VV31M6 101 a 010 2 Welding&NDT Spec

Total Sheet 18

Vendor’s name : SK E&C INFRA

Company’s Name : Nghi Son Refinery and Petrochemical LLC.

Purchaser : JGCS Consortium

Responsible OC : JVD

Plant Location : Nghi Son, Vietnam

Project name : NSRP Complex Project

P / Order No. : PV31M6-101-A

Equipment/Material Name :

Item Number :

Document Title : WELDING AND NDT SPECIFICATION

NSRP Complex Project (JOB No. : 0-6495-20)

DOCUMENT CLASS : Z

ISSUE PURPOSE : FC

RESULT CODE : A, B, R, F ( )

NEXT STATUS : FA, FR, FI, FC, AB ( )

RESUBMISSION DATE : ( )

RESPONSIBLE DEPT./PERSON : ( )

Review Date: ( )

A: Approved without Comment; B: Approved with Minor Comment

R: Not Approved ; F: Not Subject to Review

Approval or review hereunder shall not be construed to relieve Vendor / Subcontractor of his responsibilities and liability under the Contract.

Purchaser DOC. No.

ORIG. PURCHASE ORDER NO. SERIAL REV.

V V31M6-101-A- 010 2

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KH963

Text Box

04-APR-2014

KH963

Text Box

Marine/A. Yoshida

KH963

Text Box

NA

KH963

Text Box

A

NSRP Complex PJT

Vietnam NSRP Marine Construction Work - 1

WELDING AND NDT SPECIFICATION

Document No. VV31M6-101-A-010 Rev. 2 PAGE 1 of 17


Document No. : VV31M6-101-A-010

P.O No. : 0-6495-PV31M6-101-A

Project Title : NSRP Marine Construction Work - 1

Location : Nghi Son, Thanh Hoa province, Vietnam

Employer : Nghi Son Refinery and Petrochemical LLC (NSRP)

2 26/03/2013 Issue for Construction S.C KIM S.W YOUN COLIN J.K KIM

1 26/01/2013 Issue for Construction S.C KIM S.W YOUN COLIN J.K KIM

0 04/12/2013 First Issue for Review S.C KIM S.W YOUN - J.K KIM

Rev. No.

App. date (D/M/Y) Revision description Prepared Reviewed Reviewed Approved

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REVISION HISTORY

Revision No.

Status Revision Note Incorporated

Page

0 FA ISSUE FOR REVIEW 14

1 FC

ISSUE FOR CONSTRUCTION 17

Definition has been modified as the latest comment. All

The description has been updated. 8

Chapter 5 for documentation has been added. 17

2 FC

ISSUE FOR CONSTRUCTION 17

The section for ‘Abbreviation’ has been added as per

the latest comment.

8

The section for ‘Conflict of information’ has been

added as per the latest comment.

8

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JGCS Comment on revision 01

Reference JGCS Comments Status

#2.1 General Revise as the latest year of DNV-OS-F101. Contractually, DNV-OS-F101 (2012) should be used, which was the latest one during signing.

#2.2 Weld inspection

Replace the word ‘field joint coating’ with ‘hydrotest and coating’

Noted. It has been replaced.

Add the below sentence.

“Weld repair shall be in accordance with the weld repair procedure.”

Noted. It has been added.

#2.3 Cleaning Add the below sentence.

“Cleaning inside of each pipe shall be checked by Sub-contractor and Contractor/Employer before fitting-up.”


#3.2.2 Identification of welders

Sub-contractor shall clarify how to control the welder/welding operator’s NDT defection rating base on NDT result?

Sub-contractor will control for welder/welding operator' NDT defection rating as below.

"If production of welder is determined that the failure of a test is due to welder’s lack of skill, retesting shall only be performed after the welder has received further training. The period of validity of a welder qualification shall be in accordance with the standard used for qualification. A qualification can be cancelled if the welder/welding operator show inadequate skill, knowledge and performance."

This sentence will be added in section 3.2.3.

#3.4 Welding procedures

Sub-contractor shall clarify which applicable standard is used to qualify WPS?

All field welding and weld inspection of the pipe shall comply with the requirements of DNV-OS-F101.

#3.4.4 Weld map

Replace the second bullet point with ‘Type of weld’.


Add the bullet point as below.

