Guide to CE Marking of Structural Steelwork

Guide to the CE Marking of Structural Steelwork

BCSA Publication No. 46/08


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

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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

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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 construction applications 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’.

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CONTENTS

PAGE

1

INTRODUCTION AND SCOPE

7

1.1 1.2 1.3

Objective Scope Overview

7 7 7

2

CE MARKING REGULATIONS

9

2.1 2.2 2.3 2.4 2.5 2.6

Construction Products Directive Harmonised standards Certification CE Marking Construction Products Regulations Future developments

9 9 10 11 11 12

3

CE MARKING STANDARD FOR STRUCTURAL STEELWORK

13

3.1 3.2 3.3 3.4 3.5 3.6 3.7

Basis Scope Definitions Requirements Evaluation methods Evaluation of conformity Marking system

13 13 13 20 21 21 26

4

EUROPEAN FABRICATION STANDARD

29

4.1 4.2 4.3 4.4 4.5 4.6

Status and scope Documentation Constituent products Tolerances Welding Surface treatment

29 30 30 30 31 32

5

WELDING QUALITY MANAGEMENT

33

5.1 5.2 5.3 5.4 5.5

Welding as a 'special process' Control of welding Technical instructions Competence of personnel Implementation

33 33 34 34 34

6

RESPONSIBLE WELDING COORDINATORS

35

6.1 6.2

Welding coordination Tasks for welding coordinators

35 35

7

TRACEABILITY

37

7.1 7.2 7.3 7.4 7.5 7.6

Introduction Government Circular Inspection documents Requirements Batch or type traceability Welding

37 37 38 38 39 39 5

8

SUPPLY CHAIN IMPLICATIONS

40

8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8

Introduction Manufacturers Importers Distributors Stockholders Steel processors Special products and processes Transition period

40 40 40 40 41 41 41 42

9

EXECUTION CLASS

43

9.1 9.2 9.3

General Application to buildings Wider application

43 43 43

10

FACTORY PRODUCTION CONTROL

44

10.1 10.2 10.3

Introduction FPC systems System requirements

44 44 45

11

ROUTES TO CERTIFICATION

48

11.1 11.2 11.3 11.4 11.5

Introduction Assessment of the WQMS Assessment of the RWC Surveillance audits Steel Construction Certification Scheme

48 48 49 50 51

12

IMPLICATIONS FOR DESIGNERS, SPECIFIERS AND CONSTRUCTION MANAGERS

53

12.1 12.2 12.3

Introduction Designers and specifiers Construction managers

53 53 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

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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, their purchasing 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 building construction 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 10901 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 text to 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,

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SECTION 1 : INTRODUCTION AND SCOPE 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.

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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 fabricated steel 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 against the 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. 2. 3. 4. 5. 6.

Mechanical resistance and stability. Safety in case of fire. Hygiene, health and the environment. Safety in use. Protection against noise. 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 into specific measurable properties termed essential 'performance characteristics' (e.g. yield strength, toughness and load bearing capacity) and establishes the values to be met. 9

SECTION 2 : CE MARKING REGULATIONS 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 the end 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 throughout the 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

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Guide to the CE Marking of Structural Steelwork 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 made as 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 the product 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 the building 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, 3 months in prison or both.

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SECTION 2 : CE MARKING REGULATIONS 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 is equivalent 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 works requirements'. 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.

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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 and required 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 the specified 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 steel components 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 designation system. 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 13

SECTION 3 : CE MARKING STANDARD FOR STRUCTURAL STEELWORK produced to the standard possess defined levels of strength - e.g. as S275. These strength values then underpin the evaluation of the load bearing capacity of a component produced to BS EN 1090-1. In welding standards such as BS EN 1011 Welding - Recommendations for welding of metallic materials, constituent products are referred to as parent materials or parent metal and weld metal. 3.3.2 Component specification BS EN 1090-1 applies to both series and non-series production. These terms are explained by Pinney & Rein in their practical guide. Although fabricated steel components are generally bespoke, being one-offs or to a limited number typically of less than 10 identical items this may be series or non-series production.➀ Whether a component is made in series or non-series production, specific details are required before manufacture can be undertaken. The document giving all necessary information and technical requirements for manufacture is termed the component specification. For structural steelwork the suite of relevant component specifications would comprise the fabrication drawings defined in the National Structural Steelwork Specification for Building Construction (CE Marking Edition) (NSSS). One principle to be observed in CE Marking is that the manufacturer should be clear and not confusing in its declarations. The simplest way this can be achieved is to start from a definitive component specification and then to warrant that the component has been made in accordance with that specification. This procedure differs little from how steelwork contractors have been used to satisfying their purchasing clients and the national building regulations. 3.3.3 Kits A kit is defined as a construction product when it is a set of at least two separate components that need to be put together to be installed permanently in the works. For a "kit" to come within the scope of the CPD, the following conditions must be satisfied:

• The "kit" must be placed on the market, allowing a purchaser to buy it in one transaction from a single supplier,

• The "kit" must have characteristics that allow the works in which it is incorporated to satisfy the essential requirements, when the works are subject to regulations containing such requirements. It is thus possible to consider structural steel components as a kit when they are supplied as components of a whole building project or as defined phases of the whole project. Two CE Marking options are thus open to the steelwork contractor:

• To apply CE Marking to the individual components as they are delivered from the manufacturing works, using the component specifications issued for manufacture as the reference;

• To apply CE Marking to a defined set of components as a kit, using as a reference a collection of component specifications linked to, say, and erection marking plan or delivery list. ➀ For example, a manufacturer making bridges or bridge components of all sizes and shapes, where no two are ever the same, is still involved with series production. This is because the work is making bridges/bridge components. If the manufacturer were asked to make a steel door and this was not part of normal production line then that would be non-series production. If the manufacturer did not normally make purlins but then made several of a common type as a special order then that would also be non-series production. 14

Guide to the CE Marking of Structural Steelwork 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 term project 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 engineer who 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 employer or 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; 15

SECTION 3 : CE MARKING STANDARD FOR STRUCTURAL STEELWORK

• 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 structural design 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 chemical composition 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 and mechanical 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 component specification (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 load bearing 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 16

Guide to the CE Marking of Structural Steelwork 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 nondestructive 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.

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SECTION 3 : CE MARKING STANDARD FOR STRUCTURAL STEELWORK 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 and fixings. 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 for static 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 the Eurocodes. 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 by the purchaser/user.

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Guide to the CE Marking of Structural Steelwork 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 to steel 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 is not 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”.

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SECTION 3 : CE MARKING STANDARD FOR STRUCTURAL STEELWORK 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 essential characteristics that are defined in the harmonised standards for those products.

• The manufacturer incorporating those products into a structural steel component needs to ensure that:

• Incoming materials to be used as constituent products comply with the relevant specification 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 necessary traceability requirements (see section 7);

• The modification of the essential characteristics of the constituent products by the processes 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/or physical 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 of a 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 10901, the issue of durability can be addressed by declaring values that are related to the stress cycling or working temperature as relevant. 20

Guide to the CE Marking of Structural Steelwork 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 materials using the CVN impact test.

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

• Structural calculations - which may be used to evaluate load bearing capacity, fatigue strength 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 to establish their properties against the essential performance characteristics.

• The new product type is commissioned into production and representative samples from 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 modified methods 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 allows historical 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 21

SECTION 3 : CE MARKING STANDARD FOR STRUCTURAL STEELWORK 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) and defines 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 welding procedure 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 qualification of 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 meet quality 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 to a lot or cast (type 3.1 inspection certificate) or non-specific (type 2.2 test report). Specific

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Guide to the CE Marking of Structural Steelwork 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 explained below 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 would result 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 10025-1 allows 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.

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SECTION 3 : CE MARKING STANDARD FOR STRUCTURAL STEELWORK 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 initial inspection 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 on each 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 with respect 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 to develop 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 being undertaken 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, and thermal 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 the scope of the FPC;

• Accreditation of the laboratory under BS EN ISO/IEC 17025 General requirements for the 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 party inspection authority that may be appointed.

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Guide to the CE Marking of Structural Steelwork 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 handling procedural non-conformities and non-conforming product.

• Evaluation of job descriptions (e.g. based on an organogram) and requirements for competence 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 25

SECTION 3 : CE MARKING STANDARD FOR STRUCTURAL STEELWORK 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:

• • • • 3.7

New or changed essential facilities; Change of Responsible Welding Coordinator; New welding processes; New essential equipment.

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 the component 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. 26

Guide to the CE Marking of Structural Steelwork 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 the manufacturer 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 CE Marking 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 letters C 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 using MPCS Option 1);

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

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

• By reference to component geometrical data and the material properties of constituent products 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 the national 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 projectspecific 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.➁ It is likely that for bespoke project-specific items the CE Marking would be located on the

➁ In this context “accompanying” means “unambiguously linked to”, it does not mean that the commercial literature has to physically be attached to the product. 27

SECTION 3 : CE MARKING STANDARD FOR STRUCTURAL STEELWORK 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 largely unaffected 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.

28


4

EUROPEAN FABRICATION STANDARD

4.1

Status and scope BS EN 1090-2 Execution of steel structures and aluminium structures - Part 2: Technical requirements for steel structures is not a harmonised standard but it supports the application of BS EN 1090-1 by providing the technical requirements relevant to manufacture of steel components. This is analogous to BS EN 10045-1 being a supporting standard giving the test methods for CVN in support of the harmonised standards for steel products BS EN 10025-1 etc. As well as building on these test methods used to establish the characteristics of constituent products, BS EN 1090-2 includes its own test methods for such items as measuring geometrical dimensions of components. It also makes reference to other test methods in further supporting standards such as those specifying requirements for welding. The scope of BS EN 1090-2 is wider than simply the technical requirements for manufacture (e.g. by fabrication including welding), as it also covers all execution requirements for steel structures including erection. Erection and other operations (such as bolting) that take place on a project site where the construction works are being built are not relevant to the CE Marking process which merely assumes that the works will be otherwise properly designed and built.➂ In addition, the scope of BS EN 1090-2 is much wider than the individual British Standards that it will replace as it includes requirements for all types of steel structure: buildings, bridges, towers, masts, chimneys, shells, sheeting in carbon manganese steels up to S690 and stainless steels up to S700. It applies to structures subjected to fatigue or seismic actions. Despite this extremely wide scope, the requirements related to steel structures used in building construction are very close to those in previous British Standards and those in the National Structural Steelwork Specification for Building Construction (NSSS). To assist steelwork contractors and specifiers, BCSA is preparing a CE Marking Edition of the NSSS that includes only those provisions relevant to the majority of steel-framed buildings. Undertaking projects to the NSSS should ensure that the steelwork complies with the provisions relevant to all types of building construction designed for static loading in EXC2 according to BS EN 1090-2. With respect to CE Marking the relevant clauses of BS EN 1090-2 are as follows:

• • • • •

Documentation (clause 4 and Annex A); Constituent steel products (clauses 5, 12.1 and 12.2); Geometrical tolerances (clauses 11 and 12.3 and Annex D); Welding and other fabrication operations (clauses 7, 6 and 12.4); Surface treatment for corrosion protection and durability (clauses 10 and 12.6 and Annex F).

