IIW/EWF Diploma - Fabrication and Application (Foundation)
FAA1
Training & Examination Services Granta Park, Great Abington Cambridge CB21 6AL, UK
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IIW/EWF Diploma - Fabrication and Application (Foundation) Contents Section Subject Pre training briefing 1 Quality Assurance and Quality Control 1.1 Definitions 1.2 Quality system standards 1.3 Auditing and documentation 1.4 Quality requirements for welding 1.5 Calibration/validation of welding equipment 1.6 Workshop exercise 1.7 Questions on validation and in-process monitoring 2 Approval Testing 2.1 Welder approvals BS.EN.287 2.2 Training 2.3 Definitions 2.4 Codes of practice and application standards 2.5 Other welding approval standards 2.6 Questions on approval testing and quality control 2.7 Practical on procedure and welder qualification testing 2.8 Questions on welding procedure and welder approvals 2.9 Practical exercise on codes of practice and application standards 3 Development of Residual Stress and Distortion 3.1 Factors effecting residual stresses and distortion 3.2 Typical material properties 3.3 Characteristics of materials which determine the amount of distortion
and residual stresses 3.4 Correcting distortion 3.5 Questions 4 Plant Facilities and Equipment 4.1 Factory layout 4.2 Joint fit-up and jigging 4.3 Positioning equipment 4.4 Questions
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5 Safety in the Welding Shop 5.1 Arcs 5.2 Hot metal 5.3 Fire 5.4 Noise 5.5 Cables 5.6 Mechanical hazards 5.7 Filter glasses 5.8 Electrical 5.9 Gas cylinders 5.10 Fumes and gasses 5.11 Parent metal 5.12 Surface coating 5.13 Air 5.14 Ventilation 5.15 Other protective measures 5.16 Recommendations for specific processes 5.17 Questions 6 Economics of Welding 6.1 Deposition rate 6.2 Consumable efficiency 6.3 Arc time duty cycle 6.4 Joint design 6.5 Downtime 6.6 Questions 7 Non-Destructive Testing (NDT) 7.1 Visual testing 7.2 Penetrant testing 7.3 Magnetic particle inspection (MP) 7.4 Eddy current testing (ET) 7.5 Ultrasonic testing (UT) 7.6 Radiographic testing (RT) 7.7 Visual inspection 7.8 NDT Methods 7.9 Comparison between X and gamma sources 7.10 Radiological protection 7.11 Choice of method 7.12 NDT clarification schemes 7.13 PCN personal certification in NDT 7.14 Standards and specifications 7.15 Questions
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8 Repair by Welding 8.1 Introduction 8.2 Types of defects 8.3 General techniques for typical repairs 8.4 Groove shape 8.5 Welding processes 8.6 Summary 8.7 Questions 9 Typical Exam Practice Question 10 Additional information: Welding consumables storage and
handling 11 Additional information: Preheat and interpass temperature
equipment and control 12 Additional information: weld defects/imperfections
Section 1 Quality Assurance and Quality Control
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1 Quality Assurance and Quality Control 1.1 Definitions
Before we consider what quality assurance and quality control is, let us first define quality. This is best described as being the fitness-for-purpose of a product, service or activity. BS 7448 Part 1 Quality Vocabulary, describes quality as the totality of features and characteristics of a product or service that bear on its ability to satisfy stated or implied needs. Quality assurance is all those planned and systematic actions necessary to provide adequate confidence that a product or service will satisfy given requirements for quality. Quality control is described as the operational techniques and activities that are used to fulfil requirements for quality. Quality assurance is therefore the documented plans and systems by which confidence in a product is provided and comprises all of the paperwork systems that are used to plan, control and record activities, ie the documentation. Quality control is those activities which monitor the quality of the product. The operational techniques of checking materials, dimensional checks, inspection before, during and after welding, non-destructive testing, hydraulic or leak testing, ie activities which take place after the event and which check that a specified activity has been carried out correctly. Quality assurance has been introduced to ensure that the activity is right first time on the principle that prevention is better than cure. This can be achieved by planning and anticipating problems. In order to satisfy this requirement a documented quality system is needed which sets out in a formal framework the basis of control for the critical activities. This framework in general, comprises of four tiers of documentation. The highest tier being the company quality manual, cascading down through quality systems, quality plans and detailed manufacturing and inspection instructions.
1.1.1 Quality system Can be defined as: The organisation structures, responsibilities, procedures, processes and resources for implementing quality management.
The quality manual and support procedures document an organisation's quality system.
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1.1.2 Quality manual Can be defined as: A document setting out the general quality policies, procedures and practices of an organisation.
The word general, is important in this definition. The quality manual is usually the first indication a purchaser or prospective client has of a company's approach to quality. This document should contain a statement of the company's total commitment to quality by means of a quality policy statement signed by the Chairman, MD or Chief Executive of the company. This policy statement should be prominently displayed within the company.
1.1.3 Procedure Can be defined as: A document that describes how an activity is to be performed and by whom.
Note: The definitions used above are based on those given in British Standards:
BS 7448: Part 1: ISO 8402: Quality Vocabulary Internal terms. BS 4778: Part 2: Glossary of terms used in quality assurance.
Note, that a procedure is not a detailed work instruction such as a welding procedure but a statement of who does what and how, it describes the corporate plan for achieving quality. But there may be times when an organisation needs to operate in a different way from the corporate system, for example, for a unique project or to satisfy a specific customer's requirements.
In these circumstances an appropriate quality system can be documented in the form of a project off-contract specific quality plan.
1.1.4 Quality plan Can be defined as: A document setting out the specific quality practices, resources and sequence of activities relevant to a particular product, service, contract or project. A quality plan is the corporate quality system suitably modified to reflect specific equipments. It may compromise a project quality manual incorporating appropriate sections from the corporate quality manual which apply. It is generally a detailed document.
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Project procedures may well include: Existing procedures appropriate to the contract. Existing procedures amended for the contract. New procedures to meet specific requirements for the contract. Some contracts may well call for a combination of all three.
1.2 Quality system standards Quality system standards specify the minimum requirements of quality systems for application to specific products or services. Standards are normally used for the following purposes: As guidance to an organisation introducing quality assurance. As a basis for evaluating an organisation's quality system (assessment). To specify the quality assurance requirements when invoked in a
contract. The standard common in the UK is ISO 9000.
1.2.1 Quality Records A quality record is any document that indicates the inspection performed, quantities inspected, results obtained, positive identification of the material inspected to drawing or part number, the signature or stamp of the person carrying out the inspection and date of inspection. Quality records might also indicate the qualification of personnel, calibration of equipment or other records not directly related to the product. Questions that need to be addressed include: What quality records are to be maintained, eg receiving inspection reports, NDT results, test certificates, final inspection reports and non-conformance reports (including any feedback or corrective action generated). Where are the records filed and by whom? How long are the quality records retained? Are the quality records available to the customer for analysis and
review? Are records easily retrievable? Is a suitable environment available to minimise deterioration or damage
to stored records?
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1.2.2 Typical quality record contents The Quality Record Package for a welded product will be defined specifically for a contract but should include the following types of information: a) Records of stage inspections in the form of check sheets or quality plans. b) Non-conformity reports and concession records. c) Where appropriate, As built drawings. d) Welding procedures. e) Welder approvals. f) Welding consumable records. g) Weld history records. h) NDT reports. i) Heat treatment records. j) Hydraulic and/or other testing records. k) Where appropriate, material test certificates. l) Final acceptance certificates.
1.2.3 What areas of a business need to be covered by ISO 9000? This standard requires the following elements of the business to have set procedures. Management responsibility - who is responsible for what? Quality system - how does the system operate? Contract review, allows personnel to see what the requirement is and
who has been asked to do what. Design review and control, ensure smooth passage from drawing board
to end product. Documentation controls, make sure the correct documents are available. Purchasing, make sure we have the right products and services. Purchaser supplied product, make sure that these items are also OK. Product identification and traceability, what is it and where is it? Process control, lets everyone know clearly how to make the product. Inspection and test, describes how to inspect and test it. Inspection, measuring and test equipment, make sure the equipment
used is correct.
