european welding fabrication standards - introduction

8/2/2019 European Welding Fabrication Standards - Introduction

1/95


2/95


3/95

Welding Fabrication Standards Page 1

Istituto Italiano della Saldatura Lungobisagno Istria, 15 - 16141 Genova (I) - Tel. 01083411 - Fax 0108367780

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.


4/95



With review of GSI - SLV Duisburg and EWF.


5/95



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


6/95



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 tocontain air or nitrogen. ........................................................................... 62

6.1 Introduction.....................................................................................................62

6.2 EN 286-1: requirements for welding manufacturing of simple unfired pressurevessels ...........................................................................................................63

7 European standard for steel pipelines and pipework for gas supplysystems.................................................................................................... 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


7/95



8.2 EN 1090 1: Steel and aluminium structural components - General deliveryconditions.......................................................................................................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


8/95


9/95



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 verifiedby 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.


10/95



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;


11/95



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.

1However 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.


12/95



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.


13/95



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 throughimplementation 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.


14/95


15/95



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);


16/95



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

2or the design and/or other internal departments when the construction is designed by the Manufacturer.


17/95



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 andcustomer 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.


18/95



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 andpartly mechanised

Zirconium and zirconium alloys ISO 9606-5

Arc welding, fully mechanisedand 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 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.

3The same situations apply for the qualification of welding procedures

4International Welding Inspection Personnel (Comprehensive, Standard and Basic levels)

5

EWF has established a system for the qualification of welding personnel and of welding procedurespecifications. Accreditation bodies running in such a system are sometime referred as ANBCC (authorisedNational body for Certification of Companies)


19/95



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;


20/95



- 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

6The full list is reported in EN 719 / ISO 14731.


21/95



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 Characteristicsmaintenancesheet number Notes


22/95



MIG WeldingPower source

Xxx 1223123 450 A - Inverter MIG 0001 -

TIG WeldingPower Sources

Xxx 12233124 200 A - Inverter TIG 0001 -

Travelling bridge-crane

CC 12345Load capacity: 5000 Kg

Working area: 10mx10m

Crane 01 -

CO2 Laser Beamcutting 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.


23/95



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.


24/95



WPS n Rev.COMPANY NAME OR LOGO

WELDING PROCEDURESPECIFICATION (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 PolarityWELDING POSITION

Mode of MetalTransfer

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 CurrentRun(s) orLayer(s)

Weldingprocess EN designation or trade

name .Size(mm)

Type &polarity

AmperageA

VoltageV

TravelSpeed

mm/min

Heat inputKJ/mm

Other

MANUFACTURER APPROVED BY

Figure 5 Welding Procedure Specification


25/95



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 15607WPS,WPQR

General Rules

ISO 15610Qualification based on tested weldingconsumables

ISO 15611Qualification based on previous weldingexperience

ISO 15612Qualification by adoption of a standardwelding procedure

All fusion weldingprocesses

ISO 15613

All

WPQR

Qualification based on pre-production weldingtest

ISO 15609-2 WPS CompilingGas Welding

ISO 15614 - 1Steels

WPQRQualification based on welding procedure test Steels

ISO 15609-1 All WPS Compiling

ISO 15614 - 1Steels and

Nickel alloysWPQR Qualification based on welding procedure test

ISO 15614 - 2Aluminium,Magnesium

WPQR Qualification based on welding procedure test

ISO 15614 - 3 Steel castings WPQR Qualification based on welding procedure test

ISO 15614 - 4Aluminium

castingsWPQR Qualification based on welding procedure test

ISO 15614 - 5

Titanium and

zirconium WPQR Qualification based on welding procedure testISO 15614 - 6 Copper WPQR Qualification based on welding procedure test

ISO 15614 7 All applicable WPQRQualification based on welding procedure test corrosion resistance overlay, claddingrestore and hardfacing

Arc welding

ISO 15614 8 All applicable WPQRQualification based on welding procedure test- Welding of tubes to tube-plate joints

