Foreword. Welding Fabrication Standards Page 1

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3 Welding Fabrication Standards Page 1 Foreword During the year 2004, workshops regarding the Leonardo Continued Project where held in certain European Countries with the participation of experts from the welding industry in order to identify the competence profile, knowledge and experience requirements for welding engineers and inspectors. The main purpose of the project was to develop appropriate continuous education tools such as training courses (classroom instruction, distance learning) and education on the job. The initial education, qualification and certification of welding and inspection personnel itself has been harmonised by the European Federation for Welding, Joining and Cutting (EWF). However, an accessible, convenient and reliant modular method to deliver the appropriate knowledge has to be developed in order to maintain and upgrade this knowledge and develop appropriate skills for which welding engineers and inspectors are called for by the industry. This leads to the set up of learning tools to integrate and update the knowledge already achieved by the qualified personnel, in order to follow the technology trends in the welding field, avoiding duplication of training items with the previous education achieved with the IIW/EWF courses. In this framework The Italian institute of welding (Istituto Italiano della Saldatura - IIS), has developed the following educational tools for the classroom instruction: slide presentation through computer projector, to be used by teachers during the training courses; books (electronic and/or paper format), to be used by participants; exercise questions, to be used during classroom instruction. This book is therefore meant to provide direct and clear information on European standards relevant to welding fabrication, as these are subject to continuous updating; therefore knowledge of requirements of the standards is to be considered basic knowledge for welding co-ordinators and inspection personnel. Moreover this book has been recently integrated taking into consideration guidelines produced by EWF for the application of ISO 3834 requirements, produced after several years of experience of its members in technical assistance on the field of welding fabrication, education and training of welding and NDT personnel and in certification of welded products manufacturers.

4 Welding Fabrication Standards Page 2 With review of GSI - SLV Duisburg and EWF.

5 Welding Fabrication Standards Page 3 Summary 1 Quality management and welding fabrication Introduction Use and field of application of EN ISO EWF Certification scheme for EN ISO The EWF ISO 3834 certificate and schedule The integrated management system EN ISO requirements Introduction Requirements review and technical review Subcontracting Welding personnel Welders and welding operators Welding coordination personnel Welding inspection personnel Equipment Welding and related activities Production planning Welding procedures and instructions Welding related document control Welding consumables Parent material Post-weld heat treatment (PWHT) Inspection and testing Non-conformance and corrective actions Calibration and validation of measuring, inspection and testing equipment Identification and traceability Quality records Comparison of ISO 3834 Requirements Introduction Choice of the appropriate quality level Comparison chart ISO Comprehensive quality level ISO Standard quality level...41

6 Welding Fabrication Standards Page ISO Elementary quality level European standard for manufacturing unfired pressure vessels Introduction EN : General rules EN : Materials EN : Design EN : Fabrication Specific requirements for the Manufacturer Requirements for subcontracting Specific requirements for welding activities Other requirements EN : Inspection and testing EN : specific requirements for pressure vessels and parts made of spheroidal graphite cast iron CR : Guidance on the use of conformity procedures European standard for manufacturing metallic industrial piping Introduction EN : Materials EN : Design and calculations EN : Fabrication General requirements for the Manufacturer Requirements for the welding activities EN : Inspection EN : Additional requirements for buried piping CR : Guidance on the use of conformity procedures European standard for manufacturing simple unfired vessels to contain air or nitrogen Introduction EN 286-1: requirements for welding manufacturing of simple unfired pressure vessels European standard for steel pipelines and pipework for gas supply systems Introduction EN 12732: scope and structure of the standard EN 12732: Quality requirement categories EN 12732: requirements on quality systems EN 12732: Inspection of welded joints and acceptance criteria European standards for the fabrication of steel and aluminium structures Introduction...72

7 Welding Fabrication Standards Page EN : Steel and aluminium structural components - General delivery conditions Requirements for the design of structures EN : Technical requirements for the execution of steel structures Specific requirements for welding Manufacturers Requirements for inspection and testing and acceptance criteria EN : Technical requirements for the execution of aluminium structures79 9 Project European standards for the fabrication of railway vehicles and components Introduction pren Requirements for the Manufacturer Normative references... 86

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9 Welding Fabrication Standards Page 7 1 Quality management and welding fabrication 1.1 Introduction Manufacturing processes such as fusion welding are widely used to produce many products, and for some companies, these are the key production features. Products may range from simple to complex; examples include pressure vessels, domestic and agricultural equipment, cranes, bridges, transport vehicles and other items. These processes exert a profound influence on the cost of manufacture and on the quality of the product. It is therefore important to ensure that these processes are carried out in the most effective way and that appropriate control is exercised over all aspects of the operation. In general, ISO 9001 standard has been developed in order to apply a consistent Quality Management System. However, surface coating, painting, composite manufacture, welding and brazing are considered as special processes because the quality of the manufactured product cannot be readily verified by final inspection. In the case of welded products, quality cannot be inspected directly in the product, but has to be built in during fabrication, as even the most extensive and sophisticated non-destructive testing does not improve the quality of the product. For this reason quality management systems alone may be insufficient to provide adequate assurance that these processes have been carried out correctly. Special controls and requirements are usually needed, which require adequate competence control before, during and after operation. For products to be free from serious problems during production and in service, it is necessary to provide controls from the design phase through material selection, into manufacture and subsequent inspection. For example, poor design may create serious and costly difficulties in the workshop, on site, or in service; incorrect material selection may result in problems, such as cracking in welded joints. To ensure sound and effective manufacturing, the management needs to understand and appreciate the sources of potential problems and to implement appropriate procedures for their control.

10 Welding Fabrication Standards Page 8 All these considerations lead to the development of specific standards, which were the EN 729 standards for fusion welding. The first edition of this standard is dated 1997; in 2005 the new revision is meant to be ready, passed into ISO numbering system as EN ISO In this chapter an overview of the most significant clauses of EN ISO 3834 will be given considering also the normative references that could be helpful in the fulfilment of such requirements. Figure 1 Welding workshop (manufacturing of wind mills) 1.2 Use and field of application of EN ISO 3834 EN ISO 3834 is a standard independent of the type of construction manufactured that provides a method to demonstrate the capability of a Manufacturer to make products of the specified quality, both in workshops and at field installation sites. Therefore applicable measures for different circumstances are identified, such as the following: in contractual situations for the specification of welding quality requirements; by Manufacturers to establish and maintain welding quality requirements; by committees, drafting manufacturing codes or application standards to specify appropriate welding quality requirements;

11 Welding Fabrication Standards Page 9 by organisations assessing welding quality performance, e.g. third parties, customers, or Manufacturers. As a consequence, these International Standards can be used by internal and external organisations, including certification bodies, which could offer certification services by assessing the Manufacturer's ability to meet customer, regulatory or the manufacturer's own requirements. This International Standard is structured in five parts: EN ISO : Guidelines for selection and use; EN ISO : Comprehensive quality requirements; EN ISO : Standard quality requirements; EN ISO : Elementary quality requirements; EN ISO : Normative references to fulfil the requirements of EN ISO , EN ISO and EN ISO It should be noted that the above standards define specific quality requirements at different levels, but do not assign those levels to any specific product group. The Manufacturers generally select one of the three levels (as specified in part 2, 3 and 4 of the standard) based on the following considerations regarding their 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, weld imperfection, can affect product performance. When compliance to EN ISO 3834 part 2 or 3 is required, the requirements contained in this International Standard shall be adopted in full; however, in certain situations (e.g. where manufacturing is more suited to ISO or ISO , or where particular operations are not technologically applicable and therefore cannot be undertaken), such requirements may be selectively amended or deleted. Whenever this situation occurs, the evaluation of the effective need for this minimising of requirement procedure shall be properly possibly evaluated and accepted by contractual parties and/or potential certification bodies. As to the relationship between EN ISO 3834, that applies to fusion welding manufacturing, and EN ISO 9001:2000, that applies to every kind of product or service, the first can be considered as a possible way to fulfil the latter requirements 1. 1 However EN ISO 3834 are stand alone standard, as its application is viable, even if the company does not apply any quality management system to any of its activities.

12 Welding Fabrication Standards Page 10 On the basis of the above stated considerations, EN ISO 3834 should be referred to both as a system and a process standard, as it also identifies quality management requirements to obtain adequate control of the manufacturing process (e.g. the welding fabrication activities). In the chapter 2 the ISO requirements will be explained in detail,giving practical guidance on the application and use, while in chapter 3 the differences from part 2, 3 and 4 will be outlined, and guidance is given on their selection criteria. 1.3 EWF Certification scheme for EN ISO 3834 The European Federation for Welding, Joining and Cutting (EWF), by virtue of its unique international expertise has developed a high integrity and specialised certification system to assure companies compliance with EN ISO Great care has been taken to detail the interpretation of the standard in terms of third party assessment, to specify and register properly trained scheme assessors, and to devise an operational structure so that certification of companies will be consistent wherever the scheme rules are applied. This is done by appointing one organisation in each country to act for EWF, and these organisations are assessed and monitored against Rules provided by EWF itself. These organisations are known as the EWF Authorised National Bodies for Company Certification (ANBCCs), and are responsible for ensuring that the standards of assessment and certification are maintained. In this, the objective is that EWF certified companies will have demonstrated that they have achieved an identified, minimum level of capability over a specified scope of activity, irrespective of the country in which they had been qualified The EWF ISO 3834 Certificate and Schedule The primary intention of EN ISO 3834 certification is to ensure that manufacturers are competent and exercise adequate control of the special process of welding so that customers or others may have confidence that the welded products they produce will comply with the regulatory and/or contractual requirements. Moreover, in the field of quality management in fabrication, the European trend is clearly moving toward a product/process approach. The European Directives and their supporting European harmonised standards (requiring the fulfilment of specific technical requirements, typical of any merchandise sector) are exhaustive examples of that. In order to help Companies in the fulfilment of such requirements, consistently to the product manufactured, EWF have produced specific supplementary guides for the processes/products considered (e.g. railway components, pressure vessels, construction products), taking into consideration the applicable standards (also considered in this book) and the best practice manufacturing procedures, already shared by the main European Manufacturers and Customers.

13 Welding Fabrication Standards Page 11 In order to give evidence of such specific technical capabilities of Manufacturers, the EWF Certificate, where the references, against which the certification has been got, are reported together with the issue and expiry date of the Certificate itself and the Company s data, is supplemented with a Schedule, where technical information (reference standards, materials, welding processes, supplementary requirements, deviations, etc.) on the fabrication process adopted and the welded products manufactured is detailed and the name of the responsible welding co-ordinator reported. Therefore the advantages for the Manufacturers in getting a certification against the EWF ISO 3834 Certification Scheme, can be summarised as follows: welded products are differently treated according to the specificity of their welding fabrication process; manufacturers are guided to satisfy harmonised European Directives requirements through implementation of the Scheme; the specific areas of competence (for Personnel and Companies) are explicitly encompassed and registered in the Schedule; manufacturers can get visibility through the Register ( of certified Companies The Integrated Management Certification System EWF realised also a certification Scheme dealing with the environmental management in welding fabrication, having as a basis the EN ISO (Environmental management systems- Specification with guidance for use) and its EWF interpretations toward welding and allied processes. The result of that has been the EWF Environment Management Scheme (EWF EMS). More recently, a third Scheme has been introduced, related to health and safety management in welding and allied processes. The starting reference document has been the BSI 8800 (Guide to occupational heath and safety management system), interpreted and fitted on the specific technological operations, resulting in the EWF Safety Management Scheme (EWF SMS). It s anyway unquestionable that a Manufacturer can control the Environment, Health and Safety aspects of his welding fabrication process only if the welding and allied activities are already properly controlled from the production point of view, that is through implementation of the EWF EN ISO 3834 Scheme. The result of such an approach is the possibility for Companies to adopt the comprehensive EWF Integrated Manufacturer Certification System (EWF IMCS), covering all the management aspects in welding fabrication, that is: quality, environment and heath & safety.

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15 Welding Fabrication Standards Page 13 2 EN ISO requirements 2.1 Introduction EN ISO defines comprehensive quality requirements for fusion welding in workshops and/or on site. Therefore compliance to the requirements of this part should provide the best quality level achievable for the welding fabrication activities. 2.2 Requirements review and technical review The Manufacturer shall review the contractual and any other requirements together with any technical data relevant to the welding fabrication activities, in order to verify that the work content is within its capability to perform, that sufficient resources are available to achieve delivery schedules and that documentation is clear and unambiguous. All information necessary to carry out the manufacturing operations shall be therefore available prior to the commencement of the work, otherwise it should be asked the purchaser 2 to provide all the necessary data. Moreover the Manufacturer shall identify any variation between the final contract and previous quotations and notify the purchaser of any programme, cost or engineering changes that may result. Within the contract review, particular attention should be given to the product standard to be used together with any supplementary requirements, and to statutory and regulatory requirements. As for the technical subjects to be considered, the following items should be considered in detail: a) parent material(s) specification and welded joint properties; b) quality and acceptance requirements for welds; c) location, accessibility and sequence of welds including accessibility for inspection and nondestructive testing; d) the specification of welding procedures, non-destructive testing procedures and heat treatment procedures; e) the approach to be used for the qualification of the welding procedures ; f) the qualification of the personnel; g) selection, identification and/or traceability (e.g. for materials, welds);

16 Welding Fabrication Standards Page 14 h) quality control arrangements including any involvement of an independent inspection body; i) inspection and testing; j) subcontracting; post weld heat treatment; k) other welding requirements, e.g. batch testing of consumables, ferrite content of weld metal, ageing, hydrogen content, permanent backing, use of peening, surface finish, weld profile; l) use of special methods (e.g. to achieve full penetration without backing when welded from one side only); m) dimensions and details of joint preparation and completed weld; n) welds which are to be made in the workshop, or elsewhere; o) environmental conditions relevant to the process (e.g. very low temperature ambient conditions or any necessity to provide protection against adverse weather conditions); p) handling of non-conformance. Figure 2 Drawing of a pressure vessel 2 or the design and/or other internal departments when the construction is designed by the Manufacturer.

17 Welding Fabrication Standards Page 15 A possible way to demonstrate the Manufacturer s compliance with these normative requirements is the registration of the subject review by filing either the minutes meeting or the relevant check list. 2.3 Subcontracting Subcontracted services or activities (e.g. welding, inspection, non destructive testing, heat treatment), shall be managed by the Manufacturer as if they were carried out by the Manufacturer himself. Therefore Subcontractors should be considered as internal departments: all relevant specifications and requirements shall be supplied to the Subcontractor; a Subcontractor shall work under the order and responsibility of the Manufacturer; the information to be provided to the sub-contractor shall include all relevant data from the requirements review and the technical review. Additional requirements may be specified as necessary to assure the Subcontractor s compliance with technical requirements. However the Manufacturer shall ensure that the Subcontractor complies with the quality requirements as specified, and therefore shall check that the Subcontractor: provides such records and documentation of his work as may be specified by the Manufacturer; fully complies with the relevant requirements of EN ISO Standard. Compliance with these requirements may be demonstrated by acknowledgement of a document receipt or by checking that the relevant documentation is cited in the subcontracting contract. Moreover, the Manufacturer can assess the Subcontractor, or reserve the possibility to do it at a later date. 2.4 Welding personnel As welding is a special process, the human factor has a key role in the production of quality products. Therefore sufficient (in number) and competent personnel for the planning, performing and supervising of the welding and allied activities shall be available, according to standard and customer requirements Welders and welding operators Welders and welding operators shall be qualified by an appropriate test. Whenever no other specific Customer s requirement is applicable, the standards reported in the following table apply.

