table of contents - neptuneenergy.com · 2009 methods for the determination of nde acceptance...

Neptune Energy Netherlands B.V.

Specification 580 rev. 1 of 61

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



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



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



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.



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.



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



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.


Revision

Non-destructive examination of welds – Magnetic particle examination

of welds.


Revision

Non-destructive examination of welds- Magnetic particle testing –

Acceptance levels.


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


Revision

Non-destructive examination of welds – Radiographic examination of

welded joints.




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.


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


Revision

Welding consumables – Covered electrodes for manual metal arc

welding of high strength steels – Classification.


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.


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.



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.


Revision


Part 2: Comprehensive quality requirements.


Revision


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.



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%.



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.



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.



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.



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).



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



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

Table 3: Extent of testing for full penetration repair:


Full Penetration

Repair weld

1 off







Impact test 4 sets cap &

4 sets root(>20mm)

See 4.4.3




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



Table 4: Extent of testing for partial penetration repair:


Partial

Penetration

Repair to leave a

minimum of

3mm parent

metal.

1 off







Impact test 4 sets cap See 4.4.3



Bend test 2 face See 4.4.6

Table 5: Extent of testing for single pass cap repair


Single Pass Cap

Repair

1 off








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



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



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.



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.



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:



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



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.



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.



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


Butt Weld or

Half Butt Weld


Radiographic examination* 100% Section 9



Macro examination 1 test specimen See 4.4.4



Full and Partial

Penetration

Repair






Bend test 2 root & 2 face (FP)

2 face (PP)

See 4.4.6


Cap Repair Visual examination 100% Section 8







Weldolet





*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).



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.



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.



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.



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.



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.



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



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.



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.



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).



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



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.



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.



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.



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.



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.



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



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



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.



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.



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



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



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



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.



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



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



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



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.



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



Appendix 1C Sample locations Partial Penetration Repair

Appendix 1D Sample locations Cap Repair



APPENDIX 2: IMPACT TESTING DETAILS

Appendix 2A Charpy details mainline weld and full penetration repair

Appendix 2B Charpy details partial penetration repair



APPENDIX 3: HARDNESS TESTING DETAILS

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



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


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


Inclusions 12mm in 300mm and 4 in 300mm

Slag Length: 50mm


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.



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.



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.



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).

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