ISO 156093 All WPS CompilingElectron beamwelding ISO 15614 11 All applicable WPQR Qualification based on welding procedure test

ISO 15609 4 All WPS CompilingLaser Welding

ISO 15614 11 All applicable WPQR Qualification based on welding procedure test

Underwater ArcWelding Wet

Hyperbaric

ISO 15614 9 All applicable WPQR Qualification based on welding procedure test

Underwater ArcWelding Dry

HyperbaricISO 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 inwelding a standardised test piece on which

destructive and non-destructive tests are carried out in order to verify the achievement of

required properties;


26/95



- 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.


27/95



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.


28/95



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 weldingand cutting

EN 439

Flux (or metal) cored (gas) metalarc welding

EN 758

TIG EN 1668

Covered electrodes EN 499

MIG/MAG EN 440

Non alloyed and fine grain steels

Submerged arc welding (wireflux combination)

EN 756


TIG, MIG/MAG EN 12070Creep resistant steels

Flux (or metal) cored arc welding EN 12071Flux (or metal) cored (gas) metalarc welding

EN 12535

Submerged arc welding (wireflux combination)

EN 14295High strength steels

TIG, MIG/MAG EN 12534


Flux (or metal) cored (gas) metalarc welding

EN 12073Stainless 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 beapproved 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:


29/95



- 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;


30/95



- 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 manufacturingprocess


31/95



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

7For some tests or checks (e.g. welding parameters, dimensional checks, visual testing, etc.) the welder or

welding operator itself shall be considered as inspector.


32/95



TEST

Tests before welding operations Reference procedure

Checked(date)

Signature ofthe inspector

Referencereport

Suitability and validity of weldersqualification certificates

Suitability of welding procedurespecification

Identity of parent material

Identity of welding consumables

Joint preparation (e.g. Shape anddimensions)

Fit-up, jigging and tacking

Special requirements in the weldingprocedure specification (e.g.Prevention of distortion)

Arrangement for any production test

Suitability of working conditions forwelding, including environment

Tests during welding operations

Preheating / interpass temperature

Welding parameters

Cleaning and shape of runs andlayers of weld metal;

Back gouging;

Welding sequence;

Correct use and handling of weldingconsumables;

Control of distortion;

Dimensional check

Tests after welding operations

Compliance with acceptance criteriafor Visual Testing

Compliance with acceptance criteriafor other NDT examinations (e.g.Radiographic or Ultrasonic Testing)

Compliance for destructive testing(when applicable)

Results and records of post-weldingoperations (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).


33/95



Testmethod

Quality levelaccording toEN ISO 5817

Applicable standard for the testingmethod and relevant level

Standard for the acceptanceand relevant level

B

CVT

D

EN 970 no levels are specifiedRefer directly to the imperfectionsdimension as reported in EN ISO

5817

B EN 1289 2X

C EN 1289 2XPT

D

EN 527-1 no levels are specified

EN 1289 3X

B EN 1291 2X

C EN 1291 2XMT

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 2RT

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 2UT**

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


34/95



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 testingequipment

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


35/95



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 theparticular 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


36/95



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 andfiller metal, method,

position, deposition rate,etc.

Instruments should be calibrated, verifiedor validated, as appropriate.

Requirements to measuringinstruments such as weighing

instruments, vernier callipers, rulersand straightedges, etc. are found in

several EN, ISO and nationalstandards. Stopwatches may bevalidated by comparison with any

reasonably accurate clock.

Handling

Instruments used e.g. for control ofstorage conditions (temperature, humidity,

etc.) should be calibrated, verified or

validated.

Requirements - 5 % for theinstruments concerning humidity and

+ 5 C for thermometer.

Temperature in storagecabinet/room

Instruments for temperature control, e.g.thermometers and other temperature

indicators should be validatedRequirement max. +/- 5 C.

Treatment prior to welding

Instruments used for process controlshould be calibrated, verified or validated,as appropriate, depending on the nature of

the treatment: drying, cleaning, etc.

