pheonwj-w-prc-0005~2 (guidance for pipeline welding)
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SpecTRANSCRIPT
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PT. PHE ONWJ Guidance for Pipeline Welding
PHEONWJ-W-PRC-0005 Rev.2 Page 2 of 49
Revision Log Register
Document Number : PHEONWJ-W-PRC-0005
Document Title : Guidance for Pipeline Welding
Revision : 2
Page Date Revision
PHE ONWJ
Reviewer
All 29-Sep-11 Change document title:
Jimmi Beng/
Soeryono
Nano
Old: STP for Pipeline Welding
New: Guidance for Pipeline Welding
All 29-Sep-11 Replace PHE ONWJ Ltd. with PT. PHE ONWJ
Jimmi Beng/
Soeryono
Nano
All 29-Sep-11 Replace text STP with guidance
All 29-Sep-11 Replace GP 18 02 with PHEONWJ-W-SPE-0008
All 29-Sep-11 Replace GP 43 34 with API 1104
1 of 53 29-Sep-11 Replace Revision Log Register page with new standard.
2 of 53 29-Sep-11 Delete Foreword page
52 of 53 29-Sep-11 Delete Bibliography page
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PT. PHE ONWJ Guidance for Pipeline Welding
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Table of Contents
Page
Table of Contents ............................................................................................................................................3
Introduction .....................................................................................................................................................6
1 General ..................................................................................................................................................7
1.1 Scope ........................................................................................................................................7
1.2 Welding Process Restrictions ....................................................................................................7
1.3 HSSE for Pipeline Welding Operations ......................................................................................7
1.4 Pre-Production Consultation ......................................................................................................8
1.5 General Duties of the Contractor ...............................................................................................8
1.6 Quality Assurance......................................................................................................................8
1.7 Records .....................................................................................................................................8
1.8 Contractors Personnel ..............................................................................................................8
1.9 Abbreviations and Acronyms ...................................................................................................10
2 Referenced Publications ......................................................................................................................11
3 Definitions of Terms ............................................................................................................................13
3.2 Definitions ...............................................................................................................................13
4 Specifications ......................................................................................................................................13
4.1 Equipment ...............................................................................................................................13
4.2 Materials..................................................................................................................................14
4.3 Minimum design temperature (MDT) ......................................................................................16
5 Qualification of Welding Procedures for Welds Containing Filler-Metal Additives................................16
5.1 Procedure qualification ............................................................................................................16
5.2 Record .....................................................................................................................................16
5.3 Procedure Specification ...........................................................................................................17
5.4 Essential Variables ...................................................................................................................20
5.5 Welding of Test JointButt Weld ...........................................................................................22
5.6 Testing of Welded JointsButt Welds....................................................................................22
5.7 Welding of Test JointsFillet Welds.......................................................................................29
5.8 Testing of Welded JointsFillet Welds...................................................................................29
6 Qualification of Welders ......................................................................................................................30
6.1 General ....................................................................................................................................30
6.2 Single Qualification ..................................................................................................................31
6.3 Multiple Qualifications .............................................................................................................31
6.4 Visual examination...................................................................................................................31
6.6 Radiographybutt welds only .................................................................................................31
7 Design and Preparation of a Joint for Production Welding................................................................... 31
7.1 General ....................................................................................................................................31
7.2 Alignment ................................................................................................................................32
7.3 Use of Line-Up Clamp for Butt Welds......................................................................................32
7.4 Bevel .......................................................................................................................................33
7.5 Weather Conditions .................................................................................................................34
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7.6 Clearance.................................................................................................................................34
7.7 Cleaning between Beads.........................................................................................................34
7.10 Identification of Welds.............................................................................................................34
7.11 Pre-and Post-Heat Treatment ..................................................................................................34
7.12 Weld Interruption.....................................................................................................................35
7.13 Branches .................................................................................................................................36
7.14 Fillet Weld Attachments ..........................................................................................................36
8 Inspection and Testing of Production Welds........................................................................................37
8.1 Rights of Inspection.................................................................................................................37
8.2 Methods of Inspection.............................................................................................................37
8.3 Qualification of Inspection Personnel ......................................................................................37
8.4 Certification of Non-Destructive Testing Personnel .................................................................37
9 Acceptance Standards for Non-Destructive Testing ............................................................................38
9.1 General ....................................................................................................................................38
9.3 Radiographic Testing ...............................................................................................................38
9.7 Visual Acceptance Standards for Undercutting ........................................................................39
9.8 Suspect Welds ........................................................................................................................39
10 Repair and Removal of Defects ...........................................................................................................39
10.1 Authorisation for Repair...........................................................................................................39
10.2 Repair Procedure .....................................................................................................................40
10.6 Arc Burns.................................................................................................................................41
11 Procedures for Non-Destructive Testing..............................................................................................42
11.1 Radiographic Test Methods.....................................................................................................42
11.2 Magnetic Particle Test Method................................................................................................44
11.4 Ultrasonic Test Methods .........................................................................................................44
12 Mechanised Welding with Filler Metal Additions.................................................................................44
12.2 Procedure Qualification............................................................................................................45
12.3 Record .....................................................................................................................................45
12.4 Procedure Specification ...........................................................................................................45
12.5 Essential Variables ...................................................................................................................45
12.6 Qualification of Welding Equipment and Operators .................................................................45
13 Automatic Welding without Filler-Metal Additions...............................................................................46
Appendix AAlternative acceptance standards for girth welds.....................................................................46
Appendix B In-service welding....................................................................................................................46
B.1 General ....................................................................................................................................46
Appendix C Additional requirements for pipelines subject to high strain levels...........................................46
C.1 Introduction .............................................................................................................................46
C.2 General ....................................................................................................................................46
C.3 Weld procedure qualification testing .......................................................................................47
C.4 Production welding ..................................................................................................................48
Appendix DCTOD testing ...........................................................................................................................48
Appendix EPin brazing and aluminothermic welding of anode leads ..........................................................49
E.1 Joining technique ....................................................................................................................49
E.2 Specification and approval of procedure ..................................................................................49
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List of Tables
Table A - Grade and thickness limits for cellulosic electrodes........................................................................14
Table B - Diameter and test pipe thickness range of approval .......................................................................17
Table C - Minimum preheat levels for SMAW (cellulosic) welds....................................................................19
Table D - Specified minimum delay time before NDT for WPQT welds .........................................................23
Table 2 - Type and number of test specimens (a) for procedure qualification test .........................................25
Table E - Charpy impact test requirements ....................................................................................................27
Table F - Maximum permissible weld and HAZ hardness values (HV10)........................................................29
Table G - Type and number of test specimens for repair weld procedure qualification test........................... 41
Table H - IQI sensitivity levels........................................................................................................................43
List of Figures
Figure 3 - Location of test pieces from a butt weld in pipe ............................................................................24
Figure A - Charpy V notch locations ...............................................................................................................26
Figure B - Locations for hardness indents......................................................................................................28
Figure C - Fillet weld hardness indent locations.............................................................................................30
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Introduction
a. This guidance for pipeline welding is based on API STD 1104.
b. Guidance statements of this document are modifications to API 1104, Welding of
Pipelines and Related Facilities, Twentieth Edition, November 2005.
c. Modifications to API 1104 are identified as Add, Modify to Read, or Delete.
d. Paragraph numbers in this specification correspond to API 1104.
e. Paragraphs of API 1104 that are not revised remain applicable.
f. If any statement is contradictory to API 1104, the requirements of this guidance shall take
precedence.
g. The technical integrity of all aspects of design, construction, and operation of pipelines is
of the highest importance to PT. PHE ONWJ and compliance with PT. PHE ONWJ policy
shall remain paramount.
The normative text of API 1104 and this guidance is primarily applicable to the main line, double
joint, and tie-in welding operations for the construction of C-Mn steel and low alloy steel
pipelines.
This guidance has been written primarily for pipelines up to X80 grade. However, it also allows
for construction of pipelines in higher strength steels up to Grade X120 (which are not yet
included in the base API 1104 standard and for which some parameters such as mechanical
properties and defect acceptance criteria will need to be specified individually).
