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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.
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Istituto Italiano della Saldatura Lungobisagno Istria, 15 - 16141 Genova (I) - Tel. 01083411 - Fax 0108367780
With review of GSI - SLV Duisburg and EWF.
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Summary
1 Quality management and welding fabrication.................................. 7 1.1 Introduction.......................................................................................................7 1.2 Use and field of application of EN ISO 3834 ....................................................8 1.3 EWF Certification scheme for EN ISO 3834...................................................10
1.3.1 The EWF ISO 3834 certificate and schedule ........................................................10 1.3.2 The integrated management system.....................................................................11
2 EN ISO 3834-2 requirements............................................................ 13 2.1 Introduction.....................................................................................................13 2.2 Requirements review and technical review.....................................................13 2.3 Subcontracting................................................................................................15 2.4 Welding personnel..........................................................................................15
2.4.1 Welders and welding operators.............................................................................15 2.4.2 Welding coordination personnel............................................................................17
2.5 Welding inspection personnel.........................................................................19 2.6 Equipment ......................................................................................................19 2.7 Welding and related activities .........................................................................20
2.7.1 Production planning ..............................................................................................20 2.7.2 Welding procedures and instructions ....................................................................21 2.7.3 Welding related document control.........................................................................24
2.8 Welding consumables ....................................................................................24 2.9 Parent material ...............................................................................................26 2.10 Post-weld heat treatment (PWHT)..................................................................27 2.11 Inspection and testing.....................................................................................28 2.12 Non-conformance and corrective actions .......................................................32 2.13 Calibration and validation of measuring, inspection and testing equipment ...32 2.14 Identification and traceability ..........................................................................35 2.15 Quality records ...............................................................................................36
3 Comparison of ISO 3834 Requirements ......................................... 38 3.1 Introduction.....................................................................................................38 3.2 Choice of the appropriate quality level............................................................38 3.3 Comparison chart ...........................................................................................39
3.3.1 ISO 3834-2 - Comprehensive quality level............................................................40 3.3.2 ISO 3834-3 - Standard quality level ......................................................................41
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3.3.3 ISO 3834-4 - Elementary quality level...................................................................41
4 European standard for manufacturing unfired pressure vessels 42 4.1 Introduction.....................................................................................................42 4.2 EN 13445 1: General rules ..........................................................................43 4.3 EN 13445 2: Materials .................................................................................44 4.4 EN 13445 3: Design ....................................................................................44 4.5 EN 13445 4: Fabrication..............................................................................45
4.5.1 Specific requirements for the Manufacturer ..........................................................45 4.5.2 Requirements for subcontracting ..........................................................................46 4.5.3 Specific requirements for welding activities ..........................................................46 4.5.4 Other requirements ...............................................................................................47
4.6 EN 13445 5: Inspection and testing.............................................................47 4.7 EN 13445 6: specific requirements for pressure vessels and parts made of
spheroidal graphite cast iron ..........................................................................49 4.8 CR 13445 7: Guidance on the use of conformity procedures ......................50
5 European standard for manufacturing metallic industrial piping 52 5.1 Introduction.....................................................................................................52 5.2 EN 13480-2: Materials....................................................................................53 5.3 EN 13480-3: Design and calculations.............................................................55 5.4 EN 13480-4: Fabrication.................................................................................55
5.4.1 General requirements for the Manufacturer ..........................................................55 5.4.2 Requirements for the welding activities.................................................................56
5.5 EN 13480-5: Inspection ..................................................................................57 5.6 EN 13480-6: Additional requirements for buried piping ..................................58 5.7 CR 13445 7: Guidance on the use of conformity procedures ......................59
6 European standard for manufacturing simple unfired vessels to contain air or nitrogen. ........................................................................... 62
6.1 Introduction.....................................................................................................62 6.2 EN 286-1: requirements for welding manufacturing of simple unfired pressure
vessels ...........................................................................................................63
7 European standard for steel pipelines and pipework for gas supply systems.................................................................................................... 66
7.1 Introduction.....................................................................................................66 7.2 EN 12732: scope and structure of the standard. ............................................67 7.3 EN 12732: Quality requirement categories.....................................................68 7.4 EN 12732: requirements on quality systems ..................................................68 7.5 EN 12732: Inspection of welded joints and acceptance criteria......................69
8 European standards for the fabrication of steel and aluminium structures ................................................................................................ 72
8.1 Introduction.....................................................................................................72
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8.2 EN 1090 1: Steel and aluminium structural components - General delivery conditions.......................................................................................................73
8.2.1 Requirements for the design of structures. ...........................................................73 8.3 EN 1090 2: Technical requirements for the execution of steel structures....75
8.3.1 Specific requirements for welding Manufacturers .................................................76 8.3.2 Requirements for inspection and testing and acceptance criteria.........................78
8.4 EN 1090 -3: Technical requirements for the execution of aluminium structures79
9 Project European standards for the fabrication of railway vehicles and components ..................................................................................... 82
9.1 Introduction.....................................................................................................82 9.2 prEN 15085-2 Requirements for the Manufacturer.........................................83
10 Normative references ....................................................................... 86
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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.