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Inspection and test status, where is the product in the inspection cycle? Control of non-conforming product, ensures incorrect product is not
used. Corrective action, find the root cause of the problem and solve it. Handling, storage, packing and delivery, don't damage it now it's made. Quality records, the need is for documented evidence that the company
meet specific requirements. Internal quality audits, are quality activities performing as planned? Training, it cannot be manufactured effectively if people are not
adequately trained and qualified. Servicing, if carried out by the company, effective procedures are
required. Statistical techniques, use them to build-in product quality.
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Quality Programme Documentation
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The Welding Inspector Responsibilities
Ensure compliance to standard or code
Ensure welding criteria by policing work and
documentation
Ensure workmanship
Honesty integrity
Attributes
Literacy Fitness Physical Eyesight
Duties
Observe measure identify
Before welding
During welding
After welding
Material Consumables
Welding processes Joint fit-up
Preheat Tack welding/clamping
Alignment Calibration
Safety
Voltage Amperage
Travel speed Interpass temperature
Interpass cleaning
PWHT Visual assessment NDT assessment
Accept Reject
Collect and collate all documents which may
include: Code or standard
material certificates Consumable certificates Calibration certificates
Drawing(s) Welding procedure
Approval certificates Inspection records
PWHT records Other test records
Concessions Compliance certificates
Concession Repair
ID area Mark out Remove Re-weld
Re-inspect
Acceptance of the product
Inspector passes the document package to a higher authority for final
approval
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1.3 Auditing and documentation Quality manuals, procedures and work instructions, etc provide the objective evidence that the systems of control have been adequately planned. The records and documentation generated by carrying out work in accordance with these systems provides the evidence that the systems are being followed by all. Systems of control, no matter how effective they are, will tend to deteriorate because of human errors, such errors being perpetuated or because of changes in the nature of the business. In order to ensure that the systems are being followed and are effective and to determine if changes are needed it is necessary to monitor them. This is achieved by auditing the system and reviewing the results of the audit in order to implement any changes.
1.3.1 What is an audit? Quality audits examine a quality system for adequacy and correct implementation. They are defined in BS 4778 Part 1 as: Systematic and independent examinations to determine whether quality activities and related results comply with planned arrangements and whether these arrangements are implemented effectively and are suitable to achieve objectives. Auditing is carried out to provide objective evidence that the system is working in accordance with the procedures. When an audit is complete the results are analysed by management who must ensure that the quality policy is satisfied and modify the quality system if necessary.
1.3.2 Which type of audit? There are two depths of audit: A systems audit which is quite shallow and simply examines the system to confirm that it follows the quality manual and that procedures are in place. A Compliance audit, which is an in depth audit examining compliance with procedures.
1.3.3 Auditing of documentation A documentation audit is regarded as being a compliance audit, where documentation is examined in depth. Items to check in such an audit should include: Is all the documentation available? Is the documentation schedule in accordance with contract or
specification requirements?
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Does the documentation itself comply with contract or specification requirements? For example, are weld procedure and welders correctly qualified?
Is it the correct material composition? Is the documentation legible? Have all the interested parties eg inspection department, independent
third party inspectors and client inspectors, signed off where required? Have provisions been made for storage? Which includes the ability to
retrieve documents and the storage conditions to prevent deterioration? Documentation audits should be carried out by the manufacturer/supplier as a matter of course. Customers will also frequently require access to carry out their own audits. Remember that no job is finished until the paperwork is complete. Failure of a documentation audit carried out by a client will often result in a delay in payment, even though the component may have been delivered to the client. There can often be a consequential financial penalty.
1.4 Quality requirements for welding Within the international community, welding has been confirmed as a special process which means that it will require to be controlled by specialist management and utilise specialist personnel. The welding co-ordination (ISO 14731) and the welding quality systems standards (ISO 3834) have been prepared in support of this ruling. It is perceived that these standards will be references in other application standards and will be used as set criteria for the qualification of fabricators. Currently there are a number of European Standards or codes that refer to ISO 3834 EN 13445:2002 unfired pressure vessels. prEN 15085: Railway applications Welding of Railway vehicles and
components. Pr EN 1090 Execution of steel structures. EN 12732: 2000 Gas supply systems Welding steel pipework
functional requirements. EN 12592: 2001 Water tube boilers and auxiliary installations. National Structural Steelwork Specification for Building Construction (5th
Edition), (NSSSBC ). It is also becoming more common for a requirement that the fabricator has a quality system compliant with ISO 3834 to be specified as a condition of the customer contract.
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1.4.1 Qualification of welding fabricators - ISO 3834 This is in five parts. Part 1 - Guidance for use describes how the standard works. Part 2 - Quality requirements for welding - Fusion welding of metallic materials - Comprehensive quality system. This standard is suitable for use by a manufacturer or an assessment body, as a supplement to ISO 9001 or 9002 providing detailed guidance on the requirements needed to be in place to adequately control welding. Part 3 - Quality requirements for welding, Fusion welding of metallic materials, Standard quality system. This standard can be applied where a documented quality system for the control of welding is required but which will not be used in conjunction with ISO 9001 or 9002. Part 4 - Quality requirements for welding - Fusion welding of metallic materials - Elementary system. This standard provides criteria appropriate for the control of welding when neither or the following conditions apply: A quality system according to ISO 9000 is not to be applied. The combination of selected welding processes, procedures and the final
welds are such that documented welding control have minor importance in respect to the overall integrity of the product.
Part 5 - Documents with which it is necessary to conform to claim conformity to the quality requirements of ISO 3834-2, ISO 3834-3 or ISO 3834-4 This lists all of the other documents or standards that are required for compliance with ISO 3834 such as sspecification and qualification of welding procedures and approval testing of welders, etc. The manufacturer should select one of the three parts from 2-4 specifying different levels of quality requirements, based on the following criteria related to products: The extent and significance of safety-critical products; The complexity of manufacture; The range of products manufactured; The range of different materials used; The extent to which metallurgical problems may occur; The extent to which manufacturing imperfections, e.g. misalignment,
distortion or weld imperfection, affect product performance. This approach offers a cascading qualification, for example, part 2 (comprehensive) also gives compliance for lower levels.
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As previously stated, It is intended that BS EN ISO 3834 complements, rather than conflicts with, quality systems established to meet the requirements of ISO 9000 and in the case of a comprehensive quality system for welding fabrication (part 2), requires additionally to ISO 9000 that specific procedures are used to control the following: 1 Review of requirements. 2 Technical review. 3 Sub-contracting. 4 Welders and welding operators. 5 Welding co-ordination personnel. 6 Inspection and testing personnel. 7 Production and testing equipment. 8 Equipment maintenance. 9 Description of equipment. 10 Production planning. 11 Welding procedure specifications. 12 Qualification of welding procedures. 13 Batch testing of consumables (if required by contract). 14 Storage and handling of welding consumables. 15 Storage of parent material. 16 Post-weld heat treatment procedure. 17 Inspection and testing before, during and after welding. 18 Non-conformance and corrective actions. 19 Calibration or validation of measuring, inspection and testing equipment. 20 Identification during process (if required by contract). 21 Traceability if required no specific requirement (if required by contract). 22 Quality records (if required by contract). A company applying for certification to ISO 3834 will usually be required to follow certain stages such as follows: Client returns preliminary enquiry. Quotation. Detailed forms sent to client. Assessment team appointed by auditor. Preliminary visit by auditor (not mandatory but usual) to carry out a gap
analysis. Document review by auditor to review procedures against ISO 3834. On site assessment conducted by auditor to demonstrate that the client
has accrued evidence that procedures are used and that these are overseen by the welding co-ordination team.
Assessment recommendations made. Certificate issued (5 year validity). Surveillance (yearly). This process, from application to certificate issue, can take months to complete.
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1.4.2 Welding co-ordination A key part of ISO 3834 is in the definition of responsibilities of the welding co-ordination personnel. ISO 14731 defines these personnel and the technical knowledge that they require. The main role falls to the Responsible Welding Co-ordinator (RWC). One or more personnel in a company may perform the welding co-ordination function but each part of the requirements of ISO 3834 listed above will require input from the welding co-ordination team. Table 1 in ISO 14731 gives guidance to those tasks, which may require a welding co-ordinator input. The technical knowledge required by the co-ordinator will obviously depend upon the complexity of the product. The standard defines three levels of knowledge and experience: 1 Comprehensive: Equivalent to the level of an International/European Welding Engineer. 2 Specific: Equivalent to the level of an International/European Welding Technologist. 3 Basic: Equivalent to the level of an International/European Welding Specialist. It can be seen that the three levels of technical knowledge defined imply a matching with the three levels of quality requirements required from parts 2 to 4 of ISO 3834. The IIW route is not mandatory; there are in fact three possible routes to demonstrate technical knowledge: IIW Qualification and experience (via interview). Interview to assess knowledge without IIW qualification (professional
review in 3834 Audit). Externally sub contract to an external subcontractor with appropriate
knowledge and experience, again an interview is required (it would be expected that external resource will be familiar with the company applying for certification and will be contracted to visit regularly).