With respect to their application as requirements for BS EN 1090-1 these clauses form three groups as follows: ➂ Potentially there could be situations (such as on a major stadium, power station or bridge project) where a substantial amount of “manufacture” takes place on the construction site. Arguably this is outside the scope of the CPD as the fabrication (assembly and welding) work is not undertaken in a works/factory covered by the manufacturer's FPC certification. It would, however, generally be the case that the WQMS and the RWC's scope of responsibility would include such site-based operations anyhow. In special circumstances where the site facility existed for a long enough time, it would be possible for those facilities to be certified by the NB, and hence for CE Marking to be applied to the “components” produced from those facilities. 29

SECTION 4 : EUROPEAN FABRICATION STANDARD

• Those associated with inspection, testing and corrections (in clause 12 of BS EN 1090-2) that support quality control of product conformity;

• Those associated with documentary controls (in clause 4 and 5) that support quality assurance 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 on erection 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 a particular 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 the manufacturer 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.

30

Guide to the CE Marking of Structural Steelwork 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 in CC1 (see section 9 for explanation) that are designed for fatigue are in EXC2 and hence 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 the general 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 fatigue demand 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 10902 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.

31

SECTION 4 : EUROPEAN FABRICATION STANDARD 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 or weather-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.

32


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 being verified 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 of the relevant part of BS EN ISO 3834, and the stringency of requirements, is ultimately dependent on the Execution Class declared by the manufacturer for its product. With respect to the WQMS, BS EN 1090-2 invokes BS EN ISO 3834 Quality requirements for fusion welding of metallic materials as follows:

• EXC3 and 4: Comprehensive quality requirements to BS EN ISO 3834-2. • EXC2: Standard quality requirements to BS EN ISO 3834-3. (The quality level required by the NSSS is BS EN ISO 3834-3 appropriate to EXC2.)

• EXC1: Elementary quality requirements to BS EN ISO 3834-4. BS EN ISO 3834 is not a quality system standard to replace BS EN ISO 9001. It can be used independently but it is often best used to complement BS EN ISO 9001 requirements. It is also important to note that, whilst some steelwork contractors may choose to have their WQMS certified by a certification body independently of the notified body, the standards for CE Marking do not require this. Compliance with the requirements of BS EN ISO 3834 can be verified by the notified body during assessment of a steelwork contractor’s FPC system. Routes to certification of the FPC system are described in section 11. The basic principles of a welding quality management system to BS EN ISO 3834 are focused around the requirements of the principal welding-related activities, in particular:

• Control of welding as a special process; • Technical instructions for production; and • Demonstration of personnel competence. 5.2

Control of welding A manufacturer may have several people involved with the control of welding, but the manufacturer needs to identify a Responsible Welding Coordinator (RWC) with overall responsibility for all welding activities. Whilst specific requirements for the RWC are detailed in section 6 the appointed person would develop and implement documented procedures to control such aspects as:

• Identification, qualification and production of welding procedures and welder qualifications;

• • • •

Availability, suitability and maintenance of equipment; Identification of product requirements (contractual and technical); Production planning; Storage and handling of parent metals and welding consumables; 33

SECTION 5 : WELDING QUALITY MANAGEMENT

• Operation and performance of inspection activities; • Identification and traceability of the product and work in progress; and • Correction of non-conforming product. 5.3

Technical instructions BS EN ISO 3834 requires the steelwork contractor to have written technical instructions, procedures and specifications that demonstrate and ensure that the welding control system is effective. The standard identifies the typical documents necessary to demonstrate control of all welding related activities. These include instructions and procedures for the following:

• • • • • • • • • 5.4

Reviewing contract/technical requirements; Subcontracting; Qualification of procedures and personnel for welding and inspection; Storage and handling of consumables; Equipment maintenance/calibration; Production/inspection plans; Repair procedures; Traceability records; and Documentation control.

Competence of personnel Personnel competence in welding process control is the cornerstone to an effective WQMS. This is reflected in BS EN ISO 3834, by setting out the standards required for qualification of welders and welding operators, inspection personnel and perhaps most importantly, those responsible for welding coordination. Dependent on the size of company, control and coordination of welding might be undertaken by more than one person. However the RWC must have overall control of and be competent to make decisions and sign documents which affect product quality, whereas other personnel might only be qualified to undertake specialised welding coordination tasks such as control/issue of welding consumables, verification of materials etc. In allocating welding tasks and responsibilities the steelwork contractor must identify criteria for competence in terms of qualification, experience and training for each position. The manufacturer must also ensure that the competence of all welding coordinators, especially the RWC, is adequate for their allocated tasks.

5.5

Implementation Application of the appropriate WQMS is left to the discretion of the manufacturer, who can make use of PD CEN ISO/TR Quality requirements for fusion welding of metallic materials - Part 6: Guidelines on implementing ISO 3834. The manufacturer's choice should be based upon its current purchasing client base, the declared Execution Class of its product and, where possible, its future market. The NSSS requires a WQMS compliant with the requirements of BS EN ISO 3834-3 Standard quality requirements. However, this will require careful consideration so as to ensure the manufacturer is not precluded from tender invitations requiring a higher Execution Class and subsequently more stringent quality requirements.

34


6

RESPONSIBLE WELDING COORDINATORS

6.1

Welding coordination The coordination of welding activities is vital if a manufacturer wants to demonstrate control of the process and give confidence to purchasing clients of the quality of its welded product. BS EN 1090-2 states that, with respect to the welding operations being supervised, welding coordination shall be maintained during the execution of welding for all but Execution Class 1. The term Responsible Welding Coordinator (RWC) is used to identify the person who is competent to supervise the manufacturer's welding operations as demonstrated by the RWC's technical knowledge and experience for the range of products being manufactured. The level and scope of technical knowledge and experience required may thus be linked to the scope of certification of the manufacturer's FPC in terms its Execution Class, the welding processes and the parent materials covered. As noted above, this can be established using the manufacturer's portfolio of WPSs, WPQRs and WQTs as the RWC must be competent to coordinate the development of those documents.

6.2

Tasks for welding coordinators All manufacturers should nominate at least one Responsible Welding Coordinator (RWC) with overall responsibility for establishing and monitoring welding activities and for taking action when welding has not been carried out correctly. When nominating RWCs, the manufacturer should identify clearly the tasks and responsibilities that will be allocated to them and ensure that they are suitably qualified and experienced to do the job and competent to make decisions and sign documents which affect product quality. BS EN ISO 14731 Welding coordination - Tasks and responsibilities gives guidance on the essential welding related tasks that need to be considered. These might include, but are not limited to:

• • • • • • • • •

Review of contractual/technical welding requirements; Ensuring welding personnel are appropriately qualified; Suitability of welding and associated equipment; Development/qualification of welding procedures; Writing welding procedure specifications (WPSs); Production planning; Storage and handling parent materials; Control of welding consumables; and Inspection and testing before, during and after welding.

Welding coordinators thus need the ability to detect and assess defects, to instruct repairs and know how to avoid defects, as well as having knowledge about the relevant standards, regulations and specifications to be observed. With respect to the welding operations being supervised BS EN 1090-2 specifies the technical knowledge requirements for welding coordination personnel based on the three categories given in BS EN ISO 14731:

• B - Basic • S - Specific 35

SECTION 6 : RESPONSIBLE WELDING COORDINATORS

• C - Comprehensive The required category is determined by the manufacturer's declared Execution Class, the type/grades of steel used (given in terms of steel groups and reference standards) and limiting thicknesses. RWCs may demonstrate that they have sufficient technical knowledge by presenting evidence that they meet the recommendations prepared by the International Institute of Welding (IIW). However, these recommendations are generic and thus cover a much wider scope that is well in excess of that required for many steelwork manufacturers. Hence, BCSA, the Steel Construction Certification Scheme (SCCS) and the Welding Institute (TWI) have developed more focussed methods for assessing the technical knowledge and experience of welding coordinators (see section 11 and Appendix A).

36


7

TRACEABILITY

7.1

Introduction It is essential to have a suitable traceability system in place to enable checks to be made that the correct steel component has been delivered and/or erected and that it is made from the correct steel sections and fittings. Guidance on the traceability systems required for CE Marking is given in two different documents - A Government Circular and in BS EN 1090-2. These two documents give very different requirements. It is therefore important to know what they say and why the guidance given in this document is based on the traceability requirements given in BS EN 1090-2.