‘NDT requirement’


#3.7 Welding Please confirm the word as ‘Manufacturer’. Noted. It has been replaced by ‘Vendor’

#3.7.1 Pipe beveling

Replace the word 'company' with 'Vendor'. All deviation from standard should be confirmed and approved by 'Sub-contractor and Contractor/Employer'. Therefore, the 'company' should be replaced by 'Sub-contractor and Contractor/Employer'.

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Replace as the below bold sentence.

“….dimensions shall be in accordance with approved WPS and shall be checked by NDT method as per Appendix C of DNV-OS-F101.”


Add the below sentence.

“Bevel by thermal cutting only accepted when machine is not feasible for tie-in and must be agreed by JGCS.

Noted. It has been added with some modification as below.

“Bevel by thermal cutting only accepted when machine is not feasible for tie-in and must be agreed by Sub-contractor and Contractor/Employer.”

#3.7.2 Alignment of pipe


“… …the offset shall be in accordance with Table D-4 of DNV-OS-F101.”


#3.7.3 Type and removal of line-up clamps


“Line up clamps shall be used for butt welds in accordance with welding control procedure.”


#3.8 Weld repair

Add the below word.

“and welding operator”


#5.1 Engineering document

Replace as the below sentence.

“… … are summarized but not limited to the following;”


Replace the 4th bullet point with the below

words.

‘Welding control procedure’


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TABLE OF CONTENTS

PAGE

REVISION HISTORY................................................................................................................................................. 2

TABLE OF CONTENTS ............................................................................................................................................. 5

1. GENERAL .......................................................................................................................................................... 7

1.1. PROJECT BACKGROUND .............................................................................................................................................................. 7

1.2. PIPELINE DESCRIPTION ................................................................................................................................................................ 7

1.3. DEFINITIONS ................................................................................................................................................................................. 7

1.4. SCOPE ........................................................................................................................................................................................... 7

1.5. CODES AND STANDARDS ........................................................................................................................................................... 8

1.6. CONFLICT OF INFORMATION ..................................................................................................................................................... 8

1.7. ABBREVIATION ............................................................................................................................................................................. 8

2. WELDING AND NON-DESTRUCTIVE TESTING .......................................................................................... 9

2.1. GENERAL ....................................................................................................................................................................................... 9

2.2. WELD INSPECTION ...................................................................................................................................................................... 9

2.3. CLEANING ..................................................................................................................................................................................... 9

2.4. WEATHER PROTECTION ............................................................................................................................................................ 10

3. TECHNICAL REQUIREMENTS ...................................................................................................................... 10

3.1. WELDING EQUIPMENT AND TOOLS ........................................................................................................................................ 10

3.2. QUALIFICATION OF WELDERS .................................................................................................................................................. 10

3.2.1. Welder tests ................................................................................................................................................................. 11

3.2.2. Identification of welders ........................................................................................................................................ 11

3.3. WELDING CONSUMABLES ........................................................................................................................................................ 11

3.4. WELDING PROCEDURES ............................................................................................................................................................ 11

3.4.1. Preliminary welding procedure specification ............................................................................................... 11

3.4.2. Welding procedure qualification record ........................................................................................................ 11

3.4.3. Welding procedure specification ....................................................................................................................... 12

3.4.4. Weld map ..................................................................................................................................................................... 12

3.5. QUALIFICATION OF WELDING PROCEDURES .......................................................................................................................... 12

3.6. PREHEATING ............................................................................................................................................................................... 13

3.7. WELDING .................................................................................................................................................................................... 14

3.7.1. Pipe bevelling.............................................................................................................................................................. 14

3.7.2. Alignment of pipe ..................................................................................................................................................... 14

3.7.3. Type and removal of line-up clamps ............................................................................................................... 14

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3.8. WELD REPAIR ............................................................................................................................................................................. 15

4. NON-DESTRUCTIVE TESTING ..................................................................................................................... 15

4.1. NON-DESTRUCTIVE TESTING METHODS ................................................................................................................................. 15

4.2. TIMING OF NDT ....................................................................................................................................................................... 15

4.3. PERSONNEL QUALIFICATIONS .................................................................................................................................................. 15

4.3.1. Manual or semi-automatic NDT ........................................................................................................................ 15

4.4. RADIOGRAPHY TESTING ........................................................................................................................................................... 15

4.5. AUTOMATED ULTRASONIC TESTING ....................................................................................................................................... 16

4.5.1. Requirements .............................................................................................................................................................. 16

4.5.2. Procedure ...................................................................................................................................................................... 16

