Eur Ing T J Jessop - The Welding Institute
Eur Ing Dr D N Shackleton - Consultant
Presented at EUROJOIN4 - 4th European Conference on Welding, joining and cutting. Development of welding and allied processes at the beginning of the new millennium. Cavtat-Dubrovnik, Croatia, 24-26 May 2001, pp.35-41. (ISBN 953-96454-0-9)
Key words: welding, standards, control, quality, certification, compliance, manufacturing, Europe, European Welding Federation
The importance of control of welding operations in manufacture is described. The purpose and content of EN 729, Quality requirements for welding, are outlined together with advice on how the standard can be used to bring benefits to manufacturers that use welding. Certification of compliance with the standard is also covered, and the role of certification bodies and accreditation bodies is described.
The factors affecting the quality of welds have been investigated over the years, and solutions have been found to enable welding to be performed safely and predictably. These solutions now comprise a significant engineering science. Unfortunately, despite their importance they are not always appreciated by those responsible for welding.
As a result, welding problems in manufacturing occur quite frequently. These can result in costly repairs and delays, and in extreme cases, in catastrophic failure and loss of life.
Many organisations have implemented Quality Management Systems (QMSs) - often based on ISO 9001 or ISO 9002, to provide controls for the operations that affect the quality of welding products. These systems have benefited the organisations using them, yet ISO 9001/2 do not describe the essential requirements needed for special processes like welding. Thus, unless contractual agreements specify what these requirements are, it is left to the manufacturers themselves to define internal criteria. These may differ significantly from current best practice. Also, ISO 9000 third-party assessment can be ineffective in the areas of special processes if the auditors lack knowledge and experience of the processes involved.
EN 729  (also published as ISO 3834) was developed to focus on quality in welding and identify the principal requirements necessary to ensure that welding is performed in a technically satisfactory manner. It is not a comprehensive QMS, but it is a comprehensive process management system for welding.
2. EN 729 (ISO 3834) and its application
EN 729 is not a product standard, nor does it define specific technical requirements for a product. It describes the technical functions which management must address to ensure adequate assurance of the control of welding. At present the standard is limited to fusion welding of metallic materials.
EN 729 identifies three levels of quality requirements dependent on the complexity of the welding operations used by the manufacturer. This feature enables the manufacturer to select a set of requirements that are fit-for-purpose in relation to the company's activities. Even the simplest welding operations can benefit by adopting basic controls.
Table 1 shows the activities for which controls are required for each of the three levels.
The highest or 'comprehensive' controls described in Part 2 of EN 729 (ISO 3834) must be used where the manufacturer operates a QMS according to ISO 9001/2. However, it is recognised in Part 1 of EN 729 (ISO 3834) which provides general guidance that such a QMS may be in place for a manufacturing operation in which welding plays a very minor part. Therefore, the 'comprehensive' controls may be inappropriate. EN 729 allows manufacturers to 'minimise' the controls to suit the particular welding operations involved.
As well as highlighting the essential technical factors involved, EN 729 also incorporates requirements for the organisation and management of welding and related activities, by calling up EN 719 - Welding co-ordination, tasks and responsibilities  , which requires the manufacturer to employ competent technical staff.
It should also be noted that EN 719 requires the appointment of an 'Authorised Welding Co-ordinator' to take responsibility on behalf of the manufacturer for the welding operations. Authorised Welding Co-ordinators are required to demonstrate that they possess technical knowledge appropriate to their tasks and responsibilities. EN 719 indicates that these knowledge requirements can be satisfied by the person holding an appropriate qualification from the European Welding Federation  . These qualifications have since become internationally recognised under the International Authorisation Board of the International Institute of Welding.
EN 729 references the specific CEN or ISO standards, which are used for the qualification of welding procedures, welders, inspection procedures and inspectors. This posed a problem for manufacturers who worked to alternative standards. However, at the international level it was recognised that other national standards existed which provided the same scope or intent as those referenced.
Whilst the alternative standards are not accepted within EN 729, a manufacturer may still claim compliance with EN 729 if, in his declaration, the manufacturer identifies as deviations the alternative standards he is using.
This, along with various other issues, resulted in the publication of a CEN Technical Report  . This report provides useful guidance on the interpretation of EN 729. In essence it indicates the importance of satisfying the technical conditions of the standard as they apply to the manufacturer's operations, rather than following the letter of the standard in areas where no technical improvement would be brought about.
3. Benefits of complying with EN 729 (ISO 3834)
Success in welding, both in business and technical terms, is unlikely to be achieved in the absence of special attention and control. Failure to apply appropriate control not only increases the risk of failure occurring in service but also can result in rejected work, repairs and delays. The cost of repairing a welding can be many times greater than that of making the original weld. Therefore welding, perhaps more than any other activity, benefits from a get-it-right-first-time approach.