7.2

Government Circular The following requirements appear in the UK's Construction Product Regulation (SI 1991 No 1620): Regulation 3 'Requirement to be satisfied by products' This addresses all construction products whether they are CE Marked or not. It states: A construction product, other than a minor part product, shall have such characteristics that the works in which it is to be incorporated, assembled, applied or installed can, if properly designed and built, satisfy the essential requirements when, where and to the extent that such works are subject to regulations containing such requirements. In 1991 the then Department of the Environment (now called the Department of Communities and Local Government, DCLG) issued Government Circular 13/91 related to European Economic Community: Directive 89/106/EEC Construction Products. It primarily gave guidance to enforcement bodies on the application of the Construction Products Regulations. In 8 the Government Circular 13/91 reinforces the responsibilities of 'building control officers and approved inspectors to ensure the fitness of purpose for use on site in works that are subject to Building Regulations. Building control officers will need to satisfy themselves that a product (whether or not it carries the CE mark) is fit for intended use or actual use and to reject products that are unfit'. This circular includes the following statement 'The Regulations apply at all stages of the supply chain' but this statement does not single out CE Marked products for attention. Regulation 4 'Products bearing the EC mark' ➃ Any construction product which bears the EC mark shall be presumed to satisfy the relevant requirement in regulation 3 (see above) unless there are reasonable grounds for suspecting that the product does not satisfy that requirement or that the EC mark has not been affixed in accordance with regulation 5. Regulation 6 'Requirement to keep available and give information about products which bear the EC mark' The person who has affixed the EC mark… shall, for a period of 10 years after the material date, keep the EC certificate of conformity or, as the case may be, the EC declaration of conformity relating to the product, or a copy of it, available for inspection by an enforcement authority or any of its officers and, if required to do so by any such authority or officer at a reasonable time, produce the document so kept and permit any such officer to take copies of it.

➃ The EC Mark (as it was in English translation) is now termed the CE Mark throughout Europe. certified by the NB, and hence for CE Marking to be applied to the “components” produced from those facilities.

37

SECTION 7 : TRACEABILITY Regulation 7 'Requirement to give information about products which do not bear the EC mark' A person who supplies a construction product which does not bear the EC mark shall give to an enforcement authority, or any of its officers, all information which he has about the product and which the authority or officer may reasonably require for the purpose of ascertaining whether the product satisfies the requirement in regulation 3 or is one to which these Regulations do not apply. There are no explicit requirements on traceability throughout the whole of the supply chain, but given that building control authorities may need to be satisfied on the performance of the product regarding the essential characteristics of the product, appropriate documentation should accompany the product to satisfy building control officers and approved inspectors. Consequently the traceability recommendations for CE Marking given in this publication are based on the requirements given in BS EN 1090-2 which are explained below and in section 8. 7.3

Inspection documents BS EN 1090-2 gives traceability requirements for both the material delivered to the workshop or construction site and for the flow of material through the fabrication shop. Both of these requirements are explained below. Traceability of the essential characteristics of steel sections and other steel constituent products in terms of the material properties is important and only certain inspection documents (often referred to as “test certificates”) provide sufficient details. For products to BS EN 10025-1, this can be specific to a lot or cast (type 3.1 inspection certificate) or nonspecific (type 2.2 test report). BS EN 1090-2 requires type 3.1 inspection certificates for all steel products except those of the following qualities: S275JR, S275J0, S355JR or S355J0.

7.4

Requirements BS EN 1090-2 gives general recommendations for checking that supplied constituent products comply with the relevant product standards given in BS EN 1090-2 and match those on the purchase order. These general requirements apply to all Execution Classes. For Execution Classes 2, 3 and 4 the standard gives specific requirements for distinguishing between different steel grades where different grades and/or qualities are processed through the fabrication shop at the same time. Finally, for Execution Classes 3 and 4 the standard requires all constituent products to be traceable at all stages from receipt to handover and incorporation in the works. Batch or type traceability may be used unless traceability of each product is specified by the purchasing client. The requirements in 5.2 of BS EN 1090-2 are: The properties of supplied constituent products shall be documented in a way that enables them to be compared to the specified properties. Their conformity with the relevant product standards shall be checked in accordance with 12.2. For EXC3 and EXC4, constituent products shall be traceable at all stages from receipt to hand over after incorporation in the works. This traceability may be based on records for batches of products allocated to a common production process, unless traceability for each product is specified. For EXC2, EXC3 and EXC4, if differing grades and/or qualities of constituent products are in circulation together, each item shall be designated with a mark that identifies its grade. An interpretation of the above for each of the four Execution Classes is given below. Execution Class 1 - does not require traceability only control of the incoming material

38

Guide to the CE Marking of Structural Steelwork against the purchase order. This includes steel sections, fasteners, subcontracted fabrication, coating products and items delivered directly to site such as decking and purlins. Execution Class 2 - requires control of incoming material against the purchase order as described for Execution Class 1 and constituent products to be marked where more than one grade/quality is in circulation. This applies to steel sections and plate, and fasteners delivered to the workshop. Execution Classes 3 and 4 - requires control of the incoming material against the purchase order as described for Execution Class 1, marking of constituent products where more than one grade is in circulation and all products to be traceable at all stages from receipt to handover after they have been included in the structure (this includes activities on site). Unless traceability for each product is specified by the purchasing client then batch or type traceability may be used. 7.5

Batch or type traceability Batch or type traceability means nominally identical items do not need to be distinguished; hence, backwards traceability is limited. This type of traceability can be achieved by carrying out a paper check of the order against the delivery note and a physical check of the steel sections and other products against the order when the steel sections and products are delivered. Traceability through the workshop can then be achieved through a combination of shape and location within the workshop - i.e. serial size and weight can be obtained from the shape of the section and the grade and job reference can be obtained by storing different grades in different locations. Alternatively a colour coding or marking system can be used to distinguish between different grades, sections and project jobs. The steel quality (or sub-grade) is the most difficult property to trace through the workshop and it may be possible generally to limit steel sections purchased and used to a single sub-grade (e.g. J0). Where other sub-grades are used these can then be treated as specials and alternatively marking systems can be used. BS EN 1090-2 distinguishes between the documentation required to support the required traceability of completed components sent to site from that required for constituent products explained above. In both cases suitable supporting documentation is required, and this will be in the form of a component specification when components are ready for delivery to a project site.

7.6

Welding BS EN 1090-2 does not require that individual welds be identified against the qualified welder who welded them. However, the manufacturer's WQMS needs to provide a comparable level of batch or type traceability. Hence, the welding coordinator would need to be able to demonstrate that the WQMS ensures the following in terms of traceability of welding for all except EXC1:

• The portfolio of WQTs held by the manufacturer is up-to-date with respect to the scope of welding operations being undertaken;

• On a sample basis at any stage during certification of the WQMS, the conduct of the work is traceable to the extent that welding personnel with suitable and valid qualifications are assigned to appropriate welding tasks;

• Work instructions issued to welders are appropriate to the joint configuration and material to be welded;

• Work instructions issued to welders are traceable back to an appropriate WPS that is supported by an appropriate and valid WPQR. The NSSS requires that these provisions are met for EXC2 building construction. 39

SECTION 8 : SUPPLY CHAIN ISSUES

8

SUPPLY CHAIN ISSUES

8.1

Introduction The CPD applies to all construction products that are permanently incorporated into a structure. For the steel construction industry this means steel sections and plate, hollow sections, preloadable bolts, non-preloadable bolts, purlins, sheeting, decking and fabricated steelwork. It also applies to those manufacturers, importers and distributors who modify a product already placed on the market in such a way that conformity with its original CE Marking is affected. This last range of products includes proprietary products such as cellular beams, part-fabricated products such as curved steel sections and modified and/or re-tested steel sections. Clearly this has implications for all parts of the steel construction supply chain. Within the supply chain, organisations can be categorised as a manufacturer, an agent, an importer or a distributor. Importers and distributors are not subjects of the CPD because the legal responsibility for placing the product on the market and its subsequent CE marking rests with the manufacturer or his appointed agent established in the community. However, the 'Blue Guide' introduces the two more possibilities of importer and distributor and so their roles are also mentioned here.➄ It is also possible for some organisations to be placed in different categories for different products. Knowing which category one falls into is very important.

8.2

Manufacturers A manufacturer is defined as any person or organisation that is responsible for designing and manufacturing a product to be placed on the EU market. This includes steel manufacturers who place steel sections on the EU market, steelwork contractors who place fabricated steelwork on the market, purlin, sheeting and decking manufacturers. If a manufacturer is not established within the European Union, then the manufacture must appoint an agent who is to act as the manufacturer's legal entity within the EU - i.e. a person/corporate entity against which legal action can be taken by the enforcement authorities.

8.3

Importers An importer is a person within the EU, responsible for placing products on the EU market (e.g. a bolt supplier where the bolts are imported having been manufactured outside the EU). If the importer puts the products onto the EU market and its name appears on the product then it becomes a manufacturer with all the responsibilities of the manufacturer. If, however, the importer brings already CE Marked products on to the EU market with the original manufacturer's name still on the product and does not change the product in any way then it is a distributor.

8.4

Distributors A distributor is a person or organisation which stores and distributes a CE Marked product that has already been placed on the EU market. Some steel stockholders fall in to this category. The distributor does not alter the product in any way nor does it put its name on the product. For examples some stockholders re-test steel sections or plates in order to establish improved CVN values. This process changes the declared properties of the product and the stockholder then becomes a manufacturer.

➄ Further information on the role of the importer and the distributor is contained in the Pinney & Rein reference. 40

Guide to the CE Marking of Structural Steelwork Although distributors do not have any responsibilities under the CPD they do have a duty to ensure that the correct CE Marking is associated with the correct product and that clearly non-compliant products are not placed on the EU market. The issue of an organisation buying a CE Marked product changing some of its declared properties and putting it back on the market is worth exploring further with reference to certain parts of the steel construction supply chain. For example some steel stockholders offer a service to steelwork contractors which involves modifying the original CE Marked steel section. Steel benders provide a service which bends the original steel beam modifying some of declared properties. In both cases the stockholders and steel benders are classed as manufacturers. 8.5

Stockholders Steel stockholders generally purchase steel sections which have been CE Marked by the steel manufacturer to BS EN 10025-1 for I and H sections, BS EN 10210-1 for hot-finished structural hollow sections and BS EN 10219-1 for cold-formed structural hollow sections. Sometimes these sections are then cut to exact length, drilled, blast cleaned and painted by the stockholder before being supplied to the steelwork contractor. All of these activities are fabrication activities which are covered by the CE Marking standard BS EN 1090-1. For example it is important that the section is cut to exact length and the holes are drilled in accordance with the tolerances given in BS EN 1090-2. Stockholders who provide these services will therefore need to extend the CE Marking for the modified steel sections in accordance with the fabrication CE Marking standard BS EN 1090-1. This will require initial type testing (ITT) and the setting up a certified factory production control (FPC) system as described in section 10. Sometimes stockholders re-test steel sections to re-evaluate fracture toughness. Fracture toughness is one of the performance values declared on the CE Marking by the steel manufacturer. Therefore a change to the product's original performance values for fracture toughness will require the section to be re-CE Marked. The stockholder will therefore have to perform ITT for the change in the performance value for fracture toughness and set up an appropriate FPC system. In this case setting up an FPC system cannot be based on the original steel production process as the stockholder has no control over the raw materials or the production process. The FPC system will be based on documentary controls and testing of the finished product. The laboratory testing will need to be checked by the NB as described above.