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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 3834.
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;
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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 3834-1: Guidelines for selection and use;
EN ISO 3834-2: Comprehensive quality requirements;
EN ISO 3834-3: Standard quality requirements;
EN ISO 3834-4: Elementary quality requirements;
EN ISO 3834-5: Normative references to fulfil the requirements of EN ISO 3834-2, EN ISO
3834-3 and EN ISO 3834-4.
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 3834-3 or ISO 3834-4, 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 requirements1.
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.
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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 3834 - 2 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 3834. 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.
1.3.1 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.
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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 Companys 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 (www.ewf.be) of certified Companies.
1.3.2 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 14001 (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).
Its 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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2 EN ISO 3834-2 requirements
2.1 Introduction EN ISO 3834-2 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 purchaser2 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 non-
destructive 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);
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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.
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A possible way to demonstrate the Manufacturers 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 Subcontractors 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 3824-2 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.
2.4.1 Welders and welding operators
Welders and welding operators shall be qualified by an appropriate test. Whenever no other
specific Customers requirement is applicable, the standards reported in the following table apply.
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Welding process Material Applicable standard
Steel EN 287 1, ISO 9606-1 Aluminium and aluminium alloys ISO 9606-2 (EN 287 2)
Copper and copper alloys ISO 9606-3 Nickel and nickel alloys ISO 9606-4
Titanium and titanium alloys, ISO 9606-5
Arc welding, manual and partly mechanised
Zirconium and zirconium alloys ISO 9606-5 Arc welding, fully mechanised
and automatic All EN 1418 (ISO 14732)
Underwater welding All ISO 15618-1 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 considered3:
qualification is issued by a person without any recognised qualification;
qualification is issued by a qualified person (IWE, IWT, IWS, IWI-P4), with reference to his/her
qualification diploma (and relevant stamp);
qualification is issued by the Manufacturers 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 body5.
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)
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Figure 3 Welding workshop for aerospace applications
2.4.2 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;
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- 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 follows6:
- 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 14731 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
Manufacturers 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 Manufacturers 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 14731.
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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 9712. 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 Manufacturers 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
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MIG Welding Power source Xxx 1223123 450 A - Inverter MIG 0001 -
TIG Welding Power Sources Xxx 12233124 200 A - Inverter TIG 0001 -
Travelling bridge-crane CC 12345
Load capacity: 5000 Kg Working area: 10mx10m
Crane 01 -
CO2 Laser Beam cutting Equip.
00xx aio - 356 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
2.7.1 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.
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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.
2.7.2 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 ISO15609-1.
