7/28/2019 36-775 Control of Plant Construction Repair and Maintenance Welding Activities (Rev 1)
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Standard Group Technology
Title: Control of Plant Construction,Repair and MaintenanceWelding Activities
Unique Identifier: 36-775
Alternative Reference Number: N/A
Area of Applicability: Engineering
Documentation Type: Standard
Revision: 1
Total Pages: 22
Next Review Date: November 2014
Disclosure Classification: CONTROLLEDDISCLOSURE
Compiled by Functional Responsibility Authorized by
.. .. ..
P Doubell
Chief Engineer Welding, IWE
BS MacColl
Acting General ManagerResearch, Testing &Development
MM Koko
Divisional Executive GroupTechnology
Date: Date: Date:
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CONTENTS
Page
FOREWORD ................................................................................................................................................................ 41. SCOPE ..................................................................................................................................................................... 62. NORMATIVE REFERENCES .................................................................................................................................. 63. DEFINITIONS AND ABBREVIATIONS ................................................................................................................... 7
3.1 DEFINITIONS .................................................................................................................................................... 73.1.1 Classification ............................................................................................................................................. 8
3.2 ABBREVIATIONS .............................................................................................................................................. 84. REQUIREMENTS ..................................................................................................................................................... 8
4.1 GENERAL.......................................................................................................................................................... 84.1.1 Welding Requirements .............................................................................................................................. 84.1.2 Welders and welding operators ................................................................................................................. 94.1.3 WPS .......................................................................................................................................................... 94.1.4 WPQR/PQR............................................................................................................................................... 94.1.5 WPS verification ........................................................................................................................................ 94.1.6 Eskom welding coordinator/administrator ............................................................................................... 104.1.7 Welding supervision ................................................................................................................................ 104.1.8 Welding Inspector .................................................................................................................................... 104.1.9 Technical capability assessment of contractors ...................................................................................... 10
4.2 WELD QUALITY SYSTEM .............................................................................................................................. 114.2.1 SANS ISO 3834 ...................................................................................................................................... 114.2.2 Welding Quality Requirements ................................................................................................................ 114.2.3 Quality assurance function ...................................................................................................................... 114.2.4 Project quality audits ............................................................................................................................... 124.2.5 Reporting of non-conformances .............................................................................................................. 12
4.3 WELDING PROCEDURES ............................................................................................................................. 124.3.1 Construction of new plant ........................................................................................................................ 134.3.2 Weld repairs on old plant ......................................................................................................................... 134.3.3 Modification work to existing plant........................................................................................................... 134.3.4 Refurbishment and/or repair work to existing plant ................................................................................. 134.3.5 Acceptance levels for Imperfections ....................................................................................................... 134.3.6 Quality levels and assessment class for imperfections ........................................................................... 134.3.7 Basic requirements of the weld procedure specification ......................................................................... 13
4.4 WELDER QUALIFICATION............................................................................................................................. 144.5 MATERIAL CONTROL .................................................................................................................................... 14
4.5.1 Material to be used for fabrication or for weld repairs ............................................................................. 144.5.2 All Unidentified material ........................................................................................................................... 144.5.3 Marking of removed material ................................................................................................................... 154.5.4 Protection of sectioned faces .................................................................................................................. 15
4.6 WELDING CONSUMABLE CONTROL ........................................................................................................... 154.6.1 Consumable approval ............................................................................................................................. 154.6.2 Consumable identification ....................................................................................................................... 154.6.3 Consumable storage ............................................................................................................................... 154.6.4 Damaged or contaminated consumables ................................................................................................ 154.6.5 Identification on consumables ................................................................................................................. 154.6.6 Baking/drying of consumables ................................................................................................................ 154.6.7 Holding of baked/dried consumables ...................................................................................................... 154.6.8 Hot boxes for consumables ..................................................................................................................... 164.6.9 Unused consumables .............................................................................................................................. 164.6.10 Permitted re-baking cycles .................................................................................................................... 164.6.11 Welding and cutting gasses .................................................................................................................. 16
4.7 HEAT TREATMENT ........................................................................................................................................ 16
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4.7.1 Heat treatment procedures ...................................................................................................................... 164.7.2 Heat treatment equipment ....................................................................................................................... 164.7.3 Operation and monitoring of heat treatment equipment ......................................................................... 174.7.4 Measurement and maintenance of temperature for pre-heating and interpass temperature ................ 174.7.5 Heat treatment parameters for service-aged materials ........................................................................... 174.7.6 Substantiation of heat treatment ............................................................................................................. 174.7.7 Heat treatment information ...................................................................................................................... 174.7.8 Multiple heat treatments .......................................................................................................................... 174.7.9 Unplanned events during heat treatment ................................................................................................ 17
4.8 CALIBRATION OF EQUIPMENT .................................................................................................................... 184.8.1 Equipment identification .......................................................................................................................... 184.8.2 Calibration of temperature measuring equipment ................................................................................... 184.8.3 Calibration of furnaces, holding ovens and hot boxes ............................................................................ 184.8.4 Calibration of chart recorders for heat treatments................................................................................... 184.8.5 Proof of calibration .................................................................................................................................. 18
4.9 NON DESTRUCTIVE TESTING...................................................................................................................... 184.9.1 Independence of NDT contractor ............................................................................................................ 184.9.2 Eskom approval of NDT contractor ......................................................................................................... 18
4.9.3 NDT safety ............................................................................................................................................... 19
4.10 WELDING COORDINATOR/ADMINISTRATOR ........................................................................................... 195. RECORDS AND DATA PACKAGES .................................................................................................................... 196. APPENDIX ............................................................................................................................................................. 21
A.1 SUMMARY OF SANS ISO 3834 QUALITY REQUIREMENTS ...................................................................... 21
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FOREWORD
Revision History
This revision cancels and replaces Revision No. 1 of Specification or Standard No. GGS1407.