8.6

Steel processors The fabrication of structural steelwork is an assembly process that uses constituent products such as steel sections and some of these products, such as curved beams, may be part-processed but not ready for incorporation into the construction works until after further fabrication. The manufacturer of a steel component that is to be directly placed on the market needs either to be confident that the part-processed constituent products being used in fabrication have properties that conform to the standards for the original steel product manufacture (for example BS EN 10025) or to have a declaration from the steel processor of the changed performance characteristics. Processes of bending or curving a steel section may change some of its characteristics, the most obvious being its fracture toughness. The changes to the performance values will depend on the amount of bending and for small strains the changes will be so small that the original performance values may be relied upon. For higher strains the curved section will need to be CE Marked with its new performance values. The process of bending a section 41

SECTION 8 : SUPPLY CHAIN ISSUES will not change all of the originally declared performance values. For those unaltered values the steel bender is entitled to assume that the CE Marked product has been correctly tested according to the appropriate standards and therefore the performance values can be passed on without repeating the Initial Type Testing (ITT) and tests included in the FPC of the steel manufacturer. Bending a steel section is a fabrication activity and it is therefore suggested that bent or curved steel sections are CE Marked according to BS EN 1090-1. This will require setting up ITT for those characteristics whose performance values are changed by the bending process and an FPC system to control the bending processes. Similar issues arise with respect to some operations undertaken by steel service centres (e.g. thermal cutting) and by manufacturers of cellular beams and plated profiles. 8.7

Special products and processes BS EN 1090-2 anticipates that there will be circumstances where steel products etc other those listed as structural steels etc may need to be used in the construction works. Examples include proprietary products not covered by a European (EN) or International Standard (ISO) and without a European Technical Approval (ETA). Other examples would be products such as engineering steels that are covered by an EN or a national standard but which are not cited in BS EN 1090-2; such steels might be used in complex structural components as machined connectors. The general rules for manufacturers to follow in such circumstances are as follows:

• It is not allowed to use CE Marking on a product that is not covered by either a harmonised standard or an ETA under the CPD.

• It is important in all cases for the manufacturer not to confuse the market with CE Marking that might be misconstrued. BS EN 1090-2 covers such special products and processes as, although it supports BS EN 1090-1, it is written for wider application. Hence, in potentially ambiguous or uncertain circumstances the manufacturer needs to be clear in the CE Marking documentation what is covered by the CE Marking and what is not. The execution specification includes the component specifications and provides a definitive reference in this respect. The fact that such products are not covered by a harmonised standard or ETA does not prevent them being specified and used in construction works. 8.8

Transition period During the transition period between the date of applicability and the end of the co-existence period (expected to be two years), organisations in the supply chain may continue to place non-CE Marked products on the market even in those countries where CE Marking is mandatory. Then in those countries at the end of the co-existence period non-CE Marked products may not be placed on the market even if they are products that had already been manufactured before the date of applicability published on the NANDO website. In countries where CE Marking is not mandtory it may be possible for, say, steelwork contractors to use up their long-standing stocks of, say, fasteners indefinitely. However, it is arguable that the UK regulations require products to meet the essential requirements even in the absence of a relevant harmonised standard. Different provisions apply to products (such as re-used steel components) manufactured before the CPD and/or the UK Construction Products Regulations came into law in 1991. These provisions will need to be re-addressed if the European regulations are extended to encourage the “recyclability of the construction works, their material and parts after demolition”.

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9

EXECUTION CLASS

9.1

General Informative Annex B of BS EN 1090-2 provides guidance for the determination of Execution Classes (EXC) based on reference to consequences classes (CC) defined in BS EN 1990, service categories (SC) and production categories (PC) defined in BS EN 1090-2. SC relates principally to whether a component is designed for fatigue or for quasi-static actions only. BS EN 1090-2 recommends that PC1 is limited to non-welded components and welded components manufactured from steel grades below S355. In practice the distinction between PC1 and PC2 makes no practical difference to most structural steelwork. The NSSS is applicable to structural steelwork in SC1 only, and in both PC1 and PC2

9.2

Application to buildings Following the recommendations of BS EN 1090-2, the NSSS recommends that CC may be determined directly by reference to the building classes defined in Table 11 of Approved Document 'A' of the Building Regulations of England and Wales as follows: Building class

Consequences class (CC)

Class 1 (except domestic buildings)

Class 1

Classes 2A or 2B (also including domestic buildings of 4 storeys and below)

Class 2

Class 3

Class 3

Thus NSSS is based on execution of structural steelwork in EXC2 excluding steelwork in SC2, hence to Building Class 2 and without modification to Building Class 1. Structural steelwork in Building Class 3 and SC1 can also be undertaken to EXC 2 by steelwork contractors whose conformity assessment procedures are certified as meeting the requirements of EXC2, provided that the different requirements tabulated in Annex A.3 of BS EN 1090-2 are reviewed by the designer who is responsible for the structural design and specifies which, if any, of the supplementary requirements listed under EXC 3 are applicable. In terms of BS EN 1090-1 this means that amendments to the structural characteristics relevant to manufacturing would then be specified in the component specification. 9.3

Wider application BS EN 1090-2 defines EXC as a classified set of requirements specified for the execution of the works as a whole, of an individual component or of a detail of a component. In practical terms it is expected that all the components and details in the works as a whole would generally be classified with the same EXC. Hence, the NSSS ignores the possibility that some components or details could be EXC1 as BCSA believes that EXC2 is the best basis for ensuring consistent quality of steelwork appropriate for building construction. In terms of wider application, the following list provides a basis for determining EXC:

• • • •

EXC1 - Farm buildings. EXC2 - Buildings (similar to the scope of the NSSS). EXC3 - Bridges. EXC4 - Special structures (power stations, long span bridges etc.).

43

SECTION 10 : FACTORY PRODUCTION CONTROL

10

FACTORY PRODUCTION CONTROL

10.1 Introduction CE Marking requires the manufacturer to operate a factory production control (FPC) system certificated by a NB. An FPC system is a management control system that focuses mainly on the manufacturing operations although procedures for controlling design operations can be included. It aims to ensure that the quality of the product (be it a steel section, a bolt, a purlin or fabricated steelwork) is consistently maintained to the required specification. An FPC system is very similar to a BS EN ISO 9001 system and can be regarded as a subset of BS EN ISO 9001. A typical FPC system consists of regular maintenance and calibration of equipment, frequent checking to ensure product conformity and the management of non-conforming products. FPC is all about producing products with the same declared characteristics time and time again. For CE Marking of fabricated structural steelwork, steelwork contractors and those organisations involved in fabrication activities need to set up an FPC system that complies with the requirements given in BS EN 1090-1. The need for suitable FPC extends to steel stockholders that offer limited fabrication services, steel benders and those organisations that produce proprietary steel products (see section 8). FPC will include the procedures for controlling manufacture as described in BS EN 1090-1. It may also include the procedures for controlling design and/or the quality of the welds, and, excluding EXC1, a Responsible Welding Coordinator. In general based on the activities undertaken, there are four possible FPC systems and these are listed in the following table: Activities

FPC systems A

B

C

D

Manufacturing

Yes

Yes

Yes

Yes

Design

No

Yes

No

Yes

Welding

No

No

Yes

Yes

RWC

No

No

Yes

Yes

10.2 FPC systems FPC system A - applies to those organisations that have no welding activities and are not declaring design characteristics - e.g. manufacturers of purlins, decking etc. FPC system B - applies to those organisations that have no welding activities and wish to declare design characteristics - e.g. manufacturers of purlins and decking who wish to make their safe load tables part of the CE Marking. FPC system C - applies to those organisations that carry out welding activities and do not wish to declare design characteristics - e.g. this category will apply to the majority of steelwork contractors even though they may be carrying out all or part of the design. FPC system D - applies to those organisations that carry out welding activities and wish to declare design characteristics - e.g. some manufacturers of proprietary products (cellular beams) may wish to declare design values as part of the CE Marking. This system is also seen as a future development for those steelwork contractors wishing to declare design values as part of the CE Marking.

44

Guide to the CE Marking of Structural Steelwork 10.3 System requirements The following list includes the manufacturing and design procedures that should be covered in a typical FPC system to meet the requirements of BS EN 1090-1. The activities associated with managing and controlling the welding processes and the requirements for the Responsible Welding Coordinator are given in sections 5 and 6 respectively. It should be noted that FPC systems in other product standards (BS EN 10025-1 for the manufacture of steel sections and BS EN 14399-1 for the manufacture of preloadable bolts etc.) differ from the one described below. 10.3.1 Personnel (Clause 6.3.2, BS EN 1090-1) Document the responsibility, authority and the relationship between personnel that manage, perform or verify work affecting the characteristics of your steelwork. This is best done by developing an organogram which names key personnel, their function and the lines of communication. The system should also describe the measures to ensure that personnel have adequate qualifications and training for the range of steelwork the company fabricates and the Execution Class(es) used. 10.3.2 Equipment (Clause 6.3.3, BS EN 1090-1) All weighing, measuring and testing equipment that may have an influence on the characteristics of the steel frames/members must be calibrated, regularly maintained and inspected. Each company will need to decide the inspection procedures and the frequency of inspection. Manufacturing equipment (cutting, sawing and drilling equipment) must be regularly inspected and maintained to ensure that it remains sufficiently accurate and that its use, wear and failure does not cause significant inconsistency in the fabrication process. The procedures should document the frequency of inspections and maintenance and for how long this information should be retained. (Note: The Construction Products Regulations require records to be retained for a minimum of 10 years. However, as many construction contracts are signed as deeds it is recommended that records are retained for a minimum of 12 years). 10.3.3 Structural design process (Clause 6.3.4, BS EN 1090-1) In the case where structural design is carried out by the steelwork contractor and design characteristics are declared as part of the CE Marking, the steelwork contractor needs to establish procedures to control and verify compliance with the design brief, for checking calculations and for ensuring the competence of the individuals responsible for the design. With respect to building steelwork an appropriate checklist for design control adapted from BCSA's Commentary on the Fourth Edition of the National Structural Steelwork Specification for Building Construction is as follows: The Steelwork Contractor should have established procedures to control and verify the contract requirements for design. These may include:

• A design plan defining the principal design activities in a logical sequence, the type of design output and target dates to meet the programme requirements and allocation of design responsibilities.