1.5 Calibration/Validation of Welding Equipment Faulty equipment does not enhance the quality of work, it should follow that equipment used in production, or for welder and procedure approval tests, should be in a sound condition in all respects in order to avoid breakdown during production or testing. One important point to note is the accuracy of meters and the repeatability of the machine's controls in relation to output performance. Welding current connections and return leads on all arc welding equipment should be
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checked for tightness prior to commencing welding, failure to do so may lead to voltage losses affecting arcing conditions. Where semi-automatic gas shielded processes are used, care should be taken to ensure that the wire feeding systems are also repeatable and accurate. Additionally it would be expected that flowmeters controlling shielding and purging gases are calibrated. This activity is collectively known as validation A requirement in many industries during the welding operation is the use of a calibrated meter(s) to check welding current, arc voltages, travel speed and perhaps, wire feed speed. In addition, ensuring the welders are using the correct gas, the electrode wires are of the correct composition and that the preheat temperature and location have been correctly applied against the welding procedure requirements. In the case of Manual Metal Arc (MMA) and Submerged Arc Welding (SAW), attention should be paid to any special drying requirements for fluxes or covered electrodes and also the conditions they are kept in prior to use. A written procedure for storage and handling of consumables is recommended to be used and records of humidity and temperature may required to be kept. This activity is collectively known as in process monitoring.
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1.6 Workshop Exercise
1.6.1 Items to be checked during an audit on welding equipment From the power supply check: Mains input - connections - insulation - cable rating Produce your own checklist of the remaining items.
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1.6.2 Welding records (In-process monitoring) Welding records must include: Type of process (es). Identification of the materials and welding consumables. Identification of joint type(s) and fit-up. Welding procedures. Welder's identification and approval record. Inspection procedure and report identification. Defects found. Acceptance or rejection and to which acceptance levels. Corrective action taken.
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FAA1 Questions: Quality Assurance and Quality Control 1 Describe how the functions of QA, QC and inspection would operate in a small
sub-contract fabrication company.
2 How would these differ from the functions in a company, which also designs and
manufactures the product?
3 Describe the contents of a quality plan. Use a simple component/fabrication of your choice to illustrate your answer.
4 State the two types of audits that can be carried out.
5 List the personnel/departments that influence quality within a company.
6 What would be the function of a Welding Specialist in a fabrication organisation?
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1.7 Questions: validation and in-process monitoring
1 Briefly describe the different between calibration, validation and in-process monitoring.
2 Which of the following welding equipment can be validated and/or calibrated?
a. MMA transport power source without meters. b. TIG transformer-rectifier power source with meters. c. MIG/MAG inverted power source. d. Submerged-arc welding (mechanised). e. Resistance spot welder.
3 What are the tolerances specified for voltage and current values?
4 How frequently should validation be carried out?
5 You are required to monitor a critical welding procedure approval which involves the need for stringent heat input control. Briefly describe the equipment required to successfully complete this operation and provide a brief checklist on the details to ensure compliance.
1QUALITY ASSURANCE AND QUALITY CONTROL
TWI Training & Examinations ServicesCourse in Welding(EWF/IIW Diploma)
Quality
What is quality?What is quality?
Quality = degree to which a set of inherent Quality = degree to which a set of inherent characteristics fulfils explicit and implicit characteristics fulfils explicit and implicit requirementsrequirements
Quality - definitions
QualityQuality
ManagementManagementCoordinated activities to Coordinated activities to direct and control an direct and control an organisationorganisation
PolicyPolicy
Overall intentions and Overall intentions and direction of an organisation direction of an organisation related to quality as formally related to quality as formally expressed by top expressed by top managementmanagement
SystemSystemA system to direct and control A system to direct and control an organisation with regard to an organisation with regard to qualityquality
Quality management activities
QualityQuality
AssuranceAssurance
ControlControl
Part of quality management focused on Part of quality management focused on providing confidence that quality providing confidence that quality requirements will be fulfilledrequirements will be fulfilled
Part of quality management focused on Part of quality management focused on fulfilling quality requirementsfulfilling quality requirements
prevent defective workprevent defective workensure programme commitments ensure programme commitments are achievedare achievedprovide feedback to the provide feedback to the managementmanagement
Why do we need QA?Why do we need QA?
Quality assurance principle
Say what youSay what youre going to do (by re going to do (by writing procedures)writing procedures)
Do it Do it -- in compliance with in compliance with your own proceduresyour own procedures
Demonstrate that youDemonstrate that youve ve done itdone it
By keeping By keeping proper recordsproper records
By doing check By doing check auditsaudits
Quality assurance documents
Quality Quality assurance assurance documentsdocuments
SpecificationSpecification -- document stating document stating requirements (related to requirements (related to activities or products)activities or products)
Quality Quality manualmanual
-- document specifying the quality document specifying the quality management system of an management system of an organisationorganisation
Quality Quality planplan
-- document specifying which document specifying which procedures and resources shall be procedures and resources shall be applied by whom and when, to a applied by whom and when, to a specific projectspecific project
ProcedureProcedure -- specified way to carry out specified way to carry out an activityan activityCode of Code of practicepractice
-- a set of rules for a set of rules for manufacturing a specific manufacturing a specific product or activityproduct or activity
2Specification vs. procedureSpecification content:
Scope Applicable domain Terms and definitions Responsibilities Design requirements Material and/or process
requirements Inspection requirements
(including acceptance standards!)
Records
Procedure content: Scope Applicable domain Related documents
(standards, normative reference, procedures, etc)
Terms and definitions Responsibilities Procedure description Records
Quality in welding fabricationOrganisations that are involved in welding must
document their activities to show who is involved in welding decisions.
Design Material selection Procedure development and qualification Storage and issue of consumables Weld inspection PWHT and other special process survey Planning for welding
Those activities include but are not limited to:
Standards related to quality
ISO 9000 Quality ISO 9000 Quality systemsystem
EN 3834 EN 3834
Quality requirements for weldingQuality requirements for welding
EN 719/ISO 14731 EN 719/ISO 14731 Welding coordinationWelding coordination
EN 287 Approval EN 287 Approval testing of welderstesting of welders
EN ISO 15607 EN ISO 15607 Specification and Specification and
qualification of welding qualification of welding proceduresprocedures
EN 25817 (ISO EN 25817 (ISO 5817) Quality 5817) Quality
levelslevels
EN 473 EN 473 Qualification of NDT Qualification of NDT
personalpersonal
ISO 6520 ISO 6520 Classification of Classification of imperfectionsimperfections
ISO 9000 features
Provides a documented management system for quality assurance
Identifies welding as a special process (a process where the conformity of the resulting product cannot be readily verified)
Does not specify any welding requirements
Does not guarantee the welded product quality
Quality requirements for welding
EN 3834EN 3834--1 1 GuidelinesGuidelines
EN 729EN 729--2 2 Comprehensive Comprehensive
quality quality requirementsrequirements
EN 729EN 729--3 3 Standard quality Standard quality
requirementsrequirements
EN 729EN 729--4 4 Elementary quality Elementary quality
requirementsrequirements
For use when:For use when:You are accredited to ISO 9000Your products, materials, processes or procedures change frequentlyANDWelding quality is critical
For use when:For use when:Your materials, products, processes and procedures do not change frequentlyBUTWelding is an important process and weld quality is important
For use when:For use when:There are only very simple technical optionsWelding is an incidental joining processWeld quality is not crucial to product quality
EN 729/ISO 3834 requirements Part 2 Part 3 Part 4
Contract and design review M M NRSub contractor control M M NRWelder and procedure approval BOTH BOTH WELDER Inspection personnel M M MWelding co-ordination (EN719) M M NR Equipment (includes PPE) M R NR Production planning M M NR Consumable control M M MParent metal storage M M NR Post weld heat treatment M M NRWeld inspection M M NRNon-conformance & corrective action M M M Calibration M NR NRIdentification and traceability M M NR Quality records M M NR
M = mandatory R = recommended NR = not required
3Welding coordinator
His duties are stated in BS EN 14731 Welding coordination; task and responsibilities.