18 Welding Fabrication Standards Page 16 Welding process Material Applicable standard Arc welding, manual and partly mechanised Steel EN 287 1, ISO Aluminium and aluminium alloys ISO (EN 287 2) Copper and copper alloys ISO Nickel and nickel alloys ISO Titanium and titanium alloys, ISO Zirconium and zirconium alloys ISO Arc welding, fully mechanised and automatic All EN 1418 (ISO 14732) Underwater welding All ISO and 2 Table 1 Standards for the qualification of welders and welding operators All qualification records shall be filed in the last upgraded revision and properly controlled; moreover, if the production welds are of the required quality and if the test records (e.g. half-yearly documentation about radiographic or ultrasonic inspections, or fracture tests, etc.) are filed, prolongation of the certificate time of validity may be obtained, as the compliance with EN ISO 3834 requirements may demonstrate sufficient reliability. It should be noted that the standards referenced in table 1 consider the figure of the examiner or examination body as a person or organisation appointed to verify compliance with the applicable standard, without giving any specific guidance on it. As a consequence, many different situations can be considered 3 : qualification is issued by a person without any recognised qualification; qualification is issued by a qualified person (IWE, IWT, IWS, IWI-P 4 ), with reference to his/her qualification diploma (and relevant stamp); qualification is issued by the Manufacturer s qualified welding coordinator (IWE, IWT, IWS) in the name of the Manufacturer itself; qualification is issued by an independent third party, possibly authorised by the customer or by a national accreditation body 5. However, specification of the examiner or examining body for the approval of welders and/or welding procedures shall be a contractual requirement or, otherwise, a fabrication code requirement. 3 The same situations apply for the qualification of welding procedures 4 International Welding Inspection Personnel (Comprehensive, Standard and Basic levels) 5 EWF has established a system for the qualification of welding personnel and of welding procedure specifications. Accreditation bodies running in such a system are sometime referred as ANBCC (authorised National body for Certification of Companies)

19 Welding Fabrication Standards Page 17 Figure 3 Welding workshop for aerospace applications Welding coordination personnel Welding coordination is the key activity for achievement of the desired quality for the welded product as the welding coordination personnel has responsibility for quality activities, as reported in ISO 14731/EN 719. Therefore the Manufacture has to comply with the following requirements: - the number of welding coordinators shall be sufficient to provide adequate control, and therefore based on the number/dimension of workshops, employees, welders, etc. - only one responsible welding coordinator shall be appointed, who is responsible for all the welding fabrication activities in the company; - tasks and responsibilities for each other person involved in the welding coordination activities shall be described in detail, usually in an appropriate list;

20 Welding Fabrication Standards Page 18 - welding coordination personnel shall have sufficient knowledge of welding and allied process in general, and detailed knowledge of the assigned tasks. Depending on the range and complexity of the products, on the dimension and the number of the workshops, and on the relevance of the welding activities, the welding coordination personnel can be directly employed by the Manufacturer or a consultant, however assuring adequate presence in the company. Typical tasks for the welding coordinator are reported as follows 6 : - contract and design review; - evaluation of weldability and relevant choice of base material (if applicable) and welding consumables; - assessment of possible Subcontractors; - welding (and allied activities) production planning; - equipment management; - welding and testing (preliminary to final) activities; - welding documents control and management of the ISO 3834 quality system. This leads to the need of appropriate knowledge and experience, that shall comply with EN 719 / ISO requirements. In particular, three different levels of knowledge are considered: 1. comprehensive technical knowledge; 2. specific technical knowledge; 3. basic technical knowledge. The level of knowledge shall be based on normative and contractual requirements or could be a Manufacturer s choice based on the range and on the complexity of the products, on the dimension and the number of the workshops, on the relevance of the welding activities. IIW provides for guidelines for the qualification of International Welding Engineers, Technologists and Specialists, corresponding to the three above mentioned levels. IIW qualification guarantees appropriate knowledge, but is not compulsory; therefore the Manufacturer can refer to any other qualification, but shall, however, be prepared to demonstrate adequacy of such a qualification to customers or certification bodies. Concerning the experience, no specific requirement is given; two years of experience in the specific field of the Manufacturer s welded products are generally considered as sufficient, even if experience should be at least proportional to the complexity of the welding production. EWF provides for a three years based Certification programme for welding Engineers, Technologists 6 The full list is reported in EN 719 / ISO

21 Welding Fabrication Standards Page 19 and Specialists, namely C-EWE, C-EWT, C-EWS (Certified European Welding Engineer, Technologist and Specialist). 2.5 Welding inspection personnel Welding inspection activities require qualified personnel. Therefore at least NDT personnel should be adequately qualified according to EN 473/ISO Moreover, inspection activities should be managed and supervised by someone having general knowledge of the welding activities and in depth knowledge of welding inspection. Such activities may be directly managed by the welding coordinator, or by welding inspectors depending on the range and complexity of the products, on the dimension and on the number of workshops and on the relevance of the welding activities. IIW provides for a guideline regarding training courses for the following three levels of welding inspectors: - IWI C (International Welding Inspector Comprehensive) - IWI S (International Welding Inspector Standard) - IWI B (International Welding Inspector Basic) However it shall be noted that for some test or checks (e.g. welding parameters, dimensional checks, visual testing, etc.) the welder or welding operator can be considered as an inspector himself. 2.6 Equipment The Manufacturer shall have available equipment adequate to his products and production volume. All the equipment shall be included in a list, which may be considered both as a way to provide potential customers with information on the Manufacturer s capabilities and productivity, and as a tool for the equipment management. Table 2 reports an example list of equipment reporting relevant characteristics, serial number and reference to the maintenance sheet. Maintenance intervals and operations shall be reported on the maintenance sheet. All the equipment shall be properly managed, thus assuring control and maintenance; in addition its instruments (e.g ammeters, voltmeters) shall be calibrated, whenever correlated to the product quality, or certified according to a possible contractual requirement. As an example, periodic examination of cables, tips, contact tubes and general cleaning of welding power sources should be carried out at appropriate periodic intervals. Description Serial number Characteristics maintenance sheet number Notes

22 Welding Fabrication Standards Page 20 MIG Welding Power source TIG Welding Power Sources Travelling bridgecrane CO 2 Laser Beam cutting Equip. Xxx A - Inverter MIG Xxx A - Inverter TIG CC Load capacity: 5000 Kg Working area: 10mx10m Crane 01-00xx aio Power: 1 kw LBC 01 - Table 2 Example of equipment list Figure 4 Cranes in a welding workshop Moreover, appropriate tests shall be performed after the installation of new (or refurbished) equipment in order to verify the correct function. Such tests shall be carried out and documented in accordance with appropriate standards, whenever relevant. 2.7 Welding and related activities Production planning Before starting the manufacture of a product or a series of products (generally after the technical review), the Manufacturer plans its production activities in order to properly define all the activities to be performed with relevant sequences, processes and procedures, and personnel allocation.

23 Welding Fabrication Standards Page 21 The typical result of such an activity is the production and inspection plan, which will cover the production of each component (if relevant) throughout all the manufacturing stages; in some cases, this is to be registered as a production document. Moreover, it can be delivered to the final customer together with the product, whenever this is contractually required Welding procedures and instructions The Manufacturer shall prepare the Welding Procedure Specification(s) (WPS) and shall ensure that these are used correctly in production. The welding procedures applied during production shall be as specific as possible, in order to clearly identify actions and parameters to be used for the required joint. However, if the relevant WPS contains data too detailed and not useful for the welder, dedicated work instructions may be used directly derived from such a WPS containing only the necessary data. These instructions have to refer directly to the welding procedure specification they derived from, e.g. by referring to the relevant WPS number. In the next page a typical WPS form is reported, produced according to EN ISO

24 Welding Fabrication Standards Page 22 COMPANY NAME OR LOGO WELDING PROCEDURE WPS n Rev. SPECIFICATION (WPS) Supp. WPQR Date Welding process(es) a) b) c) Type(s) a) b) c) JOINTS Joint Type Backing Backing material Weld preparation Method of preparation & Cleaning PARENT METAL Group n To group n Spec. Type & grade To Spec. Type & grade Thickness Outside Diameter Other Joint drawiing WELDING CONSUMABLE GAS(ES) a) b) c) Gas(es) Mixture Flow Rate Specification n Plasma l/min Designation Shielding a) l/min Size Shielding b) l/min Trade name Trailing l/min Manufacturer Backing l/min Flux design. EN Flux Trade name ELECTRICAL CHARACTERISTIC - Weld deposit Other Current Other Polarity WELDING POSITION Mode of Metal Transfer Position Tungsten Electrode Type & size Welding Progression Electrode wire feed speed range Other Other PREHEAT TECHNIQUE Preheat Temperature String or weave beads Interpass Temperature Orifice or gas cup size Preheat maintenance Initial & interpass cleaning Other Method of back gouging PWHT and/or AGEING Oscillation Amplitude Freq. Temperature Range Distance contact tube work piece Time Range (hour) Multiple, single pass (for side) Heating rate Single or multiple electrodes Cooling rate Torch angle direction of welding Other Other Run(s) or Layer(s) Welding process Filler metal Current EN designation or trade name. Size (mm) Type & polarity Amperage A Voltage V Travel Speed mm/min Heat input KJ/mm Other MANUFACTURER APPROVED BY Figure 5 Welding Procedure Specification

25 Welding Fabrication Standards Page 23 Considering that welding is a special process and that the quality of the welded joint cannot be properly controlled only by final tests, the welding procedures significant for the final product quality shall be qualified precisely prior to production. As a consequence, those Welding Procedure Specifications should be prepared in accordance with a Welding Procedure Qualification Record (WPQR). Normative references to the specification and to the qualification of welding procedures are given in table 3. Welding process Standard Material Scope Field of application ISO WPS, WPQR General Rules ISO Qualification based on tested welding consumables All fusion welding Qualification based on previous welding ISO All processes experience WPQR Qualification by adoption of a standard ISO welding procedure ISO Qualification based on pre-production welding test ISO WPS Compiling Gas Welding Steels Qualification based on welding procedure test ISO WPQR Steels ISO All WPS Compiling ISO Steels and Nickel alloys WPQR Qualification based on welding procedure test ISO Aluminium, Magnesium WPQR Qualification based on welding procedure test ISO Steel castings WPQR Qualification based on welding procedure test Arc welding ISO Aluminium castings WPQR Qualification based on welding procedure test ISO Titanium and zirconium WPQR Qualification based on welding procedure test ISO Copper WPQR Qualification based on welding procedure test Qualification based on welding procedure test ISO All applicable WPQR corrosion resistance overlay, cladding restore and hardfacing ISO All applicable WPQR Qualification based on welding procedure test - Welding of tubes to tube-plate joints Electron beam ISO All WPS Compiling welding ISO All applicable WPQR Qualification based on welding procedure test Laser Welding ISO All WPS Compiling ISO All applicable WPQR Qualification based on welding procedure test Underwater Arc Welding Wet ISO All applicable WPQR Qualification based on welding procedure test Hyperbaric Underwater Arc Welding Dry Hyperbaric ISO All applicable WPQR Qualification based on welding procedure test Table 3 Standards for the qualification of welding procedures Different methods for the qualification of welding procedures are available: - welding procedure test this method consists in welding a standardised test piece on which destructive and non-destructive tests are carried out in order to verify the achievement of required properties;

26 Welding Fabrication Standards Page 24 - use of approved welding consumables - this method of approval may be used if the welding consumables and the base material are not particularly affecting the welding quality, provided that heat inputs are kept within specified limits; - previous welding experience - a welding procedure may be qualified by referring to previous experiences in welding if the Manufacturer is able to prove, by appropriate authentic documentation of an independent nature, that he has previously satisfactorily welded the same joint with reliable results; - use of a standard welding procedure a procedure is qualified if it is issued as a specification in the format of a WPS or WPQR based on appropriate qualification (e.g based on the relevant part of EN ISO 15614), not related to the Manufacturer and qualified by an examiner or examining body; - Pre production Test - this method is the only reliable method of qualification for those welding procedures in which the resulting properties of the weld strongly depend on certain conditions such as: components, special restraint conditions, heat sinks etc., which cannot be reproduced by standardised test pieces; it is mostly used when the shape and dimensions of standardised pieces do not adequately represent the joint to be welded. Even if different qualification methods are considered, the most commonly used are qualification by welding procedure test and pre-production test; however the applicable method of qualification is generally specified in either manufacturing codes, standards or contracts Welding related document control In order to demonstrate the achieved quality of the welded product, all the welding related documents (e.g. WPS, WPQR, Welder s Qualification record, etc) shall be properly controlled. This involves the preparation and maintenance of a procedure for the management of such documents, in order to identify issuance responsibilities, distribution methods, availability, and method for withdrawing obsolete documents. Even if it is not a normative requirement, a commonly adopted method to control documentation is the production of a written procedure, produced or approved by the welding coordinator, to be kept by the Manufacturer quality assurance department or directly by the welding coordinator himself. 2.8 Welding consumables Welding consumables are a basic element in the quality of a welded joint. As an example, covered electrodes, which have absorbed humidity due to incorrect storage or management procedures, can seriously affect the quality of a welded joint causing cold cracks, porosity, etc. Therefore welding consumables such as filler metals, shielding gases, welding fluxes, etc. shall be managed according to the supplier s recommendations.

27 Welding Fabrication Standards Page 25 Figure 6 Oven for welding electrodes As a reference, table 4 reports the standards for the classification of welding consumables sorted by material and welding process.

28 Welding Fabrication Standards Page 26 Material Welding process Standard All applicable to the process Submerged arc welding (fluxes) EN 760 All applicable to the process TIG (tungsten electrodes) EN All applicable to the processes Shielding gases for arc welding and cutting EN 439 Flux (or metal) cored (gas) metal arc welding EN 758 TIG EN 1668 Non alloyed and fine grain steels Covered electrodes EN 499 MIG/MAG EN 440 Submerged arc welding (wire flux combination) EN 756 Covered electrodes EN 1599 Creep resistant steels TIG, MIG/MAG EN Flux (or metal) cored arc welding EN Flux (or metal) cored (gas) metal arc welding EN High strength steels Submerged arc welding (wire flux combination) EN TIG, MIG/MAG EN Covered electrodes EN 1600 Stainless and heat resistant steels Flux (or metal) cored (gas) metal arc welding EN TIG - Rods and wires EN Aluminium and Aluminium alloys TIG, MIG EN Nickel and Nickel alloys Covered electrodes EN Table 4 Standards for the welding consumables 2.9 Parent material The material shall be stored in a way, which prevents from adverse effects (this applies also to client supplied material). Moreover, some materials seem to be quite similar but possess very different properties; thus, identification shall be maintained at least during the storage. Even if it is not specifically required, a written procedure, which has to be prepared or is to be approved by the welding coordinator and has to be made available to the parent material warehouse, is suggested to cover this point of the standard. In order to be sure that the product delivered by the supplier complies with the Manufacturer s needs and orders, references to the certificates for the conformance of the furnished product to the order can be made according to EN Metallic products - Types of inspection documents. In accordance with such a standard, inspection documents are divided in two groups, based on the following conditions:

29 Welding Fabrication Standards Page 27 - class 2 documents (namely 2.1, 2.2 and 2.3) are certificates or test reports issued by personnel employed in the production departments - class 3 documents (namely 3.1.A, 3.1.B, 3.1.C, 3.2) are inspection reports or certificates issued by personnel independent from the production departments. As a consequence, class 3 documents can be considered more objective, although they will add cost (and value) to the product to be delivered. It shall be noted that both above-mentioned types of documents refer to the Manufacturer order and to the relevant standards, which are to be attached to the documents. The type of document needed for the welding fabrication is not reported in the ISO 3834 Standard; possibly, this can be reported on product standards, on fabrication codes or can be a customer requirement Post-weld heat treatment (PWHT) Post-weld heat treatments as heat treatments in general can be considered as special processes. Figure 7 Hot air heat treatment of a pressure vessel Hence, the Manufacturer is anyhow responsible for the quality of the final product and has to manage properly all the activities relevant to the heat treatment, which concerns: - subcontracting; - personnel;

30 Welding Fabrication Standards Page 28 - inspection and destructive and non destructive testing; - equipment for heat treatment (suitability, maintenance, etc.); - heat treatment parameters; - heat treatment specification; - measuring of parameters; - heat treatment records. In particular a PWHT procedure shall be produced by the Manufacturer or by the potential supplier, though approved by the Manufacturer s Welding Coordinator according to the Customer or Standard/code requirements. It has to be compatible with the parent material, the welded joint, the construction etc. Moreover, the heat treatment shall be recorded during the process to evidence that the specification has been followed as well as to ensure the traceability for the particular product. Figure 8 Equipment for the heat treatment control The technical report CR/ISO TR is a reference for the management of the heat treatment activities Inspection and testing In order to guarantee the application of all the fabrication procedures and the required properties for the product, appropriate inspections and tests shall be implemented during the manufacturing process

31 Welding Fabrication Standards Page 29 Location and frequency of such inspections and/or tests will depend on the contract and/or product standard, on the welding process and on the type of construction. As a general rule the state of inspection and testing of the welded product have to be indicated in some way. Such a means shall be adequate to the type of product; as an example, a Fabrication and Control Plan may be required for big products (on which the testing activities are marked); while routing cards or confined space inside the manufacturing plant shall be sufficient for small series product to indicate the inspection and testing status. Table 5 reports a typical chart for tests to be carried out before, during and after welding operations. In some situations, the signature of the inspector 7 shall be required in order to enhance the traceability of the welding and related process activities. Moreover, the reference number of the relevant test report shall be included, if required. All the procedures or instructions relevant to inspection and testing shall be made available to the inspection personnel, and properly controlled. As to NDT, testing activities (method, technique and extension) shall be carried out in consideration of and in accordance with the quality level of the product. Some of those parameters are reported in the manufacturing codes, where the designer chooses the class of the weld taking into consideration all of the above mentioned factors. All these aspects should be considered during the design review phase by the welding coordinator. Figure 9 Welding gauge for Visual Inspection of joints 7 For some tests or checks (e.g. welding parameters, dimensional checks, visual testing, etc.) the welder or welding operator itself shall be considered as inspector.

32 Welding Fabrication Standards Page 30 TEST Tests before welding operations Reference procedure Checked (date) Signature of the inspector Reference report Suitability and validity of welders qualification certificates Suitability of welding procedure specification Identity of parent material Identity of welding consumables Joint preparation (e.g. Shape and dimensions) Fit-up, jigging and tacking Special requirements in the welding procedure specification (e.g. Prevention of distortion) Arrangement for any production test Suitability of working conditions for welding, including environment Tests during welding operations Preheating / interpass temperature Welding parameters Cleaning and shape of runs and layers of weld metal; Back gouging; Welding sequence; Correct use and handling of welding consumables; Control of distortion; Dimensional check Tests after welding operations Compliance with acceptance criteria for Visual Testing Compliance with acceptance criteria for other NDT examinations (e.g. Radiographic or Ultrasonic Testing) Compliance for destructive testing (when applicable) Results and records of post-welding operations (e.g. PWHT) Dimensional checking. Table 5 Template for testing and inspection chart. EN standard may be used as a reference for the application of NDT on welded structures, reporting cross references between testing standards, acceptance levels and quality levels (see table 6).