• Procedures for controlling design variations, changes and concessions that take 45

SECTION 10 : FACTORY PRODUCTION CONTROL place during the contract including procedures for controlling revisions to the design brief and the issue of revised fabrication drawings.

• Design of the structure so it can be safely erected, bearing in mind that the designer who is responsible for preparing the structural design must take account of safety and stability aspects of the erection method statement.

• Design documentation, production and checking procedures (verification). • A check that software used in the design has been validated. • Procedures for the acceptance of general arrangement drawings and connection design calculations by the designer who is responsible for the structural design and specifies the structural characteristics relevant to manufacturing in the component specification.

• Handling and transportation requirements for unusually shaped or large components to ensure stability during movement.

• A formal documented review of the design before issue for connection calculations and associated detail drawings. 10.3.4 Constituent products used in manufacture Constituent products are defined as materials or products used in manufacture with properties that enter into structural calculations or otherwise relate to the mechanical resistance and stability of the structure and/or the fire resistance, including durability and serviceability. For most manufacturers (i.e. steelwork contractors, stockholders, etc.) this will include the following range of products:

• • • • • •

Steel sections (open and closed), plates and strip. Structural bolts. Cladding, sheeting, purlins and side rails. Welding consumables. Painting and galvanizing. Castings, bearings.

Identify the range of constituent products used in your factory. Develop and implement a written inspection procedure for checking and recording that the constituent products coming in to your factory conform to the specification, and that traceability of the constituent products through the factory conforms to the requirements for traceability given in BS EN 1090-2 (see section 7). Retain the documentation related to the constituent products for the period of document retention. 10.3.5 The component specification (fabrication drawing) The component specification is defined as a document or documents that gives all the necessary information for fabricating the structural steelwork. For the majority of manufacturers this will be a fabrication drawing. In addition to all the usual items on the drawing (e.g. dimensions, steel grade, weld size etc.) the drawings should include a reference to the Execution Class and the Service Category (see BS EN 1090-2). Service Category is defined in BS EN 1090-2 as 'Categories that categorise a component in terms of the circumstances of use'. In simple terms this means the steelwork is designed for fatigue or not. For the majority of manufacturers the steelwork will not be subject to fatigue. 46

Guide to the CE Marking of Structural Steelwork Develop and implement a written inspection and test plan for checking and recording that the fabricated steel frame/members conform to the component specification - i.e. make sure you have made what you said you were going to make. This will generally be covered by the quality manual and only requires a project-specific quality plan if requested by the purchasing client. In those cases Annex C of BS EN 1090-2 gives a checklist for the content of a quality plan for structural steelwork with reference to the general guidelines in BS ISO 10005 Quality management - Guidelines for quality plans. Prepare the fabrication drawings from design information/specification. 10.3.6 Product evaluation The list of declared characteristics for fabricated steelwork from BS EN 1090-1 is given below:

• • • • • • • •

Tolerances on dimension and shape Weldability (as CEV for constituent products) Fracture toughness (as CVN for constituent products) Load bearing capacity Fatigue strength Resistance to fire Reaction to fire (as Class A1) Dangerous substances

• Release of cadmium and its compounds • Emission of radioactivity • Durability of performance characteristics (given with respect to the requirements for surface treatment for corrosion protection as specified in BS EN 1090-2). For steelwork used in most buildings in the UK you need only evaluate those characteristics that are highlighted in bold above. These are the characteristics that you will be declaring on your CE Marking. 10.3.7 Non-conforming products Set up a written procedure that states how your company will deal with non-conforming products (i.e. steel frames/members that do not comply with the specification). This procedure must comply with the principles of BS EN 1090-1 as amplified by the requirements of BS EN 1090-2. Non-conformities must be recorded when they occur. Records of non-conformities must be retained for the period of document retention.

47

SECTION 11 : ROUTES TO CERTIFICATION

11

ROUTES TO CERTIFICATION

11.1 Introduction For safety critical products like structural components, the manufacturer is not allowed to fix CE Marking without having a factory production control (FPC) system in place which has a valid certificate from an approved notified body (NB). This requires a NB to assess and satisfy itself that the manufacturer's FPC system is able to produce products that comply with the relevant harmonised standard. Once satisfied, the NB will issue the manufacturer with an FPC certificate. If the manufacturer undertakes welding, the NB may issue either a separate welding certificate or include the required scope of welding certification in the FPC certificate. These certificates enable the manufacturer to produce a Declaration of Conformity, and the Declaration of Conformity permits the manufacturer to affix CE Marking to its products, provided that the products fall within the scope of certification given on the certificate(s) issued by the NB. Examples of all documents are given in Appendix C. For fabricated steelwork the FPC system must comply with BS EN 1090-1 and satisfy the relevant requirements of BS EN 1090-2 where invoked in BS EN 1090-1. A typical FPC system suited to BS EN 1090-1 can be conveniently split in to three distinct parts. These are: Part 1 is that part of the FPC system controlling the manufacturing and, if relevant, design operations. These activities are given in BS EN 1090-1 (see sections 3 and 10). Part 2 is that part of the FPC system controlling the welding operations. These activities are referred to in BS EN 1090-2 and are described in the relevant part of BS EN ISO 3834 (see sections 3 and 5). Part 3 is that part of the FPC system dependent on the competence of the Responsible Welding Coordinator in terms of the RWC's technical knowledge and experience. The level of technical knowledge required is linked to the Execution Class and the role of the RWC is described in BS EN ISO 14731 (see sections 3 and 6). As explained in section 3, the NB will need to satisfy itself that all three parts of the FPC system comply with the harmonised standard BS EN 1090-1 before it issues an FPC certificate or a welding certificate. Part 1 will always be assessed by the NB. For Part 2 there are two ways in which the manufacturer can demonstrate to the NB that its welding operations are properly controlled. Similarly there are a number of options available for demonstrating the competence of the RWC. The different options available for Parts 2 and 3 are described below. 11.2 Assessment of the WQMS The manufacturer can demonstrate that its welding operations are properly controlled in accordance with the relevant part of BS EN ISO 3834 by providing independent (third party) certification of its WQMS to the NB for review. Independent certification typically acceptable to the NB would normally be issued by an Authorised National Body for Company Certification (e.g. The Welding Institute in the UK). Alternatively the NB can assess the manufacturer's WQMS as a part of the manufacturer's FPC system. Under this option the WQMS is an embedded part of the FPC system. The certification of the FPC for welding may be identified within the general FPC certificate or issued as a separate welding certificate. A separate certification explicitly according to EN ISO 3834 is not required but may be agreed between the manufacturer and the NB. More information on FPC assessment with respect to BS EN 1090-1 and on assessment of the WQMS in particular may be found in a guidance document issued by the Structural 48

Guide to the CE Marking of Structural Steelwork Metallic Products Sector Group 17 of Notified Bodies for the Construction Products Directive 89/106/EEC (GNB CPD SG17) entitled Guidance for the FPC assessment according to Annex B of EN 1090-1. An abstract of this document is included in Appendix D. 11.3 Assessment of the RWC Assessment of the relevant competence of the RWC requires the NB to:

• Assess the RWC's experience. This can be demonstrated by employment evidence over at least the last four years.

• Assess the RWC's technical knowledge. There are three ways in which this can be demonstrated and these are explained further below.

• Check that the manufacturer's FPC has defined a suitable role and has given the RWC suitable responsibilities to enable the RWC to coordinate the manufacturer's welding operations. This requires the NB to know the scope of certification of the welding operations for which the manufacturer is seeking certification.

• Assess whether the RWC is acting competently in the defined role. This can be done in parallel with the NB's assessment of the manufacturer's WQMS by questioning the RWC about the manufacturer's portfolio of WPSs, WPQRs and WQTs. Also, during this technical interview the RWC will need to demonstrate to the NB the ability to detect and assess defects, to instruct repairs and know how to avoid defects, as well as knowledge about the relevant standards, regulations and specifications to be observed. There are three ways in which the RWC can demonstrate the necessary technical knowledge. In the first two routes described below the RWC can either be a subcontractor or a member of the manufacturer's staff. Route 1 The first and simplest approach is where the RWC has an appropriate International Institute of Welding (IIW) qualification. In this case the RWC will need to supply the NB with evidence of this qualification. Clearly this qualification is portable and is not specific to the RWC's current employer or post, but the level of this qualification (Basic, Specific or Comprehensive) must match the scope of the RWC's employer's WQMS. The relationship between the IIW qualifications and the levels referred to in BS EN ISO 14731 is as follows:

• Comprehensive requires a level of technical knowledge of all tasks and responsibilities in welding fabrication - International Welding Engineer (IWE);

• Specific requires a level of technical knowledge that is sufficient within a selective or limited technical field - International Welding Technologist (IWT);

• Basic requires a level of technical knowledge that is sufficient within a limited technical field involving only simple welded constructions - International Welding Specialist (IWS). IIW qualifications are valid indefinitely and are fully portable within and beyond the steelwork industry. Route 2 In recognition of the fact that some welding coordination functions do not require the breadth of knowledge provided by the IIW qualifications, TWI Certification has developed Requirements for the Certification of Welding Coordinators in accordance with BS EN ISO 14731: 2006 under the Certification Scheme for Welding and Inspection Personnel (CSWIP). 49