Welding coordinator: must be designated by employer is appointed by the company to issue/approve the
necessary welding documents must have demonstrated competence and
knowledge must have special technical knowledge the extent of knowledge is defined by employer job specification only if required by contract
All welding related tasks must be allocated to an AUTHORISED WELDING COORDINATOR
Competence in welding
Knowledge can be demonstrated at 3 levels:
comprehensive technical knowledge ie EWE specific technical knowledge ie EWT basic technical knowledge ie EWS
A welding coordinator MUST demonstrate technical competence i.e. he MUST be academicallyqualified in welding technology
Level depends on complexity of product and is usually determined by employer
But the client can specify the level in contract specification!
Welding coordinator activities contract review design review parent metal weldability, identification, handling, storage and
traceability consumables compatibility, identification, storage and handling subcontractor suitability production planning choosing the appropriate welding process, equipment
suitability, health and safety issues approval of welders/welding procedures welding operation supervision inspection/testing issuing documentation
Quality planIs a check list that specifies which procedures and Is a check list that specifies which procedures and associated resources shall be applied, by whom and when associated resources shall be applied, by whom and when to a specific project, product, process or contract. It to a specific project, product, process or contract. It contains:contains:
a list with the main operations following manufacturing sequencea list with the main operations following manufacturing sequencestop/hold points with specific requirements (e.g. document checkstop/hold points with specific requirements (e.g. document check, , NDT witnessed by customer representative, stamp check, NDT witnessed by customer representative, stamp check, independent body supervision, procedures used, acceptance independent body supervision, procedures used, acceptance standards, etc)standards, etc)type and number of documents issued (NDT report, WPAR, welder type and number of documents issued (NDT report, WPAR, welder qualification, dimension check list, etc)qualification, dimension check list, etc)name and signature of welding coordinator in charge with each name and signature of welding coordinator in charge with each operation (if required)operation (if required)date of completion for each stepdate of completion for each step
Quality planProcess Process
description description activityactivity
Responsible Responsible personperson
Process Process reference reference documentdocument
Approval Approval /remarks/remarks
HH
H H -- Hold point: work shall stop until representative are present toHold point: work shall stop until representative are present tomonitor/observe activitymonitor/observe activity
WW
W W -- Witness point: notifiable point; should representative fail to Witness point: notifiable point; should representative fail to attend, attend, work may proceedwork may proceed
RR
R R -- Document reviewDocument review
AA
A A -- Document approvalDocument approval
MM
M M -- Monitor/periodic control of activityMonitor/periodic control of activity
American standards related to quality
ISO 9000 Quality ISO 9000 Quality systemsystem
ASME I, III and VIII ASME I, III and VIII
Quality requirements for weldingQuality requirements for welding
EN 719/ISO 14731 EN 719/ISO 14731 Welding coordinationWelding coordination
ASME IX Approval ASME IX Approval testing of welderstesting of welders
ASME IX Specification ASME IX Specification and approval of and approval of
welding procedureswelding procedures
ASNT TCASNT TC--1A 1A Qualification of NDT Qualification of NDT
personalpersonal
AWS A3.0 AWS A3.0 Classification of Classification of imperfectionsimperfections
ASME I, VIII ASME I, VIII Quality levelsQuality levels
4ASME B&PV code
Product related requirementsProduct related requirementsBoilers Boilers -- Section ISection INuclear Nuclear -- Section IIISection IIIPressure vessels Pressure vessels -- Section VIIISection VIII
Material related Material related requirements requirements
Section IISection II
Ferrous material Ferrous material requirements requirements Section IIASection IIA
NonNon--ferrous material ferrous material requirementsrequirementsSection IIBSection IIB
Filler material Filler material requirements requirements Section IICSection IIC
NDE requirements NDE requirements (standard method) (standard method)
Section VSection V
Welding qualification Welding qualification & welder approval & welder approval
Section IXSection IX
Welding map
CC44
LL11
LL22
LL33
LL44
LL55CC11
CC22
CC33
CC55
CC66
NN11NN22 NN33
NN44
SS11SS22
Information's to be supplied:Information's to be supplied:weld type and positionweld type and position
WPS and PQR numberWPS and PQR number
type and extent of NDEtype and extent of NDE
welderwelders stamp numbers stamp number
type of PWHTtype of PWHT
Quality packa.k.a. doc pack, history docketa.k.a. doc pack, history docket
Quality pack Quality pack contentcontent
Documents supplied Documents supplied before commencement before commencement
of manufactureof manufacture
Documents supplied Documents supplied on completion of on completion of
constructionconstruction
Quality pack content
certificate of conformance with different codes/standards
design calculations (optional) manufacturing drawings WPS with supporting WPQR
(copies) welder qualifications qualification of NDT personnel NDT procedures PWHT oven calibration record
(optional)
material test certificates (list!) welding production tests (if
required) PWHT record (if required) NDT test reports: dimensional,
pressure test and coating thickness are included
quality plan and weld map as-built drawings non-conformity reports (SDR) operating/mounting instructions
Documents supplied before Documents supplied before manufacturemanufacture
Documents supplied after Documents supplied after manufacturemanufacture
Auditing
Definition: systematic, independent and documented process for obtaining evidence and evaluating it objectively to determine the extent to which criteria are fulfilled
AuditAudit
a systema system Is quite shallow; examines the system Is quite shallow; examines the system to confirm that it follows the quality to confirm that it follows the quality manual and procedures are in placemanual and procedures are in place
a compliancea complianceIt goes inIt goes in--depth; examines the compliance depth; examines the compliance with procedures and quality manualwith procedures and quality manual
Traceability Definition: Ability to trace the history, application or
location of that which is under considerationTraceability Traceability
can relate to:can relate to:
The origin of The origin of materials and materials and
partsparts
The The processing processing
historyhistory
The distribution and The distribution and location of the product location of the product
after deliveryafter delivery
Traceability - HOW? hard stamping painting/etching labelling
WHEN? Immediately after the operation!
5Conformity
RequirementRequirement
ConformityConformity
fulfilmentfulfilment
NonconformityNonconformity
nonnon--fulfilmentfulfilment
Corrective Corrective actionaction
RepairRepair ScrapScrap ConcessionConcession
ReleaseRelease
Nonconformity Nonconformity reportreport
Conformity evaluation
Test
determination of one or more characteristics according to a procedure
can be non-destructive or destructive
Conformity Conformity evaluationevaluation
Inspection
evaluation by observation and judgement
can be accompanied by measurement, testing or gauging
Inspection - terminology
detectable change in the material
signal from a discontinuity typical to the testing method used
DiscontinuityDiscontinuity
IndicationIndication
DetectionDetection
Acceptance Acceptance levellevel
EvaluationEvaluation
prescribed limit below which a component is accepted
Recordable Recordable indicationindication DEFECTDEFECT
1MEASUREMENT, CONTROL AND RECORDING IN WELDING
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Measuring in welding
Parameters to be measured: welding current arc voltage travel speed shielding gas flow rate
The purposes The purposes of measuringof measuring
Demonstration of Demonstration of conformance to conformance to
specified requirementsspecified requirements
preheat/interpass temperature
force/pressure humidity
Welding Welding process process controlcontrol
Welding current measurement
Definition: the current delivered by a welding power source during welding
measured with an ammeter measured in A the ammeter may be connected at any point in the
circuit indirect measurement: tachogenerator and
tongue tester
The tongue testerused for AC currentspecial types can be used also for DC
no need to insert the meter into the circuit
Arc voltage measurement
Definition: the potential difference across the welding arc
varies with the arc length measured with a voltmeter measured in V the voltmeter may be connected only across the
circuit (to the workpiece and as close as possible to the electrode!)
if the voltmeter is connected at the welding power source, a higher voltage will be recorded (due to potential drops across cables)
Travel speed measurementDefinition: the rate of weld progression measured in case of mechanised and
automatic welding processes in case of MMA can be determined using
ROL and arc time
2Gas flow rate measurementDefinition: the rate at which gas is caused to flow
set with a gas regulator
can be checked with a flowmeter
Welding temperatures-definitionsPreheat
temperature is the temperature of the workpiece in the
weld zone immediately before any welding operation (including tack welding!)
normally expressed as a minimum
Interpass temperature
is the temperature in a multirun weld and adjacent parent metal immediately prior to the application of the next run
normally expressed as a maximum
Preheat maintenance temperature
is the minimum temperature in the weld zone which shall be maintained if welding is interrupted
shall be monitored during interruption
Minimum interpass temperature = Preheat temperatureMinimum interpass temperature = Preheat temperature
Welding temperatures-WHERE?
