning and development
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Specification 580 rev. 1 Page 51 of 61
14.4 SPECIFIC ULTRASONIC
a) Equipment type and ID
b) Probes used (including frequency, diameters, angles etc.)
c) Couplant used
d) Calibration and reference block
e) Sensitivity
f) Transfer correction
g) Range
14.5 SPECIFIC AUT
a) Equipment used
b) 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 ID
b) Type and size of film
c) Exposure time in kV and mA minutes
d) Technique used
e) 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 Criteria
h) Qualification type and level of Interpreter
i) Acceptance of interpretation by CONTRACTOR
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Specification 580 rev. 1 Page 52 of 61
15.0 DOCUMENTATION
15.1 GENERAL
15.1.1 CONTRACTOR shall provide all documentation, in the English language, to NEPTUNE ENERGY
for review as required 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
NEPTUNE ENERGY.
15.2 INITIAL SUBMISSIONS
15.2.1 Prior to the commencement of procedure qualification and production CONTRACTOR shall
provide the following documentation for review by NEPTUNE ENERGY. Documentation shall
include but not be limited to 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 Details
k) 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
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Specification 580 rev. 1 Page 53 of 61
15.3 FINAL DOCUMENTATION
15.3.1 Within 4 weeks of completion of the order, CONTRACTOR shall deliver to NEPTUNE ENERGY a
Manufacturing Record 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 NEPTUNE ENERGY.
c) all approved queries and concessions
d) 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 NEPTUNE ENERGY 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. Reports
k) welder qualification records
l) approved list of qualified welders
m) dimensional control reports
n) hydrostatic test records
o) heat treatment records
p) 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
of each length of pipe.
15.3.3 The Weld Tracking Sheet or As Laid Record shall contain the following minimum information:
a) pipe number and length
b) weld number
c) pipe number and length
d) material heat number
e) material certificate number (see 15.3.2)
f) date welded
g) shift (day/night)
h) welding procedure used
i) name/type and batch no(s) of weld consumables
j) 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
2 electronic copies shall be submitted to NEPTUNE ENERGY. 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
shall be furnished by CONTRACTOR upon the request of NEPTUNE ENERGY and/or the
CERTIFYING AUTHORITY, e.g. NDT reports and Weld tracking sheets.
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Specification 580 rev. 1 Page 54 of 61
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’clock position.
Appendix 1B Sample locations Full Penetration Repair
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Specification 580 rev. 1 Page 55 of 61
Appendix 1C Sample locations Partial Penetration Repair
Appendix 1D Sample locations Cap Repair
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Specification 580 rev. 1 Page 56 of 61
APPENDIX 2: IMPACT TESTING DETAILS
Appendix 2A Charpy details mainline weld and full penetration repair
Appendix 2B Charpy details partial penetration repair
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Specification 580 rev. 1 Page 57 of 61
APPENDIX 3: HARDNESS TESTING DETAILS
H.A.Z.:
From Fusion Line and into unaffected Base Metal at Fusion Line, Fusion Line +2mm, Fusion Line +5mm
for each transverse 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 the remainder equally spaced.
CW
CW
Mid weld
Weld MetalHAZ
2 mm APPROX
2 mm APPROX
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Specification 580 rev. 1 Page 58 of 61
APPENDIX 4: RADIOGRAPHIC ACCEPTANCE CRITERIA:
The following Acceptance Levels for radiography are based on Table G.2.2 (Tier 1) of EN 12732.
DEFECT DEFECT ACCEPTANCE LEVELS External Profile Weld reinforcement shall be uniform and not less than 1 mm. Maximum Height shall be 3mm.
The cap shall merge smoothly with the parent metal and not extend beyond the original joint
preparation by more than 3mm each side. Surface breaking defects are not acceptable.
Internal Profile The root bead or any concavity shall merge smoothly into the adjacent surface but at no point
should 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 the adjacent
parent material. If the defect image is darker than the adjacent parent metal, it shall be classed as
incomplete root penetration. Root concavity shall not exceed 25% of the weld circumference.
Cap Undercut Length: 50mm
Total: 50mm in 300mm or 15% of circumference (if less)
Depth: 1mm or 0.1 x T if less
Root Undercut Length: 25mm
Total: 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 size or its
location and the weld cut out.
Crater Cracks 4mm
Excessive Root
Penetration
Excess penetration: 2mm maximum with localised 3mm.