4.5.3. Qualification ................................................................................................................................................................. 16

4.6. WELDING ACCEPTANCE CRITERIA ............................................................................................................................................ 16

4.6.1. Visual inspection ........................................................................................................................................................ 16

4.6.2. Radiographic testing ................................................................................................................................................ 16

4.6.3. Ultrasonic testing ...................................................................................................................................................... 16

5. DOCUMENTATION ....................................................................................................................................... 17

5.1. ENGINEERING DOCUMENT ....................................................................................................................................................... 17

5.2. RECORDS .................................................................................................................................................................................... 17

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1. GENERAL

1.1. Project background

Nghi Son Refinery and Petrochemical LLC has awarded JGCS consortium for the Engineering, Procurement and Construction of a new refinery with associated loading and offloading facility at Nghi Son, in the Thanh Hoa Province approximately 200km South of Hanoi. Associated with the new refinery scope of works is twin offshore pipelines and SPM system for importing crude oil from a single point mooring (SPM) to the Refinery. The offloading SPM is located approximately 35km offshore in 27m water depth. Detailed engineering of the offshore twin pipelines is undertaken by SK E&C Infra, as part of overall deliveries for this project.

1.2. Pipeline description

Twin 48” pipelines will be utilised to transport incoming crude oil from a proposed SPM to the plant storage area. Crude oil from tankers will be discharged through the SPM to the pipelines running from offshore to onshore, towards the Refinery. The proposed route for the pipelines commences at pig trap locations in the refinery crude oil storage area. After running along a buried onshore section, the pipelines will run along their subsea route. The pipelines will be laid in a trench throughout the proposed route, and will be backfilled to protect against human activities and wave/current induced forces. Offshore end of the pipelines will terminate at PLEM flanges to provide connection to the SPM.

1.3. Definitions

Employer Owner of the Plant, Nghi Son Refinery and Petrochemical LLC (NSRP)

Contractor JGCS Consortium, a joint venture made between JGC, Chiyoda, GS, SK & Technip, the company who is entering into the Contract with the Contractor for entrusting the Works

Sub-contractor SK E&C Infra, which is undertaking to execute the Works under the Contract with JGCS

Vendor Any person or persons or firm or company to whom any part of the works is subcontracted under the responsibility of the Sub-contractor and includes any supplier of materials to be supplied by the Sub-contractor for use in the Works

Certifying Agency BV(Bureau Veritas), which performs all necessary verification and activities in accordance with DNV classification and Vietnam Register requirements

1.4. Scope

This specification defines the requirements for Welding and NDT (Non Destructive Testing) to be used for the offshore section of the Crude Oil Pipeline.

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1.5. Codes and standards

The latest editions of the following codes and standards shall apply.

API 1104 Welding and Pipelines and Related Facilities, 2013

DNV-OS-F101 Submarine Pipeline System, 2012

DNV-RP-F118 Pipe Girth Weld AUT System Qualification and Project Specific

Procedure Validation, 2010

BS EN 473 Non-destructive testing. Qualification and certification of NDT

personnel. General principles, 2008

ISO 9712 Qualification and certification of NDT personnel, 2012

ISO 17636 Non-destructive testing of welds. Radiographic testing X-ray and

gamma-ray techniques with digital detectors, 2013

1.6. Conflict of information

In the event of any conflict between this Specification and associated data sheets, or with any applicable Codes and Standards, the Vendor shall immediately inform the Sub-contractor and Contractor/Employer in writing and receive written clarification from the Sub-contractor and Contractor/Employer before proceeding with the work.

1.7. Abbreviation

ACCP ASNT Central Certification Program

API American Petroleum Institute

ASNT American Society for Nondestructive Testing

AUT Automated Ultrasonic Testing

BS British Standard

CSWIP Certification Scheme for Welding and Inspection Personnel

DNV Det Norske Veritas

ECA Engineering Critical Assessment

ISO International Organization for Standardization

LLC Limited Liability Company

NDT Non Destructive Testing

PLEM PipeLine End Manifold

PoD Probability of Detection

pWPS Preliminary Welding Procedure Specification

SAWL Submerged Arc Welded Longitudinal

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2. WELDING AND NON-DESTRUCTIVE TESTING

2.1. General

Vendor shall provide all personnel, equipment, material and consumables required to perform field welding of offshore pipelines and the subsequent non-destructive testing. All field welding and weld inspection of the pipe shall comply with the requirements of DNV-OS-F101. Vendor shall submit the welding and weld inspection procedures for Sub-contractor and Contractor/Employer review and/or approval and qualify the approved procedures in accordance with Sub-contractor and Contractor/Employer’s specified requirements. All welders to be used for the work shall pass a qualification test and shall be subject to Sub-contractor and Contractor/Employer review and/or approval. Vendor shall prepare the weld test specimens from weld test material supplied by Sub-contractor in accordance with Sub-contractor specifications for linepipe. Vendor shall furnish all other welding materials and equipment necessary to complete the welding procedure and welder qualification tests.