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1 General
1.1 Scope
The scope includes the off-line fabrication of items such as welding nipples to valve bodies or
other fittings and the fabrication welding of branches. The following items are outside the
scope of this guidance:
- Corrosion resistant alloy (CRA) clad linepipe
- Solid CRA linepipe
- The welding of process piping in terminals, pump or compressor stations, or in refineries
- Hyperbaric welding
- Wet welding
- Overlay welding
- Steel catenary risers (SCRs)
Additional requirements for high strain pipelines are given in Appendix C.
Requirements for pin brazing and aluminothermic welding of anode leads are given in
Appendix E
1.2 Welding Process Restrictions
Mechanised and automatic welding processes are preferred and should be used whenever
possible for pipeline girth welding. Main line welding should be by mechanised or automatic
gas metal arc welding (GMAW) which may include single, multi-torch, or tandem-arc variants of
the process and the use of cored wires. If the use of mechanised or automated GMAW
processes is impracticable, alternative processes may be used. In such instances, welding may
be performed by shielded metal arc welding (SMAW), manual or automated gas tungsten arc
welding (GTAW), semi-automatic GMAW processes using solid or cored wires, or a
combination of these processes.
For double or multiple jointing, girth welds should be made using submerged arc welding
(SAW) whenever possible. If SAW cannot be used, the alternative mainline processes listed
above may be utilised either alone or in combination with SAW.
The welding of pipelines by the oxy-acetylene process or by the flash butt welding process
(FBW) or by any other process not defined above is not permitted.
1 .3 HSSE for Pipeline Welding Operations
Welding, cutting, NDT, and associated operations shall be undertaken in a safe manner and
with due regard to individual health and safety and the minimisation of environmental impact.
Welding, cutting, NDT, activities and associated operations shall feature in the operational
safety planning and in the safety audit schedule.
During welding operations, adequate ventilation shall be provided and the quality of breathing
air shall be controlled.
Detail of good practice related to safety during welding, cutting, and associated
operations can be found in AWS Z49.1.
Radiography operations shall conform to local regulations regarding the dangers of ionizing
radiation.
Environmental guidance shall be taken from EN 14717 when undertaking welding and its
associated processes.
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1.4 Pre-Production Consultation
Pre-production meetings shall be held with PT. PHE ONWJ, the Contractor and any third-party
inspection personnel in order to ensure that all parties fully understand the specified
requirements. These meetings shall be held before welding procedure qualification testing and
before commencement of fabrication.
The PT. PHE ONWJ Welding Engineer shall, as a minimum, be consulted at the following
stages:
a. During bid evaluation to review the basic welding and NDT methods proposed and to
advise on acceptability.
b. Before weld procedure qualification for approval of the proposed welding procedures.
c. Before production welding for final WPS approval.
1 .5 General Duties of the Contractor
Be responsible for quality assurance.
Be responsible for the compliance of sub-contractors with this guidance.
Unless advised otherwise by PT. PHE ONWJ, supply necessary welding and associated
equipment including, but not limited to: heating equipment, fluxes, gases, filler metals,
mechanical handling, and testing equipment.
If NDT is conducted by the contractor, appropriate NDT equipment including consumables and
handling equipment shall be provided.
If NDT services and equipment are provided by sub-contractors, ensure that the equipment
provided is suitable, well maintained, and, if necessary, is calibrated.
1.6 Quality Assurance
The quality assurance system shall comply with either ISO TS 29001 (API Q1 ) or ISO 9001.
A Quality Plan for the systematic control of construction, inspection, and testing shall be
prepared and implemented. The Quality Plan shall define inspections and tests, the sequence
in which they are to be performed during fabrication, and the level of involvement for the
contractors quality control/inspection personnel, third-party inspection personnel, and PT.
PHE ONWJ.
The Quality Plan shall be submitted to PT. PHE ONWJ and approval obtained before
commencement of fabrication.
1 .7 Records
Documentation shall be collated, indexed, stored safely, and presented to PT. PHE ONWJ. A
log identifying, by number, each pipe or fitting and identifying the weld numbers joining them
to other items, shall be compiled. Each circumferential weld (whether a field joint or shop-made
weld) shall be allocated a unique number, which shall be used for reference to the weld in
reports, radiographs, and test documents.
1 .8 Contractors Personnel
1.8.1 Welding Engineer
A competent and suitably qualified Welding Engineer shall be employed. The Welding Engineer
shall be responsible for the technical aspects of welding operations including the following:
a. Selection of welding processes, equipment, and consumables
b. Preparation and qualification of welding procedures
c. Qualification of welders
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d. Providing technical oversight of the production welding
e. Liaison with PT. PHE ONWJ and the NDT sub-contractors
The minimum experience and qualification level for the Welding Engineer should be:
- In USA: Professional Engineer (PE) holding as a minimum a degree in engineering,
metallurgy or materials science and having specialised training in welding technology.
Membership of American Welding Society (AWS) is desirable and a minimum of 5 years
relevant experience in the pipeline welding or fabrication industry is essential.
- In Europe/Rest of the World: Chartered Engineer (CEng/ Dipl Ing) holding, as a minimum, a
degree in engineering, metallurgy or materials science and having specialised training in
welding technology. The requirements of 5.2.2, EN 719 should be met as demonstrated
by the European Welding Engineer (EWE) or International Welding Engineer (IWE)
qualification. Professional Membership of The Welding Institute (UK) is desirable and a
minimum of 5 years relevant experience in the pipeline welding or fabrication industry is
essential.
1 .8.2 Welding Inspectors
Competent and certificated welding inspection personnel shall be employed in sufficient
numbers to ensure that welding related activities are adequately inspected.
Welding Inspectors shall have a sound knowledge of welding processes and their application to
pipeline welding, and possess the knowledge and skills to carry out the tasks given in the
approved Quality Plan, including those necessary for the following:
- Conduct of routine inspections and checks on site or at suppliers in a systematic manner
- Production of accurate records and reports
Welding Inspectors shall hold current certification to any of the following standards as a
minimum:
- CSWIP (TWI, UK) Welding Inspector
- BGAS-CSWIP (TWI, UK) Welding Inspector
- PCN (BINDT, UK) Weld Inspection Level 2
- AWS QC1 (1996 or later edition) Certified Welding Inspector (CWI)
- MIGAS Welding Inspector
Alternative Welding Inspector certification is unacceptable unless approved by PT. PHE ONWJ.
A Senior Welding Inspector shall be employed to coordinate and supervise the work of the
welding inspectors. The role of Senior Welding Inspector requires at least 10 years relevant
experience and sound knowledge of welding processes and their application. Formal
engineering training through apprenticeship and technical college education are required.
Senior Welding Inspectors shall hold current certification to any of the following standards as a
minimum:
- CSWIP (TWI, UK) Senior Welding Inspector
- BGAS-CSWIP (TWI, UK) Senior Welding Inspector (SWI) or Senior Pipeline Inspector (SPI)
- PCN (BINDT, UK) Weld Inspection Level 3
- AWS QC1 (1996 or later edition) Senior Certified Welding Inspector (SCWI)
- MIGAS Welding Inspector
1.8.3 NDT Personnel
NDT personnel shall hold current Level 2 certification (or equivalent), specific to weld testing,
for the appropriate NDT methods to any of the following standards as a minimum:
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- CSWIP (TWI, UK)
- BGAS-CSWIP (TWI, UK)
- PCN (BINDT, UK)
- ACCP (ASNT)
- SNT-TC--1A (ASNT)
NDT personnel certificated to the requirements of a Written Practice under the rules of
SNT-TC-1A shall not be used, unless the Written Practice and the personnel certification has
been reviewed and accepted by PT. PHE ONWJ for the specific work.
