CE Book Final.pdf

8/12/2019 CE Book Final.pdf

1/73

Guide to the CE Marking

of Structural Steelwork

BCSA Publication No. 46/08


2/73

Guide to the

CE Marking ofStructural Steelwork


3/73

2

Apart from any fair dealing for the purposes of research or private study or criticism or review, as

permitted under the Copyright Design and Patents Act 1988, this publication may not be

reproduced, stored, or transmitted, in any form or by any means, without the prior permission of

the publishers, or in the case of reprographic reproduction only in accordance with terms of the

licences issued by the UK Copyright Licensing Agency, or in accordance with the terms of licences

issued by the appropriate Reproduction Rights Organisation outside the UK.

Enquiries concerning reproduction outside the terms stated here should be sent to the publishers,

The British Constructional Steelwork Association Ltd. at the address given below.

Although care has been to ensure, to the best of our knowledge, that all data and information

contained herein are accurate to the extent that they relate to either matters of fact or accepted

practice or matters of opinion at the time of publication, The British Constructional Steelwork

Association Limited, the authors and the reviewers assume no responsibility for any errors in or

misinterpretations of such data and/or information or any loss or damage arising from or related

to their use.

Publications supplied to members of BCSA at a discount are not for resale by them.

The British Constructional Steelwork Association Ltd.

4, Whitehall Court

Westminster

London

SW1A 2ES

Tel: +44(0)20 7839 8566

Fax: +44(0)20 7976 1634

E-mail: [email protected]

Website: www.steelconstruction.org

BCSA Publication No. 46/08

ISBN 10 1-85073-562-X

ISBN 13 978-1-85073-562-5

British Library Cataloguing-in-Publication Data

A catalogue record for this book is available from the British Library.

The British Constructional Steelwork Association Ltd

Printed by: Box of Tricks Advertising and Design Limited


4/73

Guide to the CE Marking of Structural Steelwork

3

THE BRITISH CONSTRUCTIONAL

STEELWORK ASSOCIATION LIMITED

The British Constructional Steelwork Association Limited (BCSA) is the national

organisation for the steel construction industry: its Member companies undertake

the design, fabrication and erection of steelwork for all forms of construction in

buildings and civil engineering. Associate Members are those principal companies

involved in the supply to all or some Members of components, materials or products.

Corporate Members are clients, professional offices, and educational

establishments etc., which support the development of national specifications,

quality, fabrication and erection techniques, overall industry efficiency and good

practice.

The principal objectives of the Association are to promote the use of structural

steelwork; to assist specifiers and clients; to ensure that the capabilities and

activities of the industry are widely understood and to provide members with

professional services in technical, commercial, contractual and quality assurance

matters. The Association's aim is to influence the trading environment in which

member companies have to operate in order to improve their profitability.

A current list of members and a list of current publications and further membership

details can be obtained from:

The British Constructional Steelwork Association Ltd.4, Whitehall Court

Westminster

London

SW1A 2ES

Tel: +44(0)20 7839 8566

Fax: +44(0)20 7976 1634

E-mail: [email protected]

Website: www.steelconstruction.org


5/73

4

SUMMARY

This document gives guidance on the CE Marking of structural steelwork. It applies to structural

steel components that are manufactured as welded or non-welded fabrications. The components

may be CE Marked individually or collectively as a kit.

The general guidance applies to structural steel components to be used in building construction.

It can also be applied, with some modification, to components to be used in other constructionapplications including bridges.

This publication has been reviewed by Stephen Rein MCIOB, MInstCES, who was a consultant to

CEN for five years and is co-author of The Construction Products Directive: A practical guide to

implementation and CE marking.


6/73


5

CONTENTS PAGE

1 INTRODUCTION AND SCOPE 71.1 Objective 7

1.2 Scope 7

1.3 Overview 7

2 CE MARKING REGULATIONS 92.1 Construction Products Directive 9

2.2 Harmonised standards 9

2.3 Certification 10

2.4 CE Marking 11

2.5 Construction Products Regulations 11

2.6 Future developments 12

3 CE MARKING STANDARD FOR STRUCTURAL STEELWORK 133.1 Basis 133.2 Scope 13

3.3 Definitions 13

3.4 Requirements 20

3.5 Evaluation methods 21

3.6 Evaluation of conformity 21

3.7 Marking system 26

4 EUROPEAN FABRICATION STANDARD 294.1 Status and scope 29

4.2 Documentation 304.3 Constituent products 30

4.4 Tolerances 30

4.5 Welding 31

4.6 Surface treatment 32

5 WELDING QUALITY MANAGEMENT 335.1 Welding as a 'special process' 33

5.2 Control of welding 33

5.3 Technical instructions 34

5.4 Competence of personnel 345.5 Implementation 34

6 RESPONSIBLE WELDING COORDINATORS 356.1 Welding coordination 35

6.2 Tasks for welding coordinators 35

7 TRACEABILITY 377.1 Introduction 37

7.2 Government Circular 37

7.3 Inspection documents 38

7.4 Requirements 387.5 Batch or type traceability 39

7.6 Welding 39


7/73

6

8 SUPPLY CHAIN IMPLICATIONS 408.1 Introduction 40

8.2 Manufacturers 40

8.3 Importers 40

8.4 Distributors 40

8.5 Stockholders 41

8.6 Steel processors 41

8.7 Special products and processes 41

8.8 Transition period 42

9 EXECUTION CLASS 439.1 General 43

9.2 Application to buildings 43

9.3 Wider application 43

10 FACTORY PRODUCTION CONTROL 44

10.1 Introduction 4410.2 FPC systems 44

10.3 System requirements 45

11 ROUTES TO CERTIFICATION 4811.1 Introduction 48

11.2 Assessment of the WQMS 48

11.3 Assessment of the RWC 49

11.4 Surveillance audits 50

11.5 Steel Construction Certification Scheme 51

12 IMPLICATIONS FOR DESIGNERS,

SPECIFIERS AND CONSTRUCTION MANAGERS 5312.1 Introduction 53

12.2 Designers and specifiers 53

12.3 Construction managers 54

APPENDICES

A ASSESSMENT OF THE RWC 56

B ISSUES ASSOCIATED WITH BRIDGES 57

C DOCUMENTARY EXAMPLES 60

D SG17 GUIDANCE ON FPC ASSESSMENT 64

E ABBREVIATIONS 70

REFERENCES 71


8/73


7

1 INTRODUCTION AND SCOPE

1.1 Objective

The objective of this document is to provide practical guidance on the CE Marking of structural

steelwork in accordance with the Construction Products Directive (CPD) and the UK's

Construction Products Regulations (CPR). The guidance is for steelwork contractors, theirpurchasing clients and supply chain including designers, specifiers and construction managers.

1.2 Scope

The guidance in this document applies to the CE Marking of structural components that are

manufactured from carbon steel as welded or non-welded fabrications. The components

may be CE Marked individually or collectively as a kit.

This document applies to components intended for installation in construction works to be

built in the United Kingdom (UK), and applies as appropriate to the Republic of Ireland (RoI).

It is addressed principally to components used in structural steelwork for buildingconstruction works undertaken to the BCSA's National Structural Steelwork Specification for

Building Construction (CE Marking Edition). It can also be applied, with some modification,

to components to be used in other construction applications including bridges, or to

structural components manufactured from stainless steel or steel castings.

As explained in this document, CE Marking is applicable to the manufacture of structural

steel components, that is to the operations undertaken by steelwork contractors in the

fabrication of structural steelwork rather than the erection of structural steel frames on site.

1.3 Overview

With respect to the European Construction Products Directive, CE Marking applies to

manufactured structural components placed on the market individually or as a kit of

components and intended for use in any form of construction works (except marine and

offshore). The basis of the regulatory regimes applicable in the UK and the Republic of

Ireland is explained in section 2.

Components manufactured from structural steel may be CE Marked once they demonstrate

compliance with the relevant harmonised European Standard using the appropriate system

of attestation. The European Standard relevant to structural steel components is EN 1090-

1 and this document assumes that the British Standard BS EN 1090-1 will be available by

the end of 2008 from which date CE Marking of structural steel components is possible. EN

documents are designated with I.S. EN when issued in the RoI with otherwise identical textto BS EN versions.

