05-3300-01-W-01-009 Pipeline Welding and NDT Spec (Onshore) Rev P2

cobra

ACS COBRA CASTOR UTE

P KENNY

CASTOR UNDERGROUND GAS STORAGE DEVELOPMENT SPECIFICATION

PROJECT No.

053300 REF

PIPELINE WELDING AND NDT SPECIFICATION (ONSHORE)

W-01-009 No OF SHEETS

17

DOCUMENT No

OFFICE CODE

PROJECT No

3300

05 COBRA No.

AREA

TYPE 01

DISC W

01

NUMBER

009

CAS-3000-JP-EG-SPE-005

r1

- %IP

KiLt---

P2

05/11/09

Re-Issued for Client comment

'

P1

13/07/09

Issued for Client comment

RCP

OLA

RCP

AFB

REV

DATE

BY

CFIK

ENG

PM

DESCRIPTION

"'

U

CLIENT


TABLE OF CONTENTS 1

INTRODUCTION............................................................................................................................. 3 1.1 1.2 1.3 1.4 1.5

2

General ............................................................................................................................... 3 Purpose of Document ....................................................................................................... 3 Definitions .......................................................................................................................... 3 Abbreviations..................................................................................................................... 3 Units.................................................................................................................................... 4

REFERENCES, CODES AND STANDARDS ................................................................................ 5 2.1 2.2 2.3

Codes and Standards........................................................................................................ 5 Project Specifications and Data Sheets.......................................................................... 5 Order of Precedence ......................................................................................................... 5

3

SCOPE............................................................................................................................................ 6

4

MODIFICATIONS OF ISO 13847: 2000 CLAUSES ...................................................................... 7

05-3300-01-W-01-009 Pipeline Welding and NDT Spec (Onshore) Rev P2.doc

Page 2 of 17


1

INTRODUCTION

1.1

General The 30” gas pipeline has an offshore section approximately 22km long and an onshore section approximately 8.5km long. It will be used to transport natural gas from the Spanish gas pipeline system to the offshore platform and return dehydrated gas from the offshore platform complex to the onshore gas treatment plant. The offshore section will be connected by a 31km Fibre Optic Cable (FOC) to the Onshore Operations Plant (OOP). All pipelines will be buried.

1.2

Purpose of Document This Specification defines the minimum technical requirements for welding and nondestructive testing of the onshore section of the pipeline during installation. It includes butt welding of linepipe and butt welding of fittings to linepipe. Welding shall be suitable for sour service according to NACE MR10175/ISO 15156-2.

1.3

Definitions For a comprehensive list of definitions refer to the Contract Agreement to which this Specification applies. For the purpose of this Specification: ACS COBRA CASTOR

ACS COBRA CASTOR UTE or its appointed representatives.

Contractor

The ACS COBRA CASTOR selected contractor for the provision of the services.

Specifications

Those Specifications contained in the Contract Agreement.

Other defined terms used in this Specification and elsewhere in the Contract Agreement shall have the meaning assigned to them as defined within the General Terms and Conditions. Within the Contract Agreement, defined terms are denoted by means of words with an initial capital. 1.4

Abbreviations EN

European Standard

ISO

International Standard Organisation

MPS

Manufacturing Procedure Specification

MUE

Manual Ultrasonic Examination

PQR

Procedure Qualification Record

QA

Quality Assurance

QC

Quality Control

QP

Quality Plan


Page 3 of 17


SI 1.5

System of International units

Units System of International (SI) units shall be used throughout the design. In accordance with standard industry practice, other units may be used as follows: •

Nominal pipe size

inches [“]

•

Pressure

bar gauge [barg]

•

Temperature

Celsius degree [°C]

Contractor shall take full responsibility for the use of any pre-treatment chemicals and shall take full responsibility for compliance with HSE requirements regarding use and disposal of pre-treatment chemical residues.