2.2. Weld inspection

During work, all welds shall be inspected by Vendor in accordance with DNV-OS-F101, Appendix C. The radiographic film shall be reviewed and approved by Sub-contractor and Contractor/Employer. In case of any dispute on acceptability the decision between Sub-contractor and Contractor/Employer should be mutually agreed based on generally accepted standards in the industry. If the results of these inspections indicate any weld to be defective, Vendor shall repair or replace and re-inspect the weld prior to hydrotest and coating. Weld repair shall be in accordance with the weld repair procedure.

2.3. Cleaning

Prior to pipe alignment but after end bevelling, (if required), the inside of each pipe shall be cleaned by Vendor to remove all debris and loose material. Cleaning inside of each pipe shall be checked by Sub-contractor and Contractor/Employer before fitting-up. Cleaning shall be performed to displace any debris that may be present in the pipe. Vendor shall submit details describing the internal cleaning of pipe length to Sub-contractor and Contractor/Employer for review and/or approval.

SPM Single Point Mooring

WPQ Welding Procedure Qualification

WPQR Welding Procedure Qualification Record

WPS Welding Procedure Specification

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2.4. Weather protection

In the event of cold, rainy, or inclement weather, sea spray, or similar environmental conditions, Vendor shall provide sufficient protection to enable the performance of the work with no deterioration in quality. Care shall be taken to ensure that all welding operations are suitably protected and are not subjected to sudden variations in temperature or any moisture ingress. Suitable precautions shall be taken by Vendor to protect the welding environment from gusts of wind and foreign objects, such as dust and other wind borne debris.

3. TECHNICAL REQUIREMENTS

3.1. Welding equipment and tools

Any proposed automatic or semi-automatic welding system shall be subject to approval for Sub-contractor and Contractor/Employer. Acceptance of any welding system shall be at Sub-contractor and Contractor/Employer's discretion. Detailed descriptions of all welding equipment, tools, (including bevelling machines and line-up clamps) proposed to be used shall be submitted to Sub-contractor and Contractor/Employer for approval. All welding machines, line-up clamps, bevelling machines, cutting torches and other equipment, tools and supplies used in connection with the welding work shall be kept in good mechanical condition so as to produce consistent fit-up, weld preparations and sound welds. Welding machines shall have adequate controls for obtaining current adjustment for all pipeline welding requirements. Sufficient meters, portable or permanent, shall be provided to calibrate machines and to regulate voltage, amperages and travel speed as may be needed. Ground clamps shall be of such design as to be dependable and not arc line pipe or cause any notch damage to the pipe. Any leads with insulation damage to the extent that wire is exposed shall be discarded. Records of welding equipment calibration shall be submitted to Sub-contractor and Contractor/Employer for review. The control software for mechanised and automatic welding systems shall be documented. The name and unique version number of control software and the executable programme in use shall be clearly visible, e.g. on displays and/or printouts. For mechanized welding, a welding system which displays the instantaneous heat input on screen with outputs for recording various parameters should be used. All welding equipment shall have a unique marking for identification. Calibration status and the validity of welding, monitoring and inspection equipment shall be summarized giving reference to the type of equipment, calibration certificate and expiry date. Welding return cables shall have sufficient cross section area to prevent concentration of current and shall be securely attached to prevent arc burns.

3.2. Qualification of welders

Vendor shall use only competent, skilled and qualified welders and all welding shall be completed to the satisfaction of the Sub-contractor and Contractor/Employer representative. Each welder employed by Vendor shall be required to pass a welding qualification test in accordance with Appendix C of DNV-OS-F101 and requirements of this specification, before that welder will be allowed to make production welds. No welder shall do any phase of welding for which qualification has not been received. All costs of qualifying welders shall be at the Vendor's expense

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3.2.1. Welder tests

Sub-contractor and Contractor/Employer’s representative shall witness all welder qualification tests given to all welders employed by Vendor for any part of the Work. All welder qualification tests shall be in accordance with Appendix C of DNV-OS-F101. Vendor shall furnish all test equipment required for destructive testing The qualification tests shall preferably be carried out under realistic conditions where the installation welding is to take place. Vendor shall prepare all pipe specimens, and furnish all welding materials, equipment and welder. Vendor will test all welds by destructive and non-destructive test method in accordance with Appendix D of DNV-OS-F101.