Date Rev. Remarks
November 2011 0 This is the first issue developed
December 2011 0.1 Issued for comments
February 2012 1 Final Document for Publication
Authorization
This document has been seen and accepted by:
Name and Surname Designation
Pius Oba Acting Section Manager: Welding & NDE, Welding Engineer
Sumaya Nassiep Acting Senior Manager: Plant Performance and Optimisation
Barry MacColl Acting General Manager: Research, Testing & Development
Titus Mathe Engineering Power Plant Manager
Dhiraj Bhimma Engineering Account Executive
Anthony Kuzelj Power Station Manager
Bheki Nxumalo Power Station Manager
Bruce Moyo Power Station Manager
Chris Schutte Senior General ManagerChristo van Niekerk Senior General Manager
Christopher Nani Power Station Manager
Deon Beukes Chief Technologist
Des Sheppard Senior Manager: Projects and Outages
Ertjies Bierman Senior Manager Engineering
Gladman Mkwai Power Station Manager
Hennie van Staden Senior Manager: Projects and Outages
Johan Du Preez Boiler Senior Consultant
Johan Prinsloo Power Station Manager
John Dean Power Station Manager
Julian Fourie Senior Manager Engineering
Julian Nair Power Station Manager
Kiren Maharaj Senior General Manager
Lebo Serekwa Boiler Senior Consultant
Leon Booyens Senior Consultant Boiler Tube Failure Reduction
Mandla Mtembu Senior Manager Engineering
Marcus Nemadodzi Boiler Senior Consultant
Mark Breetzke Corporate Consultant: Boilers
Marthinus Bezuidenhout Corporate Consultant: Materials
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Name and Surname Designation
Morris Maroga Chief Engineer
Piet Veldman Outage Integration Manager: Coal Operating Unit 1
Russel Tarr Senior Consultant: Fleet TechnologyRyno Lacock Power Station Manager
Shamiel Jappie Acting Power Station Manager
Shireen Prince Power Station Manager
Thava Govender Divisional Executive: Generation
Thomas Conradie Power Station Manager
Louise Petrick Senior Advisor Welding
Andrew Downes Senior Consultant
Hennie Coetzer Senior Advisor Projects
Werner Smit Chief Engineer
Michael Mkhize Chief Engineer
Frans Havenga Section Manager Physical Metallurgy
Thobeka Pete Chief Engineer
Leslie Too Senior Advisor
Applicability
This standard is applicable to all Eskom plant during procurement, reviewing and placing construction,maintenance and repair contracts with vendors for welding and related activities on Eskom plant by therelevant Eskom procurement departments. Routine weld repair and maintenance work by Eskom
personnel also fall within the requirements of this document. It will serve as the standard to supportEskoms position on all welding related issues and disputes. Any disputes that fall outside this standardor that appear to be in conflict with it, may be resolved with the proper weld engineering and/ormetallurgical inputs. Contractors that fail to meet these requirements may be assessed to determine thenature and significance of the shortcomings, after which they may be considered for the contract with thenecessary concessions which shall be documented and submitted to Eskom during the course of thecontract as required by the Eskom Quality Standard GGS 0462.
Development Team
The following people were involved in the development of this document:
Philip Doubell
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1. SCOPE
This standard defines uniform, fit-for-purpose requirements for performing construction, repair and/or
maintenance welding and related activities on Eskom plant. The objective is to impose good basicwelding practices of high quality levels while conforming to the construction code and weldingspecifications, thereby improving and preserving the integrity of Eskom assets. To ensure a safe andhealthy working environment as required by the Chief Inspector, the Occupational Health and Safety Actis another principal objective through compliance with the applicable requirements of the PER in thecase of pressurised equipment.
2. NORMATIVE REFERENCES
Parties using this document shall use the most recent editions of the documents listed in this section.