Page 4 of 17


2

REFERENCES, CODES AND STANDARDS The latest revision of the following Codes, Standards and Specifications shall apply unless otherwise indicated.

2.1

2.2

2.3

Codes and Standards EN 1011-2

Welding – Recommendations for welding of metallic materials – Part 2: Arc welding of ferritic steels

EN 10204

Metallic Products – Types of Inspection Documents

EN 26847 (ISO 6847)

Covered electrodes for manual metal arc welding. Deposition of a weld metal pad for chemical analysis

ISO 13847: 2000

Petroleum and natural gas industries transportation systems – Welding of pipelines

NACE MR0175/ISO 15156-2

Petroleum and natural gas industries – Materials for use in H2S-containing environments in oil and gas production – Part 2: Cracking-resistant carbon and low alloy steels, and the use of cast irons

–

Pipeline

Project Specifications and Data Sheets 05-3235-7100-1-001

Specification for Linepipe

05-3235-7100-7-004

Data Sheet for Linepipe

Order of Precedence Contractor shall notify ACS COBRA CASTOR of conflict between this Specification, the related Data Sheets, the Codes, Specifications and Standards and any other Specifications noted herein. Resolution and/or interpretation of precedence shall be obtained from ACS COBRA CASTOR in writing before proceeding with the design or manufacture. All written responses to Contractor from ACS COBRA CASTOR shall be binding. However any such response shall not relieve Contractor of his contractual obligations unless specifically stated. In case of conflict, the order of precedence shall be: 1) This Specification 2) Industry Codes and Standards 3) Approved application procedure


Page 5 of 17


3

SCOPE Field welding shall be in accordance with ISO 13847: 2000 (hereafter referred to as ISO 13847) together with the additional and requirements and amendments detailed in this specification. All sections of ISO 13847 shall apply, unless otherwise modified by this Specification. Welding shall be suitable for sour service in accordance with NACE MR0175/ISO 15156-2.


Page 6 of 17


4

MODIFICATIONS OF ISO 13847: 2000 CLAUSES The following sections of this Specification present the modified clauses of ISO 13847. Their numbering and headings are the same as those in ISO 13847. Where modifications are made to an existing clause of ISO 13847, its reference is quoted. Where a clause is added to ISO 13847, the text “Additional to ISO 13847.” is indicated in the section heading.

2

Normative References

Delete the following: “ISO 9956-2:1995 Specification and approval of welding procedures for metallic materials. Part 2: Welding procedure specification for arc welding.” “ISO 9956-3:1995 Specification and approval of welding procedures for metallic materials. Part 3: Welding procedure tests for arc welding steels.” Replace with the following: “EN ISO 15609-1:2004. Specification and qualification of welding procedures for metallic materials- Welding procedure specification -Part 1: Arc Welding. “EN ISO 15614-1: 2004. Specification and qualification of welding procedures for metallic materials- Welding procedure test-Part 1: Arc and gas welding of steels and arc welding of nickel and nickel alloys.

3

Terms and definitions

3.5

by agreement

Replace existing text as follows: agreed between ACS COBRA CASTOR and Contractor. Specification]. 3.6

[Note: see Clause 1.3 of this

company

References to “company” in ISO 13847 shall be read as “ACS COBRA CASTOR”. [Note: see Clause 1.3 of this Specification]. 3.7

contractor

References to “contractor” in ISO 13847 shall be read as “Contractor”. [Note: see Clause 1.3 of this Specification]. Add the following Section: 3.20

approved

Where relevant, ‘approved’ shall have the meaning ‘qualified and approved by ASC COBRA CASTOR’.