Appropriate standards for theprocedure should be consulted.

Table 7 EN ISO 17662 requirements applicable to welding consumables

Concerning welding processes parameters, EN ISO 17662 states that the requirement forcalibration, 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).


37/95



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 runor weaving amplitude

when weaving is applied

Instruments used for measuring should becalibrated, verified or validated, asappropriate.

Requirements to measuringinstruments such as vernier callipers,micrometer callipers, etc. are found inseveral EN, ISO and nationalstandards.

For Mechanised welding

Travel speed

Measurements by means of stopwatchesand rulers. Appropriate steel rulers neednot to be calibrated, verified or validated

provided the rulers are not visiblydamaged.

Stopwatches may be validated bycomparison with any reasonablyaccurate clock or watch. See also ENV

50184.

Wire feed speed

Measurements by means of stopwatchesand rulers. Appropriate steel rulers neednot to be calibrated, verified or validatedprovided the rulers are not visiblydamaged.

Stopwatches may be validated bycomparison with any reasonablyaccurate clock or watch. See also ENV50184.

Weawing Frequency

Calibration, verification or validation notrequired, provided size (penetration) andposition of weld can be determined bynon-destructive examination.

-

Dwell time of oscillation

Calibration, verification or validation notrequired, provided size (penetration) andposition of weld can be determined bynon-destructive examination.

-

Torch, electrode and/orwire angle

Instruments used for measuring should becalibrated, verified or validated, asappropriate.

Requirements to measuringinstruments such as vernier callipers,micrometer callipers, etc. are found inseveral EN, ISO and nationalstandards.

* The signal should be monitored continuously. The sampling time should be sufficient to give a reasonablystable reading. If tong-tests are used for measurement of current, the difference between mean valueand 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.


38/95



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 ofconsumables 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;


39/95



- records of repairs and non-conformance reports.


40/95



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


41/95



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 reviewNecessary documentation is

requiredNecessary -documentation

may be required

Necessary -documentation is not

required

Technical reviewNecessary - documentation is

requiredNecessary - documentation may be required

Sub-contractingTreat like a Manufacturer for the specific subcontracted product, services and/oractivities, however final responsibility for quality remains with the Manufacturer

Table 9 Comparison chart on ISO 3834 requirement (to be continued )


42/95



Welders and weldingoperators

Qualification is required

Welding co-

ordination personnel

Required No specific requirement

Equipmentmaintenance

Necessary as applicable toprovide, maintain and

achieve product conformity,documented plans, and

records are required

Necessary as applicable toprovide, maintain and

achieve product conformity,records are recommended

As necessary to assureequipment suitable andavailable, no specific

requirements forrecords

Production andtesting equipment

Suitable and available as required for preparation, process execution, testing,transport, lifting in combination with safety equipment and protective clothes

Production planningRequired documented plans

and records are requiredRequired documented plansrecords are recommended

No specific requirement

Welding procedurespecifications

RequiredAppropriate weldingtechnique required

Qualification of thewelding procedures Required No specific requirement

Batch testing Storageand handling of

weldingconsumables

If required No specific requirement

Storage of parentmaterial

A procedure is required in accordance with supplierrecommendations

In accordance withsupplier

recommendations

Confirmation that the requirements according to productstandard or specifications are fulfilled

Post-weld heattreatment Procedure, record and

traceability of the record to

the product are required

Procedure and record arerequired

No specific requirement

Inspection andtesting before, during

and after welding

Necessary If required

Non-conformanceand corrective

actions

Measures of control are implemented procedures for repairand/or rectification are required

Measures of control areimplemented

Calibration andvalidation ofmeasuring,

inspection andtesting 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.


43/95



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.


44/95



4 European standard for manufacturing unfired pressurevessels

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 withinternal 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.

8In the case of ferritic steels, for ferritic steels the temperature limit corresponds to calculation temperatures

below approximate

european welding fabrication standards - introduction

Documents