Incomplete Root
Penetration or Lack
of Root or Cap
Fusion
Any individual imperfection due to incomplete root penetration or lack of fusion at weld root and
cap shall not exceed 25mm in length.
The total length of such imperfections shall not exceed 25mm in any 300mm or 8% of circumference
(if less).
Incomplete Fusion
due to cold lap, Lack
of Sidewall and Lack
of Inter-run Fusion
(not in root or
capping beads)
Any individual imperfection due to incomplete fusion due to cold lap between two adjacent weld
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 continuous 300mm length of
weld shall not exceed 50mm. For any weld less than 300mm in length, the aggregate length of
indications of incomplete fusion due to cold lap shall not exceed 15% of the weld length (if less).
Worm Holes Not Acceptable
Hollow Bead Length: 50mm
Total: 50mm in 300mm or 15% of circumference (if less)
Inclusions 12mm in 300mm and 4 in 300mm
Slag Length: 50mm
Total: 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 parent adjacent
metal.
Burn through producing a darker image than that of the adjacent parent metal is not acceptable 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 the
projected weld area in the radiograph, calculated by multiplying the length of the weld affected 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 considered
unacceptable.
High Density
Indications
NEPTUNE ENERGY has the right to reject any indication on (excessive) density alone even if the
length or dimensions of that defect appear to be within the acceptance limits. CONTRACTOR shall
notify NEPTUNE ENERGY of any indications having a high density.
Copper Induced
indications
Any indication showing suspected copper or copper crack like indications shall be rejected and the
weld removed.
Defect Accumulation 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 weld
thickness to be less than that of the pipe.
Defect Interaction Inherent in defect accumulation criteria.
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Specification 580 rev. 1 Page 59 of 61
APPENDIX 5: MANUAL ULTRASONICS ACCEPTANCE CRITERIA
The following Acceptance levels for manual ultrasonic testing are in accordance with EN 12732
Tables G.3.1 and G.3.2
Recording of indications
Calibration 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 setting
amplitude below
calibration level by dB
Fault reflection lengths
to be recorded above
this length (mm)
6 < T ≤ 15 1.0 6 10
15 < T ≤ 20 1.5 6 10
20 < T ≤ 40 2.0 6 10
Assessment of indications using the Distance Gain Size method
Maximum allowable numbers and sizes of reflectors
Wall thickness T*
In mm
Number of indications
per m of seam
Maximum allowable
lengths of reflectors
per echo**
mm
Echo level above
calibration level
dB
-6 ≤ T ≤ 10 5
and 2
10
20
≤ 6
≤ 6
10 < T ≤ 20 10
and 3
and 1
10
20
10
≤ 6
≤ 6
≤ 12***
20 < T ≤ 40 10
and 4
and 1
10
25
10
≤ 6
≤ 6
≤ 12***
40 < T ≤ 60 10
and 4
and 1
10
30
10
≤ 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 the
calibration 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.
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Specification 580 rev. 1 Page 60 of 61
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
wall thicknesses, the thinnest dimension shall be applied.
A group of indications in which the individual defect lengths are deemed acceptable, shall be accepted
only when the 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 NEPTUNE ENERGY for validation prior to the
commencement of pipeline installation.
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 the indications 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 1.5mm for the root and fill and 2mm for the cap. These values may be adjusted after
validation testing has proven a better sizing accuracy.
2. If no validation to NEN 3653 is carried out, the acceptance of the proposed defects shall be
confirmed by Curved 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”)
6 ≤ Wt ≤10
20 30 1.5 – 2.5
10 15 2.5 – 3.0
Not acceptable 10 3.0 – 3.5
10 < Wt ≤ 25
25 50 1.5 – 2.5
20 40 2.5 – 3.0
0 25 3.0 – 3.5
WQT / repairs
20 25 1.5 – 2.5
10 10 2.5 – 3.0
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, in any 12.5% of Weld
Circumference Length.
2- Threshold Root / Cap 40% of 2mm Notch
3- 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 weld
7- CONTRACTOR shall also have data and information available to identify (suspected) copper induced cracking. Welds
containing (suspected) copper induced cracking shall be cut out.
Neptune Energy Netherlands B.V.
Specification 580 rev. 1 Page 61 of 61
Interaction Rules
Interaction Rules shall be applied as per API 1104 – Errata 1 , 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).