Page 7 of 17


5

Welding procedure specification testing and approval

5.1

General

Delete reference to “ISO 9956-3” in the first paragraph and replace with “EN ISO 15614-1” Add the following: Contractor shall specify in his tender the welding process, processes or combination of processes proposed for pipelay or shop welding operations. Manual, semi-automatic or automatic welding processes may be offered. Welding by the Self-Shielded Flux Cored Arc Welding (SSFCAW) process, the oxyacetylene welding process and any process not covered by ISO 13847 shall not be permitted. Preliminary welding procedure specifications (pWPS) shall be submitted to ACS COBRA CASTOR for approval prior to approval qualification testing. Qualification of each agreed pWPS shall be carried-out by non-destructive and mechanical testing of a test weld in accordance with this Specification. A procedure qualification record (PQR) shall be prepared based on the welding variables recorded during test welding and submitted to ACS COBRA CASTOR for approval. As a minimum, the PQR shall include the following documents: •

The preliminary WPS approved by ACS COBRA CASTOR for qualification;

•

A record of actual welding details/variables of the qualification test, including all the details required in Section 5.2 for the WPS;

•

Material certificates and consumable data sheets;

•

PAMS printout of the welding parameters;

•

Summary of welding parameters recorded, including heat input calculation;

•

Pre-heat treatment records (as applicable);

•

Visual Inspection Report;

•

NDT Reports;

•

Laboratory Test Report for mechanical and metallurgical tests from a laboratory approved by ACS COBRA CASTOR.

All welding procedure qualification tests shall be carried-out in the presence of a Representative of ACS COBRA CASTOR Following satisfactory completion of WPQ, a final WPS shall be produced and submitted to ACS COBRA CASTOR for approval for production welding. This shall be based on the pWPS, which shall be modified to reflect any changes that were recorded during the qualification tests. Previously qualified welding procedure specifications shall not be permitted.


Page 8 of 17


5.2

Welding Procedure Specification

Delete reference to “ISO 9956-2 “in first and last paragraph and replace with “EN ISO 156091”. Add the following to the list of requirements of WPS: -

5.3

For mechanised GMAW , GSFCAW or FCAW, the number of welding heads for each pass, contact tip to work distance, inductance setting, mode of transfer, pulse details (if applicable), oscillation frequency and width, dwell time on side wall.. Welding of test piece

5.3.5.1 Girth welds Modify existing text as follows: Test pieces for test welding shall be made by joining pipe pup pieces 1 m in length or 1.5 times the pipe diameter, whichever is greater. When an internal line-up clamp is used in production welding, the length of the pup pieces used in qualification testing shall be sufficient to accommodate the full length of the clamp. The minimum length of test rings for the qualification testing of fittings shall be subject to agreement with ACS COBRA CASTOR. 5.3.5.2 Branch connections and fillet welds Delete reference to “ISO 9956-3” in clause 5.3.5.2 and replace with “EN ISO 15614-1.” 5.4

Inspection and testing of test pieces

5.4.1

Scope of Inspection and testing

Add the following to Table 1 (Inspection and testing of the test pieces for girth welding): -

100% Magnetic particle examination (MPE)

-

100% Manual ultrasonic examination (MUE)

Add the following clarifications: Visual examination shall cover internal and external surfaces. All-weld tensile testing shall be mandatory (One specimen for each test weld). 5.4.2

Non-destructive examination

Delete 2nd paragraph and replace with the following: Non-destructive examination shall be carried-out no sooner than 48-hours after completion of welding.


Page 9 of 17


5.4.3

Destructive testing - Girth welding

5.4.3.4 Transverse tensile testing Delete 4th and 5th paragraph and replace as follows: The minimum tensile strength of the transverse tensile test specimens shall not be less than the minimum tensile strength of the linepipe parent material specified in the Data Sheet for Linepipe 05-3235-7100-7-004. 5.4.3.5 Impact testing Delete 5th paragraph and replace as follows: The Charpy V-notch impact testing temperature and acceptance criteria shall be as specified in the Data Sheet for Linepipe 05-3235-7100-7-004. 5.4.3.7 Hardness testing Add the following clarification: The results of hardness testing shall meet the requirements of Table 2 for sour service. The parent metal hardness values shall not exceed those permitted in the Data Sheet for Linepipe 05-3235-7100-7-004. 5.4.3.8