BS EN 1090-1 Execution of steel structures and aluminium structures - Part 1:

Requirements for conformity assessment of structural components defines the

manufacturing controls needed to ensure that structural steel components meet the

necessary technical requirements that are defined in BS EN 1090-2 Execution of steel

structures and aluminium structures - Part 2: Technical requirements for steel structures.

The contents of these standards are explained in sections 3 and 4.

Special provisions apply if welding is used in steel component manufacture, and these are

explained in sections 5 and 6 and Appendix A.

The fabrication of structural steelwork is an assembly process that uses constituent

products (i.e. steel sections, fasteners and welding consumables). Some of these products,


9/73

SECTION 1 : INTRODUCTION AND SCOPE

8

such as curved beams, may be part-processed but not ready for incorporation into the

construction works until after further fabrication. Sections 7 and 8 explain how CE Marking

applies to these supply chain products and the requirements applicable to the fabrication

process necessary to ensure sufficient traceability.

BS EN 1090-2 introduces the concept of Execution Class that enables specifiers to select

the level of manufacturing quality management appropriate to how safety critical the

component will be in the construction works. This is explained in section 9.

As structural steel components are safety critical, CE Marking to BS EN 1090-1 requires

that the component manufacturer's factory production control (FPC) system is

independently assessed and certified by a body notified to the European Commission by

the appropriate national agency (DCLG in the UK). A manufacturer may employ any

suitable notified body (NB) from any member state to undertake initial inspection and

continuous surveillance of its FPC. Sections 10 and 11 explain this and what manufacturers

need to do. Further guidance issued by the European Group of Notified Bodies is included

in Appendix D.

Section 12 explains that, whilst CE Marking of structural steel components is relevant

primarily to manufacturers, it also has implications for designers - whether as specifiers of

the construction works requirements or as drafters of the manufacturing specification.

The general guidance in this document applies to structural steelwork used in building

construction. It can also be applied, with some modification, to components to be used in

other construction applications, and the different issues applicable to bridgework are

explained in Appendix B.

Appendix C provides example of the documents that support CE Marking.

Appendix E lists the abbreviations used in this document.


10/73


9

2 CE MARKING REGULATIONS

2.1 Construction Products Directive

The Construction Products Directive (CPD) came into force in 1988 and introduced the concept

of CE Marking for all construction products permanently incorporated into 'construction works'.

This includes steel products such as steel sections, bolts, welding consumables and fabricatedsteel components that are used in buildings, bridges, highways or other civil engineering

projects. The CPD is a piece of European legislation that is considered as one of the 'New

Approach' Directives, though the CPD differs in certain significant ways from the typical New

Approach Directive. Like all New Approach Directives the CPD was created to remove barriers

to trade by providing a common set of 'tools' across Europe to address the different rules on

construction products in the various member states; specifically the CPD establishes the

following framework:

A system of harmonised standards (sometimes referred to as hENs);

An agreed system for demonstrating the suitability of products;

A framework of certification bodies (known as Notified Bodies); and

The ability to CE Mark products.

This is explained in summary in the document CE marking under the Construction Products

Directive, published by the Department for Communities and Local Government (DCLG) and

currently available from the DCLG website.

A more detailed guide is: The Construction Products Directive - A practical guide to

implementation and CE marking, authored by Adam Pinney and Stephen Rein, two UK experts

who have acted as consultants to CEN and the European Commission in this area. Further

information can be found on http://www.apsrconsultantsltd.com.

As the CPD relates to public safety, enforcement is by means of a criminal prosecution againstthe company and its relevant employee. Some enforcement proceedings have been

undertaken by UK regulators over the period since 1988.

2.2 Harmonised standards

The CPD lists six 'essential requirements' that apply to all civil engineering works, these are

listed below:

1. Mechanical resistance and stability.

2. Safety in case of fire.

3. Hygiene, health and the environment.4. Safety in use.

5. Protection against noise.

6. Energy economy and heat retention.

These essential requirements derive from a comparison of what public safety provisions are

included in the building and construction regulations of the EU's member states. In essence,

meeting the provisions should ensure that the products meet the regulatory requirements of all

EU member states, including, for instance, the provisions on materials and workmanship in

Regulation 7 of the Building Regulations applicable to England and Wales.

For steel products and ancillaries only mechanical resistance and stability and safety in case of

fire apply. The harmonised product standards break down these general requirements intospecific measurable properties termed essential 'performance characteristics' (e.g. yield

strength, toughness and load bearing capacity) and establishes the values to be met.


11/73

SECTION 2 : CE MARKING REGULATIONS

10

The harmonised product standards establish common test methods and reporting styles for

declaring the essential characteristics of a product in the information accompanying CE Marking

- for example the required yield strength of nominal S275 steels reducing with thickness. They

also define the test methods and the testing frequency if sampling is to be adopted.

For steel products the main harmonised product standards are:

Steel sections and plates - BS EN 10025-1;

Hollow sections - BS EN 10210-1 and BS EN 10219-1;

Preloadable bolts - BS EN 14399-1;

Non-preloadable bolts - BS EN 15048-1;

Fabricated structural steelwork - BS EN 1090-1.

Providing the attestation of conformity procedures have been complied with, then CE Marking

is possible after the harmonised standards are cited in the Official Journal (OJ) and the date of

applicability given on the NANDO website has passed.

(See http://ec.europe.eu/enterprise/newapproach/nando/index.cfm?fuseaction=cpd.hs).

The Commission and much of Europe consider CE Marking is compulsory once the date of theend of the coexistence with national technical specifications has passed: the date is also given

on the NANDO website.

For EN 10025-1 the date of applicability was 1st September 2005 and the date for the end

of the coexistence period was 1st September 2006 giving a year's transition period for

manufacturers to implement CE Marking against the standard. For EN 1090-1 it is expected

that the standard will be published by CEN around December 2008. The date of applicability

will then be published on the NANDO website. This is likely to be around August 2009. It has

been agreed that there will be a two year coexistence period which would then end around

August 2011. By then the amended Construction Products Regulations are likely to be in

force and, as explained below, these are likely to make CE Marking mandatory throughoutthe European Union.

2.3 Certification

The CPD gives four different systems (with two additional sub-systems) for attesting that a

product conforms to the performance characteristics given in the harmonised standard (this is

called attestation of conformity). The system which applies to a product is published as a

Commission Decision in the OJ and is also given in a mandate from the European Commission

to CEN and is chosen on the basis of the nature of the product, its intended end use and the

role it plays in the structure. In the case of structural steelwork this is covered in mandate M/120

for structural metallic products and ancillaries that also covers rolled steel products, fasteners

and welding consumables.

Safety critical products like structural steel components and fabricated structural steelwork

are at attestation of conformity system 2+. This means that the manufacturer is not allowed

to fix the CE Marking without having a suitable factory production control (FPC) system in

place. This is verified by a notified inspection body (NB) after initial inspection and subject to

continuing surveillance who issues a certificate confirming that the manufacturer's FPC is

adequate to give confidence that the manufacturer's processes can produce products that

comply with the relevant harmonised standard.

For a body to be a NB for the purposes of BS EN 1090-1 it must be notified as an FPC

inspection body by a member state to the Commission and to other member states. This

notification confirms the NB as competent to assess the manufacturer's FPC as capable of

ensuring conformity of products to BS EN 1090-1 and that the NB meets the criteria set out


12/73


11

in Annex IV of the CPD. This notification is therefore specific to each harmonised standard,

and once this is done the NB can undertake the tasks for which it has been notified. The Steel

Construction Certification Scheme is seeking notification and will act as a notified body for

the harmonised standard for structural steel components to BS EN 1090-1. Even before BSI

publishes BS EN 1090-1, as soon as CEN publishes EN 1090-1 it will be available for

certification bodies and steelwork contractors to use to implement and assess FPC systems.