33 Welding Fabrication Standards Page 31 Test method VT PT MT Quality level according to EN ISO 5817 B C D B C D B C D Applicable standard for the testing method and relevant level EN 970 no levels are specified EN no levels are specified EN 1290 no levels are specified Standard for the acceptance and relevant level Refer directly to the imperfections dimension as reported in EN ISO 5817 EN X EN X EN X EN X EN X EN X B EN level B EN RT C EN level B* EN D EN level C EN B EN 1714 At least level B EN UT** C EN 1714 At least level A EN D Level not applicable*** * However, the maximum area for single exposition shall be in accordance with level A ** Only for ferritic steels *** However, level D can be applied, with the same requirements of level C, if agreed by the contracting parties Table 6 Applicable standards for NDT examination according to EN Figure 10 Ultrasonic Testing on a claw

34 Welding Fabrication Standards Page Non-conformance and corrective actions As previously stated, ISO 3834 is a process standard, which refers to welding fabrication, however containing some elements relevant to the management system. Therefore, non conformances refer to either product defects or aberrations from the contract (however concerning the product itself). As a consequence, the Manufacturer has to consider proper procedures to resolve non-conformances and avoid further accidents in the future (avoidance of recurrence of non-conformances). In particular, if repair welding is needed, repair specifications shall be produced or approved by the welding coordinator, and shall be made available to the repairing site (note that qualification, according to any standard, is not required). After repair has been accomplished, the items shall be re-inspected, tested and examined in accordance with the original requirements Calibration and validation of measuring, inspection and testing equipment In general, calibration of welding equipment instruments (e.g. ammeters, voltmeters) is only required where the quality/repeatability of the weld depends on accurate and repeatable setting of parameters such as current, voltage, speed, gas flow, pulse characteristics, etc. In some cases, calibration is not needed, as appropriate repeatability of the weld quality can be simply achieved by indirect control of parameters. As an example in manual metal arc welding, heat input can be controlled via the measurement of the run out length. Oxygen cutting machines are similarly controlled by observing the quality (visual appearance) of the cut faces. Therefore it can be stated that in this case, the instrument to be calibrated shall be, the intuition and experience of qualified and skilled welders. Elaborate procedures for calibration of instruments will be in some cases impossible to be applied or however, if applicable, will simply add costs without increasing the quality. In general, calibration of instruments is required for automatic welding machines, temperature recorders for heat treatment, NDT equipment, etc. Moreover, calibration is necessary in other situations. Instruments for inspection and testing and for control of e.g. PWHT should be calibrated at regular intervals. New welding processes and new power sources, e.g. pulsed arc welding, are difficult or impossible to control just on the base of "intuition and experience", therefore objective instruments are required. Control of mechanised welding operations necessitate strict control of heat input, which also presupposes reliable instruments. A good reference for the management of calibration of welding and related processes for Manufacturers applying ISO 3834 is the EN standard Welding - Calibration, verification and

35 Welding Fabrication Standards Page 33 validation of equipment used for welding, including ancillary activities. A key issue of the standard is the discussion of the influence of various process variables on the resulting output and, in particular, of the possibilities of verification of the output by subsequent monitoring, inspection and testing. Especially the following concepts are applicable to welding manufacturing: - calibration: set of operations that establish, under specified conditions, the relationship between values of quantities indicated by a measuring instrument or measuring system, or values represented by a material measure or a reference material, and the corresponding values realised by standards ; - verification: confirmation by examination and provision of objective evidence that specified requirements have been fulfilled ; - validation: confirmation by examination and provision of objective evidence that the particular requirements for a specific intended use are fulfilled. Figure 11 Automatic Twin Arc Submerged arc welding system The specific requirements to calibration, verification and validation of a particular instrument should be derived from the required performance, which should be compatible with the permissible range as specified in the welding procedure specification (WPS) for the variable(s) in question. Moreover it should be noted that any types of instruments used for control of welding such as ammeters, voltmeters, thermocouples, stop-watches etc. are also used for non-welding purposes: the requirements on accuracy, when used for welding purposes, might be less stringent than for

36 Welding Fabrication Standards Page 34 other applications of the instruments. Normal ( standardised) procedures for calibration, verification and validation of the instruments may be too stringent and costly, if applied for welding purposes. Table 7 gives examples of the content of the standard, as relates to welding consumables. Designation Requirements Procedure Application of flux and filler metal, method, position, deposition rate, etc. Handling Temperature in storage cabinet/room Treatment prior to welding Instruments should be calibrated, verified or validated, as appropriate. Instruments used e.g. for control of storage conditions (temperature, humidity, etc.) should be calibrated, verified or validated. Instruments for temperature control, e.g. thermometers and other temperature indicators should be validated Instruments used for process control should be calibrated, verified or validated, as appropriate, depending on the nature of the treatment: drying, cleaning, etc. Requirements to measuring instruments such as weighing instruments, vernier callipers, rulers and straightedges, etc. are found in several EN, ISO and national standards. Stopwatches may be validated by comparison with any reasonably accurate clock. Requirements - 5 % for the instruments concerning humidity and + 5 C for thermometer. Requirement max. +/- 5 C. Appropriate standards for the procedure should be consulted. Table 7 EN ISO requirements applicable to welding consumables Concerning welding processes parameters, EN ISO states that the requirement for calibration, verification and validation of instruments to measure arc welding parameters should be related to the ratio between deposited weld metal and total cross sections (a high ratio corresponding to a cold process and a low ratio to a hot process): welding processes/power sources, which permit significant variations of such a ratio, necessitate calibration, verification or validation, whenever the heat input control is required (see table 8).

37 Welding Fabrication Standards Page 35 Designation Requirements Procedure Current (mean)* Arc voltage (mean) 3 Maximum width of the run or weaving amplitude when weaving is applied Travel speed Wire feed speed Weawing Frequency Dwell time of oscillation Torch, electrode and/or wire angle Electrical variables Ammeters should be validated. Voltmeters should be validated. Instruments used for measuring should be calibrated, verified or validated, as appropriate. For Mechanised welding Measurements by means of stopwatches and rulers. Appropriate steel rulers need not to be calibrated, verified or validated provided the rulers are not visibly damaged. Measurements by means of stopwatches and rulers. Appropriate steel rulers need not to be calibrated, verified or validated provided the rulers are not visibly damaged. Calibration, verification or validation not required, provided size (penetration) and position of weld can be determined by non-destructive examination. Calibration, verification or validation not required, provided size (penetration) and position of weld can be determined by non-destructive examination. Instruments used for measuring should be calibrated, verified or validated, as appropriate. See ENV Mean value of (rectified) current. See ENV Mean value of (rectified) tension. Requirements to measuring instruments such as vernier callipers, micrometer callipers, etc. are found in several EN, ISO and national standards. Stopwatches may be validated by comparison with any reasonably accurate clock or watch. See also ENV Stopwatches may be validated by comparison with any reasonably accurate clock or watch. See also ENV Requirements to measuring instruments such as vernier callipers, micrometer callipers, etc. are found in several EN, ISO and national standards. * The signal should be monitored continuously. The sampling time should be sufficient to give a reasonably stable reading. If tong-tests are used for measurement of current, the difference between mean value and RMS value measuring instruments has to be taken into consideration. Table 8 EN ISO requirements applicable to welding parameters 2.14 Identification and traceability Identification of pieces and parts, and the possibility to retrace their position during the manufacturing stages and when delivered to the customer is one of the most effective way to achieve quality of the product and to have feedback about its functionality.

38 Welding Fabrication Standards Page 36 However, it shall be noted that identification and traceability can imply expensive procedures and are therefore not required by the ISO 3834 standard. However, they can be required by standards, fabrication codes or by the customer himself. Whenever required, it shall be maintained during the manufacturing process, which means that for every piece or component it shall be possible to retrieve its history by marking the parts and controlling the relevant documentation. Documented systems to ensure identification and traceability of the welding operations shall include: - identification of production plans; - identification of routing cards; - identification of weld locations in construction; - identification of non-destructive testing procedures and personnel; - identification of welding consumable (e.g. designation, trade name, Manufacturer of consumables and batch or cast numbers); - identification and/or traceability of parent material (e.g. type, cast number); - identification of location of repairs; - identification of location of temporary attachments; - traceability for fully mechanised and automatic weld-equipment for specific welds; - traceability of welder and welding operators of specific welds; - traceability of welding procedure specification of specific welds Quality records Quality records shall be retained for a minimum period of five years in the absence of any other specified requirements. Quality records shall include, when applicable: - record of requirement/technical review; - material certificates; - welding consumable certificates; - welding procedure specifications; - equipment maintenance records; - welding procedure approval records (WPQR); - welder or welding operator qualification certificates; - production plan; - non-destructive testing personnel certificates; - heat treatment procedure specification and records; - non-destructive testing and destructive testing procedures and reports; - dimensional reports;

39 Welding Fabrication Standards Page 37 - records of repairs and non-conformance reports.

40 Welding Fabrication Standards Page 38 3 Comparison of ISO 3834 Requirements 3.1 Introduction ISO 3834 incorporates three quality levels that may be included in product standards, regulations and contracts or selected by a Manufacturer. The particular level selected will depend on the nature of the product to be manufactured, the conditions in which it will be used and the range of products manufactured. In this chapter some criteria for the choice of the appropriate level will be given, outlining the differences of every part (and level) of the standard. 3.2 Choice of the appropriate quality level Product standards that require compliance with ISO 3834 have emphasised two critical areas in the choice of quality level. On one hand has been the safety critical nature of the products whilst, on the other, there has been the inclusion of the type of loading (static, dynamic) in the product service environment. At first it should be noted that a Manufacturer compliant at a particular quality level is also compliant at a lower level. Thus, a Manufacturer demonstrating compliance to ISO is also compliant with ISO and ISO This may be relevant for a Manufacturer producing a range of products, some of which may require a comprehensive quality level while others only require a standard or elementary quality level. Such a Manufacture can apply the comprehensive quality level to all its products, or only apply the comprehensive quality level to those products where it is required, and apply the requirements at a lower level for the products for which this is more appropriate. Moreover, a Manufacturer applying ISO 3834 part 2 or part 3 can have some suppliers working on small assemblies or, in some cases, can need some extra welders properly qualified and controlled. In such situations the Manufacturer can require to his suppliers the application of a lower quality level. For example, this is the case of ISO 3834 part 4, that seems the easiest way to comply with the quality requirements for welders on loan. In general, the standard quality level should be suitable for the broad range of products that have a normal safety relevance and may experience dynamic loading. Such products would be

41 Welding Fabrication Standards Page 39 manufactured from conventional materials where the weldability is known and the precautions to be taken to ensure mechanical performance and defect avoidance are well documented. Products, which have a very limited safety component and are subjected to only moderate static loads with minor dynamic components, would normally only require the elementary quality level. Where the safety factors are significant and there are high static and dynamic loading and the materials are designed for high performance applications, the comprehensive quality level would be appropriate. Moreover, in some situations materials and loading seem to be pertinent to standard quality level, but the innovative nature of the design or the use of novel production processes can imply the choice of the comprehensive quality level in place of the standard level. It is not possible to allocate specific quality parts of ISO 3834, i.e., parts 2, 3 or 4, to particular types of products, because there can be different levels of complexity in the design, materials and fabrication processes in any product group. For example, in the case of bridges manufacturing, some bridges are highly complex in the design and are subject to significant dynamic loads. High strength steels may be employed and the product may be subjected to high levels of non destructive testing to meet tight fabrication defect acceptance levels. In contrast, foot bridges use conventional materials with little or no complexity in manufacture and are not subjected to high levels of dynamic loading. 3.3 Comparison chart In the following tables, a comparison chart of the quality requirement of the different parts of ISO 3834 is reported. Requirement ISO ISO ISO Requirements review Technical review Sub-contracting Necessary documentation is required Necessary -documentation may be required Necessary - documentation is not required Necessary - documentation is Necessary - documentation may be required required Treat like a Manufacturer for the specific subcontracted product, services and/or activities, however final responsibility for quality remains with the Manufacturer Table 9 Comparison chart on ISO 3834 requirement (to be continued )

42 Welding Fabrication Standards Page 40 Welders and welding operators Welding coordination personnel Equipment maintenance Production and testing equipment Production planning Welding procedure specifications Qualification of the welding procedures Batch testing Storage and handling of welding consumables Storage of parent material Post-weld heat treatment Inspection and testing before, during and after welding Non-conformance and corrective actions Calibration and validation of measuring, inspection and testing equipment Identification during process Necessary as applicable to provide, maintain and achieve product conformity, documented plans, and records are required Required Qualification is required Necessary as applicable to provide, maintain and achieve product conformity, records are recommended No specific requirement As necessary to assure equipment suitable and available, no specific requirements for records Suitable and available as required for preparation, process execution, testing, transport, lifting in combination with safety equipment and protective clothes Required documented plans and records are required If required Required Required Required documented plans records are recommended A procedure is required in accordance with supplier recommendations Confirmation that the requirements according to product standard or specifications are fulfilled Procedure, record and traceability of the record to the product are required Necessary Procedure and record are required No specific requirement Measures of control are implemented procedures for repair and/or rectification are required No specific requirement Appropriate welding technique required No specific requirement In accordance with supplier recommendations No specific requirement If required Measures of control are implemented Necessary If required No specific requirement If required No specific requirement Traceability If required No specific requirement Quality records If required Table 10 comparison chart on ISO 3834 requirement (continued) ISO Comprehensive quality level This part can be applied to constructions in which the failure of welds may lead to total product failure with successive significant financial consequences and a major risk of human injury. The product may be subject to pronounced dynamic loading in addition to high static loading.

43 Welding Fabrication Standards Page 41 Manufacture can be complex and the range of materials could include high performance metals as well as more standard materials such as structural boiler steels and aluminium alloys that require enhanced controls to avoid the occurrence of deleterious fabrication imperfections ISO Standard quality level This part can be applied to constructions in which failure of welds could impair the intended use of the construction and the operational unit in which it forms a part. The product would have a normal safety risk and the financial consequences would not be extreme. The manufacturing technique would be conventional without reliance on high performance materials and the production processes would be well established ISO Elementary quality level This part can be applied to constructions in which failure of welds would not fundamentally impair the intended use of the constructions. Additionally, failure would not be expected to have any adverse effects on the safety of people and would only have minor financial consequences. The materials used would be simple as well as the manufacturing technique.

44 Welding Fabrication Standards Page 42 4 European standard for manufacturing unfired pressure vessels 4.1 Introduction A possible definition of pressure vessel is housing and its direct attachments up to the coupling point connecting it to other equipment, designed and built to contain fluids under pressure. Many standards have been developed trough the years to consider the criteria for design, manufacturing and testing of these standards, mainly taking into consideration the hazard arising from possible failure of the vessels. As a consequence, all the European countries produced their own technical standards, having as a reference both the technical conditions (generally the same in every country) and the national industrial customs. After the development of the European Market, and in order to guarantee harmonisation of national legislation to abolish commercial and technical barriers, the European directive 97/23/CE on pressure equipment (PED) has been developed, applicable to all pressure equipment working with internal or external pressure higher than 0,5 bar. The application of the directive indirectly implied a standardisation work for the production of sets of standards, within the field of application of the directive and supporting its essential requirements, as a mean to demonstrate conformity. In this framework the technical committee CEN TC 54 Unfired pressure vessels prepared the standard EN 13445, harmonised to the 97/23/CE directive, relating to unfired pressure vessels subject to a maximum allowable pressure greater than 0,5 bar gauge and with maximum allowable temperatures for which creep effects need not to be considered, i.e. for maximum allowable temperatures for which the corresponding maximum calculation temperature renders a relevant proof strength smaller than the h creep rupture strength 8. 8 In the case of ferritic steels, for ferritic steels the temperature limit corresponds to calculation temperatures below approximately 380 C.

45 Welding Fabrication Standards Page 43 Figure 12 A polyethylene reactor made of Carbon steel This European Standard is not applicable to the following types of pressure equipment: - transportable pressure equipment; - items specifically designed for nuclear use, the failure of which may cause a release of radioactivity; - pressure equipment intended for the generation of steam or superheated water at temperatures higher than 110 C; - vessels of riveted construction; - vessels of lamellar cast iron or any other materials not included in EN or EN ; - multilayered, autorefragged or pre-stressed vessels; - pipelines and industrial piping. The standard is composed by 6 parts and a technical report; a brief description of which will be given in the next paragraphs. 4.2 EN : General rules This Part outlines the basic principles underpinning the standard. The Manufacturer is required to declare that the technical design specification and the supporting documentation are in compliance with the requirements of this standard.

46 Welding Fabrication Standards Page 44 Unforeseen factors may arise that require design modifications and/or manufacturing concessions. These need to be handled with the same rigour as the original design. 4.3 EN : Materials This Part deals with the general philosophy on materials, material grouping and low temperature behaviour in relation to Room Temperature performance range providing the general requirements for establishing technical delivery. It is limited to steel with sufficient ductility and excludes at present materials operating in the creep conditions. Furthermore it includes four annexes, which give further details as relate to: material grouping system, (according to CR ISO 15608:2000) with a list of all acceptable material grades based upon European base material standards; information on the requirements for the prevention of brittle fracture in the base material and the welds (two methods based upon a code of practice developed from fracture mechanics are included); information on technical delivery conditions for clad products; survey on European base material and component standards and their systematic nomenclature. 4.4 EN : Design This Part of the standard gives the rules to be used for design and calculation under internal and/or external pressure (as applicable) of pressure bearing components of Pressure Vessels, such as shells of various shapes, flat walls, flanges, heat exchanger tubesheets, including the calculation of reinforcement of openings. Rules are also given for components subject to local loads and to actions other than pressure. For all these components three different design approaches are considered: Design by Formulae (DBF), as appropriate formulae are given in order to find stresses, which have to be limited to safe values; these formulae are generally intended for predominantly non-cyclic loads, i.e. for a number of full pressure cycles not exceeding 500; Design by Analysis (DBA), which can be used either to evaluate component designs or loading situations for which a DBF method is not provided, or, more generally, as an alternative to DBF. Design by Formulae (DBF), based on limit analysis for certain components (such as flanges and tubesheets). Methods are also given where a fatigue evaluation is required, due to a number of load cycles being greater than 500. There are two alternative methods:

47 Welding Fabrication Standards Page 45 a simplified method based on DBF (valid only in case of pressure variations); a sophisticated method based on a detailed determination of total stresses using, for example, FEM or experimental methods, to be used also in the case of variable loads other than pressure. Figure 13 Chart in EN (Correction factor fm to take account of mean stress in unwelded material for N > 2x106 cycles) As already stated, for the time being, the scope of Part 3 is limited to steel components working at temperatures lower than the creep range of the specific material concerned. 4.5 EN : Fabrication The philosophy in Part 4 is based on existing good practice in current European Standards, as relates requirements for the manufacture of unfired pressure vessels and their parts, made of steels, including their connections to non-pressure parts. It specifies requirements for material traceability, manufacturing tolerances, welding requirements, production tests, forming requirements, heat treatment, repairs and finishing operations. Part 4 is not applicable for pressure vessels and parts made of spheroidal graphite cast iron for which separate and different requirements regarding manufacturing are given in EN Specific requirements for the Manufacturer According to the standard the following requirements shall be fulfilled by the Manufacturer: the organisation (and relevant responsibilities) for the control of manufacturing operations, which includes special processes such as welding, forming and heat treatment shall be clearly defined by the Manufacturer;