Point of measurement - see BS EN ISO 13916
if t 50 mm A = 4 x t but max. 50 mm
the temperature shall be measured on the surface of the workpiece facing the welder
Welding temperatures-WHERE?
Point of measurement - see BS EN ISO 13916
if t > 50 mm A = min. 75 mm where practicable, the
temperature shall be measured on the face opposite to that being heated
allow 2 min per every 25 mm of parent metal thickness for temperature equalisation
interpass temperature shall be measured on the weld metal or immediately adjacent parent metal
Welding temperatures-HOW?
Test equipment
Temperature Temperature sensitive sensitive materials materials
Contact Contact thermometer thermometer
ThermocoupleThermocouple
Optical/electrical Optical/electrical devices for devices for contactless contactless
measurement measurement
Thermistor Thermistor
Temperature test equipmentTemperature sensitive materials:
crayons, paints and pills
cheap
convenient, easy to usedoesnt measure the actual temperature!
3Temperature test equipmentContact thermometer
use bimetallic strips accurate
easy to use
gives the actual temperature
need calibration
suitable for moderate temperatures
Temperature test equipment
Thermocouple
accurate methodmeasures over a wide range of temperaturesgives the actual temperatureneed calibration
Temperature test equipment
Thermistorsare temperature-sensitive resistors whose resistance varies inversely with temperature
used when high sensitivity is required
gives the actual temperature
need calibration
can be used up to 320C
Temperature test equipment
Devices for contactless measurementIR radiation and optical pyrometermeasure the radiant energy emitted by the hot bodycontactless method can be used for remote measurements very complexfor measuring high temperatures
PAMS (Portable Arc Monitor System)
The purposes The purposes of a PAMSof a PAMS
For calibrating For calibrating and validating and validating
the welding the welding equipmentequipment
For measuring For measuring and recording and recording
the welding the welding parametersparameters
PAMS (Portable Arc Monitor System)
What does a PAMS measure?Welding Welding current (Hall current (Hall effect effect device)device)
Arc voltage Arc voltage (connection (connection leads)leads)
Temperature Temperature (thermocouple)(thermocouple)
Wire feed Wire feed speed speed (tachometer)(tachometer)
Gas flow Gas flow rate rate (heating (heating element element sensor)sensor)
4Calibration, validation and monitoring
Definitions: Measurement = set of operations for determining a value of a
quantity Repeatability = closeness between successive measuring
results of the same instrument carried out under the same conditions
Accuracy class = class of measuring instruments that are intended to keep the errors within specified limits
Calibration = checking the errors in a meter or measuring device Validation = checking the control knobs and switches provide
the same level of accuracy when returned to a pre-determined point
Monitoring = checking the welding parameters (and other items) are in accordance with the procedure or specification
Calibration and validation
When it is required?
once a year unless otherwise specified whenever there are indications that the
instrument does not register properly whenever the equipment has been damaged,
misused or subject to severe stress whenever the equipment has been rebuild or
repaired
See BS EN ISO 17662 for details!
Calibration and validation
When it is NOT required? when verification of the process is not required in case of small series and single piece production
when all the following conditions are fulfilled:- procedures are approved by procedure testing- production is carried out by the same welding machine used during procedure testing
Calibration and validation
When it is NOT required? in case of mass production when all the following
conditions are fulfilled:- production is controlled by pre-production testing, followed by testing of samples from production at regular intervals- a statistical quality control system is used- the process is stable between testing of samples- pre-production testing and sampling are performed separately for each production line (robotic cells)
Welding parameter calibration/validation
Which parameters need calibration/validation?
depends on the welding process see BS EN ISO 17662 and BS 7570 for details
How accurate? depends on the application welding current - 2,5% arc voltage - 5% wire feed speed - 2,5% gas flow rate - 20% (25% for backing gas flow
rate) temperature (thermocouple) - 5%
Example 1 - MMA elementary monitoring
IN THEORY any M.M.A. operation could require monitoring of:
welding current arc voltage R.O.L. preheat/interpass temperature electrode treatment and storage
IN PRACTICE (depending on the application) only the welding current could require monitoring with a tongue test ammeter
5Example 2 - High integrity MMA operation
IN THEORY, this might require monitoring of all the activities previously mentioned.
all of the above equipment would require calibration; any meters fitted to the power source or electrode ovens would also require calibration.
the equipment thus required would be: ammeter voltmeter stop watch tape measure thermometer calculator
OR a PAMS
Example 3 - MIG/MAG welding with a robot
IN THEORY, the following would require monitoring: wire feed speed amperage voltage travel speed gas flow rate repeatability of the controls
IN PRACTICE, a data logger would be preferred to monitor all the parameters; also a PAMS would be required to check the repeatability of the control knobs.
Summary
a welding power source can only be calibrated if it has meters fitted
the inspector should check for calibration stickers, dates etc.
a welding power source without meters can only be validated that the control knobs provide repeatability
the main role is to carryout in process monitoring to ensure that the welding requirements are met during production
Typical examination question 1
The measurement of welding parameters is common in arc welding practice. Comment on the parameters that can be measured and recorded,including the different types of equipment that maybe used.
This question by definition is related to monitoring Introduction: would include monitoring is dependent on the
integrity of the product. Welding parameters: need to be identified. (with
comments!) Equipment details: can be established from the welding
parameters identified. Conclusion: should incorporate calibration/validation and
the need for checking temperatures (interpass/preheat).
Typical examination question 2
This question is related more to the whole fabrication process: e.g.
QA/QC requirements Training, experience and qualification of welders and
inspectors Inspection procedures (during welding) Auditing to ensure that the above is taking place Calibration/validation and in process monitoring
Describe how you would ensure that the welding parameters listed in a WPS are being adhered to during production welding. Give the advantages and limitations of the methods used.
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Section 2 Approval testing, codes of practice
and application standards
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2 Approval Testing BS EN ISO 15607:2003 General rules. BS EN ISO 15609-1:2004 Specification and approval of welding procedure specification for arc welding. This standard lists all the information that is required to be recorded to describe the welding process. Part 1 deals with arc welding but other parts exist that deal with laser and electron beam welding for example. BS EN ISO 15614-1:2004+A1:2008 Specification and qualification of welding procedures for metallic materials, Welding procedure test, Part 1: Arc and gas welding of steels and arc welding of nickel and nickel alloys. This standard covers the conditions for the execution of welding procedure tests and the range of qualification for welding procedures for all practical welding operations within a defined range of variables. Although standards tests are defined, it is recognised that other application standards may also require additional testing. Where the production/joint geometry requirements do not represent the standardised test pieces as shown in this standard, the use of EN ISO 15613 shall be required (see below). Standard test pieces covered by this standard include: Butt joints in plate Butt joints in pipe T joint Branch connection A test made to meet the requirement of this standard shall be witnessed by an examiner or an examining body and once qualified does not expire with time. Because this standard confers a range of approval based on material thickness, material type and certain process variables, etc, individual welding procedure specifications detailing parameters to be used prepared in accordance with BS EN ISO 15609 can be used to give specific instruction to welders on the shop floor. Part 1 specifically refers to steel and nickel alloys as defined by metallic groupings in PD CEN ISO/TR 15608:2005. This standard also exists in many other parts that relate to other material groupings such as aluminium alloys (part 2), cast irons (part 3) copper alloys (part 6), other processes such as laser welding (part 13) and other situations such as overlay welding (part 7).