NBs can apply for notification concurrently with the final stages of the EN, which can be madeas soon as the EN passes its formal vote and is ratified. The CE Marking of products cannot

commence, however, until the date of applicability given on the NANDO website.

2.4 CE Marking

The CE Marking signifies that the products are in conformity with the relevant harmonised

technical specification (e.g. harmonised standard) and that the relevant conformity assessment

procedures have been complied with: hence the product has the declared performance for the

essential characteristics in the information accompanying the CE Marking.

CE Marking under the CPD shows purchasing clients, the authorities and others that theproduct complies with the appropriate harmonised European Standard. In the case of steel

products (such as sections, bolts and fabricated steelwork) the CE Marking is a declaration by

the manufacturer that the product is in conformity with the relevant harmonised standard(s) and

meets any threshold values required by the harmonised standard and has the values declared

in the information accompanying the CE Marking.

CE Marking and its accompanying information is a legal declaration by the manufacturer on

matters concerning health and safety about how the product performs in an intended use and

its impact is less about changing what the manufacturer has to do, and more about placing

greater onus on the manufacturer to get it right. To that end the manufacturer needs to satisfy

a notified body about the adequacy of its FPC system to avoid producing non-conforming

product.

2.5 Construction Products Regulations

The CPD is implemented in the UK by the Construction Products Regulations (CPR) and

manufacturers obey the CPR rather than the CPD directly. The CPR came into force in 1991

and describes two ways of complying with the legal provisions - by CE Marking products and

by not CE Marking products. Under the regulations CE Marked components are presumed

to comply with the harmonised technical specification and have the characteristics declared

when meeting building requirements/regulations, whilst other declarations about the product

do not carry this explicit presumption and the manufacturer may need to demonstrate to thebuilding control authorities etc that it does comply with the building regulations/requirements.

Under the non-CE Marking route, if asked, the manufacturer must supply to the authority all

the information it has on the product to enable the authority to satisfy itself whether the

product complies with the building regulations/requirements and hence can be placed on the

market for use in the works. CE Marking is therefore not mandatory in the UK but by opting

for the CE Marking route the legal position is much clearer and BCSA is recommending that

all of its members CE Mark the steel frames and components they fabricate.

The authorities responsible for enforcing the CPR are Trading Standards Officers in England,

Wales and Scotland, Environmental Officers in Northern Ireland and authorised officers in the

Republic of Ireland. The penalties for not complying with the CPR can be a 5,000 fine, 3months in prison or both.


13/73

SECTION 2 : CE MARKING REGULATIONS

12

2.6 Future developments

The European Commission is proposing to replace the CPD by a new Regulation with the

aim of further improving the free trade of construction products in the European Union and

simplifying the CE Marking process.

Unlike a European Directive, a European Regulation is enforceable as law in all member

states without the need for national legislation. In many ways a European Regulation isequivalent to an 'Act of Parliament of the European Union'. A consequence of replacing the

CPD with a European Regulation is that CE Marking will become mandatory in the UK and

the Republic of Ireland.

The proposed regulation places legal obligations on Manufacturers, Importers and

Distributors and on those companies in the supply chain who either place a product on the

market under their own trademark or modify a construction product already placed on the

market so as to change its essential characteristics. If the regulation becomes law it will have

implications for all parts of the structural steelwork supply chain including the fabrication

services provided by steel stockholders and steel benders.

The proposal also replaces the six 'essential requirements' with seven 'basic worksrequirements'. These will apply to all construction works. The first six 'basic works

requirements' are identical to the six 'essential requirements' given on page 9. The seventh

reflects the European Community's drive for a more sustainable built environment. The draft

wording of this requirement is:

7. Sustainable use of Natural Resources

The construction works must be designed, built and demolished in such a way that the use of

natural resources is sustainable and ensure the following:

a) Recyclability of the construction works, their material and parts after demolition;

b) Durability of the construction works;

c) Use of environmentally compatible raw and secondary materials in the construction

works.

The European Commission is keen for the proposed regulation to pass all stages by spring

2009, i.e. sufficiently before the European elections in early 2009. This will mean that the

Regulation will come into UK and RoI laws in July 2011 with some provisions coming into

force sooner.


14/73


13

3 CE MARKING STANDARD FOR STRUCTURAL STEELWORK

3.1 Basis

The basis of CE Marking is that the manufacturer declares that its products meet specified

performance characteristics that are defined as essential to the application of the products

in the field of construction. In order to do this the manufacturer needs to:

Know the requirements in terms of defined essential performance characteristics andrequired values to be met. For structural steel components these requirements are

defined in clause 4 of BS EN 1090-1.

Use specified test methods that can evaluate whether products conform to thespecified requirements. For structural steel components these evaluation methods

are defined in clause 5 of BS EN 1090-1.

Implement a system for controlling regular production. For structural steelcomponents the system for evaluation of conformity is defined in clause 6 of BS

EN 1090-1.

Mark its products in the correct way using a suitable classification and designationsystem. For structural steel components the marking system is defined in clauses 7

and 8 of BS EN 1090-1.

These four aspects of BS EN 1090-1 Execution of steel structures and aluminium structures

- Part 1: Requirements for conformity assessment of structural components are explained

in detail below.

BS EN 1090-1 is one of a suite of harmonised European Standards dealing with structural

metallic products and ancillaries. All harmonised standards include an Annex ZA and the

implications of this are explained in detail below.

3.2 Scope

BS EN 1090-1 deals with the manufacture of load bearing components and kits of

components for use in structures. The components can be made of steel that is hot rolled, cold

formed or produced with other technologies. They may be produced of sections/profiles with

various shapes, flat products (plates, sheet, strip), bars, castings, forgings made of steel or

aluminium materials, unprotected or protected against corrosion by coating or other surface

treatment, e.g. anodising of aluminium. The standard does not cover conformity assessment

of components for suspended ceilings, rails or sleepers for use in railway systems.

3.3 Definitions

Some important principles may be drawn from the definitions given in clause 3 of

BS EN 1090-1.

3.3.1 Constituent products

The scope of BS EN 1090-1 acknowledges that the fabrication of structural steelwork is an

assembly process that uses constituent products such as steel sections, fasteners and

welding consumables. Importantly, the application of BS EN 1090-1 relies on using the

harmonised product standards for these constituent products.

For instance, BS EN 10025-1 Hot-rolled products of structural steels - Part 1: General

technical delivery conditions is a harmonised standard and it requires that steel products


15/73


16/73


15

Generally the steelwork contractor will also be the manufacturer and hence this distinction is

not generally an issue. However, if the steelwork contractor alters components or a kit supplied

by another manufacturer, or adds to such a kit in any way and then relies upon CE Marking

as a demonstration of conformity then the steelwork contractor becomes the manufacturer of

that kit or those components.

3.3.4 Design brief

Fabricated steel components are generally bespoke because they are made for specific

projects. In the NSSS the termproject specification is used for the specification prepared for

a specific building project. With respect to those parts of the construction works described in

the project specification as structural steelwork, the NSSS anticipates that the engineerwho

is responsible for the design of structural members will prepare design drawings that include

all information necessary for the design of connections and completion of the fabrication

drawings. Irrespective of whether the engineer is working directly for the employeror for the

steelwork contractor, the NSSS assumes that the steelwork contractor will undertake the

detailing of the steelwork and the design and detailing of connections.

Thus, it is generally necessary for the steelwork contractor to undertake some design work

in preparing the details needed for the component specification. This design work will be

undertaken to what BS EN 1090-1 terms a design brief which would in essence comprise

the design drawings and the other appropriate information itemised in Tables 1.1 to 1.7 of

the NSSS.

3.3.5 Structural characteristics

BS EN 1090-1 defines some of the essential performance characteristics as structural

characteristics. These are governed in part by the design approach used to evaluate them

and refer to:

Load bearing capacity;

Fatigue strength; and

Resistance to fire.

The essential performance characteristics itemised in BS EN 1090-1 that are not defined as

structural characteristics are:

Tolerances on dimensions and shape;

Weldability;

Fracture toughness; Reaction to fire;

Emission of radioactivity; and

Release of cadmium.