1.9 Abbreviations and Acronyms
The following abbreviations and acronyms are used in this guidance:
ACCP ASNT Central Certification Program
AUT Automatic Ultrasonic Testing
BAM Federal Institute for Materials Research and Testing (Germany)
BGAS-CSWIP British Gas Approval Scheme Certification Scheme for Welding and
Inspection Personnel
BINDT British Institute of Non-Destructive Testing
CE
IIW
Carbon equivalent (IIW formula)
C Eng Chartered Engineer (UK)
CP Cathodic protection
CRA Corrosion resistant alloy
CSWIP Certification Scheme for Welding and Inspection Personnel
CTOD Crack tip opening displacement
CVN Charpy V-notch
Dipl Ing Diploma Ingenieur (Europe)
ECA Engineering Critical Assessment
FCAW Flux-cored arc welding
GMAW Gas-metal arc welding
GS-FCAW Gas-shielded flux-cored arc welding
GTAW Gas tungsten arc welding
HAZ Heat affected zone
HV Vickers hardness
ID Internal diameter
IIW International Institute of Welding
IQI Image Quality Indicator
MDT Minimum design temperature
MT Magnetic testing
MUT Manual ultrasonic testing
NDT Non-destructive testing
NIST National Institute of Standards and Technology (USA)
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OD Outside diameter
P
CM
Cracking parameter (Ito-Bessyo formula)
PCN Personnel certification in non-destructive testing
P-GMAW Pulsed gas metal arc welding
PQR Procedure Qualification Record
PT Penetrant testing
pWPS Preliminary welding procedure specification
RMS Root mean squared
RT Radiographic testing
SAW Submerged arc welding
SCR Steel catenary riser
SMAW Shielded metal arc welding
SMYS Specified minimum yield strength
SS-FCAW Self-shielded flux-cored arc welding
SWE Single wall examination
SWV Single wall viewing
TWI The Welding Institute (UK)
UT Ultrasonic testing
VT Visual testing
WPQT Welding Procedure Qualification Test
WPS Welding procedure specification
2 Referenced Publications
The following standards contain requirements that, through reference in this text, constitute
requirements of this guidance. For references below that are dated, subsequent amendments
to, or revisions of, any of these publications do not apply, although parties to agreements based
on this guidance are encouraged to investigate the possibility of applying the most recent
editions of the standards indicated below. For references below that are undated, the latest
edition of the referenced standards applies.
API
Q1 Specification for Quality Programs for the Petroleum, Petrochemical and
Natural Gas Industry
ASTM
A370 Standard Test Methods and Definitions for Mechanical Testing of Steel
Products
E23 Standard Test Methods for Notched Bar Impact Testing of Metallic Materials
E92 Standard Test Methods for Vickers Hardness of Metallic Materials
E1815 Standard Test Method for Classification of Film Systems for Industrial
Radiography
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AWS
D1.1/D1.1M Steel Structural Welding Code
A4.3 Determination of Hydrogen Content Produced by Arc Welding
C5.3 Recommended Practices for Air Carbon Arc Gouging and Cutting
A5.32 Specification for Welding Shielding Gases
BSI
BS 4515-1 Specification for Welding of Steel Pipelines on Land and Offshore Part 1 :
Carbon and Carbon Manganese Steel Pipelines
BS 7448-1 Fracture mechanics toughness tests. Part 1. Method for the determination
of K
IC
, critical CTOD and critical J values of metallic materials
BS 7910 Guide on methods for assessing the acceptability of flaws in metallic
structures
Canadian Standards Association (CSA)
CSA Z245.1 Steel Line Pipe
CSA Z662 Oil and Gas Pipeline Systems
European Standard (EN)
EN 439 Welding consumables Shielding gases for arc welding and cutting
EN 719 Welding coordination. Tasks and responsibilities
EN 875 Destructive tests on welds in metallic materials - Impact tests - Test
specimen location, notch orientation and examination
EN 1011-2 Welding recommendations for welding of metallic materials Part 2: Arc
welding of ferritic steels
EN 10045-1 Charpy impact test on metallic materials - Part 1 : Test method (V- and
U-notches)
EN 10204 Metallic products - Types of inspection documents
EN 10208-1 Steel pipes for pipelines for combustible fluids. Technical delivery conditions.
Pipes of requirement class A
EN 10208-2 Steel pipes for pipelines for combustible fluids. Technical delivery conditions.
Pipes of requirement class B
EN 14717 Welding and allied processes Environmental check list
International Organisation for Standardisation (ISO)
ISO 148 Steel - Charpy impact test (V-notch)
ISO 2504 Radiography of welds and viewing conditions for films - Utilization of
recommended patterns of image quality indicators (I.Q.I.)
ISO 3183 Petroleum and natural gas industries Steel pipe for pipeline transportation
systems
ISO 3690 Welding and allied processes - Determination of hydrogen content in ferritic
steel arc weld metal
ISO 5580 Non-destructive testing - Industrial radiographic illuminators - Minimum
requirements
ISO 6507-1 Metallic materials Vickers hardness test Part 1: Test method
ISO 9001 Quality management systems - Requirements
ISO 10005 Quality management Guidelines for quality plans
ISO 11699-1 Non-destructive testing - Industrial radiographic films Part 1: Classification
of film systems for industrial radiography
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ISO 17636 Non-destructive testing of welds Radiographic testing of fusion-welded
joints
ISO 17638 Non-destructive testing of welds Magnetic particle testing
ISO 17640 Non-destructive testing of welds Ultrasonic testing of welded joints
ISO TS 29001 Petroleum, petrochemical and natural gas industries - Sector-specific quality
management systems requirements for product and service supply
organizations
3 Definitions of Terms
3.2 Definitions
3.2.3 Company
PT. PHE ONWJ or its authorized representative
3.2.4 Contractor
A contractor responsible to PT. PHE ONWJ for construction (including welding) of the pipeline
3.2.21 Arc Energy
The unfactored energy input calculated from the current, voltage and travel speed.
Note: Heat input requires an efficiency factor dependent on the welding process.
3.2.22 PT. PHE ONWJ
PT. PHE ONWJ, an associate or subsidiary of PT. PHE ONWJ, or other organization as defined
in the Conditions of Contract on a project.
3.2.23 Lot
A single heat of filler wire, a single blend of flux, or for covered electrodes or cored wire, the
combination of a single heat of cored wire with a single dry blend of flux cover or core.
3.2.24 Quality Plan
Document specifying which procedures and associated resources shall be applied by whom
and when to a specific project, product, process or contract.
Note: Guidance for the production of Quality Plans is given in ISO 10005.
4 Specifications
4.1 Equipment
Welding power supply voltage and amperage meters shall be calibrated. Independent calibrated
instrumentation shall be provided to measure relevant parameters during production. NDT
equipment shall also be calibrated. Certificates showing that equipment calibration is valid for
the period of use shall be available.
The manufacturer, model and type of equipment shall be identified in the Procedure
Qualification Record (PQR).
SMAW electrode holders shall be fully insulated.
Welding return cables connections shall be of sufficient cross-sectional area to prevent
concentration of current and shall be securely attached to prevent arc burns.
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4.2 Materials
4.2.1 Pipe and Fittings
c. ISO 3183
d. EN 10208
e. CSA Z245.1
The requirements given apply to materials that comply with any of the standard specifications
listed in a & b (in API 1104) and c to e above. Note that API 5L is supplemented by PHEONWJ-
W-SPE-0005 and that PHE ONWJ supplementary requirements may be applied to any of the
above specifications. Other material specifications may be used if required by statutory
regulations of the countries in which the pipeline will operate.
4.2.2 Filler metal
4.2.2.1 Type and size
In principle, the yield strength of the weld metal should be selected to ensure that the yield
strength of the deposited pipeline girth welds overmatches the actual yield strength of the
parent pipe material. Additional guidance will be provided by the pipeline designer. The
deposited weld metal shall also meet the specified ductility, toughness, and limiting hardness
criteria in accordance with the pipeline design and with this guidance.
4.2.2.1 .1 Limitations of use for cellulosic electrodes
Cellulosic coated electrodes shall not be used for:
- Pipe grades and thicknesses beyond those shown in Table A
- Pipelines subject to high strain (e.g. reeled pipelines)
- Strain based design pipelines
- The welding of fittings, flanges and valves
- Fillet welding (e.g. for anode doubler plate attachment)
In applications in which cellulosic SMAW consumables are being evaluated for use, the
possibility of employing low hydrogen vertical down electrodes shall be considered.
Cellulosic electrodes shall neither be baked nor dried and shall be used straight from the
original packaging.