All-weld-metal tensile testing

Delete existing text and replace with the following: All-weld tensile testing shall be required according to Table 1. The test specimens shall be prepared and tested in accordance with EN 876 or alternative method agreed with ACS COBRA CASTOR. The measured yield strength shall not be less than the SMYS of the parent pipe metal as specified in the Data Sheet for Linepipe 05-3235-7100-7-004. 5.5

Re-testing

5.5.2

Re-testing for approval of WPS

Add the following: Should a welding procedure qualification test fail to meet the minimum requirements of nondestructive and destructive tests, or permitted retests, the welding procedure specification shall be regarded as not complying with the requirements of this specification. The cause of the failure shall be established, rectified and the welding procedure revised to the satisfaction of ACS COBRA CASTOR, before the qualification test is repeated. 5.6

Essential variables and range of approval

5.6.2

related to the contractor

Modify the second paragraph as follows: Approved and qualified welding procedures shall not be transferred from one contractor to another.


Page 10 of 17


5.6.3

Related to the material

5.6.3.1

Steel grade

Modify existing text as follows: Qualification of welding procedures for linepipe shall be carried out on linepipe supplied to the project in accordance with Specification for Linepipe 05-3235-7100-1-001 and Data Sheet for Linepipe 05-3235-7100-7-004. Qualification of welding procedures to connect line pipe directly to components such as fittings, flanges, tee or bends shall be carried out using representative test material. These shall be test rings or actual components produced by the manufacturer of the component to be welded using the same MPS. 5.6.3.2

Chemical composition

Modify existing text as follows: Based on product analysis, a change in the CE value greater than +0.01 or -0.03 or greater than +0.01 or -0.02 Pcm shall require requalification. CE shall be calculated as follows:

CE = %C +

%Mn 6

+

(%Cr + %Mo + %V) 5

+

(%Cu + %Ni) 15

Pcm shall be calculated as follows: Pcm = %C +

%Si 30

+

%Mn 20

+

%Cu 20

+

%Ni 60

+

%Cr 20

+

%Mo 15

+

%V 10

+ %B x 5

5.6.3.3 Supply condition Add the following:

Any change in the linepipe supplier shall require requalification of the WPS. 5.6.3.4 Thickness Delete 1st paragraph and replace as follows:

For girth welding, the approved pipe thickness range shall be as follows:

5.6.4 5.6.4.7

•

t ≤ 30 mm: 0.75 to 1.5 times the wall thickness of the test piece.

•

t > 30 mm: 0.75 to 1.25 times the wall thickness of the test piece.

Related to all welding processes Arc energy

Modify the existing text as follows:

Any change in arc energy for each pass outside the range in the approved WPS shall constitute an essential variable.


Page 11 of 17


The qualifying heat input range for the root pass, hot pass, fill pass and cap pass shall be considered separately. When Contractor opts to carry-out separate qualification tests at the proposed maximum and minimum heat input, in order to extend the heat input qualification range, the heat input tolerance shall not exceed the maximum and minimum recorded in all qualification tests. 5.6.4.15

Time interval

Modify existing text as follows:

The approved time lapse between root and hot pass for any welding consumable type shall not exceed that recorded during qualification. 5.6.5

Related to specific welding processes

5.6.5.1 Shielded metal arc welding and self-shielded flux-cored arc welding Add the following:

Self-shielded flux cored arc welding shall not be permitted (See Clause 5.1). 5.6.5.3 Gas metal arc welding and gas-shielded flux-cored arc welding Add the following:

For GMAW and GSFCAW the approved electrical characteristics and transfer mode shall be the same as that used for welding of the test piece.