The extent to which these essential characteristics may depend on the constituent products

used in manufacture can be identified by checking the essential performance characteristics

itemised in the harmonised standard for the constituent product. For instance, BS EN

10025-1 includes the following essential characteristics:

Tolerances on dimensions and shape;

Elongation; Tensile strength;

Yield strength;


17/73

SECTION 3 : CE MARKING STANDARD FOR STRUCTURAL STEELWORK

16

Impact strength;

Weldability.

The tolerances relevant to a constituent product continue to apply to components

manufactured from such products, unless BS EN 1090-2 (which is invoked for such

requirements by BS EN 1090-1) specifies more stringent criteria. Elongation is not directly

specified as an essential characteristic in BS EN 1090-1, but the evaluation of structuraldesign characteristics will depend on assumptions about elongation. For instance,

Eurocode designs apply to steels with minimum elongation of 15%.

Steel products to BS EN 10025-1 are designated with a steel grade, e.g.S275, which

signifies both the permitted range of tensile strength and the minimum yield strength. To the

extent that these values are affected by subsequent processes used in manufacture (e.g.

welding, hot or cold bending, or thermal cutting used in fabrication), BS EN 1090-2 specifies

restrictions on how these processes may be used.

BS EN 1090-1 defines fracture toughness and impact resistance as the same requirement.

BS EN 10025-1 refers to the impact strength of steel products which is assessed using Charpy

V-notch (CVN) impact tests, and BS EN 10025-1 defines weldability in terms of chemicalcomposition using the carbon equivalent value (CEV). Both these characteristics may be

affected by subsequent processes used in manufacture of steel components, especially in the

heat affected zone (HAZ) of the parent metal during welding. Thus BS EN 1090-2 specifies

particular requirements for the CEV of steel products that may be welded, as well as the

minimum CVN and maximum hardness permitted in the HAZ and the weld metal.

3.3.6 Load bearing capacity

The determination of the load bearing capacity of a structural component can be a complex

issue as it may involve, for instance, member design for buckling, connection design for

bearing, crushing etc. as well as an understanding of the behaviour of welds andmechanical fasteners such as preloadable bolts. Prior to the advent of a harmonised

standard for structural steel components, steelwork contractors and/or their purchasing

clients have been undertaking such design evaluations on all steelwork projects. It is not the

intention of the CPD to change this way of working or to place unnecessary impediments in

how such design matters have been undertaken in meeting the existing national regulations

for building construction etc.

Parties undertaking design in support of developing the component specification should not

expect to alter their ways of working. The only supplementary change is that the

manufacturer undertaking (some of the) design work has the option of including a warranty

on that element of the design when declaring that the component meets the componentspecification (see the optional methods for preparing the component specification explained

below).

The simplest way of looking at the issues associated with load bearing capacity is that the

component derives its capacity from that of its constituent products and the way those are

assembled. Typically the shape and yield or tensile strength of, say, a steel beam

determines its load bearing capacity - and values for safe loads are given in member

capacity tables. What the manufacturer is charged with is that the processes used in

fabrication do not impair the properties of the plain member.

BS EN 1090-1 requires the manufacturer to address how structural characteristics are

dependent on the manufacturing characteristics of the product. Most importantly for loadbearing capacity in quasi-static building construction, this depends on the yield strength of

the constituent products, and, as noted above, this can be affected by subsequent


18/73


17

processes used in manufacture such as welding. Hence, the manufacturer needs to

observe the provisions of BS EN 1090-2 with respect to welding and to have a suitable

welding quality management system (WQMS) in place. This enables the manufacturer to be

confident that any impairment of the yield strength of, say, parent materials in the HAZ is

within defined limits as evidenced by the limits on hardness etc. measured during the testing

in support of the Welding procedure qualification record (WPQR).

Then, in effect, the manufacturer may declare the equivalent of load bearing capacity by

warranting that the component has been made in accordance with its component

specification (i.e. fabrication drawing) on which appears the grade, shape, configuration etc.

of the constituent products from which load bearing capacity can be evaluated by

calculation to, say, the Eurocodes.

3.3.7 Evaluation methods

In most harmonised standards, essential characteristics are evaluated by physical testing to

a supporting European Standard. For instance the test method specified in BS EN 10025-1

for evaluating impact strength is BS EN 10045-1 Charpy impact test on metallic materials -Part 1: Test method (V-and U-notches). Physical testing is applicable to products of a

standard or standardised type but is not easily applied to bespoke products. Whilst the safe

load bearing capacity of a lifting beam might be established by a physical test, such non-

destructive proof load testing of bespoke structural components is impractical; and it may be

impossible to establish fatigue strength or resistance to fire by other than destructive testing.

Hence, BS EN 1090-1 allows measurement of geometry and/or structural calculations to be

used as evaluation methods, as well as structural testing supported by calculations.

3.3.8 Preparation of the component specification

BS EN 1090-1 includes an informative Annex A that provides guidelines for preparation of

the component specification. The annex distinguishes the following typical cases:

Manufacturer provided component specification (MPCS). This case is typical of

steelwork contracting in general whereby the detailing and connection design are

undertaken by the steelwork contractor. In this case BS EN 1090-1 allows two options:

Option 1:

The manufacturer only declares the geometry and the material properties of the

component. The manufacturer attaches the component specification to the

component and provides a CE Marking that warrants that the as-manufactured

component complies with its component specification. The manufacturer provides

no warranty with respect to the design work that it has undertaken to develop the

MPCS from the design brief.

BS EN 1090-1 relates this option to Method 1 in Guidance Paper 'L' Application and

use of Eurocodes. If this is the option that the manufacturer always uses then this

limitation should be clear on the scope statement on the manufacturer's declaration

of conformity.

Option 2:

In this case, the manufacturer declares not only the geometry and the material

properties of the component but also the structural characteristics (such as load

bearing capacity) resulting from design of the component. The manufacturer needs

to undertake the design. The manufacturer thus includes in the CE Marking a

warranty that its design work has been undertaken according to the design brief.


19/73


18

BS EN 1090-1 relates this option to Method 2 in Guidance Paper 'L' and assumes

that such a design brief would be wholly based on the relevant parts of the

Eurocodes. This would be particularly useful for manufacturers of standardised

products, such as cold-formed purlins, intended for sale throughout Europe. Then the

product could be supplied against a component specification showing dimensions

and giving constituent material properties, together with an attached data sheet

giving, for example, Eurocode-based load bearing capacities in relation to spans andfixings. The parameterisation would need to cater for National Annex values adopted

for the nationally determined parameters (NDPs) allowed by the Eurocodes.

Alternatively, Method 3 in Guidance Paper 'L' allows CE Marking of structural

characteristics to a design brief that is bespoke to a client's project. Thus BS EN

1090-1 defines an MPCS to Method 3b as one that includes structural characteristics

evaluated by design to a brief issued by the purchaser or one developed by the

manufacturer to meet the purchasing client's order. Method 3a to BS EN 1090-1 thus

allows CE Marking of components with design values evaluated at least in part to,

say, an American standard provided that this is explicitly agreed in the purchasing

client's order. For instance, the component may be designed to the Eurocodes forstatic design, but to the AISC code for seismic design resistance. It should be noted

that Method 3b is not applicable to products placed on the European market where

the purchaser is not known in advance of product delivery. In such cases it is

imperative that component specification is clearly linked to the design basis used for

calculations.

Purchaser provided component specification (PPCS). In this case the manufacturer

undertakes no design and simply provides a product that meets the fully definitive PPCS

together with the necessary supporting documentation. BS EN 1090-1 defines this as

Method 3a to Guidance Paper 'L', as this allows components to be supplied to a PPCS

based on the purchasing client's choice of design code that may be other than theEurocodes.

However, this case is more typical of a steelwork contractor subcontracting fabrication to

another fabricator/supplier on the basis that the purchasing steelwork contractor

provides fully detailed fabrication drawings for the manufacture of the sublet work. The

purchasing steelwork contractor will usually require the components to be supplied with

appropriate CE Marking, which will mean that the subcontract fabricator/supplier must

have a suitably certified FPC.