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BS EN ISO 15610:2003: Qualification based on tested consumables Approval by use of an approved welding consumable has been used for many years by some branches of industry. Approval of the welding consumables is carried out according to national schemes pending the establishment of European certification schemes. BS EN ISO 15611:2003: Previous experience Approval by reference to previous welding experience has a number of applications. Only welding procedures known from experience to be reliable should be used in such cases. BS EN ISO 15612:2004: Standard weld procedure Approval by reference to a standard welding procedure is presently used to a rather limited extent, but it is covered by a few national rules. This type of approval is attractive because it has the potential of lowering the costs related to approval testing for the individual manufacturer. BS EN ISO 15613:2004: Pre-production weld tests Approval by pre-production welding test is rarely mentioned in national standards. It is however, needed for special welding procedures and perhaps for specific applications, not covered by EN 15614-1:2004+A1:2008/15614-2:2005 Approval by a pre-production test is the only reliable method of approval for some welding procedures, of which the resulting properties of the weld strongly depend on certain conditions such as component, special restraint conditions, heat sinks etc, which cannot be reproduced by standardised test pieces. General details regarding testing etc in this standard are covered specifically by the requirements of BS EN ISO 15614 where appropriate.
2.1 Welder approvals - BS EN 287 BS EN ISO 287-1:2004 Approval testing of welders, Fusion welding: steels. This standard gives the requirements for qualification testing of welders for steels. Like BS EN ISO 15614, in order to avoid all variants of welding procedures used on the shop floor to be tested, the standard confers a range of approval based on necessary skills to produce a weld. The range of approval can be limited by material type, thickness, number of passes, joint type and welding position, etc. The extent of testing is less than for procedure qualification as it is assumed that the company will already have hold a valid procedure qualification test. The other main difference between procedure and welder qualification is that the qualification will expire with time. Prolongation can occur in six monthly intervals after which the welder shall require specific evidence that his work has been tested or shall re-test. Although not mentioned in the standard, where a large number of are required to be qualified with differing ranges of approval and differing expiry
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dates, this probably best managed by holding a register of qualified welders showing ranges of qualification or renewal dates, etc. Nowadays this can also be managed by proprietary software packages. The standard also gives guidance on the recommended job knowledge that a welder should be assessed against in order to carry out his duties. This is not mandatory at the present time. It should be noted that the standard only covers manual or partly mechanised processes. For qualification of automatic welding systems, BS EN 1418 should be used. It should also be noted that some standards such as BS EN ISO 15614 -1 do not refer to this standard but to ISO 9606-1. This is the standard that will replace BS EN 287, but as yet has not been formally issued. BS EN ISO 9606-2:2004 Approval testing of welders - Fusion welding: aluminium and its alloys. This standard gives guidance on welder qualification in aluminium alloys and is part of a family of standards that cover other material groupings such as copper (part 3) and titanium (part 5) BS EN 1418:1998 Welding personnel, approval testing of welding operators for fusion welding and resistance weld setters for fully mechanized and automatic welding of metallic materials. It is often assumed that robotic welding is a push button operation and does not require qualification. This standard requires that the operator carries out a witnessed test and that their functional knowledge shall be assessed against requirements contained in an annex. In this case range of approval is only limited by the welding unit and process. The approval period is similar to BS EN 287. Currently under review are: BS 4872 Part 1: Steels Approval testing of welders when procedure approval is not required. BS 4872 Part 2 Approval testing of welders when procedure approval is not required. Part 2: MIG and TIG welding of aluminium and its alloys. Note: BS 4872 may be withdrawn in the future when other EN equivalent standards are implemented.
2.2 Training There must be a system for identifying training needs and approval requirements for all welding operations.
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Documentation must include a record of each welder's training programme together with details of approvals gained or due for renewal. There should also be data on a welder's performance so that trends win defect occurrence can be noted and corrective training provided.
2.3 Definitions BS EN ISO 15607:2003 gives the definitions of all terms used in the completion of welding procedures and welder approval. Amongst these are: Welding procedure Specified course of action to be followed in making a weld, including the welding process(es), reference to materials, welding consumables, preparation, preheating (if necessary), method and control of welding and postweld heat treatment (if relevant), and necessary equipment to be used. Welding process For the welding processes, the nomenclature and definitions given in ISO 857-1 are followed in this standard. The numbering system for welding processes in EN ISO 4063 is also followed. Preliminary welding procedure specification (pWPS) A document containing the required variables of the welding procedure which has to be qualified has to be qualified sing one of the methods described. Welding procedure specification (WPS) A document that has been qualified by one of the methods described in clause 6 and provides the required variables of the welding procedure to ensure repeatability during production welding. Work instruction Simplified specification of the welding procedure, suitable for direct application in the workshop. Welding procedure qualification record (WPQR) Record comprising all necessary data needed for qualification of a preliminary welding procedure specification. Welding procedure test Making and testing of a standardized test piece, as indicated in the pWPS, in order to qualify a welding procedure. Pre-production welding test Welding test having the same function as a welding procedure test, but based on a non-standard test piece, representative of the production conditions.
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Standard welding procedure specification Welding procedure specification which has been qualified by a welding procedure test not related to the manufacturer and qualified by an examiner or examining body Note: A standard welding procedure may then be made available to any manufacturer. Previous welding experience When it can be shown by authenticated test data that the manufacturer's established production welding procedures have been capable of consistently producing welds of acceptable quality over a period of time. Tested welding consumable Welding consumable or consumable combination tested according to appropriate standards for testing of welding consumables. Welding consumable Materials consumed in the making of a weld, including filler metals and auxiliary materials. Essential variable Welding condition that requires qualification. Non essential variable Welding condition addressed in the WPS but not requiring qualification. Range of qualification Extent of qualification for an essential welding variable. Homogeneous joint Welded joint in which the weld metal and parent material have no significant differences in mechanical properties and/or chemical composition. Note: A welded joint made of similar parent materials without filler metal is considered homogeneous. Heterogeneous joint Welded joint in which the weld metal and parent material have significant differences in mechanical properties and/or chemical composition. Dissimilar material joint Welded joint in which the parent materials have significant differences in mechanical properties and/or chemical composition. Welding co-ordination personnel Personnel who have responsibilities in the manufacturing operation for welding and welding related activities whose competence and knowledge
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has been demonstrated by eg training, education and/or relevant manufacturing experience.
2.4 Codes of Practice and Application Standards
A welding approval test standard contains the minimum qualification requirements. For any particular product or application a code of practice or application standard may impose additional requirements or limitations, eg an all weld tensile test(s) is additionally required in PD 5500 which is not specified by BS EN 15607-15614 (formerly 288). The standards do not necessarily constitute good engineering practice and when using the approval standards this must be borne in mind.
2.5 Other welding approval standards: ASME IX An American standard welding used throughout the world, particularly in the petrochemical industries for pressure vessel, piping and storage tanks but also nuclear applications. AWS D1.1 Another American Standard specifically aimed at structural applications in carbon manganese and high strength steels. This standard allows the use of pre-qualified welding procedures, which is not common in the UK.
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2.6 Questions on approval testing and quality control
1 Sketch the following:
Butt weld in the PA position Butt weld in the PF position Fillet weld in the PC position
2 Name the abbreviations for:
Overhead butt weld in plate Overhead fillet weld in plate
3 Which weld position(s) would be required to give all-position approval in pipe?
4 To ensure that approval documentation meets the requirements of a standard, there are a number of areas which must be assessed.
Provide a checklist of the key areas that require such an assessment.
5 A welded test piece has been visually inspected and defects outside of the acceptance levels have been reported. What would be the most likely course of action you would take?
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2.7 Practical on Procedure and Welder Qualification Testing Case study 1 It is a requirement to approve both procedures and welders for the following: Production requirements Materials Low carbon and 316 stainless steel (not dissimilar joints) Thickness range: 5-30mm Joint types Butt weld with/without backing plate Welding positions All positions except vertical down Process 111 Consumables Basic electrodes Decide on appropriate tests to fulfil the above requirement: a To BS EN 15607-15614 and 287 b What are the implications with reference to range of approval? Case study 2: practical exercise Write up the pWPS, WPS, WPAR and WQR documentation requirements for the previous test piece which has been identified from Case Study 1.
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2.8 Questions on welding procedure and welder approvals 1 Describe what is meant by a welding procedure specification. How does this
differ from, but relate to, a welding procedure approval record?
2 A number of components are to be cut from a plate over a period of time for approval testing. How would you ensure that traceability of the materials is maintained?