[1] ASME Boiler and Pressure Vessel Construction Code: Section IX: 2010 (Including Addenda)
[2] BS EN 1011: 2009 Welding- Recommendations for welding of metallic materials Part 1 Generalguidance for arc welding
[3] BS EN 1011: 2001 Welding- Recommendations for welding of metallic materials Part 2 Arcwelding of ferritic steels
[4] BS EN 1011: 2000 Welding- Recommendations for welding of metallic materials Part 3 Arcwelding of stainless steels
[5] BS EN ISO 15607:2003 Specification and qualification of welding procedures for metallic materials- General rules
[6] BS EN ISO 15613: 2004 Specification and qualification of welding procedures for metallicmaterials Qualification based on pre-production welding test
[7] BS EN ISO 5817: 2003 Welding - Fusion-welded joints in steel, nickel, titanium and their alloys(beam welding excluded) Quality levels for imperfections
[8] BS EN ISO 17663 (2009): Welding Quality requirements for heat treatment in connection withwelding and allied processes
[9] BS 2633:1987 Specification for Class I arc welding of ferritic steel pipework for carrying fluids
[10] EN 10204: 2004 Metallic products: Types of inspection documents
[11] EN ISO 13916: Welding guidance on the measurement of preheating temperature, interpasstemperature and preheat maintenance temperature
[12] ISO/TR 15608: 2005 Welding Guidelines for a metallic material grouping system[13] ISO 14731:2006 Welding co-ordination. Tasks and responsibilities
[14] SANS 15614-1 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 nickelalloys
[15] SANS 15614-7 Specification and qualification of welding procedures for metallic materials -Welding procedure test Part 7: Overlay welding
[16] SANS 15609-1 Specification and qualification of welding procedures for metallic materials -Welding procedure specification Part 1: Arc welding
[17] SANS 9606-1 Approval testing of welders - Fusion welding Part 1: Steels
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[18] SANS ISO 3834-1:2005 Quality requirements for Welding Part 1 Guidelines for selection and use
[19] SANS ISO 3834-2:2005 Quality requirements for Welding Part 2 Comprehensive qualityrequirements
[20] SANS ISO 3834-3:2005 Quality requirements for Welding Part 3 Standard quality requirements[21] SANS ISO 3834-4:2005 Quality requirements for Welding Part 4 Elementary quality requirements
[22] SANS 10269:2002 Welding of thermoplastics Testing and approval of welders
[23] SANS 10270:2004 Welding of thermoplastics Approval of welding procedures and welds
[24] SANS 10268:2005 Welding of thermoplastics Welding Processes Part 10: Weld defects
[25] Pressure Equipment Regulations, 2009 (PER)
[26] SANS 347: 2010 Specification for categorization and assessment criteria for all pressure
[27] 32-632 Requirements for NDT on Eskom plant
[28] 32-631 Eskom approval of personnel performing quality related special processes on Eskom plant[29] GGS0462, Quality requirements for engineering and construction works in generation
[30] N.PSZ 45-223: High pressure pipework for fossil fired power stations
[31] 36-504: Welding of high temperature and pressure tube and pipework
[32] 36-505 Personnel and Entities Performing Welding Related Special Processes on Eskom Plant
3. DEFINITIONS AND ABBREVIATIONS
3.1 DEFINITIONS
3.1.1 Procedure Qualification Record: A record comprising all relevant data from the welding of a testpiece needed for the approval of a welding procedure specification as described in the ASME Boiler andPressure Vessel Code Section IX.
3.1.2 Welding Procedure Qualification Record: A record comprising all relevant data from thewelding of a test piece needed for the approval of a welding procedure specification as described in thewelding specification BS EN ISO 15614.
3.1.3 Welding Procedure Specification: A document meeting the requirements of BS EN 15609 orASME Boiler and Pressure Vessel Code Section IX and derived from the WPQR/PQR that sets out indetail the required variables for a specific application to assure repeatability.
3.1.4 Welder Qualification Record: A document meeting the requirements of BS EN 287 or ASMEBoiler and Pressure Vessel Code Section IX, that presents the results of the approval testing of a welderto perform a fusion welding process.
3.1.5 Eskom Welding Co-ordinator: A Welding Engineer/Technologist appointed by the Eskom ChiefExecutive Officer or his designate to oversee all welding activities within Eskom Holdings Ltd.
3.1.6 High pressure equipment: Pressure Equipment with design pressure 50 kPa which include asteam generator, pressure vessel, pressure accessory and piping.
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3.1.1 Classification
a. Controlled disclosure: controlled disclosure to external parties (either enforced by law, ordiscretionary).
3.2 ABBREVIATIONS
Abbreviation Description
AIA Approved Inspection Authority
ASME American Society of Mechanical Engineers
AWS American Welding Society
BS EN British Standard European Norm
ISO International Organization for Standardization
ITP Inspection and test plan
IW International Welder registered with the International Institute of Welding
IWE International Welding Engineer registered with the International Institute of Welding
IWS International Welding Specialist registered with the International Institute of Welding
IWT International Welding Technologist registered with the International Institute of Welding
NDT Non-destructive testing
OHS Act Occupational Health and Safety Act of 1993
PER Pressure Equipment Regulations of 2009
PWHT Post weld heat treatment
QCP Quality control plan
TCA Technical capability assessment
TPI Third Party Inspector
WA Welding administrator / coordinator
4. REQUIREMENTS
4.1 GENERAL
4.1.1 Welding Requirements
The governing rules, clauses and requirements (in order of precedence) related to welding as describedin:
PER;
Relevant plant design and /or construction codes;
Eskom Standards;
Shall be followed during application of welding activities, disposition of defects and engineeringinterventions for solving anomalies.