3.3.9 Use and location

In the case of a PPCS the use and location of a component are known in advance.

However, for a MPCS there is an important distinction to be made between components

made for a use and location that is known in advance and those whose use and location

are unknown at the time the component is placed on the market. For design to the

Eurocodes under Method 2 (Option 2) above, BS EN 1090-1 describes the former case as

Method 2a and the latter case as Method 2b. Under Method 2a the relevant NDPs in the

National Annex for the location and use will be known. Under Method 2b the structural

performance characteristics for the component will be application neutral. Hence a product

data sheet containing, say, load-span tables for such a component would need to be

carefully drafted to avoid a potential purchaser/user making a mistake about, say, the

component's load bearing capacity that is safe in the actual location and use decided bythe purchaser/user.


20/73


19

3.3.10 Reaction to fire

Reaction to fire refers to issues such as surface spread of flame, and uncoated steel

constituent products are classified as Class A1 with respect to reaction to fire. No further

documentation is required to support this classification for an uncoated steel component

manufactured to BS EN 1090-1.

There is currently no harmonised standard covering how reaction to fire for coatings applied tosteel components shall be declared. BS EN 1090-1 anticipates that this will be dealt with by

specifying the applied coating in the component specification, and providing supporting

information using the coating manufacturer's product data sheet as evidence of the coating's

properties. In due course, a standard format for declaring the properties of applied coatings is

likely to be prepared as the basis for CE Marking such products supplied for use in construction.

3.3.11 Dangerous substances

The CPD requires manufacturers to declare whether their products emit radioactivity or

release cadmium. In general, BS EN 1090-1 requires no testing for these dangerous

substances if the steel component is manufactured from steel constituent products and isnot coated. If the steel is coated the manufacturer may have to make a separate declaration

concerning the coating as with reaction to fire.

3.3.12 No performance determined

Unless an essential characteristic is regulated in the European member state where the

component is to be used, a manufacturer's CE Marking may state No performance

determined (NPD - not to be confused with a National Annex NDP) for that characteristic.

For instance, structural steelwork undertaken to the NSSS is intended for building

construction where fatigue is not a factor in design. It would then be in order to state

Fatigue strength - NPD. The manufacturer may however wish to declare performance

characteristics not regulated in certain member states for marketing purposes or for

economy reasons to facilitate easier movement of products within all member states.

In Annex ZA of BS EN 10025-1, for instance, some essential performance characteristics

are noted as threshold values (a minimum value below which the product is not fit for use).

Where performance characteristics for structural steel components are declared using the

properties of constituent products which are in turn based on threshold values, then the

restriction still applies that NPD cannot be stated for those characteristics as a minimum or

threshold value must always be met.

Although BS EN 1090-1 allows NPD to be declared for weldability for non-welded

components, it should be noted that the harmonised standards for most constituent steel

products include weldability as a threshold value (e.g. see BS EN 10025-1). In such cases,

whether the steel component is welded or not, NPD may not be declared for the component

if the declaration relies upon properties transmitted from those of its constituent products.

All the examples of CE Marking given in Annex ZA of BS EN 1090-1 state that NPD is used

for release of cadmium, and emission of radioactivity. In practice, steel products do not emit

or release either dangerous substance, and hence rather than NPD it is practical to declare

No release of cadmium and No emission of radioactivity.


21/73


20

3.4 Requirements

3.4.1 General

The basis of how the essential performance characteristics defined in BS EN 1090-1 are

specified as requirements for manufacture of a steel component is as follows:

Steel components are manufactured from steel constituent products with essentialcharacteristics that are defined in the harmonised standards for those products.

The manufacturer incorporating those products into a structural steel componentneeds to ensure that:

Incoming materials to be used as constituent products comply with the relevantspecification by documentary check supplemented by re-testing if necessary (see

section 8 on how this affects the supply chain);

The use of those constituent products in manufacture meets the necessarytraceability requirements (see section 7);

The modification of the essential characteristics of the constituent products by theprocesses of steel component manufacture, such as by welding, is controlled to

meet the requirements of BS EN 1090-2 Execution of steel structures and

aluminium structures - Part 2: Technical requirements for steel structures (see

section 4 below which explains the content of BS EN 1090-2 in detail).

Structural characteristics are established by suitable design calculations and/orphysical testing.

3.4.2 Durability

The CPD requires that the durability of the essential characteristics is established. It should

be noted that the durability required is related to the essential performance characteristics

identified in the harmonised standard.

As there is no applicable direct method for testing durability, BS EN 1090-1 introduces the

following principles to establish the durability of a steel component. The durability depends

on the constituent products. The essential characteristics of steel constituent products are

immune from degradation over time with the major exception that atmospheric corrosion

can impair cross-sectional dimensions.

Some products use structural steels with improved atmospheric corrosion resistance, for

which the required chemical composition is specified in the relevant supporting standard.

Otherwise, durability is defined in terms of the corrosion protection applied to the surface ofa steel component.

The selection of a method for protecting steel components from corrosion is covered by BS

EN 1090-2. This allows the indirect evaluation of durability in terms of the classified

exposure of the component linked to specified requirements for surface protection in the

component specification. The NSSS offers six standard specifications for applied surface

coatings that may be invoked in component specifications.

It is arguable that in two other respects - fatigue and fracture - the properties of constituent

steel products are less than permanently durable as over the longer term steel can be

susceptible to failure due to externally applied cyclic stresses or low temperatures. As both

these properties are explicitly defined as essential structural characteristics in BS EN 1090-1, the issue of durability can be addressed by declaring values that are related to the stress

cycling or working temperature as relevant.


22/73


21

3.5 Evaluation methods

The evaluation methods to be used are related to the manufacturing requirements to be

evaluated that are derived from the essential performance characteristics defined in BS EN

1090-1. A combination of three methods is included in BS EN 1090-1 and the harmonised

standards for constituent products:

Physical testing - used for example to establish fracture toughness of steel materialsusing the CVN impact test.

Measurements of geometry - used for tolerances on dimension and shape, andcovered in BS EN 1090-2.

Structural calculations - which may be used to evaluate load bearing capacity, fatiguestrength and resistance to fire.

BS EN 1090-1 allows the use of physical testing instead of or in support of calculations. For

instance, the supplementary rules in the Eurocodes for the design of steel cold-formed

members and sheeting specifies testing procedures to be used. BS EN 1990 Eurocode -

Basis of structural design defines various types of test and specifies the proper statistical

methods for the evaluation of test results.

It is also worth noting that BS EN 10025-1 relies wholly on physical testing and

measurements of geometry to establish conformity and the introduction of structural

calculations as a third evaluation method in BS EN 1090-1 is linked to the fact that it covers

bespoke products and non-series production.

3.6 Evaluation of conformity

3.6.1 Initial type testing

The general principles behind the evaluation of conformity are the use of initial type testing(ITT) and factory production control (FPC). The basis of ITT is:

A manufacturer develops a product type.

What might be termed prototype examples of the new product type are tested toestablish their properties against the essential performance characteristics.

The new product type is commissioned into production and representative samplesfrom new production are tested to establish that the production methods used can

produce conforming product.

Thus ITT is necessary at the commencement of production of a new product type including

production using new constituent products, and at the commencement of new or modifiedmethods of production.

As BS EN 1090-1 applies to the manufacture of bespoke components that may be unique

examples of their type, it is impractical to apply the simple concept of ITT described above.

Hence, the concept of initial type calculation (ITC) is introduced as a conformity evaluation

method. What this builds on is the wealth of physical testing undertaken in research

laboratories that has been codified into the design rules that underpin the ITC. Thus even a

unique example of a structural component is built up in the calculations from what might be

termed sub-types - for instance the behaviour and bearing resistance of an end plate in a

bolted connection.

ITC is built up wholly on what might be termed historical data, and BS EN 1090-1 allowshistorical data from both ITC and ITT to be used. This reduces the amount of type testing

that the manufacturer needs to perform. However, the application of historical data needs


23/73


22

to be carefully considered when, say, test results obtained in support of a product meeting

British Standards are extended to meet a European Standards. BS EN 1990 provides the

statistical basis for using such prior information.