Table A - Grade and thickness limits for cellulosic electrodes
Pipe Grade
(API 5L)
Pipe Grade
(ISO 3183)
(EN 10208)
(CSA Z.245)
Maximum Wall Thickness
(a,b)
< X65 < L450 3/4 (approx 19 mm)
X70 L485 5/8 (approx 16 mm) with E8010 fill passes
3/8 (approx 10 mm) with E9010 fill passes
X80 L555 Root & hot pass only
> X80 > L555 Not permitted
a. E6010 or E6011 electrodes may be used for root pass welding provided sufficient overall weld
strength and toughness is obtained.
b. Preheat shall be applied to cellulosic welds (see 5.3.2.13 and 7.11 .1 ).
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4.2.2.1 .2 Consumable selection for root welding
In some instances it may be necessary to select a root welding consumable having a specific
chemical analysis in order to provide resistance to preferential weld metal corrosion. The
pipeline designer will provide advice on any such requirement. If a weld metal composition is
specified, then one root weld metal chemical analysis shall be conducted for each WPS and
each weld repair procedure to check that the required composition has been achieved.
4.2.2.2 Storage and handling of filler metals and fluxes
The storage and handling of welding consumables shall be in accordance with PHEONWJ-W-
SPE-0008. A detailed consumable storage and handling plan shall be submitted for PT. PHE
ONWJ review and approval.
4.2.2.3 Consumable lot testing by supplier*
*Note: Some standards, project specifications and/or consumable
suppliers may refer to Consumable Batch Testing.
Each lot of welding consumables shall have a consumable manufacturers certificate
conforming to the relevant ISO, AWS or EN filler metal specification. The testing of each lot
shall include actual deposited weld metal chemical composition, tensile and Charpy impact
tests; refer to PHEONWJ-W-SPE-0008.
For low hydrogen SMAW consumables, manufacturers certificates shall include average-
diffusible-hydrogen level as determined and reported in accordance with ISO 3690 or
ANSI/AWS A4.3.
Certificates shall comply with PHEONWJ-W-SPE-0008 and EN 10204 type 3.1 .b.
SAW wire shall be tested in combination with the same brand and classification of flux as that
to be used during production welding.
The consumable certificates shall be examined to verify that the same weld properties can be
expected for the production welds as those obtained during weld procedure testing.
4.2.2.4 Additional lot testing
Only the lots of consumables mechanically tested during qualification of the weld procedure
shall be used for production welding of the following pipeline types:
- If the NDT acceptance criterion has been established by an ECA
- For pipe grades of X65 and above
- If consumables with an AWS G designation are used, e.g. E8010-G or ER70S-G
Testing may be conducted to gain approval for additional lots of consumables. Testing shall be
undertaken on a weld made in accordance with the production WPS and shall include:
- 2 all-weld tensile tests
- 2 sets of weld metal Charpy impact tests
- 1 macro-section and hardness survey sampled from the 3 oclock position
- 1 set of weld metal CTOD tests
The testing shall be in accordance with 5.6. The results shall meet the levels required for the
relevant weld procedure(s) and, if applicable, the ECA.
4.2.3 Shielding gases
4.2.3.3 Compliance
Shielding gases shall meet BS EN 439 or AWS A5.32. They shall be pre-mixed and bottled by
the supplier and shall have certificates of compliance. The certificates shall show the
composition and dew point. Subject to PT. PHE ONWJ approval, Ar/CO
2
gases may be mixed at
site.
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4.3 Minimum design temperature (MDT)
Unless otherwise specified in the contract, the MDT shall be 0C (32F).
5 Qualification of Welding Procedures for Welds Containing Filler-
Metal Additives
5.1 Procedure qualification
5.1 .1 General
Preliminary Welding Procedure Specifications (pWPSs) shall be submitted for PT. PHE ONWJ
agreement before commencement of the Welding Procedure Qualification Tests (WPQTs).
Welding procedures, including fillet welds and repair procedures, shall be qualified by visual
examination, NDT, and mechanical testing as specified in this guidance.
Welding, NDT and mechanical testing of the WPQT welds shall be witnessed by PT. PHE
ONWJ or an approved third party. The witnessing of mechanical tests shall include the
positioning of the notches for Charpy and CTOD tests.
A WPS written with more than one supporting Procedure Qualification Record (PQR) shall not
permit optional processes, but shall uniquely specify the process for each pass.
5.1 .2 Welding Procedure Parameters
During weld procedure qualification, relevant procedure data, irrespective of whether the item
is a listed essential variable, shall be captured and recorded. Sufficient information shall be
recorded to allow full replication of the procedure qualification welds. A record of the data shall
be kept for the purpose of aiding production and to assist with the diagnosis of problems, but
need not be formally entered on to the PQR, e.g. GMAW machine slope-in settings.
The methods of measuring the welding parameters and the records to be kept shall be agreed
with the PT. PHE ONWJ Welding Engineer.
Following qualification, the pWPS shall be revised to reflect the parameters recorded during
qualification. The revised WPS values for current, voltage, and travel speed for each pass shall
be either:
(i) Within the range recorded during WPQT. Transient or anomalous values shall not be used
to establish the range, or
(ii) The mean value +/10%.
The arc energy shall be calculated using the recorded values of current, voltage, and travel
speed without the addition of a percentage.
The final WPS shall state parameters for each pass. However, if fill passes (i.e. passes other
than root, hot pass, and cap) have similar values, the parameters may be combined on the
WPS.
If a welding consumable or group of consumables is qualified to weld several different
components or pipe sizes, every effort should be made to ensure that the parameters specified
on the individual WPSs are common across the group of WPSs.
5.2 Record
The details of each procedure shall be recorded
Forms used to record WPS and WPQT details shall contain the relevant information. The format
shall be subject to approval by PT. PHE ONWJ.
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The PQR documentation package for each WPS shall comprise:
a. As-run records
b. NDT results
c. Mechanical test results and macrographs
d. Consumable certification
e. Parent material certification
The following data shall also be available if requested by the PT. PHE ONWJ Welding Engineer:
f. Calibration certificates for equipment and measuring devices
g. SNT (ASNT) Written Practice (if applicable)
h. Welding Inspector and NDT personnel certification
i. NDT procedure qualification records
j. Testhouse approval certification
The approved WPSs and PQR packages shall also be available in a good quality electronic
format.
5.3 Procedure Specification
5.3.1 General
The relevant PT. PHE ONWJ approved WPSs shall be displayed at each work location and shall
be readily available to each welder.
5.3.2 Specification Information
5.3.2.2. Pipe and fitting materials
Pipe, valves, flanges, and fittings from different manufacturers, or manufactured from materials
supplied from different sources or in different supply conditions, shall require separate
procedure qualification as detailed in 5.4.2.2, unless a material grouping is approved by PT. PHE
ONWJ. The manufacturer(s) shall be noted on the WPS.
5.3.2.3 Diameters and wall thicknesses
The ranges of pipe diameters and wall thicknesses over which the procedure is approved are
identified in Table B unless alternative ranges are agreed by PT. PHE ONWJ.
Table B - Diameter and test pipe thickness range of approval
5.3.2.4 Joint design
The use of permanent or consumable backing rings is not permitted. An exception is the outer
pipe welds in a pipe-in-pipe system. Non-consumable temporary backing as an integral
permanent feature on an internal clamp will be permitted subject to satisfactory demonstration
of the process.
Test Pipe Diameter Range of Approval
(in) (mm) (in) (mm)
D < 2.375 D < 60.3 < 2.375 < 60.3
2.375 < D < 12.75 60.3 < D < 323.9 2.375 to 12.75 60.3 to 323.9
12.75 < D < 24.0 323.9 < D < 610 12.75 to 24.0 323.9 to 610
D > 24.0 D > 610 > 24.0 > 610
Test pipe thickness = t 0.75t to 1 .5t
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5.3.2.5 Filler metal and number of beads
The brand name, electrode or wire name, designation and ISO/AWS/EN welding consumable
classification shall be stated in the PQR.