3.2.2. Identification of welders

After Vendor has determined that the welder has passed all welder qualification requirements, Vendor shall issue an identification number to that welder and each weld made by that welder shall be so identified with an ink pipe marker on the top quarter of the pipe. Die stamping shall not be allowed. If production of welder is determined that the failure of a test is due to welder’s lack of skill, retesting shall only be performed after the welder has received further training. The period of validity of a welder qualification shall be in accordance with the standard used for qualification. A qualification can be cancelled if the welder/welding operator show inadequate skill, knowledge and performance. Any weld worked on by more than one welder shall be identified by the number of each and every welder participating in the weld. Vendor shall keep Sub-contractor and Contractor/Employer supplied with an up-to-date list of the identification numbers and welders names.

3.3. Welding consumables

Welding processes for pipeline welds shall comply with the requirements of Appendix C of DNV-OS-F101 for acceptable processes, consumables, and the requirements for consumable storage and handling.

3.4. Welding procedures

3.4.1. Preliminary welding procedure specification

A preliminary Welding Procedure Specification (pWPS) shall be prepared for each new welding procedure qualification. The pWPS shall contain the relevant information required for making a weld for the intended application when using the applicable welding processes

3.4.2. Welding procedure qualification record

The Welding Procedure Qualification Record (WPQR) shall be a record of the materials, consumables, parameters and any heat treatment used during qualification welding and the subsequent non-destructive, destructive and corrosion test results. All essential variables used during qualification welding that are relevant for the final application of the WPQR shall be documented and the welding parameters recorded in relevant positions for each pass.

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3.4.3. Welding procedure specification

A Welding Procedure Specification (WPS) is a specification based on one or more accepted WPQRs. One or more WPSs may be prepared based on the data of one or more WPQRs provided the essential variables are kept within the acceptable limits. A WPS may include one or a combination of welding processes, consumables or other variables. All limits and ranges for the applicable essential variables for the welding to be performed shall be stated in the WPS. The WPS shall be submitted together with the referenced supporting WPQR(s) for review and acceptance by Sub-contractor and Contractor/Employer prior to start of production.

3.4.4. Weld map

Vendor shall submit a detailed Weld Map to Sub-contractor and Contractor/Employer with WPS/PQR. Weld Map shall contain, as a minimum, the following information:

Outline sketch of the equipment/material

Type of weld

Material type and grade

Material thickness

Applicable WPS number

Impact test, if applicable

NDT requirement

3.5. Qualification of welding procedures

Qualification welding shall be performed based upon the accepted pWPS, using the type of welding equipment to be used during production welding, and under conditions that are representative of the actual working environment for the work shop, site, or vessel where the production welding will be performed

1) Qualification welding

Certificates for materials and consumables, including shielding, backing and plasma gases, shall be verified, and validity and traceability to the actual materials shall be established prior to start of qualification welding. The records from qualification welding shall include all information needed to establish a WPS for the intended application within the essential variables and their allowable ranges. The following requirements apply:

The welding qualification test shall be representative for the production welding with respect to

welding positions, interpass temperature, application of preheat (propane will also qualify for

induction coil preheating), heat conduction, etc.

If multiple welding arcs are combined in a single welding head the parameters for each

welding arc shall be recorded.

The direction of plate rolling (when relevant) and the 12 o’clock position (for fixed pipe

positions) shall be marked on the test piece.

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When more than one welding process or filler metal is used to weld a test piece, the

parameters used and the approximate thickness of the weld metal deposited shall be recorded

for each welding process and filler metal.

If tack welds are to be fused into the final joint during production welding, they shall be

included when welding the test piece.

Backing gas oxygen content and the duration of backing gas application before, during and

after welding shall be recorded.

Each test piece shall be uniquely identified by hard stamping or indelible marking adjacent to

the weld and the records made during test welding, non-destructive testing and mechanical

testing shall be traceable to each test piece.