48 Welding Fabrication Standards Page 46 the manufacturing procedures such as welding, forming and heat treatment shall be adequate for the purpose and the pressure vessel meets the requirements of EN ; the manufacturing equipment shall be adequate for fabrication; the staff shall be adequate for the assigned tasks, in particular as far as welding co-ordination is concerned, the qualifications, tasks and responsibilities can be defined by the Manufacturer in accordance with ISO 14731/EN 719 in the job assignment; the quality requirements for welding defined in ISO :1994 shall be met as a minimum; material traceability to the original identification markings is required through appropriate methods; the batch numbers of welding consumables shall be recorded Requirements for subcontracting When welding, forming, heat treatment and non destructive testing work is performed by a Subcontractor, the following requirements shall be met: the Subcontractor shall give information on its manufacturing capabilities by an appropriate subcontracting form; the Manufacturer shall properly asses the Subcontractor, that he applies the requirements according to this part of the standard and according to the ISO ; the Manufacturer shall also either obtain copies of the welding procedure and welding operator qualification records or take other action to ensure that they comply with this part of the standard Specific requirements for welding activities In addition to what reported in ISO , welding of the component parts of a pressure vessel shall only be undertaken if the following conditions are satisfied: a welding procedure specification for every type of joint is held by the Manufacturer; the welding procedures selected by the Manufacturer are qualified for the field of application; the welders and welding operators are qualified for the work allocated to them and their approval is in the validity period; a record shall be maintained for each weld reporting the welder or welding operator that performed the joint. The type and design of the weld detail shall be considered taking into consideration: the method of manufacture; the service conditions (e.g. corrosion); the ability to carry out the necessary non-destructive testing required in accordance with EN

49 Welding Fabrication Standards Page 47 As for the approval of welding procedures, qualification by welding procedure test and pre production test are the only applicable methods, and specific requirements for the acceptance criteria for the tests are given to integrate the ISO This is required also in the case of repair by welding. In the case of welds other than pressure retaining welds directly attached to the pressure vessels (e.g. tray rings, support feet, etc.), welding procedure specifications may be acceptable by holding welding procedure approval records by to previous experience and /or standard welding procedure for arc welding. Whenever welders not in the employ of the Manufacturer are used, they shall be under the full technical control of the Manufacturer and work to the Manufacturer's requirements. Other requirements are given for filler metals, joint preparation methods, attachment supports and stiffeners and preheat Other requirements This part of the standards reports other requirements as concerns: materials manufacturing tolerances; production tests; forming of pressure parts; post weld heat treatment (PWHT); repair; finishing operations. 4.6 EN : Inspection and testing This Part covers all those inspection and testing activities associated with the verification of the pressure vessel for compliance with the standard, including design review by the Manufacturer and supporting technical documentation. Numerous inspection activities, in addition to the Non Destructive Testing (NDT) are described including document control, material traceability, joint preparation and welding. The requirements for testing are predominantly related to individually designed single vessels. However, procedures are provided for serially produced pressure vessels. The level of testing is driven by the selection of the vessel testing group. Basically, the testing group determines the level of NDT and the joint coefficient used in the design. There are four testing groups, which are designed to give the same safety by a combination of several factors.

50 Welding Fabrication Standards Page 48 Testing groups take into consideration manufacturing difficulties associated with different groups of steels, maximum permitted thickness, welding processes, service temperature range and the thickness by means of the joint coefficient of the governing joint (i.e. the full penetration butt joint that, as a result of the weld joint coefficient, governs the thickness of the component). Table 1 reports the testing groups for steel pressure vessels. The testing groups are numbered from 1 to 4 in decreasing levels of NDT. However, testing groups 1, 2 and 3 are subdivided into subgroups 1a, 1b, 2a, 2b, 3a, and 3b in order to reflect the better behaviour to crack sensitivity of easy to weld low carbon alloyed steels and Austenitic stainless steels. As for testing group 4, it shall be applicable only for: Group 2 fluids 9 ; Ps 20 bar; and Ps bar x L above 100 C; or Ps bar x L if temperature is equal or less than 100 C; higher pressure test; maximum number of full pressure cycle less than 500; lower level of nominal design stress (according to EN ). A single testing group is normally applied to the entire vessel. However, provided specific requirements are met, a combination of testing groups is permitted. Table 11 reports the main requirements for the testing groups. In terms of quality levels for the welding imperfections, the overall philosophy has been the general adoption of the following acceptance criteria: predominantly non-cyclic loaded vessels: ISO/DIS 5817:2000 quality level 'C' vessels subject to cyclic loading: ISO/DIS 5817:2000 quality level 'B' 9 According to the 97/23/Ce Directive, Group 2 fluids are non dangerous fluids (i.e. fluids other then explosive, extremely or highly flammable or flammable, toxic and very toxic, oxidizing)

51 Welding Fabrication Standards Page 49 Requirements Permitted materials (CR ISO 15608) Extent of Visual inspection Testing group and subgroup 1 a 1 b 2 a 2 b 3 a 3 b 4 1 to , 1.2, , 9.1, 9.2, 9.3, , 1.2, , 9.1, 9.2, , 1.2, , % to the maximum possible extent 100% on first item, 10% Extent of NDT for governing 100% after satisfactory 25% 10% 0% welded joints experience NDT of other welds A specific reference table is given in the standard (Table ) Joint coefficient (to be used for design) Maximum thickness for each material Welding process 1 1 0,85 0,7 No additional requirements due to testing No additional requirements due to testing gr. 9.1, 9.2: 30 mm gr, 9.3, 8.2* 10: 16 mm gr. 1.1, 8.1: 50 mm gr, 1.2: 16 mm Fully mechanised or automatic welding processes No additional requirements due to testing No additional requirements due to testing Service temperature range No additional requirements due to testing gr. 1.1: C gr. 8.1: C * 30 mm for group 8.2 material is allowed if delta ferrite containing welding consumables are used for depositing filling passes up to but not including the capping Table 11 Testing groups and relevant requirements 4.7 EN : specific requirements for pressure vessels and parts made of spheroidal graphite cast iron This Part specifies that the Manufacturer shall select a testing factor of 0,8 (visual inspection only) or 0,9 (NDT inspection) when a cast pressure vessel or cast part is designed for pressure up to 50 bar and a maximum temperature of 300 C. As concerns welding, no production or repair welding shall be carried out on spheroidal graphite cast iron parts. Concerning component design, the DBF method is generally followed considering appropriate formulae to limit stresses up to safe values. These formulae are generally intended for predominantly static loads, which means for a number of load cycles not exceeding in the case of spheroidal graphite cast iron. However, a method for design by experiment up to 6000 bar x l without calculation is given. Inspection and testing requirements are as in Part 5 except requirements for castings and test pressure. Interaction between good design and good workmanship is so important for cast vessels that special requirements are laid down in this Part.

52 Welding Fabrication Standards Page 50 Annex A is informative for the determination of burst pressure and wall thickness minimum requirements. 4.8 CR : Guidance on the use of conformity procedures This Technical Report gives guidance on the use of conformity assessment procedures for unfired pressure vessels as covered by Article 1, of the Pressure Equipment Directive (PED). The PED requires all pressure equipment falling within its scope to have its design and manufacture assessed for conformity in accordance with a series of conformity assessment procedures given in Article 10 of the Directive, and in particular according to its Annex III. Therefore the following information are given: classification of pressure vessels in hazard categories; conformity assessment procedures, as relates of the choice of the most appropriate procedure and the involvement of responsible authorities; management of subctontracted activities. Moreover, an useful summary of Inspection and testing activities and participation of the Responsible Authority in respect of P.E. D. conformity assessment modules is given in annex C, for informative scope only.

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54 Welding Fabrication Standards Page 52 5 European standard for manufacturing metallic industrial piping 5.1 Introduction In the framework of European Directive 97/23/CEE for pressure vessels (PED), also metallic industrial piping has to fulfil certain safety requirements, as relates to materials, design and calculation, fabrication and installation, inspection and testing. Figure 14 Metallic industrial piping in a plant. Such safety requirements depend on the hazard category, based on the type of fluid (defined as dangerous or non-dangerous) in combination with the internal volume (in this case the pipe diameter) and/or the maximum allowable pressure (PS) of the pipeline. This lead to the development of the EN 13480:2002 standard Metallic industrial piping, prepared by Technical Committee CEN/TC 267 "Industrial piping and pipelines", as specific standard harmonised do the European directive.

55 Welding Fabrication Standards Page 53 The standard applies to metallic piping above ground, ducted or buried, irrespective of pressure, and does not relate to: pipelines and their accessories; stream waterways such as penstocks, pressure tunnels, pressure shaft for hydro-electricinstallations and their related specific accessories; permanently fixed piping for ships, rockets, aircraft and mobile offshore units; items specifically designed for nuclear use, failure of which may cause an emission of radioactivity; well-control equipment used in the petroleum, gas or geothermal exploration and extraction industry and in underground storage, which is intended to contain and/or control well pressure, including the piping; piping of blast furnaces including the furnace cooling, hot blast recuperators, dust extractors and blast furnace exhaust gas scrubbers and direct reducing cupolas including the furnace cooling, gas converters and vacuum; furnaces and pans for melting, re-melting de-gassing and casting of steel and non ferrous metals; enclosures for high voltage electrical equipment such as switchgear, control gear and transformers; pressurised pipes for the containment of transmission systems such as for electrical power and telephone cables; internal piping of boilers and piping integral to pressure vessels. The standard is divided in six parts; part 1 is a general introduction of the standard, the other part define specific requirements, a detail of which will be given in the next paragraphs. 5.2 EN : Materials This Part specifies the requirements for materials (including metallic clad materials) for industrial piping and supports, not serviced in the creep range temperatures. It specifies the requirements for the selection, inspection, testing and marking of metallic materials for the fabrication of industrial piping. All the materials shall have sufficient ductility, as specific values for elongation are provided (e.g. 14% in the transverse direction and 16% in the longitudinal direction). Three different methods for the evaluation of the impact tests properties are provided, based on the following different approaches: technical requirements are developed from operating experience and applicable to all metallic materials, but limited to certain thicknesses for which experience exist;

56 Welding Fabrication Standards Page 54 technical requirements are developed from the principle of fracture mechanics and from operating experiences (only applicable to C, C-Mn and low alloy ferritic steels with a specified minimum yield strength of 460 N/mm); technical requirements are derived by the application of a fracture mechanics analysis (to be used only in agreement with the parties concerned). Maximum values for the Carbon, Sulphur and Silicon content are provided depending on the considered material (see Table 12). Material Maximum content of cast analisys %C %S %P Steel 0,23 0,025 0,035 Ferritic stainless steels 0,08 0,015 0,040 Martensitic stainless steels 0,06 0,015 0,040 Austenitic stainless steels 0,08 0,015 0,045 Austenitic stainless steels 0,10 0,015 0,035 Austenitic-ferritic stainless steels 0,030 0,015 0,035 Table 12 Maximum content of alloying element for steels Special provisions are also given as relates to lamellar tearing, design temperature above 20 C, prevention of brittle fracture, fasteners and lined piping. Figure 15 Stocking of pipes and fittings The marking of the products or delivery units shall ensure traceability between the product or delivery unit and the inspection documents. For European standardised materials, the marking

57 Welding Fabrication Standards Page 55 shall fulfil the requirements of the relevant standard; for materials not contained in an European standard the marking shall at least contain: the material specification (reference, material designation); the Manufacturer's name or mark; the stamp of the inspection representative, if applicable. For material supplied with specific inspection the marking shall include an identification, which permits the correlation between the product or delivery unit and the relevant inspection document. 5.3 EN : Design and calculations The calculation rules in this part apply for operating and testing conditions as well as preset, cold spring conditions, flushing and cleaning conditions. This part considers only elastic calculation methods, although some components might exhibit plastic behaviour. The design load shall be one or a combination of the following, at least: internal and/or external pressure; temperature; weight of piping and contents; climatic loads; dynamic effects of the fluid; movements of the ground and buildings; vibrations; earthquakes. In the specific case of welds other than circumferential, depending on the pressure, size, type of fluid and inspection extent, different values for the joint efficiency factor (Z) are identified. 5.4 EN : Fabrication ISO 3834 is not directly recalled by this standard, even if some requirements are similar to those of the standard General requirements for the Manufacturer The standard requires the presence of welding supervisors, having sufficient knowledge and experience in the field of welding and capable to give the welders clear and unambiguous working instructions.

58 Welding Fabrication Standards Page 56 As relates to welding materials, in addition to what is required in part 2 of the standard, the Manufacturer is requested to have filler metals and auxiliary materials with documentation according to EN 10204, test report 2.2. For identification and traceability reasons, all the welds shall be directly correlated to the welder that performed the joint, by the welder s symbol close to the weld itself or by corresponding details in the fabrication documents Requirements for the welding activities Welders and welding operator shall be qualified according to the relevant standard (EN and EN 1418) for the intended processes, material groups and range of sizes, and shall be in possession of a valid test certificate. Welding procedures specification shall be prepared in accordance to the relevant European standard - e.g. EN (EN 288-2) -, also reporting information on the Non Destructive Testing to be applied to the joint. Specifications shall be properly qualified by an appropriate method, depending on the piping class (defined on the base of diameter, pressure and type of fluid). In the case of the higher classes (class II and III) only qualification by welding procedure test or welding pre-production test are accepted, having as examining body a third party. Less stringent requirements are given for less critical classes. During electric arc welding, piping shall be earthed so that no welding currents flow through spring hangers, constant load hangers, snubbers, machines, valves, mechanical connections etc. This has to be accomplished in order to avoid both welding defects (e.g. due to arc blow) and to avoid damage or degradation in the mechanics of these components (e.g. ball bearings) due to high welding currents. Welding defects, which require repair shall be removed by grinding, chipping, gouging, flame, plasma or machining part or all of the weld. When using thermal processes, the pipe and weld material shall not be adversely affected. Prior to repair welding, the surface of all joints shall be examined by NDT to ensure they are free from cracks and other defects. Weld repairs shall be made using approved procedures and approved welding personal; A weld defect shall not be repaired more than twice with the same procedure. Any further repair shall be done in accordance with an approved, modified and documented procedure. All weld repairs shall be documented, by reporting the test reports that lead to the repair, (e.g. by attaching the films showing the defects, if available), and the repair procedures and the report for the newly carried on tests.

59 Welding Fabrication Standards Page EN : Inspection Figure 16 Welding of a 10 inches industrial piping This Part of the Standard specifies the requirements for inspection and testing of industrial piping to be performed on individual spools or piping systems, including supports, designed in accordance with part 3 and 6 (if applicable), and fabricated and installed in accordance with EN Type, extension and acceptance criteria for the testing are reported, depending on the piping class. The following inspection phases are identified: design validation; in-process inspection and testing (including welding process indirect control, as relates to welders, to welding procedures and to inspection during welding); non destructive testing of welds; final assessment; documentation to be maintained and delivered with the product. Table 13 reports the general requirements for the non destructive testing of welds, and the relevant acceptance criteria.

60 Welding Fabrication Standards Page 58 NDT Technique Method Acceptance criteria Visual Examination (VT) Radiographic Testing (RT) Ultrasonic Testing (UT) EN 970 Penetrant Testing (PT) EN Magnetic Particle Testing (MT) Refer to EN 5817 level B EN 12517:1998: EN 1435:1997, class B a b Acceptance level 2 and additional requirements EN 1714:1998, class B b EN 1712 :1997 c : Acceptance level 2 d EN 1290 EN 1289 :1998, Acceptance level 1 EN 1291 :1998, Acceptance level 1 NOTES: a However, the maximum area for single exposure shall correspond to the requirements of EN 1435:1997, class A. b Class A for material group 1.1, 1.2, 8.1 when piping class is I or II. c For the characterisation of indications EN 1713 may be used. d Acceptance level 3 for material group 1.1, 1.2, 8.1 when piping class is I or II. Table 13 Requirements for the non destructive testing of welds Figure 17 Ultrasonic testing of a pipe to pressure vessel connection 5.6 EN : Additional requirements for buried piping This Part of EN identifies specific requirements for industrial piping either totally buried or partly buried and partly run in sleeves or similar protection, running at an operating temperature up to 75 C. This part must be used in conjunction with the other six parts of EN

61 Welding Fabrication Standards Page 59 Figure 18 Lining of a buried pipeline in the nearby of a chemical plant Where buried piping subject to this standard connects to piping installed under other jurisdiction such as pipelines, the transition should be made at a closing element e.g. an isolating or regulating valve separating the two sections, that should be close to the boundary of the industrial site, but may be inside or outside the boundary. The standard reports therefore some additional requirements, as relates to: safety depth of installation; pipes marking and recording; design and calculation; installation (trenches, pipe laying and back filling); sleeves or casings; corrosion protection; examination and testing. As concerns welding activities, no specific requirements are given. 5.7 CR : Guidance on the use of conformity procedures This Technical Report gives guidance on the use of conformity assessment procedures for industrial piping and pipelines as covered by Article 1, of the Pressure Equipment Directive (PED). The PED requires all pressure equipment falling within its scope to have its design and manufacture assessed for conformity in accordance with a series of conformity assessment procedures given in Article 10 of the Directive, and in particular according to its Annex III. Therefore the following information are given:

62 Welding Fabrication Standards Page 60 classification of industrial piping vessels in hazard categories; conformity assessment procedures, as relates to the choice of the most appropriate procedure and the involvement of responsible authorities; management of subcontracted activities. Moreover, an useful Summary of Inspection and testing activities and participation of the Responsible Authority in respect of PED conformity assessment modules is given in annex C, for informative scope only.

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64 Welding Fabrication Standards Page 62 6 European standard for manufacturing simple unfired vessels to contain air or nitrogen. 6.1 Introduction Meeting a variety of safety objectives, Directive 87/404/EEC (amended by Directive 93/68/EEC) relating to simple pressure vessels came into force in the European Community on 1 July To ensure the disposal of existing stocks before the application date of this directive, a transition period was authorised until 1 July 1992, the date upon which the national regulations were abrogated in all Member States. This directive establishes the methods of inspection of these vessels, permitting them to be sold and commissioned in all Member States and benefit from free circulation. The Directive is applicable to series-produced simple pressure vessels introduced on the European market, regardless of origin, if subjected to an internal pressure greater than 0.5 bar, intended to contain air or nitrogen and not exposed to fire or flame. Other limitations also apply in relation to the materials used, the shape of the vessels, the maximum pressure, the product PS x V (working pressure PS, volume -V), and the minimum and maximum operating temperatures. The Directive also includes a list of exceptions. The Directive introduces the following concepts: a classification of simple pressure vessels according to the risk created by the combination of working pressure and volume, as expressed by PS x V; Essential safety requirements, compliance with which may be assumed further to the use of a harmonised European standard, or by submitting a prototype representative of the production under consideration, or a combination of both; Conformity assessment procedures by risk class, which give Manufacturers the option of selecting the most stringent class. 4. increased Manufacturer responsibility. The Manufacturer is now required to issue a declaration of conformity with the Directive for his equipment; The obligation on the part of the Manufacturer to supply the user with a user manual specifying the intended areas of use and the maintenance and installation conditions required for safety purposes.