5.3.2.6 Electrical characteristics
The following parameters shall be specified on WPSs:
a. Welding current (including pulse rate, pulse shape or dwell time, and max/min current for
pulsed welding procedures)
b. Diameter of electrodes or welding wires
c. Wire-feed speed (and pulse rate or frequency for pulsed wire procedures)
d. Arc energy for each pass. For multiple (electrically isolated) tandem electrode welding
processes, e.g. SAW or P-GMAW, the effective arc energy per pass shall be calculated as
the sum of the individual arc energies for each electrode. For pulsed procedures, the
effective arc energy shall be calculated on the basis of RMS values. Voltage and current
shall be determined with calibrated meters and recorded for each pass during WPQT
welding using suitable PT. PHE ONWJ approved data monitoring equipment.
If applicable, the following parameters shall be specified in the WPS:
e. Type, diameter and angle of tip for GTAW tungsten electrodes
f. Hot wire diameter, feed speed, current, and voltage
g. Head angle, electrode spacing from top-dead centre and direction of rotation for 1G-
rotated welding
h. Contact tip to workpiece distance
i. Electrode spacing and individual angles relative to pipe surface (for welding with multiple
electrodes)
j. Torch separation and angle for multiple torch welding
k. Torch oscillation frequency for mechanised (automatic) welding
l Shroud (gas-cup) diameter
The welding unit, power supply type, manufacturer, model number, and software version
number shall be stated for automatic, mechanised, or semi-automatic welding procedures.
5.3.2.8 Position
The welding position shall be stated on the WPS and PQR documents.
5.3.2.10 Time between passes
The time between completion of the root bead and commencement of deposition of the hot-
pass shall be not greater than that qualified in the WPQT and should not be greater than
10 minutes.
If cellulosic welding is used, the second run (hot-pass) shall be deposited immediately after
completion of the root bead.
5.3.2.11 Type and removal of line-up clamp
For pipe-to-pipe joints over 150 mm (6 in) diameter, an internal line-up clamp should be used. If
it is agreed by PT. PHE ONWJ that this is impracticable, e.g. for tie-ins, an external line-up
clamp shall be used.
If an internal line-up clamp is used, the root run shall be 100% complete before the clamp is
removed. If an external line-up clamp is used, the root run shall be at least 50% complete
before the clamp is removed. In either case, the pipes on both side of the joint shall not be
raised, lowered or otherwise moved until both the root and the second weld pass (hot pass)
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have been completed, unless it can be demonstrated to the satisfaction of PT. PHE ONWJ that
the root run alone is adequate to resist the deformation. For SMAW welding using cellulosic
coated electrodes, the hot pass shall always be completed before the pipe is moved.
5.3.2.13 Pre- and post-heat treatment
As a minimum, a preheat temperature shall be selected to ensure that:
a. The pipe is dry before welding
b. The metal temperature is greater than 30C (86F)
c. The metal temperature is greater than 50C (122F) if moisture is present on the pipe
and/or if ambient temperatures are below 5C (41C)
d. The hardness requirements of 5.6.8.3 are met for the weld metal and HAZ
e. The weld metal is not at risk of hydrogen cracking (for cellulosic welds see Table C for
guidance on minimum preheat levels)
f. Sufficient heat is present to prevent cold (hydrogen) cracking in the HAZ
Note: Guidance for the avoidance of HAZ cracking is given in EN 1011-2,
AWS D1.1/D1.1M Annex XI, and BS 4515-1 Annex E.
Table C - Minimum preheat levels for SMAW (cellulosic) welds
The preheat temperature shall not be lower than that recorded during WPQT welding.
The interpass temperature shall not be less than the preheat temperature and shall not exceed
the highest value recorded during WPQT. In no case shall the interpass temperature exceed
300C (572F).
The preheat and interpass temperatures shall be measured in accordance with 7.11 .1 .
If any form of post-weld heat treatment or delayed cooling of the weld is to be used, it shall be
specified in the WPS.
If the weld is to be cooled rapidly to allow immediate AUT, then this shall be simulated during
WPQT. Assisted cooling shall not commence until the weld temperature has cooled without
interference to below 400C (750F).
5.3.2.14 Shielding gases and flow rate
Shielding gas type, composition, and flow rate (for each torch in multi-torch systems) shall be
specified in the WPS.
5.3.2.17 Bead map
A sketch of the weld cross-section showing the bead sequence shall be made for each WPS.
If bead deposition is by a weaving technique, this shall be designated on the WPS.
Filler Grade
(AWS Designation)
Wall Thickness Minimum Preheat
Temperature
(in) (mm) (F) (C)
E6010
< 0.4 < 10 122 50
0.4 < 0.6 10 < 15 167 75
> 0.6 < 0.8 > 15 < 20 212 100
E7010
&
E8010
< 0.4 < 10 176 80
0.4 < 0.6 10 < 15 212 100
> 0.6 < 0.8 > 15 < 20 248 120
E9010 < 0.4 < 10 212 100
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Low hydrogen SMAW electrodes shall not be weaved by more than 3 times the nominal
electrode core wire diameter.
5.3.2.18 Period of validity for welding procedures
For new pipeline construction projects, new WPSs shall be prepared and qualified.
For the purposes of undertaking further work to an existing pipeline, a WPS may remain valid
indefinitely. The PT. PHE ONWJ Welding Engineer shall be consulted before re-using the WPS.
5.4 Essential Variables
5.4.1 General
An approval of a WPS obtained by a contractor is valid in workshops or sites of that contractor
under identical or equivalent technical and quality control. The validity shall be subject to the
approval of the PT. PHE ONWJ Welding Engineer. Welding procedures shall not be transferred
from one contractor or sub-contractor to another without requalification.
5.4.2 Changes Requiring Requalification
5.4.2.1 Welding process or method of application
Any change from a single torch per motorised head to multiple torches, or vice-versa, shall
constitute an essential variable.
Any change of wire delivery system for SAW or mechanised (automatic) GMAW/ GTAW,
including from single to double or multiple wires and/or from cold to hot-wire systems, or vice
versa, shall constitute an essential variable.
5.4.2.1 .1 Line-up clamp
A change from internal to external line up clamp, or vice-versa; or, from internal clamp without
an internal welder to an internal clamp incorporating an internal welder, shall constitute an
essential variable.
Removal of a line-up clamp at an earlier stage than qualified in the WPQT constitutes an
essential variable.
5.4.2.1 .2 Weld or joint backing
Use or removal of copper backing rings or shoes, or combination of these, shall be considered
an essential variable.
5.4.2.1 .3 Number of welders or welding operators
The number of welders shall be at least as many as during welding of the test piece and shall
be considered as an essential variable for each pass.
5.4.2.1 .4 Interpass cleaning
The method of interpass cleaning shall be considered an essential variable.
5.4.2.2 Base material
Base material grouping by strength shall only be allowed for materials with an SMYS less than
or equal to 42,000 psi (290 MPa); but, for all grades of material, the following shall constitute
essential variables:
a. Change of manufacturing facility for strip, billet, plate, pipe or forging
b. Change of steel making, plate rolling, forging or pipe manufacturing process
c. For grades up to and including X80, a change of composition resulting in a change of
greater than 0.03CE
IIW
or greater than 0.02P
cm
value. For sour service pipelines, a
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change in composition resulting in greater than +0.01 or 0.03CE
IIW
or greater than +0.01
or 0.02P
cm
value.
1556
CuNiVMoCrMn
CCE
IIW
+
+
++
++=
B
VMoNiCrCuMnSi
CP
cm
5
1015602030
++++
++
++=
d. For grades above X80, composition limits will be advised on a project by project basis.
5.4.2.3 Joint design
For narrow gap welding, e.g. mechanised (automatic) GMAW, any change in bevel angle
beyond 1, root face beyond 50% or root gap +0.5 mm (0.02 in) constitutes an essential
variable. Any weld preparation with an included angle of less than 20 shall be considered to be
narrow gap welding.
For other welding, any changes in bevel angle by more than 5, or variation in root gap/root
face by more than 50%, constitutes an essential variable.
Note: For pipe grades above X80 (L555), it may be necessary to impose more
stringent limits on the joint design for mechanised (automatic) welding
than those quoted above as minor changes can result in significant
differences in mechanical properties of the girth welds.