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In addition to this, welding shall be performed to the requirements of BS EN 1011 Parts 1, 2 and 3 whichprovide general guidance on how to achieve and control basic good quality weldments in ferritic andstainless steels with emphasis on:
Welding principles
Requirements on welding production
Parent metals and welding consumables
Planning of welding activities
Welding fabrication
Elimination of distortion or inherent stresses
Post-weld heat treatment
Surface cleaning and treatment
Inspection and documentation.
More specific to tube and pipe welding activities, basic principles stipulated in BS 2633 shall be followedwhere applicable. This specification details arc welding using manual, semi-automatic or automaticprocesses; parent metals, welding consumables, preparation for welding, butt joints, branches,attachments, flanges, inspection, acceptance criteria, procedure and welder approval tests.
4.1.2 Welders and welding operators
Welders and welding operators working within the scope of this guideline shall be coded in-accordancewith the requirements of the latest construction code relevant to the plant and have the minimum IWqualifications specified in Eskom Standard 36-505. Execution of the WPQR / PQR activities shall bewitnessed by a suitably qualified TPI employed by the Eskom appointed AIA company if qualificationactivities are not witnessed by the responsible IWE or IWT.
4.1.3 WPS
Welding performed on plant built to a code or standard of manufacture shall be done in accordance witha valid WPS reflecting the requirements of the applicable code.
4.1.4 WPQR/PQR
A WPS shall be supported by a valid WPQR/PQR for all Level I and II plant work, while this isrecommended in the case of Level III plant work as set out in Table 1 of Appendix A. The PQR/WPQRshall be approved by a registered IWE or IWT with minimum qualifications as defined in Eskom Standard36-505. Any other qualification from another country that is considered to be equivalent shall beevaluated by the Eskom Welding Co-ordinator or his delegate for relevance. Execution of the procedurequalification activities shall be witnessed and/or verified by a suitably qualified TPI if qualificationactivities are not witnessed by the responsible IWE or IWT.
4.1.5 WPS verification
A suitably qualified TPI employed by an Eskom appointed AIA company shall verify that the information
on the WPS accurately reflects the parameters reported on the WPQR/PQR before use on Eskom
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equipment. Although approval of this document by an IWE/IWT is not mandatory, it is recommendedpractice.
4.1.6 Eskom welding coordinator/administrator
The appointed welding coordinator/administrator at the Eskom Site for the control of repair andmaintenance welding on Eskom plant, shall as a minimum be qualified as required by Eskom standard36-505. Any other qualification from another country that is considered to be equivalent shall beevaluated by the Eskom Welding Co-ordinator or his delegate for relevance. It is recommended that histasks contain the basic elements of ISO 14731.
4.1.7 Welding supervision
Supervisors for controlling welding activities at site level shall have the necessary practical experiencewith supervising contracts relating to the components relevant to the contract and as a minimumqualification be a certified IWS as required by Eskom Standards 36-775 and with the requirements
specified in Eskom Standard 36-505.
4.1.8 Welding Inspector
The Eskom or contractor welding inspector responsible for inspection of welding set-ups, weldingpreparations and completed weldments shall have a minimum qualification as stipulated in EskomStandard 36-505. Any other qualification acquired from another country that is considered to beequivalent shall be evaluated by the Eskom Welding Coordinator for maintenance and repair projects orhis delegate during the time of contract placement negotiations.
4.1.9 Technical capability assessment of contractors
Contracted companies (main and subcontracted) performing work on high value and safety critical Level1 and 2 Eskom plant shall be evaluated for acceptance on the Eskom vendor list for selected contractsthrough a technical capability assessment (TCA) convened and coordinated by the Eskom QualityDepartment. The assessment team shall as a minimum consist of:
IWE / IWT
NDT specialist
Quality specialist
Relevant Eskom plant engineer
Subsequent to each TCA a full report with findings shall be compiled for future reference by the relevantEskom plant line groups. The list of approved Level 1 and 2 vendors shall be maintained by the EskomQuality Department and distributed to the Eskom procurement departments. Follow up TCAs shouldideally be conducted at 3 year intervals, or when a contractor company is subjected to major structuralchanges. In cases where a major breakdown in a contracting companys capabilities is suspected, aTCA can be motivated at any time by the responsible Eskom plant engineer.
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4.2 WELD QUALITY SYSTEM
4.2.1 SANS ISO 3834
SANS ISO 3834 provides the framework for quality levels pertinent to the welding process. All weldquality related activities on Eskom plant shall use a system based on the requirements of SANS ISO3834. Exemptions from this requirement will be acknowledged for plant built in accordance with theASME Boiler and Pressure Vessel Code in which cases a quality system related or referenced to thisconstruction code may be used as stated in the ASME BPV Code, Section VIII Division 1 Appendix 10.
The vendor shall clearly define the welding function, its control and interaction with the rest of thecompanys production functions in the quality manual.
4.2.2 Welding Quality Requirements
The welding quality requirements will depend on:
The category level of Eskom plant being worked on
The contract requirements as agreed on between Eskom and contracting party
Any unusual conditions such as emergency repairs.
The different quality requirements as described in ISO 3834 are summarised in Table 1 of Appendix A.