Adopting EN 729 ensures that the manufacturer addresses the important areas of control appropriate to the welding activities undertaken. Regular reviews of compliance with EN 729 can provide a framework for enhanced internal discipline for continuous improvement, driving the manufacturer towards adoption of best practice. This alone can bring about improvements in technical efficiency and cost effectiveness of welding operations, whatever their degree of complexity.
EN 729 (ISO 3834) requires the manufacturer to apply the EN 729 criteria on any subcontracted welding work. As a result, such contractors are less likely to be affected by problems with their suppliers in fulfilling the requirements in accordance with the quality criteria and the timescale laid down in the contract.
Adoption of EN 729 may also be necessary where :
- The welded product has to be produced in accordance with an application standard which specifies that fabricators must work to the standard
- An industry sector or other regulatory body opts to use this standard as a pre-qualification requirement for fabricators tendering for work within that industry sector
- A purchaser specifies that suppliers of welded products must comply with the standard.
Table 2 shows examples of standards and specifications which refer to EN 729 or EN 719 - and this list is growing.
4. Certification to EN 729 (ISO 3834)
EN 729 does not require third party certification of compliance, but in the absence of such certification claims of compliance by manufacturers are unlikely to be convincing to their clients unless they undertake compliance audits themselves. As a result, a number of third party certification bodies offer certification to EN 729.
In turn, certification is only convincing if it is backed by recognised accreditation. The association of national accreditation bodies in Europe, called European co-operation for Accreditation (EA), see Table 3 , has recognised the need for special accreditation criteria in order to ensure that assessment of compliance with EN 729 is carried out in a technically correct and uniform manner. This is achieved through new EA Guidelines, EA-6/02  . These guidelines give comprehensive requirements for the competence of the assessment team and for the assessment procedure: it establishes as a cornerstone for certification that the assessment of welding capability of a manufacturer is a specialist job requiring assessors with proven expertise and auditing capability. The EA Guideline is currently being presented to the International Accreditation Forum for recognition at the international level.
The publication of the EA Guideline was welcomed by the European Welding Federation because it embraced almost all of EWFs pre-existing criteria for EN 729 certification. EWF itself operates a network of certification bodies that offer EN 729 certification. These Authorised National Bodies for Company Certification (ANBCCs) are now obliged to follow both the EA Guideline EA-6/02 and the additional EWF criteria.
One of the important additional EWF criteria is for the ANBCC to submit to EWF details of all the manufacturers they have certified under the EWF EN 729 scheme. These details are entered on to a central web site  , with freely available access. The web site details include the products, processes and materials for which the manufacturer has demonstrated compliance with EN 729.
An example of an entry is shown in Table 4 .
The current position of the EWF ANBCCs is shown in Table 4 . Taking into consideration the magnitude of the European industry for manufacturing by welding, and the fact that there are 24 member countries of EWF, Table 5 shows a very low level of activity, with most of the interest coming from central or eastern European countries.
EWF ANBCCs are not the only certification bodies involved in certification of compliance to EN 729, but it is difficult to obtain information about such certification bodies outside the EWF network. With regard to bodies operating without national accreditation, there is no information at all but the number is likely to be very small. With regard to accredited certification outside the EWF network, it is believed that a small number of EN 729 certificates have been issued in the UK, Norway, Sweden, Denmark and Finland.
Overall, these levels of activity in EN 729 certification in EWF and elsewhere appear to be much lower than would be expected from the level of interest in the standard, at least judging from enquiries received from companies in the UK and from the growing number of standards which call up EN 729. It is felt this is likely to change as the new application standards calling up EN 729 are developed and introduced.
5.1 EN729 (also published as ISO 3834) provides guidance on the control of welding and related operations. Manufacturers that use welding can benefit by complying with the standard because doing so will reduce the possibility of things going wrong.
5.2 EN 729 and associated documentation has sufficient flexibility to bring benefits to any welding operations from the most simple to the most complex.
5.3 Third party certification of compliance with EN 729 is available but the criteria applied by certification bodies may be variable. European co-operation for Accreditation (EA) have recently issued stringent new criteria for EN 729 certification. Therefore manufacturers seeking certification should use a certification body carrying accreditation to the EA criteria.
5.4 The European Welding Federation administers a network of EN 729 certification bodies called Authorised National Bodies for Certifying Companies (ANBCC). These bodies comply with the EA criteria. EWF maintains a web site showing details of all companies within its network which have been certified to EN 729.
5.5 The demand for EN 729 certification is currently low but is expected to rise as new European Standards and Directives come into force.