5.4.2.4 Position
A change of welding position shall constitute an essential variable. Welding positions 5G and
2G shall be qualified separately. 6G qualification shall be required if the angle of the pipe is
between 25 and 65 to the horizontal.
5.4.2.5 Wall thickness
Any change outwith the grouping ranges of pipe by diameter and wall thickness designated in
5.3.2.3, shall constitute an essential variable.
5.4.2.6 Filler metal
The following changes in filler metal constitute essential variables:
a. Any change in filler metal designation, filler metal manufacturer, manufacturing location or
brand name
b. Any change in welding consumable or size
c. Lot testing as per 4.2.2.3 is required
The compatibility of the base material and the filler metal should be considered from the
standpoint of mechanical properties.
5.4.2.7 Electrical characteristics
Any change in the following shall be considered essential variables:
a. The welding current, arc voltage and travel speed outside that recorded on the WPS
b. For pulsed current welding the pulse rate, pulse shape, and max/min current recorded on
the WPS
c. For GMAW, cored wire welding and hot wire GTAW any change of wire feed speed
outwith the range qualified
d. Arc energy for each pass outside of the range recorded on the WPS
e. Head angle, electrode spacing from top dead centre and direction of rotation for 1G-
Rotated welding
f. Electrode spacing for welding procedures utilising multiple electrodes, e.g. tandem-wire
SAW, or mechanised (automatic) tandem wire or twin torch processes
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g. Diameter of electrodes or welding wires
h. For semi-automatic and mechanised (automatic) welding, the welding unit, power supply
type, manufacturer, model number and software version number
5.4.2.8 Time between passes
If using cellulosic electrodes, the time lapse between the start of the root bead and the start of
the second bead shall not exceed the time lapse recorded during welding of the test piece.
5.4.2.10 Shielding gas and flow rate
Any change of shielding gas flow rate greater than 15% of that qualified shall constitute an
essential variable.
5.4.2.11 Shielding flux
For pipeline grades greater than X52, any change of shielding flux manufacturer, manufacturing
location, brand or type constitutes an essential variable. Any change of flux for pipeline grades
X52 and below shall be subject to the agreement of the PT. PHE ONWJ Welding Engineer.
5.4.2.12 Speed of travel
A change in speed of travel beyond the range on the qualified WPS constitutes an essential
variable.
5.4.2.13 Preheat
Any change in the preheat application method shall constitute an essential variable.
5.4.2.15 Arc energy per pass
Any change in arc energy outside of the range in the approved WPS shall constitute an
essential variable.
5.4.2.16 Interpass temperature
An increase in the specified interpass temperature shall constitute an essential variable. The
use of rapid cooling of welds constitutes an essential variable unless simulated in the WPQT.
5.5 Welding of Test JointButt Weld
5.5.1 Test Pipe for WPQT
The WPQT shall simulate the production welding of the pipelines and shall be undertaken as far
as practicable, under site ambient conditions. For land pipelines, lifting and lowering off shall be
simulated using full pipe lengths.
If an internal line-up clamp will be used in production welding, the length of the nipples used in
the WPQT shall be sufficient to accommodate the full length of the clamp. The minimum
length of any nipple piece used during qualification should be 1 m (3.3 ft) or 1 .5 pipe diameters
whichever is the greater.
The minimum length of test rings for the WPQT of fittings and flanges shall be subject to
agreement with PT. PHE ONWJ .
5.6 Testing of Welded JointsButt Welds
5.6.1 Preparation
Reference Figure 3 and Table 2, in accordance with this guidance
The blanks from which the mechanical test pieces are machined may be cut from the
qualification weld using oxy-fuel gas cutting, but its dimensions shall be sufficient to allow the
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material of the final machined test piece to remain unaffected by the heat from the cutting
operation.
Test specimens shall not be subjected to any elevated temperature degassing treatment.
5.6.1 .1 Non-destructive testing of WPQT welds
WPQT welds shall be visually examined (VT) as soon as possible after completion of welding
with 100% coverage of weld surfaces. WPQT welds shall meet the same requirements for
weld profiles and VT as those specified for production welds.
The full circumference of WPQT welds shall be examined by radiographic testing (RT),
ultrasonic testing (AUT or MUT), and magnetic particle testing (MT). For WPQT welds, there
shall be a minimum delay time as specified in Table D between completions of welding and
non-destructive testing of the welds.
Table D - Specified minimum delay time before NDT for WPQT welds
Acceptance by PT. PHE ONWJ shall be required before sectioning of WPQT welds for
mechanical testing.
The NDT procedures for WPQT welds shall be qualified and subject to approval by PT.
PHE ONWJ.
5.6.1 .2 Mechanical testing
Mechanical testing shall be performed by a certified testing laboratory approved by PT. PHE
ONWJ.
Test specimens shall be taken from pipeline WPQT butt welds as shown in Figure 3. Repair
weld mechanical testing locations and specimen types/ numbers shall be in accordance with
Table H. Test specimens not shown in Figure 3, e.g. CTOD test pieces, may be taken from any
position around the weld where spare material is available, but the exact locations should be
agreed in each instance with the PT. PHE ONWJ Welding Engineer. More than one weld may
be required to provide sufficient material for testing. Table 2 shows the type and number of
test specimens required.
5.6.1 .3 Test temperature
Destructive testing shall be performed at ambient temperature, except for impact testing (see
5.6.6.3) or CTOD testing (see 5.6.10).
For design service temperatures above 100C (212F), elevated temperature transverse and
weld tensile testing shall be undertaken. The test temperature, extent of testing and required
strengths shall be specified on a project specific basis.
5.6.1 .4 Repair of WPQT welds
Weld repairs to WPQT welds are not permitted, except if the purpose is to qualify a repair
procedure.
5.6.2 Tensile-Strength Test
5.6.2.1 Preparation
Preparation of the tensile test piece shall be as per Figure 4, except that internal and external
weld reinforcement shall be removed before testing.
WPQT Welds in API/ISO Pipe Grades Welding Process Minimum Delay Before NDT
< API X70 / ISO L485 Any process except cellulosic SMAW 24 hours
< API X70 / ISO L485 Cellulosic SMAW
a
48 hours
> API X70 / ISO L485 Any welding process 72 hours
a
Welds made with cellulosic root/hot pass only may be inspected after 24 hours.
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The position of failure shall be recorded, i.e. weld metal, HAZ or base metal.
Figure 3 - Location of test pieces from a butt weld in pipe
> 114.2mm (4.500)
but < 323.9mm (12.750)
3
1
3
4
4
2
2
6
1
5
5
6
5
3
1
3
4
4
2
2
6
1
5
5
6
5
1
1
1
1
3
22
3
3
3
2
4
4
4
4
2
5
5
5
6
6
1
1
1
1
3
22
3
3
3
2
4
4
4
4
2
5
5
5
6
6
Key:
1) Face or side bend
2) Transverse tensile
3) Root or side bend
4) Nick-break
5) Macrosection
6) Charpy V-Notch
Greater than 323.9mm (12.75)
NOTE: Test specimens not shown in Figure-3, e.g. CTOD test pieces, may be taken from any position around the
weld where spare material is available. More than one weld may be required to provide sufficient material for
testing.