Repair and maintenance work on Level 1 Category components shall be supported by ISO 3834-2 for
comprehensive quality requirements where BS or AD Merkblatt (TRD) construction rules apply. This byimplication requires the contractor to be an SANS ISO 3834 Part 2 certified company.
For components built to the ASME Boiler and Pressure Vessel Code, the requirements applicable to thatcode shall apply. For work on Level 2 and Level 3 components a quality level will be decided on by theEskom project manager or his delegate.
4.2.3 Quality assurance function
4.2.3.1 Minor repairs and maintenance
The appointed site welding co-ordinator / welding administrator shall perform the quality assurancefunction at this level.
4.2.3.2 Major repairs and maintenance
The authorised principal contractor shall employ a suitably qualified person to perform the qualityassurance function. The appointed site welding co-ordinator/administrator or his delegate shall maintaina monitoring presence and report any concerns to the Eskom project manager or the senior personresponsible for quality at the plant.
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Quality of welding activities performed on pressure Equipment, particularly pipework and boilercomponents, shall be monitored and verified by the Eskom appointed AIA as required by the PER andEskom Standard N.PSZ 45-223.
The authorised principal contractor shall appoint an AIA for any off-site repair and or refurbishment doneon pressure equipment if required by SANS 347.
The contractor shall prepare quality control documentation as required by Eskom Quality Standard GGS0462 and submit it to the welding co-ordinator for approval before commencing with any contract orwelding work.
4.2.4 Project quality audits
The Eskom welding co-ordinator or his delegate shall carry out spot checks on the overall welding
activities of a major contract with emphasis on:
Compliance with the Eskom Generation standard GGS0462 and SANS ISO 3834 quality levelrequirements as stated in the contract documents
Conformance of the contractor to the welding quality system as presented to the EskomCorporate Audit team during the vendor approval phase.
Application of sound welding principles
Adherence to PERs
NDT
These checks should also form part of technical capability assessments follow-ups when vendorcompanies are evaluated for acceptance on the Eskom vendor list for selected contracts on EskomLevel 1 and 2 plants.
4.2.5 Reporting of non-conformances
All issues shall be addressed through the reporting system as required by the contract.
Issues that might jeopardise the integrity of Eskom plant, transgressing the requirements of theapplicable construction code and/or the OHSAct and/or the rules set out by the Chief inspector of
Machinery in the PER shall be investigated as required by these authorities.
4.3 WELDING PROCEDURES
Welding procedure qualification for metallic weldments shall be in accordance with the appropriatecombination of EN and ISO/EN family codes of specification; BS EN ISO 15607, SANS 15609, SANS15614-1, SANS 15614-7, BS EN ISO 15613 and ISO 15608; as is applicable to the relevant plant and tothe Eskom quality Level requirements stipulated in Table 1 of Annexure A. An exception to this shallapply to Eskom plant at sites constructed to the ASME Boiler and Pressure Vessel codes in which casethe requirements stipulated in Section IX of the code shall be met. Any other possible exceptions shallbe motivated for approval by the responsible Eskom plant engineer.
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Welding procedure qualification for thermoplastic weldments shall be in accordance with SANS 10270.
4.3.1 Construction of new plant
Construction of new plant shall be performed to welding procedures qualified to the requirements of thelatest version of the applicable construction code.
4.3.2 Weld repairs on old plant
Weld repairs to be performed on old plant shall conform to the latest version of the construction code.Any deviations from the requirements resulting from technological advancement of equipment,processes and techniques shall be noted and submitted for approval by Eskom. For this type ofapplication the original welding procedure can be used but must be re-written to reflect the latest weldspecification format. Only old procedures with the required supporting documents such as the heattreatment chart and report from the mechanical test laboratory will be eligible for use.
4.3.3 Modification work to existing plant
Modification work to existing plant shall be performed to welding procedures qualified to therequirements of the latest version of the applicable construction code.
4.3.4 Refurbishment and/or repair work to existing plant
Refurbishment and/or repair work on existing plant that require non-standard weld preparations shall besupported by suitably qualified welding procedures that accommodate the geometry of the intendedrepairs. In the majority of cases this will require overlay or built-up type welding techniques. It isrecommended that the basic rules stipulated in SANS 15614 Part 1 be complemented by elements ofSANS 15614 Part 7 and BS EN 15613. For this approach the welding procedure will closely reflect the
geometry, sequence and technique required for the production weld.
4.3.5 Acceptance levels for Imperfections
Acceptance levels for imperfections B,C or D as described in BSENISO 5817 as required for specificweldments shall be prescribed to the contractor before production commences, preferably at the inquiryor order stage. In case no requirements are specified, by default the most stringent quality Level B shallapply. For special purposes additional conditions and details may be prescribed. The quality levels referto production quality and not to fitness for purpose of the situation.
4.3.6 Quality levels and assessment class for imperfections
Quality levels and assessment class for imperfections as described in SANS 10268 for thermoplasticweldments shall be prescribed to the contractor before production commences, preferably at the inquiryor order stage. For special purposes additional conditions and details may be prescribed. The qualitylevels refer to production quality and not to fitness for purpose of the situation.