6

Approval and testing of welders and welding operators

Add the following general clarification:

Welders shall be qualified by CENIM (Centro Nacional de Investigaciones Metalurgicas) or third party authorized to check compliance according to Reglamento de Gases Combustibles. 6.5

Inspection and testing of test welds

6.5.1



Non destructive examination of welder test pieces shall include visual examination of external and internal surfaces and radiography. In the case of welds carried out by the GMAW and GSFCAW processes, manual ultrasonic examination shall be carried-out in addition. 6.7

Range of approval

Add the following to g):

Same electrode manufacturer and brand name. Delete j) and replace as follows:

j) welding equipment and system: same make and model of welding equipment or system.


Page 12 of 17


6.8

Records

Add the following:

For details on the procedure qualification record (PQR) reference is made to Section 5.1. 6.9

Period of validity

Delete 2nd paragraph, 1st sentence and replace as follows:

The qualification and ACS COBRA CASTOR approval of a welder or welding operator shall remain valid for a period of one year provided that:

7

Production Welding

7.1

General

Add the following:

Contractor shall provide independent means for accurate monitoring of the welding parameters defined in the agreed welding procedure specifications. 7.2

Equipment

Add the following:

Automatic welding equipment shall be the same make and model as used in production. 7.10

Electrodes and filler materials

Add the following:

Filler metals and fluxes shall conform to the appropriate American Welding Society (AWS) and/or British Standard and shall be subject to approval by ACS COBRA CASTOR before starting work. The use of cellulosic electrodes for welding butt joints in pipe and fittings shall be restricted to welding of the root and hot pass only. Repair welding and welding of fittings shall be carried out using low hydrogen consumables. Additional requirements for handling and control of consumables are as follows: Records of consumable usage shall be maintained such that source, type and batch of welding consumables used for each weld can be identified. Consumables shall be supplied in sealed, dirt and moisture-resistant packages. Damaged packages and any consumables showing any signs of damage, deterioration, corrosion or any other contamination shall not be used. Each coil of filler wire, bag of flux and tin or packet of electrodes shall be clearly marked with its batch number and shall be stored completely separated. Consumables shall be stored and handled at all times in such a way as to avoid damage and contamination to them or their containers. Any consumables in open containers shall be protected from excessive moisture changes.


Page 13 of 17


Special care shall be taken by Contractor to ensure that basic coated low hydrogen electrodes are stored in sealed containers in a warm, dry environment. Prior to use, low hydrogen electrodes shall be baked in accordance with the manufacturer’s instructions to give a diffusible hydrogen content of less than 5ml/100g of deposited weld metal. After baking, the electrodes shall be transferred to a holding oven operating at 150˚C minimum, where they may be stored for a period of up to 7 days and after which they shall be re-baked. Electrodes shall not be re-baked more than two times. A procedure for marking and tracking electrodes on their baking route shall be proposed by Contractor for ACS COBRA CASTOR approval. Low hydrogen electrodes shall be issued for use from the holding ovens into heated quivers held at 70˚C minimum. Any low hydrogen electrode remaining unused after 4 hours in a quiver shall be returned to the baking oven and re-dried for 2 hours at 350˚C before being returned to the holding oven. Vacuum packed, low hydrogen electrodes may be used without prior baking, provided they are used within the consumable manufacturer’s guidelines. Add the following mandatory requirements for batch testing of welding consumables:

Batch testing of welding consumables is required as detailed below: The purpose of batch testing is to verify that the consumables used for girth welds remain nominally equivalent to that used for welding procedure qualification, with respect to chemistry and mechanical properties. A batch is defined as the volume of product identified by the consumable manufacturer under one unique batch number, manufactured in one continuous run from batch controlled raw materials. Each individual product (brand name and dimensions) shall be tested once per batch, except for solid wire originating from the same heat, where one diameter may represent all. SAW fluxes do not require individual testing, however, SAW wires shall be tested in combination with a selected, nominal batch of flux. The testing shall be performed on samples taken from girth welds welded according to the welding procedure specification to be used in production. Three samples shall be removed from the 12 and 6 o'clock position and from the 3 or 9 o'clock position. The testing of each sample shall include: a)