The steel constituent product standards, such as BS EN 10025-1, measure the essential

performance characteristic of weldability in terms of chemical composition as a carbon

equivalent value (CEV). Welding to BS EN 1090-2 builds on this concept of weldability by

applying the concepts behind ITT in the methods used to evaluate conformity of welded

components, as follows:

A manufacturer wishes to develop a welding procedure specification (WPS) anddefines parent and weld materials, welding process, joint design and preparation,

welding position and technique etc. in a preliminary welding procedure specification

(pWPS).

Using the pWPS as the reference document, the manufacturer carries out a weldingprocedure test, which is then subjected to destructive and non-destructive tests

(NDT) to specified standards. The results of the testing and the actual welding

parameters used are recorded in a welding procedure qualification record (WPQR).

The WPQR is used to support application of the WPS in practice and the qualificationof other WPS to be used in production within a defined range of essential variables,

for example material type/thickness, joint types, welding position etc.

The fact that the WPS may be used over a range of actual welds that differ somewhat from

the initial type tested is an example of the allowance in BS EN 1090-1 to extend application

of ITT to other situations in a family. The range of qualification allowed in the welding

standards defines how big the family may be, which in terms of parent materials is done

using steel groups cited in BS EN 1090-2.

BS EN 1090-2 also builds on the ITT concept with respect to using a qualified WPS in

production as it specifies that the first five joints made to the same new WPS must meetquality levels comparable to those in the procedure test when subjected to NDT. This

establishes that a WPS can produce conforming quality when implemented in production.

Thereafter the NDT on production welding is reduced to sampling as part of FPC.

BS EN 1090-1 restricts the application of a given ITT programme to a production of

components within a defined Execution Class (EXC). This concept is explained further

below, but it has a particular implication for production welding in that requirements for the

welding quality management system (WQMS), the methods of qualification, the extent of

FPC testing and the production quality levels required differ for EXC2, EXC3 and EXC4. For

EXC4, BS EN 1090-2 requires production welds to meet a higher quality than that

established by ITT in the WPQR.

3.6.2 Factory production control

Factory production control (FPC) is needed to establish that a manufacturer can produce

conforming product in regular ongoing production. In essence what the manufacturer does

is to establish the key control checks during the ITT phase and then to sample test actual

production to compare it with necessary quality levels established by ITT. FPC is thus used

to prove that products conform to the product type, given that ITT has been used to prove

that the product type meets the required essential performance characteristics.

As FPC is based on sampling, the minimum frequency and extent of sample testing is

defined in the harmonised standard. For products to BS EN 10025-1, this can be specific toa lot or cast (type 3.1 inspection certificate) or non-specific (type 2.2 test report). Specific


24/73


23

testing is required for all steel products except those of the following qualities: S275JR,

S275J0, S355JR or S355J0.

As BS EN 1090-1 covers bespoke non-series production the required number of samples

is specified as only one (i.e. the component may be its own unique type) when applied to

calculations of structural characteristics, dimensional measurements, and the checking of

CEV and CVN values for the constituent steel products. More extended sampling is required

when the conformity evaluation is established by physical testing rather than calculation.

In practice, production to BS EN 1090-2 as a supporting standard for BS EN 1090-1 means

that many requirements relating to production are specified. As noted above this has

particular application to the use of NDT to establish that production continues to produce

conforming welds treating further joints welded according to the same WPS as a single

continuing production lot. The NSSS uses the term routine testing for this aspect of FPC.

In many ways FPC may be seen as a sub-set of the controls necessary in a quality

management system based on BS EN ISO 9001, and BS EN 1090-1 allows (but does

not require) an FPC conforming to BS EN ISO 9001 to be used as the basis for the

required system.

The detailed requirements for the FPC are explained in section 10, and it should be noted

that the system is defined in terms of written procedures, regular/routine inspection (i.e.

quality control) supported by competent personnel and suitable equipment for production

and testing.

3.6.3 Attestation levels

Attestation of conformity is the term used to define the whole system needed to ensure that

only conforming products are placed on the market. This allocates certain tasks to the

manufacturer and others to an independent organisation that the manufacturer appoints to

certify defined aspects of its operations as meeting the required standard.

Certification organisations themselves need to be suitably competent to undertake their

allotted tasks. Their competence is established against BS ISO/IEC 17021 Conformity

assessment - Requirements for bodies providing audit and certification of management

systems and the scope of competence of the organisation is accredited by, say, UKAS. This

accreditation is then used by the competent authority (DCLG in the UK) to notify the

European Commission and the certification organisation then becomes a notified body (NB).

Depending on the attestation level which has been chosen by the European Commission,

the NB may be involved as a third party in certifying:

The FPC system, as is required for all structural steel components and explainedbelow with respect to BS EN 1090-1. This is system 2+ and it permits the

manufacturer to issue a Declaration of Conformity related to its products. The role of

the NB under system 2+ is defined as that of an inspection body rather than that of a

certification body as the latter implies that product or product type certification is

involved (as below);

The product type by involvement in the ITT/ITC. This would be system 1+ and wouldresult in the NB issuing a Certificate of Conformity related to the manufacturer's

product types; or

The products themselves. Outside of the CE Marking requirements, BS EN 10025-1allows this option for certain higher quality steels whereby the purchaser's authorised

inspection representative endorses the declaration that the products supplied are in

compliance with the requirements of the order.


25/73


24

The attestation level specified for all structural steel components is level 2+ which allocates

the tasks as follows:

Tasks under the responsibility of the manufacturer: ITT, FPC and product testing.

Tasks for the NB: Certification of the manufacturer's FPC on the basis of both initialinspection and continuous surveillance.

3.6.4 Product testing

BS EN 1090-1 specifies the amount of product testing by the manufacturer as follows:

Checking those essential dimensions that are critical to use of the component oneach component or a suitable sample if components are manufactured under similar

conditions. The requirements for dimensions that are essential are listed as essential

tolerances in BS EN 1090-2.

Checking the manufactured components against the component specification withrespect to the requirements for surface treatment for corrosion protection as specified

in BS EN 1090-2. Checking that the inspection documents for constituent products conform to the

required values for CEV, CVN, and yield, proof or tensile strengths as specified in BS

EN 10025-1 or other relevant harmonised standards for steel products.

For design undertaken by the manufacturer, verifying that the calculations used todevelop the component specification are relevant and have been carried out in

accordance with the design brief.

Checking that manufacturing processes that affect structural characteristics are beingundertaken to BS EN 1090-2. This is relevant to processes that may alter the

essential performance characteristics of constituent products. Hence, BS EN 1090-2

specifies the relevant procedure and production testing for welding, bending, andthermal cutting.

3.6.5 Laboratory testing

The possibility for third party endorsement of the product type is comparable to third party

endorsement of actual laboratory test results as opposed to endorsement that the system

for control of laboratory testing has been checked within the scope of the FPC

endorsement. In terms of BS EN 10025-1 laboratories undertake material tests to establish

CEV, CVN etc., and the system for control of laboratory testing requires;

A direct check of the performance of the manufacturer's own laboratory within thescope of the FPC;

Accreditation of the laboratory under BS EN ISO/IEC 17025 General requirements forthe competence of testing and calibration laboratories (or equivalent) with the

accreditation being specific for the tests carried out; or

Direct assessment of an external laboratory by the NB.

In terms of BS EN 1090-1 there are similar requirements that treat laboratory testing as part

of the manufacturer's FPC. For EXC2 and above this applies to tests associated with

welding, and the NSSS thus requires a competent examiner or examining body to verify the

WPQRs, to witness welder qualification tests (WQTs) and to endorse the WQT certificates.

These responsibilities are distinct from those of a possible project-specific third partyinspection authority that may be appointed.


26/73


25

3.6.6 Design control

As noted above, control of design is seen as part of FPC to the extent that the manufacturer

chooses to warrant the design work it undertakes to develop the component specification

from the design brief. The NB is not required to verify the content of the design or that the

component specification complies with the design brief as this would be equivalent to

product type certification to attestation system 1.