4.3.7 Basic requirements of the weld procedure specification
4.3.7 Pertinent to welding procedure qualifications, the following information shall always be recordedin addition to the basic requirements of the weld specification:
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Heat input: the speed of weld progression shall be recorded in mm/s; the weld current range shallbe measured with a clip-on gauge/ tong tester; the open circuit voltage of the welding machineand the weld voltage range shall be measured with a volt-meter (multi meter).
Commercial trade name of the welding consumable. The yield strength and tensile strength of the coupons shall be recorded during the tensile tests.
A copy of the actual graph generated during execution of the tensile tests shall be part of therecord package.
The heat treatment chart (where applicable) shall form part of the permanent record of theWPQR / PQR.
Material certificates for both filler and parent material(s) shall be part of the permanent record ofthe WPQR / PQR.
The mechanical test samples shall be retained and preserved for at least six months aftercompletion of the tests for evaluation/examination by Eskom when required.
4.4 WELDER QUALIFICATION
WPQR / PQR testing for metallic materials shall be performed in accordance to SANS 9606. For weldingactivities on plant constructed to the ASME Boiler and Pressure Vessel Code Section IX of the codeapplies.
Welder qualification pertinent to thermoplastic materials shall be performed in accordance to SANS10269.
4.5 MATERIAL CONTROL
Prescriptions of the Quality Standard relevant to the contract shall be adhered to including the followingbasic requirements that are pertinent to all welding related tasks
4.5.1 Material to be used for fabrication or for weld repairs
Material to be used for fabrication or for weld repairs shall be identified by a material test or mill testcertificate.
All high pressure valves, fittings, tubes and pipe work must be supplied with an EN 10204: 2004 Type
3.2 material certificate.
All other components may be supplied at least with an EN 10204: 2004 3.1 material certificate.
4.5.2 All Unidentified material
Unidentified material shall be isolated / quarantined and identified by a full chemical analysis andmechanical testing as required by the relevant material specification, before being considered for furtheruse.
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4.5.3 Marking of removed material
Any pieces or parts removed from original material shall be clearly marked with low stress hard stampsin the presence of the WA/TPI before any cutting is performed.
4.5.4 Protection of sectioned faces
Sectioned faces shall be inspected for material defects and then protected from atmospheric conditionsand contamination and stored in a clean and dry environment until required for use.
4.6 WELDING CONSUMABLE CONTROL
The prescriptions of the Quality Standard relevant to the contract shall be adhered to including thefollowing basic requirements that are pertinent to all welding related tasks.
4.6.1 Consumable approval
Consumables shall be approved by the national standard requirements of the country of origin as aminimum. It is recommended that consumables with approval according to AWS A5.X family ofspecifications and/or BSEN family of consumable specifications be used on Level 1 and 2 Eskom plant.
4.6.2 Consumable identification
Batch identification numbers shall be clearly marked on each individual package.
4.6.3 Consumable storage
Consumables shall be stored in a clean atmosphere with humidity kept below 50% and a minimum of at
least 30C above atmospheric dew point shall be maintained inside the original packaging as long aspossible.
4.6.4 Damaged or contaminated consumables
All consumables showing signs of damage to coatings, rust or contamination by any carbonaceous(paint, oil, polymers etc.) substance shall be promptly removed from storage or circulation and properlydisposed of.
4.6.5 Identification on consumables
Consumable grade markings/ stamps shall be visible on each individual wire or rod. There shall be no
mixing of different class/grade consumables in one container.
4.6.6 Baking/drying of consumables
Baking or drying temperature and duration shall be at least in accordance with the suppliers minimumrequirements.
4.6.7 Holding of baked/dried consumables
After baking/drying, the consumables shall be promptly transferred to a holding oven and stored at120C to 150C for a maximum of one week prior to u se.
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4.6.8 Hot boxes for consumables
Consumables shall be issued to welding personnel in hot boxes and the temperature shall be maintainedabove 70C.
4.6.9 Unused consumables
After each working shift the unused electrodes shall be accounted for by the welding supervisor or aproperly trained delegate and returned to the holding oven until issued for a next working shift. Theseunused consumables shall be the first to be issued on the next working shift.
4.6.10 Permitted re-baking cycles
The number of permitted re-baking cycles shall be in accordance with the supplier recommendations. Ifthis is not clearly specified, the maximum number of baking cycles shall be three.
4.6.11 Welding and cutting gasses
All gases used for welding and cutting tasks shall be clearly identifiable and accompanied by an analysiscertificate.
4.7 HEAT TREATMENT
Heat treatment procedures shall be compiled to meet the requirements of BS EN ISO 17663. Theprescriptions of this quality standard and the contractors works instructions relevant to the contract shallbe adhered to including the following basic requirements pertinent to all welding related tasks.
4.7.1 Heat treatment procedures
Heat treatment procedures shall be compiled strictly in accordance with the WPS. A clear and concisedrawing indicating the position and orientation of the heating source (resistance heating mats, inductioncoils, gas flame) as well as the positions for the controlling and monitoring thermocouples shall form partof the heat treatment method statement. This document shall be kept by the heat treatment technicianat the work site. For PWHT on Eskom plant the temperature variation between set and actual measuredshall be maximum or better than quality Class III in Table 1 of BS EN ISO 17633.