1 all-weld metal tensile test. Hardness testing (HV10) of the centre at the end of each grip;

b)

1 macro section taken adjacent to the all-weld metal tensile test. The macro section shall be hardness tested (HV10) vertically through the weld centre line with indentations spaced 1.5mm apart;

c)

1 set of Charpy V-notch test at weld centre line in half thickness. temperature shall be as specified in clause 5.4.3.5;

d)

Chemical analysis. For solid wire and metal powders, the analysis shall represent the product itself. For coated electrodes and cored wires, the analysis shall represent the weld metal deposited according to EN 26847 (ISO 6847). The analysis shall include all elements specified in the relevant classification standard and the relevant data sheet.


The test

Page 14 of 17


The mechanical properties shall meet the specified requirements for the welding procedure specification. Batch tests shall be documented by an inspection certificate to EN 10204 3.1 with reference to a recognised product qualification standard and contain all specified results. 7.12

Preheating

Add the following:

The minimum preheat shall comply with EN 1011-2. Preheat shall be applied when required by the qualified WPS. In all cases, preheat shall be required when the ambient temperature measured on the pipe is below 10˚C and to ensure that the weld area is dry. A minimum preheat temperature of 150˚C shall be used for welding fittings and for repair welds. The use of hand held torches for the application of preheat is not permitted. 7.18

Partially completed welds

Delete the existing text of the 5th paragraph as follows:

“Partially completed welds should be rejected when welding has been interrupted before completion of three passes. Additional inspection may be specified in case completion of such welds is permitted” Replace with the following:

Welding shall not be interrupted before the joint has sufficient strength to avoid plastic yielding and cracking during handling. Prior to restart after an interruption, preheating to the minimum inter-pass temperature of the pass in question shall be applied. 7.19

Post-weld heat treatment

Post weld heat treatment shall not normally be required.


Page 15 of 17


8


8.1

General

Add the following:

All production welds shall be subjected to the following visual and NDE: a)

100% radiography.

b)

100% external visual.

Manual UE may be used as an aid in interpretation of radiography. 8.6

Ultrasonic examination

8.6.4

Manual ultrasonic examination

Add the following:

Manual UE shall not be used as the primary NDE method, without the prior approval of ACS COBRA CASTOR. 8.6.5

Mechanised examination

Not applicable.

9

Acceptance criteria for non destructive examination

9.3

Visual examination

Add the following:

External surface breaking lack of fusion or lack of penetration is unacceptable. 9.6

Surface testing

9.6.2

Acceptance criteria

Add the following:

External surface breaking lack of fusion or lack of penetration is unacceptable.


Page 16 of 17


9.8

Acceptance criteria - ECA

Not applicable.

10

Repair and removal of defects

10.1

General


The extent of testing to qualify welding repair procedure specifications shall be as follows: a)

Full penetration repairs.

Testing and inspection requirements are the same as normal production welds.

b)

Partial penetration repairs.

Any relaxation of testing requirements, compared to normal production welds, shall be subject to approval of ACS COBRA CASTOR.

c)

Single pass repairs.

In the case of single pass repairs, mechanical qualification testing shall comprise one macro/hardness examination.

10.4

Defect removal and preparation for repair

Add the following:

In the event that cracks are detected in a weld, the complete weld shall be cut out of the pipeline. The cause of the cracking shall be determined by Contractor and precautions against a reoccurrence of the cracking justified to ACS COBRA CASTOR.

Annex A

Hyperbaric welding

Not applicable.

Annex B

Special requirements for welding of CRA-clad steel and CRA pipelines

Not applicable

Annex C

Recommendations for brazing and aluminothermic welding of anode leads

Not applicable.


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05-3300-01-W-01-009 Pipeline Welding and NDT Spec (Onshore) Rev P2

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