SECTION 11 : ROUTES TO CERTIFICATION This allows a manufacturer's nominated RWC to gain appropriate, industry-specific, CSWIP certification as a welding coordinator working in structural steelwork. The scheme assesses the knowledge, experience and competence of the nominated RWC by assessing a portfolio of evidence, interview, additional training where necessary and examination. The successful candidate will, in this case, be issued with a CSWIP certification. The CSWIP process includes both an off-the-job knowledge examination, and a job-specific assessment focussing on the competence of the RWC to fulfil the job specification. This latter step could take place during the certification process when a manufacturer is seeking independent certification of its WQMS to BS EN ISO 3834. Under this option the RWC will need to supply the NB with a copy of the RWC's CSWIP certificate to demonstrate the RWC's technical knowledge. A technical interview with the NB may be required to demonstrate the RWC's competence in the context of the welding operations covered by the manufacturer's WQMS. Again, the level of this qualification must match the scope of the RWC's employer's WQMS. This certification is valid for review after three years and re-assessment after six years. It has limited portability as it would only be suitable for another manufacturer with a congruent scope of WQMS certification. Route 3 The third route is available to those manufacturers working within a limited scope of operations and whose RWC is a directly employed member of staff. The assessment may differ from certification body to certification body but it is likely to involve an assessment of the individual's experience based on a typical portfolio of information (see Appendix A). A successful assessment would lead to company-specific qualification of the nominated RWC who would be embedded in its WQMS and, as such, not transferable should they decide to leave. The table below summarises how the required level of technical knowledge relates to welding processes and the grades and thicknesses of parent materials for building steelwork in EXC2 undertaken in accordance with the NSSS. TECHNICAL KNOWLEDGE OF RWC Scope of welding operations being supervised Welding of S275 steel products

Maximum parent metal thickness t (in mm) t ≤ 25 (1)

25 < t ≤ 50 (2)

t > 50

Basic

Specific

Specific

Welding of S355 steel products

Basic

Specific

Comprehensive

Welding of S420 steel products

Specific

Specific

Comprehensive

(1) Column base plates and endplates ≤ 50mm. (2) Column base plates and endplates ≤ 75mm. With respect to this table, Appendix A describes the limited scope of operations to which route 3 might typically apply. 11.4 Surveillance audits To maintain its declaration of conformity, the company's FPC system is subject to regular surveillance audits. The interval between these audits is related to the Execution Class. For EXC1 and EXC2 surveillance audits will take place one year after the initial assessment, two years after that and then every three years. These periods are only applicable in the case of no major non-conformities. If major non-conformities are identified the regime must

50

Guide to the CE Marking of Structural Steelwork be at such intervals that give confidence that the non-conformity has been corrected. For EXC3 and EXC4 the audits will take place at yearly intervals for the first two years, the third audit will be two years after that and then every three years. The table below shows the relationship between Execution Class and audit inspection intervals: Execution Class

Intervals between inspection of manufacturer's FPC after ITT (years)

EXC1 and EXC2

1-2-3-3

EXC3 and EXC4

1-1-2-3-3

In periods where the interval between surveillance is two or three years audits the manufacturer must make an annual declaration to the NB that none of the following changes have been made:

• New or changed essential facilities; • Change of RWC; • New welding procedures, change to the type of parent material and associated WPQRs;

• New equipment, where it affects the declared characteristics. There is no formal requirement for the FPC system to be re-certified at each surveillance audit as it is merely a confirmation that the manufacturer still has the FPC system under control as was the case at the initial inspection. Thus the FPC certification does not have an “expiry date” as such. However, it is likely that the NB will wish to state the date of the next required surveillance audit in accordance with intervals stated in BS EN 1090-1 and this is shown in the example documents in Appendix C. If a separate welding certificate is issued this also does not have an expiry date as such as it is indefinitely valid in terms of time but not in terms of circumstances. Hence, if any of the four changes listed above do occur this automatically means that the details listed on the existing welding certificate will become either invalid or incomplete. For instance, a change of RWC or move of factory location and hence site address would render the whole certificate invalid. On the other hand, the addition of a new factory, new welding process or manufacture using materials not listed would not invalidate the existing certificate, but those new additions would not be covered. Hence, CE Marking could not be applied to welded components manufactured using those new facilities etc until the welding certificate had been updated. In practice the company needs to agree a suitable programme of certification with the relevant NB. Audit visits to BS EN ISO 9001 would often be undertaken on a six-monthly basis. In those circumstances, and with the need to keep a close watch on changes in welding circumstances, the practical way would be to undertake FPC surveillance on an annual basis using the intervening six-monthly visit to audit the other aspects of the quality management system covered only by BS EN ISO 9001. Thus, welding changes could be identified and dealt with within a maximum of six months. In terms of the latitude allowed by BS EN 1090-1 to extend the FPC surveillance intervals beyond a year, the practical way would be to use that latitude not to extend the interval but to reduce the scope of the annual FPC audit in terms of which facilities or processes are audited. 11.5 Steel Construction Certification Scheme The Steel Construction Certification Scheme (SCCS) is the steel construction industry's 51

SECTION 11 : ROUTES TO CERTIFICATION dedicated certification scheme. SCCS will become a notified body for CE Marking of structural steelwork and is already able to offer FPC gap analysis of FPC systems to BS EN 1090-1. Within the limited but common scope of operations explained above, SCCS has competent welding and fabrication assessors which allow it to assess WQMSs and the associated RWC as an integral part of the FPC assessment. SCCS may be contacted via the BCSA's website www.steelconstruction.org.

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12

IMPLICATIONS FOR DESIGNERS, SPECIFIERS AND CONSTRUCTION MANAGERS

12.1 Introduction CE Marking already appears on some construction products and CE Marking in general has been with us for many years. Most of the manufactured products that we buy have CE Marks on them. It is therefore important that all parts of the supply chain, including specifiers, designers and construction managers are aware of their responsibilities and the benefits of CE Marking. In essence CE Marking is a declaration by the manufacturer that the product meets certain minimum public safety requirements. Although CE Marking is currently not a legal requirement in the UK it is in most other European countries and under the UK's Construction Products Regulations a CE Marked product is assumed to comply with the law. For fabricated structural steelwork CE Marking, applies both to the steel constituent products (steel sections, structural bolts, purlins, cladding and propriety products such as cellular beams) and to the fabricated steelwork itself. This imposes implications on the designer when specifying steel components, designing the structure and when choosing an appropriate steelwork contractor. It also has implications for construction managers. 12.2 Designers and specifiers 12.2.1 Roles For building steelwork in the UK there are generally two design roles that are fulfilled separately. In terms of the NSSS one role is allocated to the engineer who is the responsible for the design of structural members and will prepare design drawings. The engineer may be appointed by the purchasing client, or on design-and-build projects the engineer will be appointed by the steelwork contractor. The design drawings and the associated project specification will form the design brief that includes all information necessary for the design of connections and completion of the fabrication drawings. The latter design work is generally undertaken by designers and detailers working for the steelwork contractor. The completed fabrication drawings and associated project specification agreed between the engineer and the steelwork contractor comprise a portfolio of component specifications for the structural steelwork to be manufactured. 12.2.2 Components CE Marking is already in place for steel products such as rolled steel beams to BS EN 10025-1, and their inspection documents (test certificates) are now endorsed with a CE Marking. Similarly structural fasteners to BS EN 14399-1 and BS EN 15048-1 now have CE Marking on their packaging. One of the benefits of CE Marking is that it includes technical information in the form of the product's declared characteristics (in the case of steel sections one of the declared properties is its grade - e.g. S275). Hence the CE Marking can be seen as a technical data sheet. The information given in the CE Marking together with the appropriate harmonised standard gives the information needed for the specifier to judge whether the product is suitable for a particular intended use in terms of the requirements in the building regulations 53

SECTION 12 : IMPLICATIONS FOR DESIGNERS, SPECIFIERS & CONSTRUCTION MANAGERS related to materials and workmanship. Furthermore because CE Marking is a legal requirement in most European countries specifiers can have confidence in the declared characteristics. Another benefit of CE Marking is that there is only one set of requirements and procedures with which to comply. The various national regulations are eliminated. As a result the product no longer has to be adapted to the specific requirements of the different member states, such as the U-Marking scheme used hitherto in German building construction. Designers and specifiers are therefore strongly advised to keep abreast of the developing CE Marking standards (called harmonised standards) for construction products and to specify CE Marked materials and products where appropriate. 12.2.3 Fabricated steelwork The new European fabrication standard introduces the concept of Execution Class (EXC) for steel structures. The choice of EXC is a design issue and sets the level of quality required for different types of structure. EXC can be applied to the whole structure, part of a structure and individual details. Recommendations for determining the EXC are give in BS EN 1090-2 and it is linked to Consequences Class (risk to life and the environment), Production Category and Service Category (static or fatigue). The link between Consequences Class and type of structure is still being discussed with national authorities but it is likely that the following simple relationship between EXC and type of structure will be the basis:

• Execution Class 1 - Farm buildings. • Execution Class 2 - Buildings (similar to the scope of the National Structural Steelwork Specification).

• Execution Class 3 - Bridges. • Execution Class 4 - Special structures (power stations, long span bridges etc.). The designer will need to specify the Execution Class for each structure. This also has implications for choosing a steelwork contractor. Under the CE Marking rules for fabricated steelwork each steelwork contractor will be assessed against a chosen Execution Class and will only be able to use CE Marking on its products for certain Execution Classes. Therefore a steelwork contractor will need to be selected both on the ability to do the job and on the Execution Class related to its certified manufacturing facilities. BCSA is developing a web based facility listing the execution class for steelwork contractors who are members of BCSA. BCSA has also developed a CE Marking Edition of its National Structural Steelwork Specification based on EXC2 as the most common basis for building steelwork in the UK. 12.3 Construction managers Construction managers have a duty of care to ensure that the correct CE Marking is associated with the correct product and that they are not using clearly non-compliant products that have been placed on the EU market. This means developing a purchasing system that requires CE Marking of products and checking that the appropriate CE Marking is on products which are delivered to site. CE Marking standards are continuously being developed for new and existing products, therefore construction managers need to keep abreast of these developments and update their procedures accordingly. When choosing a steelwork contractor construction managers need to select one with the correct certified Execution Class. BCSA is developing a web based facility listing the Execution Class for steelwork contractors who are members of BCSA. 54

Guide to the CE Marking of Structural Steelwork Fabricated steel components are often bespoke products made to a particular purchasing client's order and specification and designed for a particular project site. It is current practice for the purchasing client to select the steelwork contractor rather than choose an off-theshelf product. On this basis CE Marking might seem to add little, however this would be wrong as CE Marking does add the following:

• The regulatory imperative from the Construction Products Directive ensures attention is given to key public safety concerns;

• The requirement for certification of the manufacturer's FPC provides assurance of comparable and appropriate controls across the market place;

• The declared characteristics can be relied upon as being accurate; • A consistent technical language is used by authorities, specifiers and manufacturers to describe the characteristics of products.