4.7.2 Heat treatment equipment
Equipment used for heat treatment shall be in a well maintained condition, in particular:
Valid calibration certificates for the power source and the control units shall be available forscrutiny at the work site
All connections for thermocouples and heating elements shall be mechanically sound. No barewires wedged into connection points on the power source and control panel will be allowed onEskom plant
No bare wire connections between lengths of compensating cable, and between compensatingcables and the thermocouple wires are permissible. Proper connectors designed for this purposeshall be used.
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4.7.3 Operation and monitoring of heat treatment equipment
Heat treatment equipment shall be attended to by suitably qualified operators at all times, includingautomated units which shall also be monitored continuously.
4.7.4 Measurement and maintenance of temperature for pre-heating and interpass temperature
Measurement of temperature for preheating and interpass maintenance shall be in accordance with ENISO 13916. Unless otherwise indicated by Eskom, the controlling thermocouple shall be positioned atthe perceived point of lowest temperature during the heat treatment operation. This position will bedetermined by factors such as the effect of gravity on radiant heat flow, insulation techniques andconduction heat flow effects due to the close proximity of heavy walled components. Thermocouples, inparticular the controlling one, shall be insulated from the direct radiant heat flux caused by the heatingmat/coil/element (by recognised means such as heat resistant putty) in order to ensure true metaltemperature is measured.
4.7.5 Heat treatment parameters for service-aged materials
When welding is performed on service-aged materials, heat treatment parameters may have to bereviewed/revised to accommodate the material condition. Typical requirements are reduced heating andcooling ramp rates, flush grinding of weld reinforcements before PWHT commences. Additionalmeasures to reduce cooling rates in the event of power source failure shall be in place. As a minimum,insulation of the affected component shall extend at least 1 meter either side of the heating source. Aback up power generator is strongly recommended.
4.7.6 Substantiation of heat treatment
Each heat treatment performed shall be substantiated by chart recordings or accurately kept hand
written recordings of time versus temperature
4.7.7 Heat treatment information
These heat treatment graphs shall form part of the welding data package.
4.7.8 Multiple heat treatments
Multiple heat treatments of the same area on a component must be avoided. If this is unavoidable, theeffect of multiple heat cycles on material metallurgical properties as well as on complicated geometriesshall be investigated by the contractors suitably qualified engineering department. This investigationmay also be contracted out to a suitably qualified metallurgical consultant.
4.7.9 Unplanned events during heat treatment
Unplanned events that may occur during execution of the heat treatment procedure such as:
Loss of power to the power source and/or controlling unit and/or data recorder
Detached thermocouples
Detached insulation
Electrical shorts on thermocouple compensation cables
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These events shall be investigated immediately after being discovered by the project team, with thequalified metallurgical engineering input to determine the course of remedial action. A written report withrecommendations shall be issued by the contractor for Eskom records.
4.8 CALIBRATION OF EQUIPMENT
The prescriptions of the Quality Standard relevant to the contract shall be adhered to including thefollowing basic requirements that are pertinent to all welding related tasks.
4.8.1 Equipment identification
Each welding machine, heat treatment power source and plasma cutter shall be identifiable by an uniquenumber. Machines shall be serviced and calibrated at least once a year when in constant use andproper records shall be kept. In case of infrequent use longer inspection and calibration cycles may bemotivated by the vendor. Periodic checks by using a calibrated tong tester shall be performed to ensurethat a reasonable level of accuracy is maintained.
4.8.2 Calibration of temperature measuring equipment
Temperature measuring equipment shall be calibrated at least once a year and a record shall be kept.Other inspection and calibration cycles may be motivated and agreed between Eskom and the vendor.
4.8.3 Calibration of furnaces, holding ovens and hot boxes
Consumable baking furnaces, holding ovens and hot boxes shall be calibrated at least once a year and arecord shall be kept. In case of infrequent use longer inspection and calibration cycles may be motivatedby the vendor.
4.8.4 Calibration of chart recorders for heat treatments
Chart recorders used for heat treatment shall be calibrated at least once a year and a record shall bekept. In case of infrequent use longer inspection and calibration cycles may be motivated by the vendor.
4.8.5 Proof of calibration
Proof of calibration status of the calibration and test equipment itself shall be included on eachcalibration certificate.
4.9 NON DESTRUCTIVE TESTING
4.9.1 Independence of NDT contractor
Non-destructive testing (NDT) shall be performed by an entity suitably independent from the weldingoperation to ensure unbiased inspection.
4.9.2 Eskom approval of NDT contractor
All Technicians performing NDT shall be Eskom approved and shall be employed by an Eskomapproved company in accordance with the requirements of Eskom Standards 32-631 and 32-632.
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4.9.3 NDT safety
Safety measures required by radiographic testing shall be strictly adhered to by the welding personnel.