2) Pipeline girth welds

The welding qualification test shall be representative for the production welding with respect to

angle of pipe axis, interpass temperature, application of preheat, heat conduction, etc.

For girth welds in welded pipe in all positions, except flat position and horizontal position, it is

recommended that one of the pipes used for the welding procedure qualification test be fixed

with the longitudinal weld in the 6 or 12 o'clock position.

For girth welds of pipe, the weld circumference shall be divided in appropriate sectors around

the circumference. The welding parameters shall be recorded for each pass in each sector

and for each welding arc. For manual welding, the heat input for a sector shall be recorded as

average of all the average heat inputs for the run-out lengths in each pass in that sector.

The release of external line-up clamps shall be simulated during qualification welding. Clamps

should not be released until the completed sections of the root pass covers a minimum of 50%

of the circumference with even spacing. The length of each section, the spacing of the

sections, the number of sections welded and the percentage of welded sections of the

circumference shall be recorded.

If it is expected that the interpass temperature will drop below preheat temperature during

installation welding, this scenario shall be simulated during qualification welding. The number

of passes completed before cooling to below preheat temperature shall be recorded.

Accelerated cooling of the weld shall be performed during qualification welding if accelerated

weld cooling, e.g. for Automated Ultrasonic Testing (AUT) will be performed in production. The

cooling method and the weld temperature at the start of the cooling shall be recorded.

3.6. Preheating

When, for any reason, preheating is necessary for a specific welding procedure and material combinations to alleviate existing conditions that would limit the welding technique or adversely affect the quality of the weld. The weld area shall be heated to the minimum preheat temperature specified in the WPS. Pre-heating shall also be performed whenever moisture is present or may condense in the weld area

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and/or when the ambient temperature or material temperature is below 5°C. Welding below 20°C should not be performed.

3.7. Welding

All welding shall be performed using the type of welding equipment and under the conditions that are representative for the working environment during procedure qualification welding. All welding equipment shall be maintained in good condition in order to ensure the quality of the weldment. All welding shall be performed under controlled conditions with adequate protection from detrimental environmental influence such as humidity, dust, draught and large temperature variations. All instruments shall have valid calibration certificates and the adequacy of any control software shall be documented. All welding shall be carried out strictly in accordance with the accepted welding procedure specification and the requirements in this subsection. If any parameter is changed outside the limits of the essential variables, the welding procedure shall be re-specified and re-qualified. Intermittent tack welding of the SAWL groove shall not be used unless Contractor/Employer has approved data furnished by Vendor to demonstrate that all mechanical properties specified for the pipe are obtainable at both the tack weld and intermediate positions.

3.7.1. Pipe bevelling

Pipe ends should be field beveled by machine tool or machine oxygen cutting. If authorized by the Sub-contractor and Contractor/Employer, manual oxygen cutting may also be used. The beveled ends shall be reasonably smooth and uniform, and dimensions shall be in accordance with approved WPS and shall be checked by NDT method as per Appendix C of DNV-OS-F101. Bevel by thermal cutting only accepted when machine is not feasible for tie-in and must be agreed by Sub-contractor and Contractor/Employer.

3.7.2. Alignment of pipe

The alignment of abutting ends shall minimize the offset between surfaces. For pipe ends of the same nominal thickness, the offset shall be in accordance with Table D-4 of DNV-OS-F101. Larger variations are permissible provided the variation is caused by variations of the pipe end dimensions within the pipe purchase specification tolerances, and such variations have been distributed essentially uniformly around the circumference of the pipe. Hammering of the pipe to obtain proper lineup should be kept to a minimum.

3.7.3. Type and removal of line-up clamps

Lineup clamps shall be used for butt welds in accordance with the welding control procedure. When it is permissible to remove the lineup clamp before the root bead is completed, the completed part of the bead shall be in approximately equal segments spaced approximately equally around the circumference of the joint. However, when an internal lineup clamp is used and conditions make it difficult to prevent movement of the pipe or if the weld will be unduly stressed, the root bead shall be completed before clamp tension is released. Root-bead segments used in connection with external clamps should be uniformly spaced around the circumference of the pipe and shall have an aggregate length of at least 50% of the pipe circumference before the clamp is removed.