65 Welding Fabrication Standards Page 63 Figure 19 Simple unfired pressure vessel containing Air (Left side) and Nitrogen (Right) In this framework, CEN TC 54 Simple pressure vessels produced a series of standard, namely the EN 286 Simple unfired pressure vessels made to contain air or nitrogen, made of 4 parts: Part 1: design, manufacture and testing; Part 2: Pressure vessels for air braking and auxiliary systems for motor-vehicles and their trailers; Part 3: Steel pressure vessels designed to contain compressed air for rail rolling stock Part 4: Aluminium pressure vessels designed to contain compressed air for railway rolling stock. In the following paragraph the requirements to be met during welding fabrication as relates to EN part 1 will be briefly described. 6.2 EN 286-1: requirements for welding manufacturing of simple unfired pressure vessels This Standard applies to the design and manufacture of simple unfired serially made pressure vessels with a single compartment manufactured by welding (even if some design can entail the use of bolts) having a simple geometry and have branches not lager in diameter than 0,5 of the diameter of the cylinder to which they are welded. The two following production procedures are considered:

66 Welding Fabrication Standards Page 64 a cylindrical part of circular cross section is closed by outwardly dished and/or flat ends which revolve around the same axis as the cylindrical part; two outwardly dished ends revolving around the same axis; Moreover, the field of application of the standard considers the following technical conditions are met: the vessel is subjected to an internal gauge pressure greater than 0,5 bar; the parts and assemblies contributing to the strength of the vessel under pressure are made either of non-alloy quality steel or of non-alloy aluminium or non-age hardening aluminium alloys; the maximum working pressure is 30 bar and the product of that pressure and the capacity of the vessel (PS x V) is greater than 50 bar litres and not exceeding bar litres; the minimum working temperature -50 C and maximum working temperature not higher than 300 C for steel and 100 C for aluminium or aluminium alloy vessels. It does not apply to vessels specifically designed for nuclear use, to vessels specifically intended for installation for the propulsion of ships and aircraft, or to fire extinguishers. Aspects of Quality Assurance are dealt with in various clauses and annexes of this Standard, even if there is no specific requirements as relates to the application of quality management standards. Therefore the fulfilment of EN ISO can only be suggested, and is not compulsory. As concerns specific requirements for welding activities, the following apply: there shall be no welding carried out on the pressurised parts of a vessel once the hydraulic test has been successfully completed; however reinforcing plates for supports and brackets are not considered to be pressurised parts; if a manual root on the reverse side is made prior to a second run made by an automatic process then the root weld shall be taken back to the sound metal to remove any inclusion i.e. slag, etc.; welding procedures shall be qualified by welding procedure test or previous satisfactory experience; the testing and qualification of welding procedures, welders and welding operators shall be carried out by an approved inspection body. The standards also reports specific testing criteria and relevant acceptance depending on the type of joint, stresses and materials considered in the design phase. 10 The EN ISO 3834 part 3 or part 4 seem to be enough significant to guarantee proper management of welding operations.

67 Welding Fabrication Standards Page 65 As relates to the equipment, it is required to the Manufacturer to calibrate the testing equipment and to maintain the relevant record.

68 Welding Fabrication Standards Page 66 7 European standard for steel pipelines and pipework for gas supply systems. 7.1 Introduction Gas supply systems are complex and the importance on safety of their construction and on their use has led to the development of very detailed codes of practice and operating manuals in the European countries. These detailed statements embrace recognised standards of gas engineering and the specific requirements imposed by the legal structures of each country. Some basic elements are common to the production and testing of weld joints for the installation and modification of onshore steel pipelines and pipework used in gas supply systems, including inservice pipelines, for all pressure ranges for the carriage of processed, non-toxic and noncorrosive natural gas as relates to materials, manufacturing techniques, location and design temperature. Figure 20 Pipeline welded in the northern areas. In this framework the CEN TC 234 supply systems produced the EN 12732:2000 gas supply systems welding steel pipework functional requirements with the purpose of identifying

69 Welding Fabrication Standards Page 67 commonly adopted requirements and to be intended as state of the art in the field of pipelines constructions for gas supply system. 7.2 EN 12732: scope and structure of the standard. This standard contains requirements for the production and testing of weld joints for the installation and modification of onshore steel pipelines and pipework used in gas supply systems, including inservice pipelines, for all pressure ranges for the carriage of processed, non-toxic and noncorrosive natural gas accordingly, where: the pipeline elements are made of unalloyed or low-alloyed carbon steel; the pipeline is not located within commercial or industrial premises as an integral part of the industrial process on those premises except for any pipelines and facilities supplying such premises ; the pipework is not located within household installations according to EN 1775:1998; the design temperature of the system is between -40 C and 120 C inclusive. Figure 21 - Welding of a Buried Pipeline The standard can be considered as divided in different parts, the first reporting general requirements applicable to all supply systems, the others giving specific indications for distribution systems, for transmission systems and for metering, regulating and compressor stations.

70 Welding Fabrication Standards Page EN 12732: Quality requirement categories The standard considers different categories of pipelines, depending on which the requirements to comply with are identified. Table 14 reports this assignment based on the materials used and on the operating pressure. Category A B C D Operating pressure Lower than 100 mbar 100 mbar up to 5 bar 5 bar up to 16 bar Higher than 16 bar Base material C and C-Mn steels, with R s 360Mpa* C and C-Mn steels, with R s 360Mpa* C and C-Mn steels, with R s 360Mpa* Low alloyed C, C-Mn, microalloyed and quenched and tempered steels** NOTES * Steels classified as Group 1 according to CR ISO and reported in EN ** Steels classified as Group 1 to 3 according CR ISO and reported in EN Table 14 Allocation to quality requirements categories Example of use Mains and service pipes in gas supply systems Mains and service pipes in gas supply systems, pipework in stations Pipeline including pipework in stations and gas distribution systems Pipeline including pipework in stations and gas distribution systems However, depending on particular conditions, such as materials used, line routing, design or welding techniques, higher or lower quality categories can be assigned in order to identify the more coherent quality requirements. 7.4 EN 12732: requirements on quality systems Depending on the quality requirement category, some specific requirements on the application of quality systems are identified by the standards. This involves the application of an appropriate quality level of EN ISO 3834, the qualification grade of the welding coordinator, the NDT personnel and the approval of welding procedures; giving the exact interpretation and integrating the clauses of EN ISO Table 15 reports a summary on the recommended quality requirements to be fulfilled.

71 Welding Fabrication Standards Page 69 Quality requirement Quality category A B C D Quality system according to EN ISO EN ISO (Comprehensive) OPT. OPT. REC. REC. - EN ISO (Standard) OPT. OPT. REC. REC. - EN ISO 3834 (elementary) REC. REC. - - Welding co-ordination personnel - Welding engineer OPT. OPT. OPT. REC. - Welding technologist OPT. OPT. REC. - - Welding Specialist OPT. REC. REC. - - Foreman with several years of experience REC. REC. - - Qualification of welders According to EN in on-site conditions REC. REC. REC. REC. Welding procedures qualification According to EN 288-2* REC. REC. REC. REC. Applicable method of qualification of welding procedure: - Welding procedure test OPT. OPT. REC. REC. - Use of approved welding consumables REC. REC Previous experience REC Standard welding procedures OPT. OPT. REC. REC. - pre-production welding tests OPT. REC. REC. - - welding procedure test for site welding OPT. OPT. OPT. REC. Key: REC. Recommended OPT. Optional - not required Notes: * This standard refers to the old Qualification standards; EN has been replaced by EN Table 15 Recommended quality requirements according to EN Particular attention should be devoted to the qualification of welders for the installation of buried pipelines, that should carry on approval test in on site conditions, by examination conducted in an area, which simulates a pipe trench of the following dimensions: maximum length: 1,5 m; maximum spacing between pipe wall and trench bottom: 0,4 m; maximum spacing between pipe wall and trench wall: 0,5 m. Welders certificate shall clearly indicate, by reference to this standard, that the welders qualification test has been performed under the conditions mentioned above. 7.5 EN 12732: Inspection of welded joints and acceptance criteria Weld quality shall be ensured by inspection of the welds using destructive tests and/or nondestructive examination. The results of these tests shall be documented.

72 Welding Fabrication Standards Page 70 Non-destructive examination shall be carried out in accordance with approved procedures and destructive testing acceptance criteria shall be the same as for the original welding procedure. The minimum extent of non-destructive examination depends on the quality requirement category and the type/position of the weld joint, as reported in table 16. Cate gory Type/position of the weld VT (by welding supervisor Volumetric inspection NDT (RT/UT)* Superficial NDT inspection Circumferential welds, branches, nozzles and fillet welds; longitudinal seams ** ** / *** - A Unconcealed pipe spans; pipelines on bridges, pipeline sections crossing railways, navigable waterways or 100% **** - landing strips/runways Circumferential welds ** ** - Branches, nozzles and fillet welds ** ** B Longitudinal seams 100% 10% - Unconcealed pipe spans; pipelines on bridges, pipeline sections crossing railways, major roads and motorways, 100% **** - navigable waterways or landing strips/runways Circumferential welds 20% 10% - Branches, nozzles, fillet welds 100% - 10% Longitudinal seams 100% 100% - C Weld joints not included in the pressure test 100% 100% - Unconcealed pipe spans; pipelines on bridges, pipeline sections crossing railways, major roads and motorways, 100% 100% - waterways or landing strips/runways Circumferential welds 100% 20% - Branches, nozzles, fillet welds 100% ******* 20% ***** Longitudinal seams 100% 100% - D Weld joints not included in the pressure test 100% 100%***** - If pipelines/units are laid or installed in built-up areas 100% 100% - Unconcealed pipe spans; pipelines on bridges, pipeline sections crossing railways, major roads and motorways, waterways or landing strips/runways 100% 100% - NOTES * The proportion of both techniques shall be agreed. ** Representative random sample on the basis of the total number of weld joints made by a welder during the course of one year. *** One destructive test of field weld per year by means of tensile and/or bending test for welders qualified only for gas welding (process 311) or only for fillet welds. **** The pipeline operator shall specify the extent of non-destructive examination taking into account the design conditions, for example: - external loads in addition to internal pressure; - supports; - expansion due to temperature. ***** Where welds with incomplete penetration are used, the pipeline operator can require 100 %. ***** Seams shall be tested 100 % by two different inspection techniques. ******* For branches and nozzles, consideration should be given by the pipeline operator to these methods. Table 16 Minimum extent of NDT according to EN Where less than 100 % non-destructive examination has to be performed, the pipeline operator shall select which welds are to be tested. Whenever the quality of the weld joint does not meet the requirements, further welds shall be examined to determine the extent of the problem (except

73 Welding Fabrication Standards Page 71 when otherwise agreed, two further welds shall be inspected for each rejected weld) and the cause of the fault shall be eliminated. The definition of acceptance criteria is under the responsibility of the Manufacturer, depending on the design, the quality requirement category and the inspection level. Useful information on the applicable NDT techniques for the inspection of the pipelines are given in Appendixes C to F. As example, figure 22 reports the calibration block suggested for the application of Ultrasonic Testing. Figure 22 Calibration block with rectangular grooves and edge (dimensions in mm)

74 Welding Fabrication Standards Page 72 8 European standards for the fabrication of steel and aluminium structures 8.1 Introduction Many standards have been developed trough the years to consider the criteria for design, manufacturing and testing of steel structures; as a consequence all the European countries produced their own technical standards, having as a reference both the technical conditions (generally the same in every country) and the national industrial customs. In the same framework as pressure vessel one, after the development of the European Market, and in order to guarantee harmonization of national legislation to abolish commercial and technical barriers, the European directive 89/106/CE on construction products (CPD) has been developed. Figure 23 Steel structure manufacturing (covering of a swimming pool)

75 Welding Fabrication Standards Page 73 For the purposes of this Directive, construction product means any product which is produced for incorporation in a permanent manner in construction works, including both buildings and civil engineering works. Construction products are hereinafter referred to as 'products'; construction works including both buildings and civil engineering works are hereinafter referred to as Works. Therefore the directive does not directly refer to the whole product, but to all those single elements (e.g. beams, connections, etc), that assembled realize the final work. Member States shall presume that products are fit for use if they enable works in which they are employed, provided the latter are properly designed and built, to satisfy the essential requirements referred to in Article 3 of the directive. The application of the directive indirectly implied a standardisation work for the production of sets of standards, within the field of application of the directive and supporting its essential requirements, as a mean to demonstrate conformity. In this framework the technical committee CEN TC 135 Steel structure fabrication is now preparing the standard (the name will be EN 1090) harmonized to the 89/106/CE directive. This standard is made of 3 parts: - Part 1: Steel and aluminium structural components - General delivery conditions - Part 2: Technical requirements for the execution of steel structures - Part 3: Technical requirements for the execution of aluminium structures 8.2 EN : Steel and aluminium structural components - General delivery conditions This European Standard specifies general technical delivery conditions in terms of performance characteristics for structural steel and aluminium components placed on the market as construction products. The components may be used directly or for inclusion in construction works or as structural components in the form of kits. The Standard also specifies requirements for the evaluation of conformity to the specified performance characteristics and for the test methods to be used Requirements for the design of structures. Structural characteristics of a component covered in this Standard refer to its load bearing capacity, fatigue strength and resistance to fire Those structural characteristic shall refer to National Determined Parameters (referred as NPD in the standard), that are parameters specified in the National Annex to the relevant Eurocode, defined by the member states

76 Welding Fabrication Standards Page 74 The load bearing capacity for a component shall refer to the specified actions and combination of actions, referring to situations for which the loads are predominantly static such that the influence of repetitive loads need not be considered. The fatigue strength for steel components shall be determined in accordance with EN 1993 (Eurocode 3) for steel structures and with EN 1999 (Eurocode 9) for aluminium components and are usually expressed by reference to S-N diagrams. The resistance to fire shall be determined according to the relevant part of Eurocodes. In conclusion, the standards does not give specific guidance for the design, as the structural characteristics shall be determined in accordance the relevant Eurocodes, as follows: - EN 1990 (Eurocode 0) - Basis of structural design; - EN 1991 (Eurocode 1)- Actions on structures; - EN 1993 (Eurocode 3)- Design of steel structures, for steel components; - EN 1994 (Eurocode 4)- Design of composite structures of steel and concrete, for the steel parts; EN 1999 (Eurocode 9)- Design of aluminium structures, for aluminium components. Figure 24 Workshop for bridge manufacturing.

77 Welding Fabrication Standards Page EN : Technical requirements for the execution of steel structures This European Standard specifies general requirements for execution of structural steelwork. The pursued objective during the realization of a project of structure is to control risks connected to it by controlling possible execution defects. Nature and extend of risks being specific in every structure according to its purpose and complexity, execution classes are specified in this European Standard, to which correspond execution requirements with different severity levels. In accordance with EN 1990:2001, which defines consequence classes in its annex B for the purpose of reliability differentiation, three different consequence classes for structural elements are distributed in three levels noted as CC1, CC2 and CC3. The consequence classes of the elements of a structure may be indicated on the basis of indications given in table 17. Consequences Class CC3 CC2 CC1 Description High consequence for loss of human life, or economic, social or environmental consequences very great Medium consequence for loss of human life, economic, social or environmental consequences considerable Low consequence for loss of human life, and economic, social or environmental consequences small or negligible Examples of buildings and civil engineering works Grandstands, public buildings where consequences of failure are high (e.g. a concert hall) Residential and office buildings, public buildings where consequences of failure are medium (e.g. an office building) Agricultural buildings where people do not normally enter (e.g. storage buildings), greenhouses Table 17 Definition of consequences classes It should be noted that a same work, or part of it, can contain elements with different consequence classes. Moreover, in the definition of requirements for the product (and for the Manufacturer) also the use condition of the component shall be considered (execution and use); as a consequence the standard defines the execution categories, based on the table 18.