< 60.3mm (2.375)
4
3
2
2
6
5
5
5
> 60.3mm (2.375) but
< to 114.3mm (4.500)
Also, < 114.3mm (4.500) when
wall thickness > 12.7mm (0.500)
2
3
3
4
4
2
5
6
5
5
2
3
3
4
4
2
5
6
5
5
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Table 2 - Type and number of test specimens (a) for procedure qualification test
Number of Specimens for Wall Thickness 12.7 mm (0.500 in)
OD of Pipe
mm (in)
Tensile
Strength
(Cross
Weld
Tensile)
All-Weld
Metal
Tensile
(c)
Nick
Break
(d)
Root
Bend
Face
Bend
Side
Bend
Charpy
Impact
Tests
(set of 3)
(e)
Macro/
HV10
CTOD
(set of 3 )
(f & g)
323.9 (>12.750) 4 1 4 4 4 0 4 3 3
Number of Specimens for Wall Thickness > 12.7 mm (0.500 in)
OD of Pipe
mm (in)
Tensile
Strength
(Cross
Weld
Tensile)
All-Weld
Metal
Tensile
(c)
Nick
Break
(d)
Root
Bend
Face
Bend
Side
Bend
Charpy
Impact
Tests
(set of 3)
(e)
Macro/
HV10
CTOD
(set of 3)
(f & g)
114.3-323.9
(>4.500-12.750)
2 1 2 0 0 4 4 3 3
>323.9 (>12.750) 4 1 4 0 0 8 4 3 3
NOTES:
a Specimen locations shall be in accordance with 5.6 and Figure 3.
b One nick-break and one root-bend specimen shall be taken from each of two test welds, or for pipe less than or
equal to 34 mm (1 .315 in) diameter, two full section tensile strength specimens shall be taken.
c If an ECA is to be used for defect acceptance levels, three all-weld metal tensile specimens shall be taken.
d. Nick breaks are not required for mechanised (automatic) welding.
e Charpy impact tests shall comprise weld metal and fusion line specimens machined from the pipe outside diameter.
Pipes with wall thickness > 20 mm shall have additional specimens machined from the ID .Additional sets of Charpy
Impact specimens may be required by the PT. PHE ONWJ welding engineer, e.g. if very thick pipe is to be utilised
or the combination of processes or consumables have not been adequately sampled by the specified locations.
f CTOD tests shall comprise a minimum of one set of weld metal and two sets of HAZ samples (see paragraph D.4 of
Appendix D).
g CTOD tests are only required for pipelines with ECA based acceptance criteria or if required by the pipeline designer.
5.6.2.3 Requirements
The results of transverse weld tensile tests shall meet or exceed the specified requirements
for the pipe (base metal) with respect to specified tensile strength. Transverse weld tensile
specimens shall fail at a location within the HAZ or base metal.
If base metals of different strength levels are used, then acceptance criteria shall be based on
the lower strength base metal.
5.6.6 Charpy V Notch Testing
5.6.6.1 Scope
WPQT butt welds shall be subjected to Charpy V notch impact testing.
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5.6.6.2 Preparation
The test pieces shall be prepared and tested in accordance with ISO 148, EN 10045-1 and
EN 875 or ASTM A370 and E23.
A set of Charpy impacts shall comprise three specimens. Sets of Charpy specimens shall be
taken from the locations shown in Figure 3.
Specimens shall be notched with the axis of the notch perpendicular to the pipe surface. The
position of the notch for each set shall be as depicted in Figure A.
Full size specimens shall be used if possible.
5.6.6.3 Method
The impact test temperature shall be the minimum design temperature when the following
conditions apply:
- The minimum design temperature is minus 10C (14F) or higher
- The wall thickness is 25 mm (1 in) or lower
- The material SMYS is 555 N/mm
2
(80 ksi) or lower
In addition to the above, for gas pipelines the impact test temperature shall be no higher than
minus 10C (14F).
Test temperatures for welds outside of the above conditions shall be advised by
PT. PHE ONWJ.
Figure A - Charpy V notch locations
5.6.6.4 Requirements
The Charpy impact values shall meet or exceed the values given in Table E.
NOTES:
1 Specimens shall be positioned between 1 2 mm from the pipe outer surface. Additional specimens for
thicknesses greater than 20 mm shall be positioned within 1 2 mm from the inner surface.
2 Fusion line Charpy specimens shall sample 50% weld metal and 50% HAZ.
A(i) Weld Centreline
A(ii) Fusion Line
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Table E - Charpy impact test requirements
For specimens below 10 mm in thickness, the energy requirement shall be reduced pro rata,
e.g. a 7.5 mm specimen shall achieve 75% of the required full size value.
The ductile shear area shall exceed 50%.
Individual samples may be replaced if there is evidence of a weld defect on the fracture
surface. Re-testing may be allowed following discussion with the PT. PHE ONWJ Welding
Engineer.
Test results, including percentage ductile shear area, shall be recorded.
5.6.7 Macro-Section
5.6.7.1 Method
Macro-sections shall be extracted from procedure qualification test welds at three locations
approximately 90 apart. For welds containing any pass made in the 5G position, macro-
sections shall be extracted as close as practicable to the 12 oclock, 3 oclock and 6 oclock
positions.
When girth welding seam-welded linepipe, an additional macro-section shall be extracted from
the girth-weld at the T-intersection region between the girth weld and seam weld.
Macro-sections shall be polished to a metallographic (1 m) finish and etched in a 2-10% Nital
solution, or other suitable PT. PHE ONWJ approved etchant. The etched specimens shall be
thoroughly examined at 10 times magnification.
Original photo-macrographs of macro-sections at approximately 3 to 5 times magnification shall
be included in the PQR documentation.
5.6.7.2 Acceptance criteria
When examined at 10 times magnification, the macro-section shall reveal:
a. No cracks
b. Complete fusion between adjacent layers of weld metal and between weld metal and
base metal
c. Complete fusion at the root
d. No lack of cross penetration
e. No undercut (unless weld surfaces are to be ground smooth). If weld surfaces are to be
ground smooth, minor undercut may be removed by the surface grinding operation. If the
undercut is of such depth that its removal would result in encroachment of the minimum
specified thickness of the pipe, it shall be deemed unacceptable.
f. No excess cap reinforcement exceeding 1.6 mm (1/16 in) above the base metal surfaces
for weld surfaces not specified to be ground smooth
g. Weld reinforcement shall blend smoothly into the adjacent base metal
h. No penetration of the root bead into the bore exceeding 3 mm (1/8 in). For pipe diameters
less than 60 mm (2-3/8 in) this penetration shall not exceed 1.5 mm (1/16 in).
i. At no point shall the weld surface, ID or OD, lie below the adjacent base metal
Any observed defects shall be within the limits given in Section 9.
Grade Minimum Average Energy Minimum Individual Energy
ft lbs J ft lbs J
< X80 < L555 37 50 30 40
X80 L555 44 60 33 45
> X80 > L555 To be advised
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5.6.8 Hardness test
5.6.8.1 Preparation
The hardness testing technique shall be the Vickers method with an applied load of 10 kg in
accordance with ISO 6507-1 or ASTM E92.
The hardness surveys shall be undertaken on each of the macro-section specimens specified in
5.6.7. For non-sour pipelines, surveys on the 12 oclock and 6 oclock macro-sections may be
omitted.
5.6.8.2 Method
Each survey shall consist of three rows of indents. One traverse shall be located below the cap,
one above the root (or internal surface) and one at mid-thickness. The positions are shown in
Figure B. The mid-thickness traverse may be waived for single sided welds below 12.7 mm.
The PT. PHE ONWJ Welding Engineer may require additional hardness indent positions, e.g. if
a consumable type has not been sampled by the specified three traverses.
Figure B - Locations for hardness indents
t/2
1 - 2mm
1 - 2mm
t/2
1 - 2mm
1 - 2mm
The macrophotographs shall show the position of each hardness indent and shall be included in
the PQR along with a tabulation or diagram showing the result and location of each indent. The
maximum and minimum values shall be identified.
5.6.8.3 Requirements
The individual hardness values shall not exceed the values given in Table F.
The parent material hardness values shall not exceed the values permitted in the relevant
material specification.
NOTES:
1. Parent material indentations shall be at least 20 mm from the fusion line.
2. The first HAZ indentation shall be placed as close to the fusion line as possible. Further indentations into the
HAZ shall be separated by approximately 0.5 mm, however the minimum centre-to-centre separation
requirement of 2.5 or 3 times the mean diagonal of the nearest indentation shall be maintained (ref.
ISO 6507-1 and ASTM E92).
3. The same survey pattern shall be applied to double-sided welds.
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Table F - Maximum permissible weld and HAZ hardness values (HV10)
5.6.9 Weld Metal Tensile Test (All-Weld Metal Tensile Test)
Weld metal tensile test specimens shall be in accordance with ASTM A370. For narrow gap
welds in which the width of the weld bead is insufficient to permit a conventional all-weld
metal tensile test piece to be prepared, the geometry of the test piece shall be agreed
with PT. PHE ONWJ. The longitudinal axis of the tensile test specimen shall coincide with the
procedure qualification test-weld axis. The tensile specimen shall be prepared by machining,
and its size and location shall be such that the gauge length consists only of weld metal.