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WPS n Rev. COMPANY NAME OR LOGO WELDING PROCEDURE 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 Other Flux Trade name ELECTRICAL CHARACTERISTIC - Weld deposit 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
Filler metal Current Run(s) or Layer(s)
Welding process
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
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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 15607 WPS, WPQR General Rules
ISO 15610 Qualification based on tested welding consumables
ISO 15611 Qualification based on previous welding experience
ISO 15612 Qualification by adoption of a standard welding procedure
All fusion welding processes
ISO 15613
All WPQR
Qualification based on pre-production welding test
ISO 15609-2 WPS Compiling Gas Welding
ISO 15614 - 1 Steels
WPQR Qualification based on welding procedure test Steels ISO 15609-1 All WPS Compiling
ISO 15614 - 1 Steels and Nickel alloys WPQR Qualification based on welding procedure test
ISO 15614 - 2 Aluminium, Magnesium WPQR Qualification based on welding procedure test
ISO 15614 - 3 Steel castings WPQR Qualification based on welding procedure test
ISO 15614 - 4 Aluminium castings WPQR Qualification based on welding procedure test
ISO 15614 - 5 Titanium and zirconium WPQR Qualification based on welding procedure test
ISO 15614 - 6 Copper WPQR Qualification based on welding procedure test
ISO 15614 7 All applicable WPQR Qualification based on welding procedure test corrosion resistance overlay, cladding restore and hardfacing
Arc welding
ISO 15614 8 All applicable WPQR Qualification based on welding procedure test - Welding of tubes to tube-plate joints ISO 15609 3 All WPS Compiling Electron beam
welding ISO 15614 11 All applicable WPQR Qualification based on welding procedure test ISO 15609 4 All WPS Compiling
Laser Welding ISO 15614 11 All applicable WPQR Qualification based on welding procedure test
Underwater Arc Welding Wet
Hyperbaric ISO 15614 9 All applicable WPQR Qualification based on welding procedure test
Underwater Arc Welding Dry
Hyperbaric ISO 15614 10 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;
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- 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.
2.7.3 Welding related document control
In order to demonstrate the achieved quality of the welded product, all the welding related
documents (e.g. WPS, WPQR, Welders 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 suppliers recommendations.
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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.
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Material Welding process Standard All applicable to the process Submerged arc welding (fluxes) EN 760 All applicable to the process TIG (tungsten electrodes) EN 26848
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 Covered electrodes EN 499 MIG/MAG EN 440
Non alloyed and fine grain steels
Submerged arc welding (wire flux combination) EN 756
Covered electrodes EN 1599 TIG, MIG/MAG EN 12070 Creep resistant steels Flux (or metal) cored arc welding EN 12071 Flux (or metal) cored (gas) metal arc welding EN 12535
Submerged arc welding (wire flux combination) EN 14295
High strength steels
TIG, MIG/MAG EN 12534 Covered electrodes EN 1600 Flux (or metal) cored (gas) metal arc welding EN 12073
Stainless and heat resistant steels
TIG - Rods and wires EN 12072 Aluminium and Aluminium alloys TIG, MIG EN 18273
Nickel and Nickel alloys Covered electrodes EN 14172
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 Manufacturers
needs and orders, references to the certificates for the conformance of the furnished product to
the order can be made according to EN 10204 Metallic products - Types of inspection
documents.
In accordance with such a standard, inspection documents are divided in two groups, based on the
following conditions:
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- 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.
2.10 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;
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- 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 Manufacturers 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 17663 is a reference for the management of the heat treatment
activities.
2.11 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
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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 inspector7 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.
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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 12062 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).
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Test method
Quality level according to EN ISO 5817
Applicable standard for the testing method and relevant level
Standard for the acceptance and relevant level
B C VT D
EN 970 no levels are specified Refer directly to the imperfections dimension as reported in EN ISO
5817
B EN 1289 2X C EN 1289 2X PT D
EN 527-1 no levels are specified EN 1289 3X
B EN 1291 2X C EN 1291 2X MT D
EN 1290 no levels are specified EN 1291 3X
B EN 13445 level B EN 15817 - 1 C EN 13445 level B* EN 15817 2 RT D EN 13445 level C EN 15817 3 B EN 1714 At least level B EN 1712 2 C EN 1714 At least level A EN 1712 2 UT** 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 12062.
Figure 10 Ultrasonic Testing on a claw
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2.12 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.
2.13 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 17662 standard Welding - Calibration, verification and
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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
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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.
Instruments should be calibrated, verified or validated, as appropriate.
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.
Handling
Instruments used e.g. for control of storage conditions (temperature, humidity,
etc.) should be calibrated, verified or validated.