78 Welding Fabrication Standards Page 76 Execution and use categories Consequences Class CC1 CC2 CC3 E1 Elements for which fatigue assessment is necessary Elements not concerned by E1 but by some particular conditions, as following: - Temperature of service of elements < -20 C, - Welded elements made of S355 steel grade with thickness > 25 mm - Welded elements made of S355 M and ML steel grade with thickness > 50 mm E2 - Main elements assembled by welding on construction site, Elements with hot forming manufacturing or receiving thermic treatment, - Elements of CHS lattice girder requiring end profile cuts, - Elements of crane way and corresponding skeleton, - Elements of structure with more than five floors, - Elements with full contact bearing surfaces. E3 Elements neither C1 nor C Table 18 Definition of execution classes Specific requirements for welding Manufacturers Welding shall be undertaken in accordance with the requirements of the relevant part of EN 729 "Quality requirements for welding Fusion welding of metallic materials" or EN ISO "Quality requirements for welding - Resistance welding of metallic materials" as applicable. When using EN ISO or EN ISO qualification procedures, the following conditions are required: a) where impact tests are required, they shall be carried out at the lowest temperature for which the standard of the steel grade requires impact properties; b) for steels according to EN (Quenched and tempered steels), one specimen for microexamination is required. Photographs of weld metal, fusion line zone and HAZ shall be recorded; c) for fillet welds on steel grades higher than S355 subject to tensile load, tests shall be completed by an additional cruciform tensile test performed in accordance with pren ISO 9018; d) when welding on shop primers, tests shall be carried out on the maximum (nominal + tolerance) accepted layer thickness. e) if any welding process qualified in accordance with EN ISO has not been used by the constructor for a certain period, following requirements apply: - for steel grades up to S355, and if the procedure has not been used for a period of more than three years, a macro specimen taken from a production trial shall be inspected for acceptability;

79 Welding Fabrication Standards Page 77 - for steel grades above S355, and if the procedure has not been used for a period between one and three years, a production welding test, where shape and dimensions are according to the requirements of EN ISO , shall be carried out (examination and testing shall include visual inspection, radiographic or ultrasonic inspection, surface crack detection, macro-examination and hardness test); - for steel grades above S355, and if the procedure has not been used for a period of more than three years, new welding procedure tests shall be carried out. Depending on the execution classes, different requirements apply, according to table 19. Requirements Quality requirements for fusion welding Execution Class EN ISO EN ISO EN ISO Welding procedures specification EN ISO Qualification of welding procedures by: Required Not required - welding procedures test* (EN ISO ) - pre production test* (EN ISO 15613) - use of tested welding consumables (EN ISO 15610) - previous welding experience (EN ISO 15611) - standard welding procedure (EN ISO 15612) Welders and welding operators qualification Base materials inspection documents (ref. EN 10204) Welding Coordinator Recommended Recommended -- Recommended Recommended -- NOT recommended Recommended -- NOT recommended Recommended -- NOT recommended Recommended -- Required according to pren ISO (EN 287-1) - welders and with EN 1418** - welding operators. type 3.1 type 2.2 type 2.1 Required, with comprehensive technical knowledge Required: all levels are accepted Not required * Time validity of the certificates and qualification tests are subject to special rules, specified in the following. ** For welding hollow section lattice structures, welders shall be qualified by a single-side welding test carried out on a branch connection Table 19 Requirements for welding according to the execution classes For execution classes 1 and 2, if welding with deep penetration processes or two pass welding from both sides without back grinding is used, an appropriate macro or fracture specimen in accordance with EN 1321 or EN 1320 respectively, shall be tested at intervals not exceeding six months, in addition to the welding procedure test. Welding procedure specifications for joints in hollow section lattice structures shall define the start and stop zones, and method to be used in order to cope with situation where the welds change from fillet to butt aroundjoint.

80 Welding Fabrication Standards Page Requirements for inspection and testing and acceptance criteria Inspection and testing follow the general rules reported in EN ISO 3834; moreover different criteria are considered for extension and timing, depending on the following parameters: - place of execution (Worksop pre-fabrication on site production); - type of weld (transverse welds, longitudinal welds, strength welds, attachment welds); - joint utilisation factor - k (defined as k = σ / σ e, relationship ULS stress / yield stress in the weld); - execution class (E.C., already previously defined). Visual inspection has to be performed for the overall length of the welds, independently from the above cited factors; moreover for execution classes 1 to 3 additional testing is required, according to the following table. It has to be noted that there is not any specific guidance on the testing method, as general criteria reported in EN for the field of application of NDT testing apply. Requirements, depending on the joint type Independently from the joint type, general extension for NDT activities Transverse butt welds subjected to tensile stress Transverse butt welds subjected to compression stress Transverse fillet welds at end of lap joints and at connection gussets. Longitudinal welds and welds to stiffeners. Attachment welds (e.g. for fixing purlins, side rails, etc.) Execution Class - Execution Class On site Workshop 1 and and 2 3 The first 5 joints of each same type* shall be tested according to the following values. All joints shall be tested according to the following values The first 5 joints of each same type* shall be tested according to following values. The extent of additional NDT is reduced to 50 % (minimum of 10%) 0.8 k 100 % 50 % 100 % 100 % 0.3 < k< % 20% 100% 50% k % 5% 20% 10% 10 % 5 % 20 % 10 % 20 % 10 % 20 % 10 % 10 %, 5 % 20 % 10 % * Same basic dimensions, material grades, weld geometry and welded to the same procedures. Table 20 Additional Requirements for NDT extension for Execution Classes 1 to 3. Unless otherwise specified, the acceptance criteria for welds shall be as follows, with reference to EN ISO 5817: Any special requirements on weld geometry and profile shall be taken into account. Execution class Acceptance criteria 4 EN ISO 5817 Quality level D 3 EN ISO 5817 Quality level C 2 EN ISO 5817 Quality level B 5%

81 Welding Fabrication Standards Page 79 1 EN ISO 5817 Quality level B, with the following additional requirements Type of defect Acceptance undercut (5011) not permitted excess weld metal (502) 2 mm incorrect toe (505) 165 internal pores (201) 1 mm solid inclusions (300) not permitted linear misalignment (507) < 0,05t Table 21 Acceptance criteria depending on execution classes. 8.4 EN : Technical requirements for the execution of aluminium structures 12 This European Standard specifies general requirements for execution of aluminium structures produced from rolled, welded, casted, forged, drawn and extruded products, and covers components made with material thickness not less than 0.6 mm, and for welded components, not less than 1.5 mm. Moreover it is applicable to fixed and temporary aluminium structures. Figure 25 - Part of a lattice aluminium structure As for the steel structures, different execution classes are defined, taking into consideration consequence classes (already defined in table 1, according to EN 1990) and structural classes (dependent on the orientation and intensity of the static and cyclic stressing at a cross section of a member or in a joint, according to EN 1999 Eurocode 9). Next table reports criteria for the definition of execution classes. Consequence Structural class classes Significant fatigue Standard Reduced static CC1 IV III III CC2 III III II CC3 III II I (II)* * Execution class I may be selected for structures or part of a structure 12 Up to the date of publishing, this part of EN seems to be at a very early stage; consequently, many concepts reported in this paragraph may be subject to significant changes, even if the general concept for this standard should be definitively stated.

82 Welding Fabrication Standards Page 80 where the risk of loss of human life is nil and the consequences of personal injury, economic loss or pollution is negligible. Table 22 Execution classes for aluminium structures. Welding shall be undertaken in accordance with the requirements of the relevant part of EN ISO 3834 (EN 729) "Quality requirements for welding Fusion welding of metallic materials" or EN ISO "Quality requirements for welding - Resistance welding of metallic materials" as applicable; in particular different requirements apply depending on the execution classes, following same rules as for steel (see table 22). As for the extent of non destructive testing and for the acceptance criteria, very detailed tables are reported in the standard, where requirements are given on the basis of execution class, testing method, joint type and geometry, joint orientation in respect of the main member of the structure.

83 Welding Fabrication Standards Page 81

84 Welding Fabrication Standards Page 82 9 Project European standards for the fabrication of railway vehicles and components 9.1 Introduction As already stated in other Chapters of this book, over the last few years, standardisation at international level has become more and more product-oriented, considering not only the technical requirements of the product itself, but also specific requirements to be fulfilled by the Manufacturer, in its fabrication process. Figure 26 Manufacturing of a boogie for railway application

85 Welding Fabrication Standards Page 83 Therefore CEN TC 256 WG 31 has started working on the development of a new European standard for design, fabrication and maintenance of railway vehicles and components, which has been developed as pren in This document has been produced considering the commonly agreed best practice fabrication criteria, as the main Customers (the national railway Companies) and Manufacturers were strongly represented in this standardisation phase. The standard will be composed by several parts, as follows: - pren : general guidelines and definitions; - pren : requirements for the Manufacturer; - pren : design requirements; - pren : production requirements; - pren : the guidelines of inspection, testing and documentation. In the next paragraph only the requirements for the welding Manufacturer (as relates to part 2) will be described. 9.2 pren Requirements for the Manufacturer Differently from other standards, this standard requires that the Manufacturer complies with specific technical requirements, in order to demonstrate its capability to fabricate railway vehicles and components. Such a capability must be evaluated and assessed by an authorised body ( recognition of a welding Manufacturer ). The standards defines different Manufacturer certification levels, taking into consideration the type of product manufactured and the safety relevance, intended as complexity of the design and the consequence of failure. Precise criteria for the definition of the safety relevance are still under discussion. Next table shortly summarizes the criteria for the identification of those levels. Level Definition New build, conversion and repair of rail vehicles and relevant components with high safety 1 relevance 2 New production of parts of railway vehicles with medium safety relevance 3 New production of parts of railway vehicles with low safety relevance 4 Design and/or assembly of railway vehicles and relevant components with High, medium or low safety relevance, when welding activities are sub-contracted and not performed. Table 23 Identification of the level of the Manufacturer of railway vehicles and components 13 Because of the early stage of development of this standard, some of the information contained can be subject to changes in the future. However the general approach to the standard should not be changed in the future.

86 Welding Fabrication Standards Page 84 Depending on such levels, different requirements are considered for the Manufacturer to comply with. As relates to the welding coordinator, depending on the level of the Manufacturer and on the number and dimension of the workshops, one or more welding coordinators are required, having different level of qualification, according to three grades, defined as follows. - Welding Coordinator - Grade 1: a Welding coordinator with comprehensive technical knowledge as specified in EN 719 (EWE, EWT with proof of comprehensive technical knowledge or suitable qualification with comprehensive technical knowledge as specified in EN 719 and evidence of experience over many years). - Welding Coordinator - Grade 2: a Welding Coordinator with specific technical knowledge as specified in EN 719 (EWT, EWS with proof of specific technical knowledge or suitable qualification with specific technical knowledge as specified in EN 719 and evidence of experience over many years). - Welding Coordinator - Grade 3: Welding Coordinator with basic technical knowledge as specified in EN 719 (EWS, EWP with proof of basic technical knowledge or suitable qualification with basic technical knowledge as specified in EN 719 and evidence of experience over many years). As relates to the welding inspection, the assessment of the weld seam tests is done basically under the responsibility of the welding coordinator of the Manufacturer. Alternatively the assessments can be done by an International Welding Inspector at the Comprehensive level, properly qualified according to IIW guidelines. However, It is possible that the welders or welding operators are responsible for checking the weld seams themselves; in this case the welders or welding operators shall be instructed by the responsible welding coordinator for the Manufacturer and a corresponding test instruction shall be available. Table 24 shortly summarises the requirements for the Manufacturer, as decided up to time.

87 Welding Fabrication Standards Page 85 Requirements for the welding Manufacturer Recognition of the Manufacturer Certification Levels Level 1 Level 2 Level 3 Level 4 Necessary Necessary Not necessary Necessary Quality requirements EN ISO EN ISO EN ISO EN ISO Welding Coordinator Grade 1 Grade 2 or 3 no requirement Deputy of the Welding Coordinator Deputy: Grade 1* Further Deputies: Grade 2 or 3** Grade 1, 2 or 3 depending on the relevant welding work Deputy: Grade 3 no requirement no requirement Welders Qualified according to EN 287 not necessary Welding operators Qualified according to EN 1418 not necessary Welding quality tests Responsible welding coordinator or IWI-C not necessary NDT personnel Qualification according to EN 473 not necessary WPS According to EN ISO 15609; not necessary Qualification of welding procedures ISO to -13 ISO ISO ISO ISO not necessary * Equally empowered deputy (Grade 1). Not necessary for small welding Manufacturers (Welding Manufacturers with small welding production and one welding shop). * For welding Manufacturers with several welding shops a further deputy, Grade 3, is necessary for each welding shop. Table 24 Requirements for the Manufacturer

88 Welding Fabrication Standards Page Normative references In the following table the list of the European (EN) standards, sorted by number is reported. Standard Title EN SPECIFICATION AND APPROVAL OF WELDING PROCEDURES FOR METALLIC MATERIALS - PART 4: WELDING PROCEDURE TESTS FOR THE ARC WELDING OF ALUMINIUM AND ITS ALLOYS EN 288-4/A1 SPECIFICATION AND APPROVAL OF WELDING PROCEDURES FOR METALLIC MATERIALS - PART 4: WELDING PROCEDURE TESTS FOR THE ARC WELDING OF ALUMINIUM AND ITS ALLOYS EN SPECIFICATION AND APPROVAL OF WELDING PROCEDURES FOR METALLIC MATERIALS - PART 7: APPROVAL BY A STANDARD WELDING PROCEDURE FOR ARC WELDING EN SPECIFICATION AND APPROVAL OF WELDING PROCEDURES FOR METALLIC MATERIALS - PART 8: APPROVAL BY A PRE-PRODUCTION WELDING TEST EN SPECIFICATION AND APPROVAL OF WELDING PROCEDURES FOR METALLIC MATERIALS-PART 9: WELDING PROCEDURE TESTS FOR PIPELINE WELDING ON LAND AND OFFSHORE SITE BUTT WELDING ON TRANSMISSION PIPELINES EN 439 WELDING CONSUMABLES - SHIELDING GASES FOR ARC WELDING AND CUTTING EN 440 WELDING CONSUMABLES - WIRE ELECTRODES AND DEPOSITS FOR GAS SHIELDED METAL ARC WELDING OF NON ALLOY AND FINE GRAIN STEELS - CLASSIFICATION EN 499 WELDING CONSUMABLES - COVERED ELECTRODES FOR MANUAL METAL ARC WELDING OF NON ALLOY AND FINE GRAIN STEELS - CLASSIFICATION EN ISO 544 WELDING CONSUMABLES - TECHNICAL DELIVERY CONDITIONS FOR WELDING FILLER MATERIALS - TYPE OF PRODUCT, DIMENSIONS, TOLERANCES AND MARKINGS EN 559 GAS WELDING EQUIPMENT - RUBBER HOSES FOR WELDING, CUTTING AND ALLIED PROCESSES EN 560 GAS WELDING EQUIPMENT - HOSE CONNECTIONS FOR EQUIPMENT FOR WELDING,AND ALLIED PROCESSES EN 561 GAS WELDING EQUIPMENT - QUICK-ACTION COUPLING WITH SHUT-OFFVALVES FOR WELDING, CUTTING AND ALLIED PROCESSES EN 562 GAS WELDING EQUIPMENT - PRESSURE GAUGES USED IN WELDING, CUTTING AND ALLIED PROCESSES EN 719 WELDING COORDINATION - TASKS AND RESPONSABILITIES EN QUALITY REQUIREMENTS FOR WELDING - FUSION WELDING OF METALLIC MATERIALS - PART 1: GUIDELINES FOR SELECTION AND USE EN QUALITY REQUIREMENTS FOR WELDING - FUSION WELDING OF METALLIC MATERIALS - PART 2: COMPREHENSIVE QUALITY REQUIREMENTS EN QUALITY REQUIREMENTS FOR WELDING - FUSION WELDING OF METALLIC MATERIALS - PART 3: STANDARD QUALITY REQUIREMENTS EN QUALITY REQUIREMENTS FOR WELDING - FUSION WELDING OF METALLIC MATERIALS - PART 4: ELEMENTARY QUALITY REQUIREMENTS EN GAS WELDING EQUIPMENT - SAFETY DEVICES-PART 1: INCORPORATING A FLAME (FLASHBACK) ARRESTOR EN GAS WELDING EQUIPMENT - SAFETY DEVICES-PART 2: NOT INCORPORATING A FLAME (FLASHBACK) ARRESTOR EN 731 GAS WELDING EQUIPMENT - AIR ASPIRATED HAND BLOWPIPES - SPECIFICATIONS AND TESTS EN 756 WELDING CONSUMABLES - SOLID WIRES, SOLID WIRE-FLUX AND TUBULAR CORED ELECTRODE-FLUX COMBINATIONS FOR SUBMERGED ARC WELDING OF NON ALLOY AND FINE GRAIN STEELS - CLASSIFICATION EN 757 WELDING CONSUMABLES - COVERED ELECTRODES FOR MANUAL METAL ARC WELDING OF HIGH STRENGHT STEELS - CLASSIFICATION EN 758 WELDING CONSUMABLES - TUBULAR CORED ELECTRODES FOR METAL ARC WELDING WITH AND WITHOUT GAS SHIELD OF NON ALLOY AND FINE GRAIN STEELS - CLASSIFICATION EN 760 WELDING CONSUMABLES - FLUXES FOR SUBMERGED ARC WELDING - CLASSIFICATION EN 874 GAS WELDING EQUIPMENT-OXYGEN/FUEL GAS BLOWIPES (CUTTING MACHINE TYPE) OF CYLINDRICAL BARREL-TYPE OF CONSTRUCTION, GENERAL SPECIFICATION, TEST METHODS EN 875 DESTRUCTIVE TEST ON WELDS IN METALLIC MATERIALS-IMPACT TEST-TEST SPECIMEN LOCATION,NOTCH ORIENTATION AND EXAMINATION EN 876 DESTRUCTIVE TEST ON WELDS IN METALLIC MATERIALS-LONGITUDINAL TENSILE TEST ON WELD METAL IN