The weld metal yield strength shall not be less than the SMYS of the pipe. Weld metal
overmatching of the typical pipe yield strength is considered desirable. The weld metal
strength, in relation to the actual pipe yield strengths, shall be considered if an ECA is used or
the pipeline design requires this.
5.6.10 CTOD Testing
Requirements concerning CTOD testing can be found in Appendix D.
5.7 Welding of Test JointsFillet Welds
The tests specified in 5.8 do not provide comprehensive information on the mechanical
properties of the joint. If mechanical properties are relevant to the application, then an
additional qualification shall be made, e.g. a butt weld.
5.8 Testing of Welded JointsFillet Welds
5.8.1 Preparation
Two macro-sections shall be taken from the test weld at locations agreed with the PT. PHE
ONWJ Welding Engineer. The specimens shall be prepared and examined in accordance with
5.6.7.
5.8.2 Method
One of the macro-sections shall be subject to hardness testing. The test method shall be
Vickers with an applied load of 10 kg in accordance with ISO 6507-1 or ASTM E92. The survey
shall consist of two traverses with indentations as shown in Figure C.
Grade Location Sour
Non-Sour
SMAW Cellulosic
a
Other Processes
< X80 < L555 Inside Surface &
Mid-Thickness
Weld 248 275 275
HAZ 248 275 275
Outside Surface Weld 275 275 275
b
HAZ 275 325 350
> X80 > L555 To be advised
NOTES:
a Use of cellulosic electrodes is limited to the applications shown in 4.2.2.1 .1
b For grade X80 (L555), outside surface weld metal hardness levels up to 300HV10 are permitted
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Figure C - Fillet weld hardness indent locations
1 2 mm1 2 mm
A macrophotograph shall show the position of each hardness indent and shall be included in
the PQR along with a tabulation or diagram showing the result and location of each indent. The
maximum and minimum values shall be identified.
5.8.3 Requirements
If the fillet weld is on the outside of the pipe wall and, therefore, not in contact with the
process fluids, then the criteria given in Table F for outside surface shall apply.
6 Qualification of Welders
6.1 General
Welder qualification tests shall be carried out on full diameter project pipe nipples. Test welds
shall be visually sealed at each end until at least the root bead and hot pass have been
completed around the full circumference. Testing shall be witnessed by a PT. PHE ONWJ
representative or a PT. PHE ONWJ approved third party inspector.
Welders shall be qualified for each welding process that they will use in production. Welders
shall complete at least 50% of the circumference for the passes they are being qualified for.
For automatic, mechanised or semi-automatic welding, each welder shall be qualified for each
type, manufacturer, and model number of the welding unit(s) and power supply to be used in
production welding or for weld repair.
Welders shall be qualified before welding on the pipeline.
A welder who has satisfactorily completed a procedure qualification test is automatically
qualified for that procedure.
Previous welder qualifications tests may be accepted by PT. PHE ONWJ provided they are fully
documented, supported by production records demonstrating satisfactory welder performance,
and is less than 6 months old. These tests shall have been conducted utilizing a WPS
substantially the same as that for the current work and, for automatic, mechanised or semi-
automatic welding procedures, utilizing the same type, manufacturer, and model number of
welding unit and power supply. Additionally, these tests shall have been conducted by the
same fabrication contractor and witnessed by PT. PHE ONWJ or have been conducted by a PT.
PHE ONWJ approved independent testing laboratory.
In addition to the practical welding test and before the commencement of production welding,
welders shall be required to attend a briefing session arranged jointly with the PT. PHE ONWJ
Welding Engineer. This briefing shall detail the elements of good welding practice and the
specification requirements applicable to production welding. These requirements shall be
further emphasized during regular tool-box sessions and each welder shall be issued a card or
booklet summarising these requirements. This card or booklet shall be available for reference at
all times when welding.
NOTE: Notes 1 and 2 from Figure B are applicable.
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Any welder who, in the opinion of PT. PHE ONWJ, is either consistently ignoring good welding
practice or specification requirements or is responsible for a high level of repairs during
production shall be removed from the work, and shall undergo a re-training programme
approved by PT. PHE ONWJ before a retest may be considered.
6.2 Single Qualification
6.2.1 General
Qualification welds shall be assessed by VT and shall also be subject to RT. The agreed NDT
regime shall reflect production NDT and shall examine the full weld circumference.
Qualification of welders using GMAW (solid or cored wire) shall be by VT, RT, MUT, and
mechanical testing to include face and root bends or side bends. In the case of manual welds,
nick break tests are also required.
If the application of AUT for the inspection of production girth welds has been agreed
by PT. PHE ONWJ, it may be used for assessment of the welder qualification welds in place of
RT. However, the acceptance criterion used shall be Section 9 rather than an ECA based
criterion.
The position of the pipe used in the test shall determine the extent of qualification as follows:
a. Horizontal pipes shall be used to qualify for welds between pipes positioned within 25 of
the horizontal.
b. Vertical pipes shall be used to qualify for welds between pipes positioned within 25 of
the vertical.
c. Pipes at 45 to the horizontal shall be used to qualify for welds between pipes positioned
at intermediate angles between 25 and 65 to the horizontal.
6.2.2 Scope
For SMAW, a change of electrode manufacturer and brand name
6.3 Multiple Qualifications
Multiple qualification of the welder shall not be permitted.
6.4 Visual examination
Filler wire protruding into the pipe bore shall not be permitted.
6.6 Radiographybutt welds only
6.6.1 General
RT (or AUT: see 6.2.1 above) shall be performed on the qualification welds using the same RT
(AUT) procedure as to be used in production.
Testing procedures and acceptance criteria shall be subject to approval by PT. PHE ONWJ.
7 Design and Preparation of a Joint for Production Welding
7.1 General
Any protective coating on the end bevel shall be removed before welding by a PT. PHE ONWJ
approved method.
Before welding, the pipe end shall be cleaned inside and out using power driven wire brushes,
grinders or other method approved by PT. PHE ONWJ, for a minimum distance of 40 mm
(1 in) from the edge of the weld bevel.
If AUT is to be used, a reference line at a specified distance from the root face shall be scribed
onto the pipe surface to allow the AUT equipment to identify the exact location of the root
bead.
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Arc burns outside of the weld groove shall not be permitted. Remedial action on arc burns shall
be in accordance with 10.6.
Attachment of welding return cables by welding shall not be permitted. Arc burns caused by a
faulty attachment shall be removed in accordance with 10.6.
Repair of the pipe body by welding shall not be permitted.
7.1 .1 Weld Proximity
The distance between pipeline girth welds shall not be less than twice the outside diameter of
the pipe.
The distance between pipeline girth and branch/attachment welds shall not be less than one
pipe diameter.
The distance between branch/attachment welds on the pipeline shall not be less than one pipe
diameter.
7.2 Alignment
Pipe ends shall be aligned by rotating pipes, avoiding pipe end bevel damage, thereby achieving
accurate fit up for welding.
The misalignment between the internal surfaces shall not exceed the lesser of 3.0 mm (1/8 in.)
or 1% of the pipe internal diameter at any point.
The longitudinal (or spiral) weld ends shall be separated, at the circumferential weld, by 90 or a
circumferential distance of 250 mm (10 in), whichever is the smaller.
Longitudinal welds shall lie within the top half of the pipe circumference.
If abutting pipes have the same outside diameter with different nominal bores, the smaller bore
shall be machined, ground or filed, to produce an internal taper no steeper than 1 in 4;
alternatively, a transition piece may be inserted. Internal tapering shall be subject to PT. PHE
ONWJ approval if the taper will interfere with ultrasonic inspection. Internal tapering may not
be used with AUT.
Any misalignment in pipe to fitting girth weld set-ups, which exceeds 3.0 mm (1/8 in.) at any
point on the internal surface, shall be subject to corrective action agreed with PT. PHE ONWJ .
Slight misal