The NB is required to certify during initial inspection and continuous surveillance that

suitable design control procedures are in place (e.g. for revising drawings), and that design

work is being undertaken using suitable equipment and other resources (e.g. suitable

computer programs and latest copies of design codes). During initial inspection the NB is

also asked to certify that that design work is being undertaken by suitably competent

personnel with defined job descriptions.

3.6.7 Certification of the FPC

BS EN 1090-1 defines those minimum aspects of the FPC that must be assessed by the

NB. During initial inspection these relate to checking whether the resources (premises,personnel and equipment) are adequate for the manufacture of steel components to BS EN

1090-2. This also comprises:

Checking that the FPC has procedures for checking conformity and handlingprocedural non-conformities and non-conforming product.

Evaluation of job descriptions (e.g. based on an organogram) and requirements forcompetence of personnel (e.g. for weld inspection personnel).

During continuous surveillance the NB:

Checks that the manufacturer is undertaking the specified product testing described

above that is associated with execution work. Checks that the FPC procedures for checking conformity and handling procedural

non-conformities and non-conforming product are being operated properly.

3.6.8 Welding certification

Specifically for those manufacturers who use welding and following the initial inspection, the

NB is required to identify the scope of certification of the FPC in terms of the welding

processes and parent materials covered. The manufacturer can establish the basis for this

scope by using its portfolio of WPSs, WPQRs and WQTs as those documents underpin the

operation of the FPC for welding. In this regard it is required that for each main welding

process the manufacturer shall have available welder(s) with suitably qualified welding

procedures.

As the NB also needs to confirm on the certificate which Execution Class is relevant to the

manufacturer's FPC for welding, the NB needs to assess the welding quality management

system (WQMS), the methods of qualification, the extent of FPC testing and the production

quality levels and to relate these to the Execution Class using the requirements specified in

BS EN 1090-2 (see section 5).

Unless the scope of certification is limited to EXC1, the Responsible Welding Coordinator

(RWC) also needs to be identified on the certificate. The certification of the FPC for welding

may be identified within the general FPC certificate or issued as a separate welding certificate.

Although it is not required, it may also be agreed between the manufacturer and the NB that

the WQMS is certificated according to the appropriate level of BS EN ISO 3834. If the


27/73


26

manufacturer already has its WQMS certified to BS EN ISO 3834, then this may be relied upon

as relevant when the NB issues the general certificate for the FPC.

During continuous surveillance, the NB is not specifically required to re-certificate the FPC for

welding, but in practice re-certification of the FPC will include a review of the WQMS for a

manufacturer of welded components. The NB also has the authority to undertake a surveillance

audit if circumstances change. In this respect, the manufacturer is required to inform the NB of

changes that could affect the validity of the certificate, such as:

New or changed essential facilities;

Change of Responsible Welding Coordinator;

New welding processes;

New essential equipment.

3.7 Marking system

3.7.1 General

The basis of the marking system is that the component shall be identifiable against the relevant

essential performance characteristics that are to be warranted by the manufacturer as

complying with the requirements of BS EN 1090-1. This requires that the component is linked

uniquely to its component specification, and if this is in the form of a fabrication drawing the

information required by BS EN 1090-1 can be given on the drawing.

In addition, BS EN 1090-2 specifies certain requirements related to traceability (see section 7)

and identification methods applicable to component manufacture, and links these to the

marking necessary for correct use of the component in terms of erection.

Most often bespoke steel components are supplied to a given project for eventual erection as

a complete structural frame for, say, a building. In such cases the components may be seen as

a kit, and the marking can be done on a collective basis for them all. Typically this might be

done using the erection marking plan as a central reference point to define the kit, and then to

attach the necessary CE Marking information to the whole kit via the marking plan. This method

has an obvious extension for steelwork contractors undertaking design-and-build projects and

who wish to warrant the design as well as the manufacture of all the components by reference

to the design calculation sheets.

3.7.2 Classification and designation

BS EN 1090-1 requires that the Execution Class relevant to its manufacture is given on thecomponent specification.

The requirements for dimensions that are essential performance characteristics are listed as

essential tolerances in BS EN 1090-2. For some essential tolerances, such as those for

cylindrical and conical shells, more than one class is specified. In which case, the component

specification needs to identify the class that is relevant to the component.

3.7.3 CE Marking

BS EN 1090-1 includes an informative Annex ZA related to the application of the CPD to

structural steel components. It is informative as it pertains to application of national regulations

which cannot be made mandatory by a European Standard. Instead the framework is given in

the informative annex which is then mandated in practice by the appropriate regulations in each

European member state.


28/73


27

The annex links together the following elements of the required CE Marking system:

The FPC certificate issued by the NB (as described above).

The declaration of conformity made by the manufacturer. This is a document that themanufacturer prepares and maintains which then entitles the manufacturer to affix the

CE Marking. It must be signed by an appropriate employee of the manufacturing

company, and is the basis for criminal proceedings if the regulators believe that the CEMarking has been wrongly applied by the manufacturer. Appendix C illustrates an

example of a declaration of conformity.

The CE Marking of the component. This includes the CE Mark itself (literally the lettersC and E in a particular type style and size) as well as other information as illustrated in

Appendix C.

BS EN 1090-1 allows the CE Marking to be done on one of four templates linked to the

preparation of the component specification via the methods defined in Guidance Paper 'L' as

follows:

By reference to component geometrical data and the material properties of constituent

products with NPD for structural characteristics determined by design (Method 1 usingMPCS Option 1);

As above but including values for structural characteristics determined by design to therelevant Eurocodes (Method 2 using MPCS Option 2);

As above but including values for structural characteristics determined by design to thepurchaser's design requirements (Method 3b using MPCS Option 2); or

By reference to component geometrical data and the material properties of constituentproducts with a cross-reference to the purchaser's design but no specific values for

structural characteristics determined by design (Method 3a using PPCS).

As noted previously, at the present time CE Marking under the CPD is not mandatory under thenational regulations implemented in the UK and the RoI. Most often CE Marking of structural

steel components to BS EN 1090-1 applies to production intended for a bespoke project-

specific application that is known in advance of manufacture. In such cases, even if CE Marking

were mandatory or adopted voluntarily, it would be reasonable to apply BS EN 1090-1 to the

final completed component that is directly ready for site assembly and/or erection. Whether the

steelwork contractor as manufacturer of the completed component requires CE Marking to be

used by its supply chain (see section 8) then depends on how the manufacturer wishes to

exercise FPC. Clearly the steelwork contractor will require most constituent products to be CE

Marked, but might control the operations of some sublet suppliers undertaking steel processing

within the purchasing steelwork contractor's own FPC system. This has particular relevance for

the WQMS and the control of welding by sublet suppliers.

3.7.4 Affixing the CE Marking

The CE Marking may be located in one of the following places:

on the product;

on the packaging; or

in the manuals or other supporting commercial literature accompanying the product.

It is likely that for bespoke project-specific items the CE Marking would be located on the

In this context accompanying means unambiguously linked to, it does not mean that the commercial

literature has to physically be attached to the product.


29/73


28

fabrication drawings that comprise the component specification. The component itself then

only needs an identity mark (such as the piece marks in use currently) that links it

unambiguously to the relevant drawing, perhaps via a delivery list or marking plan as

currently.

For series items, such as proprietary purlins, it is more likely to be placed on the product

label. For steel products it is generally on the inspection document, and for fasteners and

welding consumable it is generally on the packaging.

3.7.5 Packaging

In principle the importance of packaging for a product with CE Marking is that the

manufacturer produces conforming product ex-works and the obligation on the

manufacturer is to use packing that is sufficient to preserve the essential performance

characteristics for a reasonable time reflecting the period until the purchaser is ready to

install the product in the construction works.

For structural steel components, the context is somewhat different, as the components are

nearly always made to order, and the essential performance characteristics are largelyunaffected by exposure during the period between leaving the manufacturer's works and

being installed on site. Furthermore, in bespoke cases a steelwork contractor would be

liable to rectify any damage that the component received before it was finally handed over

as part of the construction works.