89 Welding Fabrication Standards Page 87 FUSION WELDED JOINTS EN 895 DESTRUCTIVE TEST ON WELDS IN METALLIC MATERIALS-TRANSVERSE TENSILE TEST EN 910 DESTRUCTIVE TESTS ON WELDS IN METALLIC MATERIALS - BEND TESTS EN 970 NON DESTRUCTIVE EXAMINATION OF FUSION WELDS - VISUAL EXAMINATION EN WELDING - RECOMMENDATIONS FOR WELDING OF METALLIC MATERIALS - PART 1: GENERAL GUIDANCE FOR ARC WELDING EN /A1 WELDING - RECOMMENDATIONS FOR WELDING OF METALLIC MATERIALS - PART 1: GENERAL GUIDANCE FOR ARC WELDING EN /A2 WELDING - RECOMMENDATIONS FOR WELDING OF METALLIC MATERIALS - PART 1: GENERAL GUIDANCE FOR ARC WELDING EN WELDING-RECOMMENDATIONS FOR WELDING OF METALLIC MATERIALS - PART 2: ARC WELDING OF FERRITIC STEELS. EN /A1 WELDING - RECOMMENDATIONS FOR WELDING OF METALLIC MATERIALS - PART 2: ARC WELDING OF FERRITIC STEELS EN WELDING-RECOMMENDATIONS FOR WELDING OF METALLIC MATERIALS - PART 3: ARC WELDING OF STAINLESS STEELS EN /A1 WELDING - RECOMMENDATIONS FOR WELDING OF METALLIC MATERIALS- PART 3: ARC WELDING OF STAINLESS STEELS EN WELDING-RECOMMENDATIONS FOR WELDING OF METALLIC MATERIALS - PART 4: ARC WELDING OF ALUMINIUM AND ALUMINIUM ALLOYS EN /A1 WELDING - RECOMMENDATIONS FOR WELDING OF METALLIC MATERIALS- PART 4: ARC WELDING OF ALUMINIUM AND ALUMINIUM ALLOYS EN WELDING-RECOMMENDATIONS FOR WELDING OF METALLIC MATERIALS - PART 5: WELDING OF CLAD STEEL EN WELDING - RECOMMENDATIONS FOR WELDING OF METALLIC MATERIALS - PART 7: ELECTRON BEAM WELDING EN DESTRUCTIVE TESTS ON WELDS IN METALLIC MATERIALS - HARDNESS TESTING - PART 1: HARDNESS TEST ON ARC WELDED JOINTS EN DESTRUCTIVE TESTS ON WELDS IN METALLIC MATERIALS - HARDNESS TEST -PART 2: MICRO HARDNESS TESTING ON WELDED JOINTS EN 1044 BRAZING - FILLER METALS EN 1045 BRAZING - FLUXES FOR BRAZING - CLASSIFICATIONS AND TECHNICAL DELIVERY CONDITIONS EN ISO 1071 WELDING CONSUMABLES - COVERED ELECTRODES, WIRES, RODS AND TUBULAR CORED ELECTRODES FOR FUSION WELDING OF CAST IRON -CLASSIFICATION EN 1256 GAS WELDING EQUIPMENT - SPECIFICATION FOR HOSE ASSEMBLIES FOR EQUIPMENT FOR WELDING, CUTTING AND ALLIED PROCESSES EN 1289 NON DESTRUCTIVE EXAMINATION OF WELDS - PENETRANT TESTING OF WELDS - ACCEPTANCE LEVELS EN 1289/A1 NON DESTRUCTIVE TESTING OF WELDS - PENETRANT TESTING OF WELDS - ACCEPTANCE LEVELS EN 1289/A2 NON DESTRUCTIVE TESTING OF WELDS - PENETRANT TESTING OF WELDS - ACCEPTANCE LEVELS EN 1290 NON DESTRUCTIVE EXAMINATION OF WELDS - MAGNETIC PARTICLE EXAMINATION OF WELDS EN 1290/A1 NON DESTRUCTIVE TESTING OF WELDS - MAGNETIC PARTICLE TESTING OF WELDS EN 1290/A2 NON-DESTRUCTIVE TESTING OF WELDS - MAGNETIC PARTICLE TESTING OF WELDS EN 1291 NON DESTRUCTIVE EXAMINATION OF WELDS - MAGNETIC PARTICLE EXAMINATION OF WELDS - ACCEPTANCE LEVELS EN 1291/A1 NON DESTRUCTIVE TESTING OF WELDS - MAGNETIC PARTICLE TESTING OF WELDS - ACCEPTANCE LEVELS EN 1291/A2 NON-DESTRUCTIVE TESTING OF WELDS - MAGNETIC PARTICLE TESTING OF WELDS - ACCEPTANCE LEVELS EN 1320 DESTRUCTIVE TESTS ON WELDS IN METALLIC MATERIALS - FRACTURE TESTS EN 1321 DESTRUCTIVE TESTS OF WELDS IN METALLIC MATERIALS - MACROSCOPIC AND MICROSCOPIC EXAMINATION OF WELDS EN 1326 GAS WELDING EQUIPMENT- SMALL KITS FOR GAS BRAZING AND WELDING EN 1327 GAS WELDING EQUIPMENT- THERMOPLASTICS HOSES FOR WELDING AND ALLIED PROCESSES EN 1418 WELDING PERSONNEL- APPROVAL TESTING OF WELDING OPERATORS FOR FUSION WELDING AND RESISTANCE WELD SETTER FOR FULLY MECHANIZED AND AUTOMATIC WELDING OF METALLIC MATERIALS EN 1435 NON DESTRUCTIVE EXAMINATION OF WELDS - RADIOGRAFIC EXAMINATION OF WELDED JOINTS EN 1435/A1 NON DESTRUCTIVE TESTING OF WELDS - RADIOGRAFIC TESTING OF WELDED JOINTS EN 1435/A2 NON-DESTRUCTIVE TESTING OF WELDS - RADIOGRAPHIC TESTING OF WELDED JOINTS EN WELDING CONSUMABLES- TEST METHODS- PART 1- TEST PIECE FOR ALL- WELD METAL TEST SPECIMENS IN STEEL, NICKEL AND NICKEL ALLOYS EN WELDING CONSUMABLES- TEST METHODS- PART 2- PREPARATION OF TEST PIECE FOR SINGLE AND TWO RUN TECHNIQUE TEST SPECIMEN IN STEEL EN WELDING CONSUMABLES- TEST METHODS- PART 3: TESTING OF POSITIONAL CAPABILITY OF WELDING CONSUMABLES IN A FILLET WELD EN 1598 HEALTH AND SAFETY IN WELDING AND ALLIED PROCESSES - TRANSPARENT WELDING CURTAINS, STRIPS AND SCREENS FOR ARC WELDING PROCESSES EN 1598/A1 HEALTH AND SAFETY IN WELDING AND ALLIED PROCESSES - TRANSPARENT WELDING CURTAINS, STRIPS

90 Welding Fabrication Standards Page 88 AND SCREENS FOR ARC WELDING PROCESSES EN 1599 WELDING CONSUMABLES- COVERED ELECTRODES FOR MANUAL METAL ARC WELDING OF CREEP RESISTING STEELS- CLASSIFICATION EN 1600 WELDING CONSUMABLES- COVERED ELECTRODES FOR MANUAL METAL ARC WELDING OF STAINLESS AND HEAT RESISTING STEELS- CLASSIFICATION EN 1668 WELDING CONSUMABLES- RODS, WIRES AND DEPOSITS FOR TUNGSTEN INERT GAS WELDING OF NON ALLOY AND FINE GRAIN STEELS- CLASSIFICATION EN WELDING- BASIC WELD JOINT DETAILS IN STEEL- PART 1: PRESSURIZED COMPONENTS EN /A1 WELDING - BASIC WELD JOINT DETAILS IN STEEL - PART 1: PRESSURIZED COMPONENTS EN WELDING - BASIC WELD JOINT DETAILS IN STEEL - PART 2: NON INTERNAL PRESSURIZED COMPONENTS EN 1711 NON DESTRUCTIVE EXAMINATION OF WELDS - EDDY CURRENT EXAMINATION BY COMPLEX PLANE ANALYSIS EN 1711/A1 NON-DESTRUCTIVE EXAMINATION OF WELDS - EDDY CURRENT EXAMINATION OF WELDS BY COMPLEX PLANE ANALYSIS. EN 1712 NON DESTRUCTIVE EXAMINATION OF WELDS - ULTRASONIC EXAMINATION OF WELDED JOINTS - ACCEPTANCE LEVELS EN 1712/A1 NON DESTRUCTIVE TESTING OF WELDS - ULTRASONIC TESTING OF WELDED JOINTS - ACCEPTANCE LEVELS EN 1712/A2 NON-DESTRUCTIVE TESTING OF WELDS - ULTRASONIC TESTING OF WELDED JOINTS - ACCEPTANCE LEVELS EN 1713 NON DESTRUCTIVE EXAMINATION OF WELDS - ULTRASONIC EXAMINATION- CHARACTERIZATION OF INDICATIONS IN WELDS EN 1713/A1 NON DESTRUCTIVE TESTING OF WELDS - ULTRASONIC TESTING - CHARACTERIZATION OF INDICATIONS IN WELDS EN 1713/A2 NON-DESTRUCTIVE TESTING OF WELDS - ULTRASONIC TESTING - CHARACTERIZATION OF INDICATIONS IN WELDS EN 1714 NON DESTRUCTIVE EXAMINATION OF WELDS - ULTRASONIC EXAMINATION OF WELDED JOINTS EN 1714/A1 NON DESTRUCTIVE TESTING OF WELDS - ULTRASONIC TESTING OF WELDED JOINTS EN 1714/A2 NON-DESTRUCTIVE TESTING OF WELDS - ULTRASONIC TESTING OF WELDED JOINTS EN 1792 WELDING- MULTILINGUAL LIST OF TERMS FOR WELDING AND RELATED PROCESSES EN ISO 2503 GAS WELDING EQUIPMENT - PRESSURE REGULATORS FOR GAS CYLINDERS USED IN WELDING, CUTTING AND ALLIED PROCESSES UP TO 300 BAR (SOSITUISCE EN 585?) EN ISO 3677 FILLER METAL FOR SOFT SOLDERING, BRAZING AND BRAZE WELDING -DESIGNATION EN ISO 3690 WELDING AND ALLIED PROCESSES - DETERMINATION OF HYDROGEN CONTENT IN FERRITIC ARC WELD METAL EN ISO 4063 WELDING, BRAZING, SOLDERING, AND BRAZE WELDING OF METALS -NOMENCLATURE OF PROCESSES AND REFERENCE NUMBERS FOR SYMBOLIC REPRESENTATION ON DRAWINGS EN ISO 5172 GAS WELDING EQUIPMENT - MANUAL BLOWPIPES FOR WELDING, CUTTING AND HEATING - SPECIFICATIONS AND TESTS EN ISO RESISTANCE WELDING EQUIPMENT- ELECTRODE ADAPTORS, MALE TAPER 1:10 - CONICAL FIXING, TAPER 1:10 EN ISO RESISTANCE WELDING EQUIPMENT - ELECTRODE ADAPTORS, MALE TAPPER 1:10 - PART 2: PARALLEL SHANK FIXING FOR END-THRUST ELECTRODES EN ISO 5817 WELDING - FUSION-WELDED JOINTS IN STEEL, NICKEL, TITANIUM AND THEIR ALLOYS (BEAM WELDING EXCLUDED) - QUALITY LEVELS FOR IMPERFECTIONS EN ISO 5826 RESISTANCE WELDING EQUIPMENT - TRANSFORMERS - GENERAL SPECIFICATIONS APPLICABLE TO ALL TRANSFORMERS (ISO 5826:1999) EN ISO 5828 RESISTANCE WELDING EQUIPMENT - SECONDARY CONNECTING CABLES WITH TERMINALS CONNECTED TO WATERCOOLED LUGS - DIMENSIONS AND CHARACTERISTICS EN ISO WELDING AND ALLIED PROCESSES - CLASSIFICATION OF GEOMETRIC IMPERFECTIONS IN METALLIC MATERIALS - PART 1: FUSION WELDING EN ISO WELDING AND ALLIED PROCESSES - CLASSIFICATION OF GEOMETRIC IMPERFECTIONS IN METALLIC MATERIALS - PART 2: WELDING WITH PRESSURE EN ISO 6847 WELDING CONSUMABLES - DEPOSITION OF A WELD METAL PAD FOR CHEMICAL ANALYSIS EN ISO 6947 EN ISO 7284 EN ISO 7287 EN ISO 7291 EN ISO 8166 EN ISO EN ISO EN ISO WELDS - WORKING POSITIONS - DEFINITIONS OF ANGLES OF SLOPE AND ROTATION RESISTANCE WELDING EQUIPMENT-PARTICULAR SPECIFICATION APPLICABLE TO TRANSFORMERS WITH TWO SEPARATE SECONDARY WINDINGS FOR MULTI SPOT WELDING AS USED IN THE AUTOMOBILE INDUSTRY GRAPHICAL SYMBOLS FOR THERMAL CUTTING EQUIPMENT GAS WELDING EQUIPMENT- PRESSURE REGULATORS FOR MANIFOLD SYSTEMS USED IN WELDING, CUTTING AND ALLIED PROCESSES UP TO 300 BAR RESISTANCE WELDING - PROCEDURE FOR THE EVALUATION OF THE LIFE OF SPOT WELDING ELECTRODES USING CONSTANT MACHINE SETTINGS WATER COOLED SECONDARY CONNECTION CABLES FOR RESISTANCE WELDING PART 1: DIMENSIONS AND REQUIREMENTS FOR DOUBLE-CONDUCTOR CONNECTION CABLES WATER COOLED SECONDARY CONNECTION CABLES FOR RESISTANCE WELDING PART 2: DIMENSIONS AND REQUIREMENTS FOR SINGLE-CONDUCTOR CONNECTION CABLES WATER COOLED SECONDARY CONNECTION CABLES FOR RESISTANCE WELDING PART 3: TEST

91 Welding Fabrication Standards Page 89 REQUIREMENTS EN ISO 8249 WELDING- DETERMINATION OF FERRITE NUMBER (FN) IN AUSTENITIC AND DUPLEX FERRITIC-AUSTENITIC CR- NI STAINLESS STEEL WELD METAL EN ISO 9013 THERMAL CUTTING - CLASSIFICATION OF THERMAL CUTS - GEOMETRICAL PRODUCT SPECIFICATION AND QUALITY TOLERANCES EN ISO 9013/A1 THERMAL CUTTING - CLASSIFICATION OF THERMAL CUTS - GEOMETRICAL PRODUCT SPECIFICATION AND QUALITY TOLERANCES EN ISO 9018 DESTRUCTIVE TESTS ON WELDS IN METALLIC MATERIALS TENSILE TEST ON CRUCIFORM AND LAPPED JOINTS EN ISO 9312 RESISTANCE WELDING EQUIPMENT - INSULATED PINS FOR USE IN ELECTRODE BACK-UPS EN ISO SOFT SOLDERING FLUXES - CLASSIFICATION AND REQUIREMENTS - PERFORMANCE REQUIREMENTS EN ISO SOFT SOLDERING FLUXES - TEST METHODS-PART 2: DETERMINATION OF NON VOLATILE MATTER, EBULLIOMETRIC METHOD EN ISO SOFT SOLDERING FLUXES - TEST METHODS-PART 3: DETERMINATION OF ACID VALUE, POTENTIOMETRIC AND VISUAL TITRATION METHODS EN ISO SOFT SOLDERING FLUXES - TEST METHODS - PART 6 : DETERMINATION AND DETECTION OF HALIDE (EXCLUDING FLUORIDE) CONTENT EN ISO SOFT SOLDERING FLUXES - TEST METHODS-PART 9: DETERMINATION OF AMONIA CONTENT EN ISO SOFT SOLDERING FLUXES - TEST METHODS -PART 10: FLUX EFFICACY TEST, SOLDER SPREAD METHOD EN ISO SOFT SOLDERING FLUXES - TEST METHODS-PART 12: STEEL TUBE CORROSION TEST EN ISO SOFT SOLDERING FLUXES - TESTS METHODS - PART 13: DETERMINATION OF FLUX SPATTERING EN ISO SOFT SOLDERING FLUXES - TESTS METHODS - PART 15: COPPER CORROSION TEST EN ISO SOFT SOLDERING FLUXES-TEST METHODS-PART 16: FLUX EFFICACY TESTS,WETTING BALANCE METHOD EN ISO APPROVAL TESTING OF WELDERS- FUSION WELDING - PART 3 - COPPER AND COPPER ALLOYS EN ISO APPROVAL TESTING OF WELDERS - FUSION WELDING - PART 4 - NICKEL AND NICKEL ALLOYS EN ISO APPROVAL TESTING OF WELDERS - FUSION WELDING - TITANIUM AND TITANIUM ALLOYS, ZIRCONIUM AND ZIRCONIUM ALLOYS ENISO WELDING AND ALLIED PROCESSES RECOMMENDATIONS FOR JOINT PREPARATION PART 1: MANUAL METAL-ARC WELDING, GAS-SHIELDED METAL-ARC WELDING, GAS WELDING, TIG WELDING AND BEAM WELDING OF STEELS EN ISO WELDING AND ALLIED PROCESSES - JOINT PREPARATION - PART 2: SUBMERGED ARC WELDING OF STEELS EN ISO WELDING AND ALLIED PROCESSES - RECOMMENDATION FOR JOINT PREPARATION - PART 3: METAL INERT GAS WELDING AND TUNGSTEN INERT GAS WELDING OF ALUMINIUM AND ITS ALLOYS EN ISO /A1 WELDING AND ALLIED PROCESSES - RECOMMENDATIONS FOR JOINT PREPARATION - PART 3: METAL INERT GAS WELDING AND TUNGSTEN INERT GAS WELDING OF ALUMINIUM AND ITS ALLOYS EN ISO WELDING AND ALLIED PROCESSES - RECOMMENDATIONS FOR JOINT PREPARATION - PART 4: CLAD STEELS EN ISO * SPECIFICATION AND APPROVAL OF WELDING PROCEDURES FOR METALLIC MATERIALS-PART 10: WELDING PROCEDURE SPECIFICATION FOR ELECTRON BEAM WELDING EN ISO * SPECIFICATION AND APPROVAL OF WELDING PROCEDURES FOR METALLIC MATERIALS-PART 11: WELDING PROCEDURE SPECIFICATION FOR LASER BEAM WELDING EN ISO SOLDERING AND BRAZING MATERIALS - METHODS FOR THE SAMPLING OF SOFT SOLDERS FOR ANALYSIS EN ISO HEALTH AND SAFETY IN WELDING AND ALLIED PROCESSES - SAMPLING OF AIRBORNE PARTICLES AND GASES IN THE OPERATOR'S BREATING ZONE - PART 1: SAMPLING OF AIRBONE PARTICLES EN ISO HEALTH AND SAFETY IN WELDING AND ALLIED PROCESSES - SAMPLING OF AIRBORNE PARTICLES AND GASES IN THE OPERATOR'S BREATING ZONE - PART 2: SAMPLING OF GASES EN NON DESTRUCTIVE EXAMINATION OF WELDS - GENERAL RULES FOR METALLIC MATERIALS EN 12062/A1 NON DESTRUCTIVE TESTING OF WELDS - GENERAL RULES FOR METALLIC MATERIALS EN 12062/A2 NON DESTRUCTIVE TESTING OF WELDS - GENERAL RULES FOR METALLIC MATERIALS EN WELDING CONSUMABLES - WIRE ELECTRODES, WIRES AND RODS FOR ARC WELDING OF CREEP RESISTING STEELS - CLASSIFICATION EN WELDING CONSUMABLES - TUBULAR CORED ELECTRODES FOR GAS SHIELDED METAL ARC WELDING OF CREEP RESISTING STEELS - CLASSIFICATION EN WELDING CONSUMABLES - WIRE ELECTRODES, WIRES AND RODS FOR ARC WELDING OF STAINLESS AND HEAT RESISTING STEELS - CLASSIFICATION EN WELDING CONSUMABLES - TUBULAR CORED ELECTRODES FOR METAL ARC WELDING WITH OR WITHOUT A GAS SHIELD OF STAINLESS AND HEAT RESISTING STEELS - CLASSIFICATION EN WELDING CONSUMABLES-QUALITY REQUIREMENTS FOR MANUFACTURE, SUPPLY AND DISTRIBUTION OF CONSUMABLES FOR WELDING AND ALLIED PROCESSES EN ISO SOLDER WIRE, SOLID AND FLUX CORED - SPECIFICATION AND TEST METHOD - PART 1: CLASSIFICATION AND PERFORMANCE REQUIREMENTS EN ISO FLUX CORED SOLDER WIRE - SPECIFICATION AND TEST METHODS - PART 2: DETERMINATION OF FLUX CONTENT EN ISO SOLDER WIRE, SOLID AND FLUX CORED SPECIFICATIONS AND TEST METHODS PART 3: WETTING BALANCE TEST METHOD FOR FLUX CORED SOLDER WIRE EFFICACY