- EN 729:1995 Quality requirements for welding. Fusion welding of metallic materials:
(Note: EN 729 is also published as ISO 3834)
- EN 729 Part 1: Guidelines for selection and use
- EN 729 Part 2: Comprehensive quality requirements
- EN 729 Part 3: Standard quality requirements
- EN 729 Part 4: Elementary quality requirements
- EN 719:1994 Welding co-ordination - Tasks and responsibilities
- i) IIW Guideline: International Welding Engineer. Doc IAB-002-2000/EWF-409
ii) IIW Guideline: International Welding Technologist. Doc IAB-003-2000/EWF-410
iii) IIW Guideline: International Welding Specialist. Doc IAB-004-2000/EWF-411
- PD CR 13576 199 The implementation of EN 729 on quality requirements for fusion welding of metallic materials.
- EA-6/02 March 2000 EA Guidelines on the Use of EN 45011 and EN 45012 for Certification to EN 729. Published by European co-operation for Accreditation.
- EWF web site address: www.ewf.be
Table 1: Comparison of requirements in EN 729, Quality Requirements for Welding
|Requirement||Comprehensive Quality Requirements|
|Standard Quality Requirements|
|Elementary Quality Requirements|
||Full documented review
||Less extensive review
||Establish that capability and information is available
||Design for welding to be confirmed
||Design for welding to be confirmed
||Treat like a main fabricator
||Must comply to standard
||Approved to EN 287 or EN 1418
||Welding co-ordination personnel with appropriate technical knowledge according to EN 719, or persons with similar knowledge
||Not demanded but personal responsibility of manufacturer
||Sufficient and competent personnel to be available
||Sufficient and competent access for third parties, as needed
||Required to prepare, cut, weld, transport, to lift, together with safety equipment and protective clothes
||Has to be carried out. Maintenance plan necessary
||No specific demands - must be adequate
||More restricted plan necessary
|Welding Procedure Specifications (WPS)
||Instructions to be available to Welder. See appropriate part of EN 288
|Weld Procedure Approval
||To appropriate part of EN 288 - Approved as application standard or contract demands
||Welding Specification or dedicated instructions to be available (WPS)
|Batch testing of consumables
||Only if specified in contract
|Storage and handling of welding consumables
||As per supplier recommended as minimum
|Storage of parent materials
||Protection required from influence by the environment, identification shall be maintained
|Post Weld Heat Treatment
||Specification and complete record
||Confirmation to Specification necessary
|Inspection before - during - after welding
||As required for specified operations
||Responsibilities as specified in contract
||Procedures must be available
||Procedures must be in operation
||Required when appropriate
||Required when appropriate
||Must be available to meet the rules for product liability, retained for five years minimum
||As required by contract
Table 2: List of standards and specifications referring to EN 719/729
|ENV 1090 1
||General rules and rules for buildings
||Welding of railway Vehicles Part 2
||Light alloy armour
|EEMUA Draft Specification
||The Fabrication of Non-Primary structural Steelwork for Fixed Offshore Installations (March 99)
||Eurocode 9: Design of aluminium structures - Part 2 Structures susceptible to fatigue (April 97)
||Gas supply systems - Welding steel pipework - Functional requirements (January 97)
||Water tube boilers - Part 5: Workmanship and construction (July 97)
||Welding - Recommendations for welding of metallic materials - Part 4: Arc welding of aluminium and aluminium alloys
Table 3: Membership of European co-operation for Accreditation (EA)
||United Kingdom (UKAS)
Table 4: Extract from the EWF web site ( www.ewf.be) showing the details of manufacturers certified according to the EWF EN 729 scheme
|Company name||Contact person||Address and Tel, Fax||Expiration Date and C9||Standard||Product||Process (1)||Materials (2)|
|Babcock Offshore and Marine
||Mr S Heneghan, Quality & Safety Manager
||Rosyth Royal Dockyard, Rosyth, Fife KY11, Scotland
Tel: 01383 422268
Fax: 01383 423426
|Offshore structures, associated secondary structures and pipework, marine vessels, general fabrication for process, petrochemical, marine, defence and construction industries
|Va = valid
(1) = Processes are coded according to EN 287
(2) = Materials are coded according to PD CR 13576 1999
Table 5: List of EWF ANBCCs - Authorised National Bodies for Company Certification at 28 February 2001
|Country||ANBCC||Number of Companies Certificated|
||Istituto Italiano della Saldatura
||TWI Certification Ltd
||COSK Certiweld - VUZ
||Welding Structures Department - University of Zagreb
||Zveza Drustev za Varilno Tehniko Slovenije
||ISIM CERT 729