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3.8. Weld repair

Separate welding procedure of repair specifications shall be qualified by Vendor and approval by Sub-contractor and Contractor/Employer for repair welding simulating the proposed repair to be carried out. Separate procedures are required to be qualified for

Through thickness repair (root opening)

Partial thickness repair

Cap repair

Qualification testing and requirements shall be same as the original WPS for a through thickness repair (root opening). Qualification tests acceptance criteria of testing shall be as per DNV-OS-F101. Repair Welding Procedures for each grade, pipe diameter and wall thickness shall be separately qualified. Welders and welding operator shall be qualified in advance for the repairs as per DNV-OS-F101 and shall be trained on special methods of repairs, if any. Repair of cracks by welding shall not be permitted. No more than two repairs shall be allowed at a single location. Such welds shall be cut-out and rewelded to make a joint.

4. NON-DESTRUCTIVE TESTING

4.1. Non-destructive testing methods

The extent of NDT for installation girth welds shall be 100% ultrasonic or radiographic testing. Radiographic testing shall be supplemented with ultrasonic testing in order to enhance the probability of detection and/or characterisation/sizing of defects.

4.2. Timing of NDT

NDT of pipeline installation girth welds in linepipe can be performed as soon as the welds have cooled sufficiently to allow the NDT to be performed.

4.3. Personnel qualifications

4.3.1. Manual or semi-automatic NDT

Operators performing interpretation shall be certified to Level 2 by a Certification body or Authorised qualifying body in accordance with EN 473, ISO 9712 or the ASNT Central Certification Program (ACCP). In addition they shall document adequate training and field experience with the equipment in question, by passing a specific and practical examination. If requested, they shall be able to demonstrate their capabilities with regard to calibrating the equipment, performing an operational test under field conditions and evaluating size, nature and location of imperfections.

4.4. Radiography Testing

Radiographic testing shall be performed in compliance with ISO 17636 and DNV-OS-F101. Radiographic testing shall be performed by use of X-ray according to accepted procedures. Use of radiographic isotopes (gamma rays) may be required in some situations and is subject to approval for Sub-contractor and Contractor/Employer

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Each radiographic procedure and the consumables used shall be qualified by making radiographic exposures of a welded joint or base material with the same or typical configuration and dimensions, and of material equivalent to that which shall be used in production radiography.

4.5. Automated ultrasonic testing

4.5.1. Requirements

The primary requirement to any AUT system is that its performance is documented in terms of adequate detection and sizing, or rejection abilities, in relation to specified / determined acceptable defects. The performance of the AUT system has through the qualification to be demonstrated to meet or exceed the requirements in terms of detection or rejection set by the applicable acceptance criteria

4.5.2. Procedure

A detailed AUT Procedure shall be prepared for each weld joint geometry to be examined prior to the start of any welding in accordance with Appendix E of DNV-OS-F101.

4.5.3. Qualification

The AUT system shall be qualified according to DNV-RP-F118 for the applications it is intended used for. The qualification shall be based on the required performance as identified by the requirements for Probability of Detection (PoD) and sizing ability; or, alternatively a requirement to defect rejection.

4.6. Welding acceptance criteria

Engineering Critical Assessment (ECA) shall be performed to establish acceptable welding defect in accordance to DNV-OS-F101.

4.6.1. Visual inspection

Visual inspection shall meet the requirement of DNV-OS-F101. Acceptance criteria for Visual inspection shall be in accordance with Table D-4 in Appendix D of DNV-OS-F101.

4.6.2. Radiographic testing

Acceptance criteria for radiographic testing shall be in accordance with Table D-5 in Appendix D of DNV-OS-F101.

4.6.3. Ultrasonic testing

Acceptance criteria for ultrasonic testing shall be in accordance with Table D-6 in Appendix D of DNV-OS-F101.

INDRA08-APR-2014

NSRP Complex PJT




5. DOCUMENTATION

5.1. Engineering document

Engineering documents to be submitted for Sub-contractor and Contractor/Employer review and/or approval are summarized but not limited to the following:

Inspection and test plan

Inspection and test procedures

Traceability system

Welding control procedure

Welding procedure specification and register

Consumable handling procedure

Welder training procedure

NDT procedure

Mechanical testing procedures and testing laboratory details

WPS (Welding Procedure Specification)

WPQ (Welding Procedure Qualification)

NDT procedure qualification

NDT operators qualification

5.2. Records

Documents of each weld record to be submitted for Sub-contractor and Contractor/Employer review and/or approval are summarized but not limited to the following:

Consumable batch testing records

Qualification test record

Performance records

Heat treatment time temperature report

NDT reports

Equipment calibration records

Document control records

INDRA08-APR-2014