92 Welding Fabrication Standards Page 90 EN WELDING - MULTILINGUAL TERMS FOR WELDED JOINTS WITH ILLUSTRATIONS CR DESTRUCTIVE TESTS ON WELDS IN METALLIC MATERIALS -ETCHANTS FOR MACROSCOPIC AND MICROSCOPIC EXAMINATION EN NON DESTRUCTIVE EXAMINATION OF WELDS - RADIOGRAPHIC EXAMINATION OF WELDED JOINTS - ACCEPTANCE LEVELS EN 12517/A1 NON-DESTRUCTIVE TESTING OF WELDS - RADIOGRAPHIC TESTING OF WELDED JOINTS - ACCEPTANCE LEVELS EN 12517/A2 NON-DESTRUCTIVE TESTING OF WELDS - RADIOGRAPHIC TESTING OF WELDED JOINTS - ACCEPTANCE LEVELS EN WELDING CONSUMABLES- WIRE ELECTRODES, WIRES, RODS AND DEPOSITS FOR GAS SHIELDED METAL ARC WELDING OF HIGH STRENGTH STEELS- CLASSIFICATION EN WELDING CONSUMABLES- TUBULAR CORED ELECTRODES FOR GAS SHIELDED METAL ARC WELDING OF HIGH STRENGTH STEELS- CLASSIFICATION EN WELDING CONSUMABLES- RODS FOR GAS WELDING OF NON ALLOY AND CREEP-RESISTING STEELS- CLASSIFICATION EN IMPERFECTIONS IN OXYFUEL FLAME CUTS, LASER BEAM CUTS AND PLASMA CUTS: TERMINOLOGY EN BRAZING- DESTRUCTIVE TESTS OF BRAZED JOINTS EN 12797/A1 BRAZING- DESTRUCTIVE TESTS OF BRAZED JOINTS EN BRAZING- NON-DESTRUCTIVE EXAMINATION OF BRAZED JOINTS EN 12799/A1 BRAZING - NON-DESTRUCTIVE EXAMINATION OF BRAZED JOINTS EN BRAZING - BRAZER APPROVAL EN BRAZING - PROCEDURE APPROVAL CR IMPLEMENTATION OF EN 729 ON QUALITY REQUIREMENTS FOR FUSION WELDING OF METALLIC MATERIALS EN GAS WELDING EQUIPMENT - TERMINOLOGY - TERMS USED FOR GAS WELDING EQUIPMENT EN ISO WELDING - GUIDANCE ON THE MEASUREMENT OF PRE-HEATING TEMPERATURE, INTERPASS TEMPERATURE AND PRE-HEAT MAINTENANCE TEMPERATURE EN ISO WELDING - STUDS AND CERAMIC FERRULES FOR ARC STUD WELDING EN GAS WELDING EQUIPMENT - INTEGRATED FLOWMETER REGULATORS USED ON CYLINDERS FOR WELDING, CUTTING AND ALLIED PROCESSES -CLASSIFICATION, SPECIFICATION AND TESTS EN ISO WELDING - ELECTRON AND LASER BEAM WELDED JOINTS- GUIDANCE ON QUALITY LEVELS FOR IMPERFECTIONS-PART 1: STEEL EN ISO WELDING AND ALLIED PROCESSES - ELECTRON AND LASER BEAM WELDED JOINTS - GUIDANCE ON QUALITY LEVEL FOR IMPERFECTIONS - PART 2: ALUMINIUM AND ITS WELDABLE ALLOYS EN ISO /A1 WELDING - ELECTRON AND LASER BEAM WELDED JOINTS - GUIDANCE ON QUALITY LEVELS FOR IMPERFECTIONS - PART 2: ALUMINIUM AND ITS WELDABLE ALLOYS EN ISO WELDING - GENERAL TOLLERANCES FOR WELDED CONSTRUCTIONS -DIMENSIONS FOR LENGTHS AND ANGLES - SHAPE AND POSITION EN ISO GAS WELDING EQUIPMENT- RUBBER AND PLASTIC HOSES ASSEMBLED FOR COMPRESSED OR LIQUEFIED GASES UP TO A MAXIMUM DESIGN PRESSURE OF 450 BAR EN ISO GAS WELDING EQUIPMENT- ACETYLENE MANIFOLD SYSTEMS FOR WELDING, CUTTING AND ALLIED PROCESSES- GENERAL REQUIREMENTS EN ISO WELDING CONSUMABLES - COVERED ELECTRODES FOR MANUAL METAL ARC WELDING OF NICKEL AND NICKEL ALLOYS -CLASSIFICATION EN ISO SPECIMEN DIMENSIONS AND PROCEDURE FOR MECHANIZED PEEL TESTING RESISTANCE SPOT, SEAM AND EMBOSSED PROJECTION WELDS EN ISO VICKERS HARDNESS TESTING OF RESISTANCE, SPOT PROJECTION AND SEAM WELDS (LOW LOAD AND MICROHARDNESS) EN ISO SPECIMEN DIMENSIONS AND PROCEDURE FOR CROSS TENSION TESTING RESISTANCE SPOT AND EMBOSSED PROJECTION WELDS EN ISO SPECIMEN DIMENSIONS AND PROCEDURE FOR SHEAR TESTING RESISTANCE SPOT, SEAM AND EMBOSSED PROJECTION WELDS EN WELDING CONSUMABLES - WIRE AND TUBULAR CORED ELECTRODES AND ELECTRODE-FLUX COMBINATIONS FOR SUBMERGED ARC WELDING OF HIGH STRENGTH STEELS - CLASSIFICATION EN ISO RESISTANCE SPOT WELDING - DESTRUCTIVE TESTS OF WELDS - METHOD FOR THE FATIGUE TESTING OF SPOT WELDED JOINTS EN ISO RESISTANCE WELDING - DESTRUCTIVE TESTS OF WELDS - FAILURE TYPES AND GEOMETRIC MEASUREMENTS FOR RESISTANCE SPOT, SEAM AND PROJECTION WELDS EN ISO WELDING CONSUMABLES - DETERMINATION OF MOISTURE RESISTANCE OF MANUAL METAL ARC WELDING ELECTRODES BY MEASUREMENT OF DIFFUSIBLE HYDROGEN EN ISO QUALITY REQUIREMENTS FOR WELDING - RESISTANCE WELDING OF METALLIC MATERIALS - COMPREHENSIVE QUALITY REQUIREMENTS EN ISO QUALITY REQUIREMENTS FOR WELDING - RESISTANCE WELDING OF METALLIC MATERIALS - ELEMENTARY QUALITY REQUIREMENTS EN ISO WELDING - ARC STUD WELDING OF METALLIC MATERIALS

93 Welding Fabrication Standards Page 91 CR TERMS AND DEFINITIONS FOR WELDING PURPOSES IN RELATION WITH EN 1792 EN ISO WELDING - ACCEPTANCE INSPECTION OF ELECTRON BEAM WELDING MACHINE- PART 1: PRINCIPLES AND ACCEPTANCE CONDITION EN ISO WELDING - ACCEPTANCE INSPECTION OF ELECTRON BEAM WELDING MACHINE- PART 2: MEASUREMENT OF ACCELERATING VOLTAGE EN ISO WELDING - ACCEPTANCE INSPECTION OF ELECTRON BEAM WELDING MACHINE- MEASUREMENT OF BEAM CURRENT CHARACTERISTIC EN ISO WELDING - ACCEPTANCE INSPECTION OF ELECTRON BEAM WELDING MACHINE- MEASUREMENT OF WELDING SPEED EN ISO WELDING - ACCEPTANCE INSPECTION OF ELECTRON BEAM WELDING MACHINE- MEASUREMENT OF RUN-OUT ACCURACY EN ISO WELDING - ACCEPTANCE INSPECTION OF ELECTRON BEAM WELDING MACHINE- PART 6: MEASUREMENT OF STABILITY OF SPOT POSITION EN ISO HEALTH AND SAFETY IN WELDING AND ALLIED PROCESSES-LABORATORY METHOD FOR SAMPLING FUMES AND GASES GENERATED BY ARC WELDING- PART 1: DETERMINATION OF EMISSION RATE AND SAMPLING FOR ANALYSIS OF PARTICULATE FUME EN ISO HEALTH AND SAFETY IN WELDING AND ALLIED PROCESSES - LABORATORY METHOD FOR SAMPLING FUME AND GASES GENERATED BY ARC WELDING -PART 2: DETERMINATION OF EMISSION RATES OF GASES, EXCEPT OZONE (ISO :2003) EN ISO SPECIFICATION AND QUALIFICATION OF WELDING PROCEDURES FOR METALLIC MATERIALS - GENERAL RULES CR ISO WELDING - GUIDELINES FOR A METALLIC MATERIAL GROUPING SYSTEM EN ISO SPECIFICATION AND QUALIFICATION OF WELDING PROCEDURE FOR METALLIC MATERIALS - WELDING PROCEDURE SPECIFICATION - PART 2: GAS WELDING EN ISO /A1 SPECIFICATION AND QUALIFICATION OF WELDING PROCEDURE FOR METALLIC MATERIALS - WELDING PROCEDURE SPECIFICATION - PART 2: GAS WELDING EN ISO SPECIFICATION AND QUALIFICATION OF WELDING PROCEDURES FOR METALLIC MATERIALS - QUALIFICATION BASED ON TESTED WELDING CONSUMABLES EN ISO SPECIFICATION AND QUALIFICATION OF WELDING PROCEDURES FOR METALLIC MATERIALS - QUALIFICATION BASED ON PREVIOUS WELDING EXPERIENCE EN ISO 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 EN ISO SPECIFICATION AND QUALIFICATION OF WELDING PROCEDURES FOR METALLIC MATERIALS - WELDING PROCEDURE TEST - PART 5: ARC WELDING OF TITANIUM, ZIRCONIUM AND THEIR ALLOYS (ISO :2004) EN ISO SPECIFICATION AND QUALIFICATION OF WELDING PROCEDURES FOR METALLIC MATERIALS - WELDING PROCEDURE TEST- PART 8: WELDING OF TUBES TO TUBE-PLATE JOINTS EN ISO SPECIFICATION AND QUALIFICATION OF WELDING PROCEDURES FOR METALLIC MATERIALS - WELDING PROCEDURE TEST- PART 11: ELECTRON AND LASER BEAM WELDING EN ISO GAS WELDING EQUIPMENT-ACETYLENE MANIFOLD SYSTEMS FOR WELDING, CUTTING AND ALLIED PROCESSES-SAFETY REQUIREMENTS IN HIGH-PRESSURE DEVICES EN ISO ACCEPTANCE TESTS FOR CO2-LASER BEAM MACHINES FOR HIGH QUALITY WELDING AND CUTTING - PART 1: GENERAL PRINCIPLES, ACCEPTANCE CONDITIONS (ISO :2003) EN ISO ACCEPTANCE TESTS FOR CO2-LASER BEAM MACHINES FOR HIGH QUALITY WELDING AND CUTTING - PART 2: MEASUREMENT OF STATIC AND DYNAMIC ACCURACY (ISO :2003) EN ISO ACCEPTANCE TESTS FOR CO2-LASER BEAM MACHINES FOR HIGH QUALITY WELDING AND CUTTING - PART 3: CALIBRATION OF INSTRUMENTS FOR MEASUREMENT OF GAS FLOW AND PRESSURE (ISO :2003) EN ISO APPROVAL TESTING OF WELDERS FOR UNDERWATER WELDING - PART 1: DIVER-WELDERS FOR HYPERBARIC WET WELDING EN ISO APPROVAL TESTING OF WELDERS FOR UNDERWATER WELDING - PART 2: DIVER-WELDERS AND WELDING OPERATORS FOR HYPERBARIC DRY WELDING EN ISO WELDING - FRICTION WELDING OF METALLIC MATERIALS EN ISO WELDING - TEST FOR SHOP PRIMERS IN RELATION TO WELDING AND ALLIED PROCESSES - PART 1: GENERAL REQUIREMENTS (ISO :2003) EN ISO WELDING - TEST FOR SHOP PRIMERS IN RELATION TO WELDING AND ALLIED PROCESSES - PART 2: WELDING PROPERTIES OF SHOP PRIMERS (ISO :2003) EN ISO WELDING - TEST FOR SHOP PRIMERS IN RELATION TO WELDING AND ALLIED PROCESSES - PART 3: THERMAL CUTTING (ISO :2003) EN ISO WELDING - TEST FOR SHOP PRIMERS IN RELATION TO WELDING AND ALLIED PROCESSES - PART 4: EMISSION OF FUMES AND GASES (ISO :2003) EN ISO DESTRUCTIVE TESTS ON WELDS IN METALLIC MATERIALS-TORSION TEST OF RESISTANCE SPOT WELDS (ISO 17653:2003) EN ISO DESTRUCTIVE TESTS ON WELDS IN METALLIC MATERIALS - RESISTANCE WELDING - PRESSURE TEST ON RESISTANCE SEAM WELDS (ISO 17654:2003)

94 Welding Fabrication Standards Page 92 EN ISO DESTRUCTIVE TESTS ON WELDS IN METALLIC MATERIALS - METHOD FOR TAKING SAMPLES FOR DELTA FERRITE MEASUREMANT (ISO 17655:2003) CR ISO GUIDELINES FOR QUALITY REQUIREMENTS FOR HEAT TREATMENT IN CONNECTION WITH WELDING AND ALLIED PROCESSES EN ISO BRAZING - IMPERFECTIONS IN BRAZED JOINTS EN FILLER MATERIALS FOR MANUAL WELDING - SIZE REQUIREMENTS EN DIMENSIONS OF SEAM WELDING WHEEL BLANKS EN SLOTS IN PLATENS FOR PROJECTION WELDING MACHINES EN ELECTRODES TAPER FIT FOR SPOT WELDING EQUIPMENT - DIMENSIONS EN COVERED ELECTRODES - DETERMINATION OF THE EFFICIENCY, METAL RECOVERY AND DEPOSITION COEFFICIENT EN WELDED, BRAZED AND SOLDERED JOINTS - SYMBOLIC REPRESENTATION ON DRAWINGS EN STRAIGHT RESISTANCE SPOT WELDING ELECTRODES EN RESISTANCE SPOT WELDING ELECTRODE CAPS EN SPOT WELDING EQUIPMENT - TAPER PLUG GAUGES AND TAPER RING GAUGES EN SPOT WELDING - ELECTRODE BACK-UP AND CLAMPS EN TUNGSTEN ELECTRODES FOR INERT GAS SHIELDED ARC WELDING AND FOR PLASMA CUTTING AND WELDING - CODIFICATION EN GRAPHICAL SYMBOLS FOR RESISTANCE WELDING EQUIPMENT EN INSULATION CAPS AND BUSHES FOR RESISTANCE WELDING EQUIPMENT EN WELDS IN STEEL - CALIBRATION BLOCK N 2 FOR ULTRASONIC EXAMINATION OF WELDS EN PROJECTIONS FOR RESISTANCE WELDING EN ACCEPTANCE TESTS FOR OXYGEN CUTTING MACHINES - REPRODUCIBLE ACCURACY OPERATIONAL CHARACTERISTICS EN RESISTANCE SPOT WELDING - ELECTRODE HOLDERS - PART 1: TAPER FIXING 1:10 EN RESISTANCE SPOT WELDING - ELECTRODE HOLDERS- PART 2: MORSE TAPER FIXING EN RESISTANCE SPOT WELDING - ELECTRODE HOLDERS - PART 3: PARALLEL SHANK FIXING FOR END THRUST EN GAS TIGHTNESS OF EQUIPMENT FOR GAS WELDING AND ALLIED PROCESSES EN RESISTANCE SPOT WELDING - COOLING TUBES EN SOFT SOLDER ALLOYS - CHEMICAL COMPOSITIONS AND FORMS EN SOFT SOLDERING FLUXES - CLASSIFICATION AND REQUIREMENTS -PART 1: CLASSIFICATION, LABELLING AND PACKAGING EN SOFT SOLDERING FLUXES - TEST METHODS PART 1: DETERMINATION OF NON-VOLATILE MATTER, GRAVIMETRIC METHOD EN SOFT SOLDERING FLUXES - TEST METHODS-PART 5: COPPER MIRROR TEST EN SOFT SOLDERING FLUXES - TEST METHODS-PART 8: DETERMINATION OF ZINC CONTENT EN SOFT SOLDERING FLUXES - TEST METHODS -PART 11: DETERMINATION OF NON-VOLATILE MATTER, GRAVIMETRIC METHOD EN SOFT SOLDERING FLUXES - TEST METHODS-PART 14: ASSESSMENT OF TACKINESS OF FLUX RESIDUES EN MATERIALS FOR EQUIPMENT USED IN GAS WELDING, CUTTING AND ALLIED PROCESSES EN METAL-ARC WELDING WITH COVERED ELECTRODES, GAS-SHIELDED METAL-ARC WELDING - JOINT PREPARATION FOR STEEL EN ARC-WELDED JOINTS IN ALUMINIUM AND ITS WELDABLE ALLOYS - GUIDANCE ON QUALITY LEVELS FOR IMPERFECTIONS

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