4.10 WELDING COORDINATOR/ADMINISTRATOR
The site welding co-ordinator / administrator shall be appointed by the relevant Eskom Power StationManager, this function will depend on the Eskom site personnel structure and his/her job model shall atleast include the following:
1. Assuring that all welding and related activities are performed in accordance with this guideline.
2. Any welding activity that could affect Eskom plant detrimentally in any way that is not specificallyaddressed in this guideline shall be investigated, reported and/or referred for in depthinvestigation.
3. Quality control of all welding and NDT activities as per relevant site procedures.
4. Compile repair procedures, Quality Control Plan (QCPs) and witness mandatory inspection holdpoints or witness points as required by the QCP
5. Accepts contractors repair procedures and QCPs.
6. Issue non-conformance reports on non-compliant materials, spares and workmanship.
7. Liaise with the TPI working for the Eskom appointed AIA on all repairs.
8. Interpret radiographs (if qualified to do so) and determine compliance to acceptance criteria.
9. Setting of quality criteria for special material requirements.
10. Check quality of special materials when delivered.
11. Ensure that only approved and qualified NDE personnel are employed on site.12. Ensure that special processes controlling or verifying weld quality, heat treatment and NDT are
performed by qualified personnel using qualified procedures in accordance to specifiedrequirements.
13. Preparing, recording, maintaining and issuing welder performance qualification records andensuring all Eskom and Contractor welders are qualified in accordance with the specifiedconstruction code.
14. Ensure all welding equipment is calibrated and maintained and records kept up to date.
5. RECORDS AND DATA PACKAGES
Records pertaining to any manufacture, repairs or modifications shall be compiled and /or updated andstored as required by Regulation 14 of the PER. All documents required by the applicable codes,standards and specifications shall be included in the contract/project data package.
Eskom shall retain all original documentation. As a minimum, the following shall be present:
1. WPQR/PQR register.
2. WPS register.
3. WQR register.
4. Register with calibration certificates for welding, measuring and recording equipment.
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5. Welding consumable and material test certificates.
6. Heat treatment recorded data.
7. NDT certificates/records and radiographs stored in accordance with Eskom requirements.
8. Weld record sheet/weld map relating all the above records to each individual weld, for example,which welder performed the welding to which WPS with which batch of consumables and whatwere the NDT results for that joint.
9. Record of non-conformances.
10. Record of performance of each individual welder with regard to repair rates and exceptionalperformance for future reference.
11. Inspection reports
12. Repair recommendations/instructions
13. QCP / ITP
14. Release certificate
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6. APPENDIX
A.1 SUMMARY OF SANS ISO 3834 QUALITY REQUIREMENTS
ELEMENTS
SANS ISO 3834-2(Comprehensive
quality requirements) ESKOM LEVEL 1
PLANT
SANS ISO 3834-3(Standard Qualityrequirements) ESKOM LEVEL 2
PLANT
SANS ISO 3834-4(Elementary quality
requirements) ESKOMLEVEL 3 PLANT
CONTRACT REVIEWFull documented
reviewLess extensive
reviewEstablish that capability
and information isavailableDESIGN REVIEW Design for welding can be reviewed
SUB-CONTRACTOR Treat like main contractorShall comply with
standard
WELDERS,OPERATORS
Approved to SANS 9606 (Metallic weldments); SANS10269(Thermoplastics)
WELDINGCOORDINATION
Welding co-ordination personnel withappropriate technical knowledge according toISO14731, or persons with similar knowledge
Not demanded butresponsibility of
contractor
INSPECTIONPERSONNEL
Sufficient and competent personnel to beavailable
Sufficient and competent,access for third parties,
as needed
PRODUCTIONEQUIPMENT
Required to prepare, cut, weld, transport, lift,together with safety equipment and protective
clothes
No specific demand
EQUIPMENTMAINTENANCE
Has to be carried out,maintenance plan
necessary
No specific demand.Shall be adequate
No demands
PRODUCTION PLAN NecessaryRestricted plan
necessaryNo demands
WPSInstructions to be available to welder (BS EN
15609)No specific demands
WELDINGPROCEDURE
APPROVAL
In accordance with BS EN15614 series(formetallics), approved as application standard or
contract demands
For thermoplastic weldments refer to SANS10270
No demands
WORKINSTRUCTIONS
WPS or dedicated work instructions to beavailable
No demands
DOCUMENTATION Necessary Not specified No demands
BATCH TESTING OFCONSUMABLES
Only if specified incontract
Not specified No demands
STORAGE ANDHANDLING OFWELDINGCONSUMABLES
In accordance with supplier recommendation as minimum
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STORAGE OFPARENT MATERIALS
Protection required from influence by theenvironment
No demands
POST WELD HEAT
TREATMENT
Specification andcomplete record
necessary
Confirmation tospecification
necessary
No demands
INSPECTIONBEFORE, DURING,AFTER WELDING
As required for specific operationsResponsibilities asspecified in contract
NON-CONFORMANCES
Procedures shall be available
CALIBRATIONProcedures shall be
availableNot specified
IDENTIFICATION Required whenappropriate
Required , whennecessary
Not specified
TRACEABILITY Not specified
QUALITY RECORDS
Shall be available to meet the rules for productliability As required by contract
Retained for five years minimum 5 years (or as contractually required)