3 A pipe welded welder approval test piece has been found to be non-identifiable. What steps must be taken before the weld may be allowed into production welding?
4 List all the essential variables that would be found on a WPS.
5 Give typical examples of the range of approval for the essential variables specified in 4 using the abbreviations specified in BS EN 15607-15614 and 287.
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2.9 Practical exercise on codes of practice and application standards
By now you should have a fair understanding of the requirements for procedure/welding approval. So see how well you can complete the following exercises: Exercise: A welder successfully completed the following test weld to BS EN 287 Part 1. Fill in the welder approval certificate (including the appropriate test results). Manufacturers name: JBEL Welder's name and identification: Joe Bloggs No. 007 Material specification: Low carbon steel Material form: Pipe Material dimension: 80mm diameter, 8mm wall thickness Joint type: Single vee but welded from one side Welding process: Manual metal arc welding Consumables: 3.2mm diameter. Basic coated electrodes to BS EN 499 - E5152NiB Welding parameters: 100-200 amps. 22-24 arc volts. Test position: HLO45
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FAA1 Questions: BS EN 287 By using EN 287 Part 1 complete the following: 1 If a client requires 'all position' approval in pipe, what test position is necessary? 2 With reference to range of approval, what does 'thickness' refer to on: a) A butt joint b) A fillet weld 3 If a butt welded test piece is completed in 6.0mm, what is the approval range? 4 If a welder completes a test in pipe is he covered to weld plate? 5 List the mechanical tests required for a butt weld in pipe. 6 Give three (3) reasons for re-approval of a welder. 7 What are the requirements for retesting of welders? 8 What is the extent of approval, with reference to joint types, if the test piece is a
single vee butt welded from one side? 9 In MMA welding what other types of electrodes are approved if a basic is used on
the test? 10 What is the period of validity of initial welder approval tests?
1WELDING PROCEDURE QUALIFICATION
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What is a What is a ProcedureProcedure?? A specified way to carry out an activity or a A specified way to carry out an activity or a process (see BS EN ISO 9000)process (see BS EN ISO 9000)
What is a What is a Welding procedureWelding procedure ??
Specified course of action to be followed in making a weld, including the welding process(es), reference to materials, welding consumables, preparation, preheating, method and control of welding and PWHT and necessary equipment to be used (see BS EN ISO 15607)
WELDING PROCEDURES
Most procedures are qualified, but not all?Most procedures are qualified, but not all?
A qualified welding procedure is one that has been tested to ensA qualified welding procedure is one that has been tested to ensure ure that the procedure is carried out to produce a weld that satisfithat the procedure is carried out to produce a weld that satisfies a es a minimum level of quality for the mechanical, physical or chemicaminimum level of quality for the mechanical, physical or chemical l properties desired.properties desired.
If these are not required, then If these are not required, then procedure qualification is procedure qualification is unnecessaryunnecessary
Do all welding procedures need to be qualified?Do all welding procedures need to be qualified?
Most production welding procedure are formatted on written documents or computer spreadsheets, but they need not to be written and may be a product of experience
Do all welding procedures need to be written?Do all welding procedures need to be written?
Procedure qualification-YES or NOProcedure qualificationProcedure qualification--YES or NOYES or NOA A Welding Procedure Specification (WPS)Welding Procedure Specification (WPS) is a is a document that has been qualified and provides document that has been qualified and provides the required variables of the welding procedure to the required variables of the welding procedure to ensure repeatability during production welding ensure repeatability during production welding (recommended form (recommended form -- see ASME Code, Section see ASME Code, Section IX, QWIX, QW--482 and BS EN ISO 15609)482 and BS EN ISO 15609)
To evaluate a To evaluate a Provisional Welding Procedure Provisional Welding Procedure Specification (pWPS)Specification (pWPS) we need to check if all the we need to check if all the parameters set will work together to produce the parameters set will work together to produce the desired resultsdesired results
What is a welding procedureWhat is a welding procedureWhat is a welding procedure
WPS
It is the main document used in welding activitiesIt contains information about:It contains information about:
welding processparent/filler material(s)joint preparationwelding positionpreheat/interpass temperaturePWHTwelding parameterssupplementary informations
Purpose of a WPS
to give information to the welder, inspector to achieve specific properties: mechanical
strength, corrosion resistance, etc to ensure freedom from defects to enforce quality assurance procedures to standardize on methods and costs to control production schedules to form a record to ease the application of a standard or contract
requirement give confidence to a product
2Types of WPS
BS EN ISO 15609
Part 1Part 1ArcArc
weldingwelding
Part 2Part 2GasGas
weldingwelding
Part 3Part 3ElectronElectron
beambeamweldingwelding
Part 4Part 4LASERLASERbeambeam
weldingwelding
Part 5Part 5ResistanceResistance
weldingwelding
Welding procedure qualification terms
Definitions (see BS EN ISO 15607):
Essential variable - welding condition that requires qualificationSupplementary essential variable - variable which influences the toughness of the weld joint (only in ASME Code, Section IX - see QW-401.3!) Non essential variable - welding condition addressed in the WPS but NOT requiring qualificationRange of qualification - extent of qualification for an essential variableExamining body - organisation who verifies compliance with the applicable standard
Range of qualification
Is the extent of qualification for an essential welding variable
Also known as extent of approval, range of approval or scope of approval
Provides a working range for each welding procedure approval or welder approval
Outside the range of qualification reOutside the range of qualification re--qualification is qualification is MANDATORY!MANDATORY!
a) Material thickness and pipe diameter (depending on the type of joint!)
b) Welding process
c) Welding position, amperage range, current type or number of runs
d) Parent material groups
e) Filler material type and size
f) Preheat/interpass temperature
g) PWHT type and parameters
h) Heat input range (kJ/mm)
Examples of Examples of Range of qualificationRange of qualification include:include:
Range of qualificationRange of qualification
Welding process designation
111 - MMA 114 - FCAW - no gas shield 121 - SAW single wire 122 - SAW - strip 131 - MIG 135 - MAG 136 - FCAW - active gas 137 - FCAW - inert gas 141 - TIG 15 - Plasma arc 311 - Oxy-acetylene welding
Designation acc. EN ISO 4063:Designation acc. EN ISO 4063:
Parent material grouping system
ISO 15608
SteelsSteels
Al andAl andAlAl
alloysalloys
Ni andNi andNiNi
alloysalloys
Ti andTi andTiTi
alloysalloys
CastCastironsirons
Cu andCu andCuCu
alloysalloys
Zr andZr andZrZr
alloysalloys
3Grouping system for steels
Group 1 C-Mn steels Group 2 Fine grain/TMCP steels Group 3 QT steels (except stainless) Group 4 Low Vanadium Cr-Mo steels Group 5 Vanadium free Cr-Mo steels Group 6 High Vanadium Cr-Mo steels Group 7 Ferritic, martensitic and stainless steels Group 8 Austenitic stainless steels Group 9 Ni alloy steels Group 10 Duplex stainless steels Group 11 HSLA steels
Welding position designationButt welds in plate (see ISO 6947)
Flat - PA Overhead - PE
Vertical up - PF
Vertical down - PG
Horizontal - PC
Welding position designationButt welds in pipe (see ISO 6947)
Flat - PAaxis: horizontal pipe: rotated
H-L045axis: inclined at 45pipe: fixed
Horizontal - PCaxis: vertical pipe: fixed
Vertical up - PFaxis: horizontal pipe: fixed
Vertical down - PGaxis: horizontal pipe: fixed
J-L045axis: inclined at 45pipe: fixed
Welding position designation
Fillet welds on plate (see ISO 6947)
Flat - PA Overhead - PD
Vertical up - PF Vertical down - PG
Horizontal - PB
Welding position designationFillet welds on pipe (see ISO 6947)
Flat - PA axis: inclined at 45 pipe: rotated