55

APPENDIX A : ASSESSMENT OF THE RWC

APPENDIX A – ASSESSMENT OF THE RWC Manufacturers working within a limited scope of operations may choose to ask the NB to assess the knowledge and competence of the RWC as an “embedded” part of the WQMS (i.e. the third route to assessment described in section 11) In adopting this route the RWC may only be assessed for evidence of Basic or Specific technical knowledge in accordance with BS EN ISO 14731. Assessment of Comprehensive technical knowledge is not possible. As a NB, SCCS also generally applies the following limitations:

• • • •

The RWC has to be a directly employed member of staff; Manufacturing operations are limited to EXC2; Steel grades up to and including S355 for qualities JR, J0 or J2; Parent metal thicknesses up to a general maximum of 50mm with column base plates and endplates up to 75mm;

• Use of MMA or MAG welding (processes 111 and 135) for general welding or SAW (process 121) for mechanised “automatic” production. Where all of the above apply, the following five step procedure is appropriate: Step 1 - The manufacturer provides a written declaration confirming:

• • • • •

The Execution Class of its fabricated product range (EXC1 or EXC2). Its product range and the welding processes and materials used in fabrication. The level of knowledge required for its RWC - Basic or Specific. A job specification for the RWC. The RWC's roles and responsibilities.

Step 2 - The nominated RWC provides for review/assessment:

• A detailed authenticated CV highlighting the RWC's technical knowledge and experience in welding and fabrication.

• Documentary evidence of training and qualifications (e.g. photocopy of certificates). • Examples of job-related documents that the RWC has been responsible for (e.g. WPSs, WPQRs, WQTs, project-specific quality plans etc.) Step 3 - Professional Interview A suitably qualified welding specialist acting on behalf of SCCS will interview the RWC focussing on the RWC's knowledge and competence to fulfil the job specification during discussion. As part of the interview process, the candidate would also be required to complete a technical question paper tailored to suit the manufacturer's declared product range and welding activities. Step 4 - Successful candidates If the candidate is successful they will form an integral part of the company's WQMS. This route does not provide the RWC with separate certification and, as with other routes to certification, a change in job specification or the nominated RWC will invalidate both the WQMS and FPC systems and will require reassessment by SCCS. Step 5 - Unsuccessful candidates If the candidate is unsuccessful the company can either retrain the candidate, or nominate another employee or engage the services of a suitably qualified and competent external RWC. If the RWC is engaged on a subcontract basis by the manufacturer the RWC will be expected already to hold a recognised and appropriate IIW or CSWIP qualification in welding or equivalent.

56


APPENDIX B – ISSUES ASSOCIATED WITH BRIDGES Introduction The use of CE Marking for bridge components in the UK is an additional requirement to the existing contractual provisions for quality management. This Appendix is based on those arrangements that currently exist between steel bridgework contractors and the Highways Agency (HA), although similar provisions underpin steel bridgework contracts for Network Rail and the County Surveyors. It is already mandatory for steel bridgework contractors working for the HA to have their quality management certified to BS EN ISO 9001. Whilst this is a contractual provision and not a public safety regulation, the fact that the HA (and most other bridge authorities) is an organisation whose activities are covered by the Public Procurement Regulations means in practice that contractual provisions carry public obligations with them. The HA will wish to make use of CE Marking to implement its obligations to ensure that safe and reliable components are used in its bridges. This is a general policy and will affect how the HA deals with type approvals, product certification etc for proprietary products and specific items supplied for installation such as bridge bearings. This wider context is not considered further in this Appendix, but additional information can be found on the HA website on standards: http://www.standardsforhighways.co.uk/index.htm. Quality management In order to identify a common interpretation of BS EN ISO 9001 for organisations and certification bodies engaged in the sector, the HA sponsors the development of Sector Scheme Documents (SSD). National Highways Sector Scheme 20 (NHSS 20) relates to the quality management system requirements for the execution of steelwork in transportation infrastructure assets for the supply of new steelwork and for work on existing steelwork in new and existing assets. NHSS 20 is entitled Sector Scheme Document for the Execution of Steelwork in Transportation Infrastructure Assets. Potentially it can be used for a wider scope of steelwork infrastructure projects including toll plazas, railway bridges and station buildings. It is expected that NHSS 20 will be published by the end of 2008 to coincide with the publication of BS EN 1090-1 and -2. Steel bridgework contractors will then be expected to have their BS EN ISO 9001 certifications “endorsed” as complying also with the provisions of NHSS 20 when they are next re-certified. As BCSA steel bridgework contractors have collaborated in its development, its provisions should reflect existing good quality management practice in the sector. Certification bodies As NHSS 20 is one of many National Highways Sector Schemes, there are already many certification bodies that are familiar with using them. Several of these have already endorsed the development of NHSS 20. Steel bridgework contractors will need to match the certification body they use for their existing BS EN ISO 9001 certification with those able to certify to NHSS 20. Also, it is not necessarily the case that existing certification bodies operating in the sector will seek to become notified bodies under BS EN 1090-1. Hence, steel bridgework contractors need to be aware of this in order to avoid unnecessary duplication of certification audits. Basis of NHSS 20 NHSS 20 clearly states that it is based on the requirements of BS EN 1090-1 for conformity 57

APPENDIX B : ISSUES ASSOCIATED WITH BRIDGES assessment of manufacturing operations, BS EN 1090-2 as the specification for the execution of steel structures and BS EN ISO 3834-2 and -3 as the basis for the welding quality requirements. It should be noted that NHSS 20 covers a much wider scope than FPC to BS EN 1090-1, as it covers, for instance, all site-based operations including bridge refurbishment. However, with respect to conformity assessment of manufacturing operations and manufacturing welding quality requirements it is congruent in its requirements with BS EN 1090-1. Hence, the guidance provided in the main sections of this document applies directly to the CE Marking of manufactured steel bridgework components. NHSS 20 is also based on using BS EN 1090-2 as the basis for the execution specification. This supersedes the use of BS EN 5400-6 Steel, concrete and composite bridges - Part 6: Specification for materials and workmanship, steel. In order to assist with the transition between these two standards, the Steel Bridge Group (on which BCSA sits) has prepared SCI Publication P382 Model Project Specification for the Execution of Steelwork in Bridge Structures. The SCI will also be issuing updates as relevant to its publication P185 Steel Bridge Group: Guidance Notes on Best Practice in Steel Bridge Construction. As BS EN 1090-2 is the supporting standard for BS EN 1090-1, steel bridgework contractors seeking to have their FPC certified as complying with BS EN 1090-1 and NHSS 20 should ensure that they follow the guidance in those two SCI publications. Execution Class Publication P382 is based on EXC3, whereas the guidance provided in the main sections of this document refers generally to EXC2. The principal implications of this for CE Marking to BS EN 1090-1 are for:

• • • •

The traceability requirements for constituent products used in manufacture; The manufacturer's WQMS; The technical knowledge of the RWC; Weld inspection and acceptance requirements.

Traceability Section 7 defines the requirements for all Execution Classes and P382 provides a detailed definition of how those requirements are implemented in practice, as follows: A record shall be maintained of the source of, and test certificates for, main structural steel elements in order to provide traceability for each product. Traceability shall be by piece, by type or by stock certificate, as follows:

• For flanges, webs and diaphragms in main girders, the records shall be maintained for each individual piece. A unique item mark shall be made on each piece.

• For stiffeners, splice plates, bracing members, and fasteners, the records shall be maintained for each item type, of which there can be many individual pieces. Products of one type may come from more than one source and be installed in more than one location.

• For welding consumables and shear connectors, the records shall be maintained according to stock certification, which shall show that the stock material meets the project requirements. WQMS and RWC EXC3 requires that the manufacturer's WQMS shall be certified as complying with BS EN ISO 3838-2, i.e. Comprehensive quality requirements. The technical knowledge for the RWC responsible for a WQMS to BS EN ISO 3838-2 is as follows:

58

Guide to the CE Marking of Structural Steelwork TECHNICAL KNOWLEDGE OF RWC Scope of welding operations being supervised Welding of S275 or S355 steel products Welding of S420 steel products

Maximum parent metal thickness t (in mm) t ≤ 25 (1)

t > 25 (1)

Specific

Comprehensive

Comprehensive

Comprehensive

(1) Column base plates and endplates ≤ 50mm. BS EN 1090-2 states that the technical knowledge required is with respect to the welding operations being supervised. It may be seen that a Specific level of knowledge may be suitable for bridgework contractors only undertaking the manufacture of footbridges and sign gantries, but otherwise a Comprehensive level of knowledge of welded steel bridgework would be required. Weld inspection and acceptance requirements BS EN 1090-2 requires routine supplementary NDT to be undertaken on a more frequent basis for EXC3 than EXC2. BS EN 1090-2 also requires that production welds meet quality level B for EXC3 (i.e. as required for WQTs and WPQRs). The implications of these quality level requirements are explained in section 4. Publication P382 deals with this issue in more detail, as well as recommending an approach for dealing with weld acceptance criteria for welded fatigue details that avoids the difficulties (noted in section 4 above) that would occur with trying to meet the weld quality levels for EXC4 if these were specified for general production. The approach requires the execution specification to identify specific joints that are designed for significant fatigue so that the extent and method of testing can be chosen to detect imperfections and to characterise them. Assessment of whether such imperfections are non-conforming defects is then judged using published fitness-for-purpose criteria that relate the function of the component to the characteristics of the imperfections (type, size, location) in order to decide whether the weld is either acceptable or shall be repaired. In effect this replaces routine inspection with joint-specific inspection for “fatigue welds” which is based on the same fitness-for-purpose weld acceptance criteria that underpin BS 5400-6.