For these reasons, BS EN 1090-1 is largely silent about packaging requirements, and BS

EN 1090-2 includes the requirements for rectification of any damage sustained in delivery

or erection.


30/73


31/73

SECTION 4 : EUROPEAN FABRICATION STANDARD

30

Those associated with inspection, testing and corrections (in clause 12 of BS EN1090-2) that support quality control of product conformity;

Those associated with documentary controls (in clause 4 and 5) that support qualityassurance of product conformity; and

The rest which underpin the procedural controls of processes of fabrication.

It is assumed that clauses 8 and 12.5 on mechanical fastening, clauses 9 and 12.7 onerection and Annexes E, G, H, J, K and M generally have little or no relevance to the CE

Marking of structural steel components.

4.2 Documentation

BS EN 1090-2 uses the term execution specification for the set of documents covering

technical data and requirements for a particular steel structure. This equates to the project

specification referenced in the NSSS, and both include the portfolio of component

specifications that are the key documents referred to in BS EN 1090-1.

Annex A of BS EN 1090-2 lists all those requirements that may need specifying for aparticular project and hence for specific components. Annex A.3 lists several that are linked

to the choice of Execution Class. The application of the concept of Execution Class is

explained in section 9 below which notes how the NSSS requires who is responsible for the

structural design to review A.3 for its implications.

In terms of documentation and as part of FPC, the manufacturer should review the

extensive list of supporting standards given in clause 3 of BS EN 1090-2 to ensure that its

library contains up-to-date versions of those relevant to its scope of operations.

4.3 Constituent products

Section 3 above explains the concept of constituent products. The manufacturer needs to

know that it is using the right products and to ensure that its manufacturer's processes do

not impair those properties that underpin the declared essential characteristics of the

finished component. Many of the requirements in BS EN 1090-2 for traceability and welding

relate to these needs.

4.4 Tolerances

Those geometrical tolerances that are essential to the evaluation of the strength of a

component (e.g. straightness required to avoid premature strut buckling) are defined in BS

EN 1090-2 as essential requirements. It is those and only those tolerances that themanufacturer warrants when CE Marking under the CPD. As noted in section 3 above, it is

necessary to choose which class applies for some essential tolerances and to include this

in the component specification.

It should be noted that BS EN 1090-2 also gives requirements in two tolerance classes for

what are termed functional tolerances. The functional tolerances are outside the application

of the CPD to structural steel components, but they are relevant to the contractual

obligations that the manufacturer has to its purchasing client. Thus the manufacturer may

choose to link the component to the relevant functional tolerance class by showing this

information on the fabrication drawings. To simplify this process, a statement on the marking

plan that the component is manufactured in accordance with the NSSS makes the link to

functional tolerance class 1.


32/73


31

4.5 Welding

BS EN 1090-2 covers fabrication requirements in clauses dealing with preparation of

constituent products, assembly and welding. The implications of BS EN 1090-2 for CE

Marking of welded structural components are widely discussed throughout this document

as welding is a special process and has the most relevance to the potential impairment of

the properties of the constituent products. Similar procedural restrictions apply to other

processes used in manufacture that have such a risk if not properly controlled (e.g. hot or

cold bending, or thermal cutting used in fabrication).

In terms of welding, it should be noted that the NSSS applies the requirements of BS EN

1090-2 to building structures to EXC2. These requirements are broadly similar to the

requirements in the previous editions of the NSSS except that the conceptual principle is

now made clear that welding of a given type (as defined by a given WPS) may be

considered as a single continuing production lot in quality management terms.

BS EN 1090-2 includes a National Foreword that explains that whilst the Service Category

(see section 9) differentiates between quasi-static (SC1) and fatigue (SC2) applications, this

is too coarse a differentiation with respect to the control of weld quality in fatigue. BS EN

1090-2 uses the quality levels in BS EN ISO 5817 in four steps as listed below:

EXC1: Quality level D.

EXC2: Quality level C generally;

EXC3: Quality level B (i.e. as required for WQTs and WPQRs);

EXC4: Quality level B+.

Whilst the levels above may be partly suitable for use in the manufacturer's WQMS to

establish, prequalify and certificate the general quality level of the manufacturer's welding

operations, they are incomplete as follows:

Using informative Annex B of BS EN 1090-2, low consequences risk structures inCC1 (see section 9 for explanation) that are designed for fatigue are in EXC2 andhence the suggested quality level is C generally. This quality level is unsafe for any

but the most modest levels of fatigue, and reduced consequences do not

compensate for inappropriate specification.

The EXC4 level is impractical as it requires the manufacturer to demonstrate thegeneral capability of meeting quality level B+ which is more stringent than that

required for WQTs and WPQRs. The only way of assuring a quality level above the

prequalification standards is to undertake 100% testing on the (minority of) welds

which the designer specifies as demanding such a high standard and individually

assess them for acceptance.

The conclusion from the above is that the specifier needs to identify the fatiguedemand placed on individual welds subjected to dynamic loads and to decide the

acceptance criteria that are relevant on a fitness-for-purpose basis using fracture

mechanics based on the function of the component and the characteristics of the

imperfections (type, size, location). Whilst this procedure is allowed by BS EN 1090-

2 after non-conformities are identified, it is more sensible to start with a properly

classified set of values. This is available in ISO 10721-2 which specifies a suite of

acceptance criteria appropriate to a series of fatigue classes. These acceptance

criteria are consistent with those used in previous British Standards and the NSSS,

and should be used by specifiers in fatigue applications rather than relying on the

coarse SC2 categorisation.


33/73

SECTION 4 : EUROPEAN FABRICATION STANDARD

32

4.6 Surface treatment

As explained in section 3 above, for structural steel components there is no applicable direct

method for testing durability of the essential characteristics defined in BS EN 1090-1.

Provided it can be protected from corrosion, there is no tendency for the properties of steel

to decay over time; it is stable chemically and does not creep.

Hence, the simplest ways to ensure durability are to make the component from stainless orweather-resistant steel (e.g. with improved atmospheric corrosion resistance), or to protect

its surface from atmospheric corrosion by paint, galvanizing or sprayed metal. In terms of

declared characteristics, it is simple enough in principle to specify the required surface

coating and the surface preparation necessary in the component specification and for the

manufacturer to warrant that the component conforms to its component specification. This

is the basis that BS EN 1090-2 provides, allowing the manufacturer to check the

manufactured components against the component specification according to the specified

testing requirements for surface preparation and treatment.

It is less simple to warrant that the component is durable for a specified time as this involves a

simultaneous specification of a corrosivity category for the expected environment in the intended

component application and a measure of the durability of the surface protection material.

Thus, a direct warranty on the durability of the steel component would be dependent on a

warranty on the durability of the surface coating material. Even though there are standard

tests that can be used to establish the long term performance of, say, paints, none of these

yet form the test standards supporting harmonised product standards for paints. In this

circumstance, BS EN 1090-2 allows purchasing clients and steelwork contractors to agree

the execution specification durability in more prescriptive terms and for this to be used to

develop the component specification. Thus, whilst the standard coating specifications given

in the NSSS are scientifically related to particular environmental classifications, there is no

warranty on the coatings.


34/73


33

5 WELDING QUALITY MANAGEMENT

5.1 Welding as a 'special process'

For many years welding has been classed as a 'special process' as defined in BS EN ISO

9000 and it is widely recognised that welding normally requires continuous control and/or

that specified procedures are followed since the end result may not be capable of beingverified by testing. In light of this, a fundamental requirement of CE Marking is that the

manufacturer using welding needs to implement an appropriate welding quality

management system (WQMS).

The CE Marking fabrication standard, BS EN 1090-2, states that all welding shall be

undertaken in accordance with the quality requirements of the relevant part of BS EN ISO

3834 which identifies the controls and procedures required. Determination

Date post:	03-Jun-2018
Category:	Documents
Upload:	helder-reis
View:	230 times
Download:	0 times

CE Book Final.pdf

Documents