Overhead - PD axis: vertical pipe: fixed
Vertical up - PF axis: horizontal pipe: fixed
Vertical down - PG axis: horizontal pipe: fixed
Horizontal - PB axis: vertical pipe: fixed
Horizontal - PB axis: horizontal pipe: rotated
Welding position ranges-ISO 6947
4WPQRWPQRWPQRIt is the document that supports WPS
It contain all the information needed to qualify a pWPS:welding processparent and filler material(s)welder identificationjoint preparation for test piecewelding positionpreheat/interpass temperaturePWHTwelding parametersNDE and mechanical tests resultsrange of approval
WPQR form (see also ASME IX, QW-483)WPQR form (see also ASME IX, QW-483)
Welding procedure qualification
Standards used for procedure qualification:
BS EN ISO 15607 - Specification and qualification of welding procedures for metallic materials - General rules
A.S.M.E. Boiler and pressure vessel code Section IX -Qualification standard for welding and brazing procedures, welders, brazers and welding and brazing operators
Methods of qualification
BS EN ISO15607
BS EN ISO 15610Tested welding consumable
BS EN ISO 15611Previous welding experience
BS EN ISO 15612Standard welding procedure
BS EN ISO 15613Pre-production welding test
BS EN ISO 15614Welding procedure test
BS EN ISO 15614 contentBS EN ISO 15614 Specification and qualification of
welding procedures for metallic materials Welding procedure test; material related parts:
Part 1: Arc and gas welding of steels/arc welding of Ni and Ni alloys
Part 2: Arc welding of Al and Al alloys
Part 3: Arc welding of cast irons
Part 4: Finishing welding of Al castings
Part 5: Arc welding of Ti, Zr and their alloys
Part 6: Welding of Cu and Cu alloys
BS EN ISO 15614 contentBS EN ISO 15614 Specification and qualification of
welding procedures for metallic materials Welding procedure test; application related parts:
Part 7: Overlay weldingPart 8: Welding of tubes to tube-plate jointsPart 9: Underwater hyperbaric wet weldingPart 10: Hyperbaric dry weldingPart 11: Electron and LASER beam weldingPart 12: Spot, seam and projection weldingPart 13: Resistance butt and flash welding
BS EN 288 Part 9 Pipeline welding (on land & offshore)BS EN 288 Part 9 Pipeline welding (on land & offshore)
5BS EN ISO 15614-1 provisions
Type of test pieces
Butt joint in plate
Butt joint in pipe
T joint (fillet or bevel) Branch connection
BS EN ISO 15614-1 provisions
Required tests (butt joint)
visual (EN 970)visual (EN 970)radiographic (EN 1435) or radiographic (EN 1435) or ultrasonic (EN 1714 ultrasonic (EN 1714 -- not to be used not to be used for t < 8mm!)for t < 8mm!)dye penetrant (EN 571dye penetrant (EN 571--1) or 1) or magnetic particle (EN 1290)magnetic particle (EN 1290)
NDTNDT Destructive testsDestructive tests
transverse tensile (EN 895) transverse tensile (EN 895) -- 2 2 specimensspecimenstransverse bend (EN 910) transverse bend (EN 910) -- 4 4 specimensspecimensimpact (EN 875) impact (EN 875) -- 2 sets2 setsmacroscopic (EN 1321) macroscopic (EN 1321) -- 1 1 specimenspecimenhardness (EN 1043hardness (EN 1043--1)1)
BS EN ISO 15614-1 provisions
Required tests (fillet joint)
visual (EN 970)dye penetrant (EN 571-1) or magnetic particle (EN 1290)radiographic (EN 1435) or ultrasonic (EN 1714) for full penetration T and branch welds only!
NDTNDT Destructive testsDestructive tests
macroscopic (EN 1321) - 2 specimenshardness (EN 1043-1)if mechanical properties are relevant to the application, an additional butt weld qualification is required!
BS EN ISO 15614-1 provisions
Acceptance standards
BS EN 25817 level BBS EN 25817 level C for excess weld metal, excess convexity, excess throat thickness and excessive penetration
NDT + MacroNDT + Macro Destructive testsDestructive teststensile test min. UTS of parent metalbend test no flaw > 3 mm in any directionimpact test avg. value per set = min. for parent metal at test temperaturehardness test - see Table 2 (non HT vs. PWHT!)
BS EN ISO 15614-1 provisions
Re-test
Failed NDTFailed NDT Failed testsFailed tests
Weld one new Weld one new test piecetest piece
Failed NDT on Failed NDT on new test piecenew test piece
Test 2 new specimens Test 2 new specimens for any failed test for any failed test
specimenspecimen
Failed new testsFailed new tests
REJECTREJECT
BS EN ISO 15614-1 provisions
Range of qualification for manufacturer:validity restricted to workshops and sites under the same technical and quality controlsame technical and quality control = manufacturer who perform the procedure test retains complete responsibility for welding
material grouping according ISO 15608range of qualification - see Tables 3 and 4
Range of qualification for parent material:
6BS EN ISO 15614-1 provisions
Thickness definitions:butt parent metal thicknessfillet - THICKER material at jointT-butt - PREPARED plate thicknessset-on branch - BRANCH pipe thicknessset-in/through branch - MAIN pipe thickness
BranchBranch Main Main pipepipe
BS EN ISO 15614-1 provisions
Range of qualification for thickness - butt welds (for fillet welds see Table 6):
*If impact requirements are specified:*If impact requirements are specified:
Range of qualification (mm)Range of qualification (mm)Thickness of the test Thickness of the test piece piece tt (mm)(mm)
t t 333 3 t t 1212
0,7t0,7t--1,3t1,3t0,5t0,5t--1,3t(min.3 mm)*1,3t(min.3 mm)*
Single runSingle run Multi runMulti run
12 12 t t 100100t t 100100
0,5t0,5t--1,1t1,1tN/AN/A
0,7t0,7t--2t2t3 mm3 mm--2t*2t*
0,5t0,5t--2t2t50 mm50 mm--2t2t
no impact test performed upper limit of qualification is 12 mmimpact test performed upper limit of qualification is 1,3t or 2t respectively
BS EN ISO 15614-1 provisions
Diameter definitions:butt outside diameter of the pipebranch - outside diameter of the BRANCH pipe
Range of qualification for outside pipe diameterRange of qualification for outside pipe diameter
Outside diameter of the Outside diameter of the test piece test piece DD (mm)(mm)
Range of qualification Range of qualification (mm)(mm)
D D 2525D D 2525
0,5D0,5D--2D2D 0,5D (min. 25 mm)0,5D (min. 25 mm)
qualification on plates covers fixed pipes with OD > 500 mmqualification on plates covers rotated pipes in PA or PC position with OD > 150 mm
BS EN ISO 15614-1 provisions
Range of qualification for welding process:approval valid only for process usedmulti-process procedures - valid for order usedduring approval testmulti-processes procedures processes may be qualified separately or in combination.each degree of mechanization (manual, mechanized or automatic) need to be qualified separatelyfor 121 (automatic, mechanized, etc) each variant need separate qualificationfor 135 qualification using dip transfer qualifies only dip transfer
BS EN ISO 15614-1 provisions
Range of qualification for welding positions:
welding in any position qualifies for all positions except PG and J-L045 which requires a separate test.
in case of impact/hardness requirements, impact tests shall be taken from highest heat input position (i.e. PF) and hardness tests from the lowest heat input position (i.e. PC or PE) in order to qualify all positions
BS EN ISO 15614-1 provisions
Range of qualification for type of joint/weld:
butt welds qualify full/partial penetration butt welds and fillet weldsbutt welds on pipe qualify also branch connections with angle over 60T joints only qualify T joints and filletfillet welds qualify only fillet welds (recommended if they are the predominant form of production welding!)cannot change multi-run to single run or vice versa
7BS EN ISO 15614-1 provisions
Range of qualification for type of weld/joint:
single side welds made without backing qualify double side welds and single side welds using backingsingle side welds made using backing qualify double side weldsfor 141 process, welds without backing gas qualify welds with backing gasdouble side welds made without gouging qualify for double side welds made with gouging
BS EN ISO 15614-1 provisions
Range of qualification for filler material:the filler used during qualification covers other fillers with equivalent mechanical properties, same type of covering/flux, same composition and same or lower hydrogen contentif impact test is required, for processes 111, 114, 121, 136 and 137, qualification is valid ONLY to the specific make used during the testother makes can be used ONLY after supplementary impact test on weld metalchanges in size of the filler are allowed if heat input conditions are satisfied
BS EN ISO 15614-1 provisions
Range of qualification for filler material:
for 141 and 311 processes, welding with filler doesnt qualify autogenuos welds and vice versa
qualification given to the shielding gas is restricted to the to the symbol of the gas (see BS EN 439)
BS EN ISO 15614-1 provisions