36-775 control of plant construction repair and maintenance welding activities (rev 1)

7/28/2019 36-775 Control of Plant Construction Repair and Maintenance Welding Activities (Rev 1)

1/22

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:


2/22

Control of Plant Construction, Repair and MaintenanceWelding Activities

CONTROLLED DISCLOSURE

When downloaded from the EDMS, this document is uncontrolled and the responsibility rests with the user to ensure it is in linewith the authorised version on the system.


Revision: 1

Page: 2 of 22

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


3/22





Revision: 1

Page: 3 of 22

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


4/22





Revision: 1

Page: 4 of 22

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


5/22





Revision: 1

Page: 5 of 22

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


6/22





Revision: 1

Page: 6 of 22

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


7/22





Revision: 1

Page: 7 of 22

[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.


8/22





Revision: 1

Page: 8 of 22

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.


9/22





Revision: 1

Page: 9 of 22

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


10/22





Revision: 1

Page: 10 of 22

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.


11/22





Revision: 1

Page: 11 of 22

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.


12/22





Revision: 1

Page: 12 of 22

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.


13/22





Revision: 1

Page: 13 of 22

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:


14/22





Revision: 1

Page: 14 of 22

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.


15/22





Revision: 1

Page: 15 of 22

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.


16/22





Revision: 1

Page: 16 of 22

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.


17/22





Revision: 1

Page: 17 of 22

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


18/22





Revision: 1

Page: 18 of 22

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.


19/22





Revision: 1

Page: 19 of 22

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.


20/22





Revision: 1

Page: 20 of 22

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


21/22





Revision: 1

Page: 21 of 22

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


22/22




Revision: 1

Page: 22 of 22

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)

36-775 control of plant construction repair and maintenance welding activities (rev 1)

Documents