Requirements - 5 % for the instruments concerning humidity and
+ 5 C for thermometer.
Temperature in storage cabinet/room
Instruments for temperature control, e.g. thermometers and other temperature
indicators should be validated Requirement max. +/- 5 C.
Treatment prior to welding
Instruments used for process control should be calibrated, verified or validated, as appropriate, depending on the nature of
the treatment: drying, cleaning, etc.
Appropriate standards for the procedure should be consulted.
Table 7 EN ISO 17662 requirements applicable to welding consumables
Concerning welding processes parameters, EN ISO 17662 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).
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Designation Requirements Procedure
Electrical variables
Current (mean)* Ammeters should be validated. See ENV 50184. Mean value of (rectified) current.
Arc voltage (mean)3 Voltmeters should be validated. See ENV 50184. Mean value of (rectified) tension.
Maximum width of the run or weaving amplitude
when weaving is applied
Instruments used for measuring should be calibrated, verified or validated, as appropriate.
Requirements to measuring instruments such as vernier callipers, micrometer callipers, etc. are found in several EN, ISO and national standards.
For Mechanised welding
Travel speed
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.
Stopwatches may be validated by comparison with any reasonably accurate clock or watch. See also ENV 50184.
Wire feed speed
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.
Stopwatches may be validated by comparison with any reasonably accurate clock or watch. See also ENV 50184.
Weawing Frequency
Calibration, verification or validation not required, provided size (penetration) and position of weld can be determined by non-destructive examination.
-
Dwell time of oscillation
Calibration, verification or validation not required, provided size (penetration) and position of weld can be determined by non-destructive examination.
-
Torch, electrode and/or wire angle
Instruments used for measuring should be calibrated, verified or validated, as appropriate.
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 17662 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.
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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.
2.15 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;
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- records of repairs and non-conformance reports.
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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 3834-2 is also
compliant with ISO 3834-3 and ISO 3834-4.
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
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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 3834 - 2 ISO 3834 - 3 ISO 3834 - 4
Requirements review Necessary documentation is required Necessary -documentation
may be required
Necessary - documentation is not
required
Technical review Necessary - documentation is required Necessary - documentation may be required
Sub-contracting 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 )
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Welders and welding operators Qualification is required
Welding co-ordination personnel Required No specific requirement
Equipment maintenance
Necessary as applicable to provide, maintain and
achieve product conformity, documented plans, and
records are required
Necessary as applicable to provide, maintain and
achieve product conformity, records are recommended
As necessary to assure equipment suitable and available, no specific
requirements for records
Production and testing equipment
Suitable and available as required for preparation, process execution, testing, transport, lifting in combination with safety equipment and protective clothes
Production planning Required documented plans and records are required Required documented plans records are recommended No specific requirement
Welding procedure specifications Required
Appropriate welding technique required
Qualification of the welding procedures Required No specific requirement
Batch testing Storage and handling of
welding consumables
If required No specific requirement
Storage of parent material
A procedure is required in accordance with supplier recommendations
In accordance with supplier
recommendations
Confirmation that the requirements according to product standard or specifications are fulfilled
Post-weld heat treatment Procedure, record and
traceability of the record to the product are required
Procedure and record are required
No specific requirement
Inspection and testing before, during
and after welding Necessary If required
Non-conformance and corrective
actions
Measures of control are implemented procedures for repair and/or rectification are required
Measures of control are implemented
Calibration and validation of measuring,
inspection and testing equipment
Necessary If required No specific requirement
Identification during process If required No specific requirement
Traceability If required No specific requirement
Quality records If required
Table 10 comparison chart on ISO 3834 requirement (continued)
3.3.1 ISO 3834-2 - 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.
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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.
3.3.2 ISO 3834-3 - 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.
3.3.3 ISO 3834-4 - 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.
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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 100 000 h creep rupture strength8.
8 In the case of ferritic steels, for ferritic steels the temperature limit corresponds to calculation temperatures below approximately 380 C.
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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 13445-2 or EN 13445-
6;
- 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 13445 1: 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.
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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 13445 2: Materials This Part deals with the general philosophy on materials, material grouping and low temperature
behaviour in