59

APPENDIX C : DOCUMENTARY EXAMPLES

APPENDIX C – DOCUMENTARY EXAMPLES

60


61

APPENDIX C : DOCUMENTARY EXAMPLES

62


63

APPENDIX D : SG17 GUIDANCE ON FPC ASSESSMENT

APPENDIX D – SG17 GUIDANCE ON FPC ASSESSMENT This is an abstract of a draft position paper prepared by SG17, the Structural Metallic Products Sector Group of Notified Bodies for the Construction Products Directive 89/106/EEC on which SCCS is represented.

Introduction The aim of this document is to give Notified Bodies (NB) and manufacturers of steel or aluminium structural components or kits of components➅ guidance for the performance of FPC assessment according to Annex B of EN 1090-1. In addition to Annex B of EN 1090-1 this document identifies the tasks of the NB both for the Initial Inspection and for the Continuous Surveillance.➆ This guidance applies to factories whether they produce series or non-series production.➇

1

Initial Inspection of the Factory and FPC

1.1

General

1.1.1 The manufacturer shall demonstrate that the FPC fulfils the requirements given in clause 6.3 of EN 1090-1. The tasks for the NB for the Initial Inspection are given in Table B.1 of EN 1090-1. 1.1.2 The FPC system shall cover all processes, production lines, units or departments including those outsourced or operated by subcontractors. 1.1.3 If the manufacturer declares with the CE Marking symbol characteristics influenced by the structural design (clause ZA 3.3 or ZA 3.5 of EN 1090-1) the assessment of the FPC also includes the control of tasks related to structural design work in Table B.1 of EN 1090. The manufacturer may be selective in its declaration of the structural characteristics for products provided that the manufacturer's declaration is unambiguous in this respect.➈ 1.1.4 The certificate issued by the NB shall make it clear whether the design process is included or not. 1.1.5 As specified in 6.3.5 of EN 1090-1, if constituent products or structural components bearing CE marks are incorporated into finished products during the manufacturing of EN 1090-1 products, they shall be traceable in accordance with the provisions for the relevant Execution Class given in 6.3.5 of EN 1090-2 or -3 as appropriate. 1.1.6 For finished products to be supplied to a Member State where CE Marking is mandatory and a harmonised standard exists for a constituent product, the manufacturer shall use a constituent product with a CE mark.

➅ A manufacturer may make a single declaration of conformity for a kit of components provided that all components are intended for incorporation in the same construction work. ➆ A checklist made by the Notified Body and specific to EN 1090-1 and to this document is strongly recommended as a tool for the assessment. ➇ Series production may be taken as batch sizes of 10 or more identical components. ➈ For instance, the load bearing capacity of a beam's connections could be declared even though the manufacturer's declaration is silent about the capacity of the beam in bending. 64

Guide to the CE Marking of Structural Steelwork 1.1.7 The factory covered by a single FPC system may comprise several production units, production lines and/or departments. The NB shall define the scope of certification in terms of processes, units, lines and departments in all records issued to verify that the FPC system has been certified. 1.1.8 If the manufacturer is performing any testing in its own laboratory, the testing facilities shall be included in the assessment. The capability of the laboratory shall be demonstrated to the Notified Body according to one of the following possibilities: -

direct check of the performance of the manufacturer's own laboratory testing operations within the scope of the FPC;

-

independent accreditation of the laboratory under ISO/IEC 17025 or equivalent accreditation; the accreditation shall be specific for the tests carried out;

-

assessment of a subcontracted laboratory by the Notified Body.

1.1.9 After a new ITT program based on physical testing has been undertaken the manufacturer shall inform the NB. The NB should review the FPC to ensure that it is capable of controlling the production of the new product. The NB does not need to undertake a supplementary assessment visit if the method of production is covered by the existing certified FPC system. This requirement does not apply where a product type is developed by calculation (ITC). 1.1.10 If the FPC is part of a certified EN ISO 9001 and/or EN ISO 3834 quality management system and the NB has satisfied itself that the system is compliant with the requirements of EN 1090-1 and this document then the NB may use any EN ISO 9001 or EN ISO 3834 certification information in support of the FPC certification according to the CPD. 1.1.11 The number of samples used to establish product quality during ITT/ITC is defined as a single item in Table 1 of EN 1090-1. This is because many structural components are non-series items and with a unique component specification 10 . If a new product type is developed using physical testing then suitable statistical techniques shall be used to assess product characteristics based on the number of samples tested. 11 1.1.12 The sampling procedure to be used during production is given in Table 2 of EN 1090-1. 1.1.13 The component specification defines the initial type and is thus the primary control document that links ITT/ITC with production requirements. The NB shall check that typical component specifications issued for manufacture are fully definitive in terms of the characteristics that support the manufacturer's declaration of conformity. 1.1.14 Special processes shall be assessed according to 1.3.

10 There could be a single set of calculations to verify the load bearing capacity of the component. This would be based on verification procedures given in, for example, the Eurocodes which are based on many “type tests” undertaken in support of the codified rules. 11

Annex D of EN 1990 provides a reference for structural product design assisted by physical testing.

65

APPENDIX D : SG17 GUIDANCE ON FPC ASSESSMENT 1.2

Performance of the Initial Inspection of the Factory and FPC

1.2.1 During the initial assessment of the factory all processes, units, lines and departments covered by a single FPC system shall be inspected individually. This shall include those outsourced or operated by subcontractors unless their FPC is certified by a NB for the scope of the work being undertaken. 1.2.2 During the initial inspection of factory and FPC the NB shall take into account the Initial Type Calculation (ITC) and/or the Initial Type Testing (ITT) as applicable (see 6.2 of EN 1090-1). This also applies if ITC is outsourced or done by subcontractors. 12 1.2.3 The manufacturer or its subcontractors shall make available the records of the ITC if applicable and ITT. The NB shall check that the results of the ITC/ITT procedure are consistent with the scope of processes, product types, materials and production lines covered (see Annex B of EN 1090-1). 1.2.4 During the initial inspection the NB shall check that the factory has the necessary resources (premises, personnel and equipment) to achieve conformity of products. 1.2.5 Initial visits to packaging and warehouse units shall check that the FPC system ensures that products retain their traceability such that the product shall be delivered with a mark that clearly identifies it, with reference to the component specification. 1.2.6 The certificate issued by the NB shall be definitive in terms of the scope and Execution Class of product types, the applicable standards and the facilities covered. 1.2.7 If the product types produced in a factory do not incorporate welding, the certificate shall explicitly exclude welding. 1.2.8 If the product types produced in a factory incorporate welding, the certificate shall be explicit concerning the welding processes and parent materials covered. Unless the scope of certification is limited to Execution Class 1, the Responsible Welding Coordinator (RWC) shall also be identified on the certificate. This may be by means of certification to EN ISO 3834 (see 1.3.2.3). 1.3

Initial Inspection for Special Processes

1.3.1 General 1.3.1.1 Special processes are those processes where the conformity of the finished product cannot be readily or economically verified. 1.3.1.2 Special processes require special consideration during the initial inspection. 1.3.1.3 Welding is most widely used special process for products covered by EN 1090-1 and is dealt with in detail in 1.3.2. 12 The requirement to consider ITC undertaken by others only applies if the manufacturer is using that ITC as the basis for its declaration of the structural characteristics of the finished product.

66

Guide to the CE Marking of Structural Steelwork 1.3.2 Initial Inspection for the Special Process “Welding” 1.3.2.1 The quality requirements are defined in terms of the Execution Class according to EN 1090-2/-3 as appropriate. 1.3.2.2 EN 1090-2/-3 as appropriate also defines the quality requirements for fusion welding according to EN ISO 3834 and the relevant to the Execution Class for the products being manufactured. 13 1.3.2.3 The NB shall be satisfied that the manufacturer is deploying suitable resources to ensure proper operation of the FPC for welding with respect to the following: -

Welders

For each main welding process the manufacturer shall have available welder(s) with valid qualification according to EN 287-1 for steel or EN ISO 9606-2 for aluminium. Welders for fillet welds should have a suitable qualification for welding fillet welds. -

Operators

For each main fully mechanised or automatic welding process the manufacturer shall have available operator(s) with valid qualification according to EN 1418. -

Welding Coordination

RWCs identified as managing welding coordination should be competent to manage the processes under their supervision and understand the limits of their competence 14 . Guidance on suitable knowledge is given in EN 1090-2/-3 as appropriate in terms of EN ISO 14731 and the relevant Execution Class. -

Qualification of Welding Procedures

Except where welding is undertaken to Execution Class 1, all welding operations shall be performed according to qualified welding procedures. The welding procedure specifications (WPSs) to be used shall be based on a Welding Procedure Qualification Record (WPQR). The method of qualification shall be according to EN 1090-2/-3 as appropriate. 1.3.3 Performance of the Initial Inspection for the Special Process “Welding” 1.3.3.1 The requirements for the FPC of the manufacturer's factory where welding is performed are given in clause 6.3 of EN1090-1. 1.3.3.2 The NB shall assess whether the personnel, procedure qualifications and equipment of the manufacturer meet the requirements of EN 1090-2/-3 as appropriate. 1.3.3.3 During the initial inspection of the welding factory it has to demonstrate that the production process is under control in accordance with the requirements for welding given in EN 1090-2/-3 as appropriate.

13

Certification to EN ISO 3834 is not required but may be agreed between the manufacturer and the Notified Body.

The RWC is permitted to rely on additional assistance from an outside specialist source of welding advice to coordinate welding operations outside his general scope of competence on a “unit verification” basis (e.g. wider range of parent materials to be welded). 14

67

APPENDIX D : SG17 GUIDANCE ON FPC ASSESSMENT 1.3.3.4 The audit and the independent assessment of the RWC's competence and knowledge shall be performed by experienced auditors. 15 1.3.3.5 With respect to the processes being used, the Execution Class for the products being produced, the constituent products being welded and the welding consumables being used, the assessment of the RWC's competence shall include the following checks with respect to the RWC's ability to coordinate the processes etc within the FPC system: - During a technical discussion, check the knowledge of the welding coordinator(s) about the relevant standards, regulations and specifications to be observed. - Check the ability of the welding coordinator(s) to detect and assess defects, to instruct repairs and to know how to avoid defects. 1.3.3.6 With respect to the processes being used, the Execution Class for the products being produced, the constituent products being welded and the welding consumables being used, the audit of the FPC system shall include the following checks: -

Check that the certificates of welders, operators and NDT-Personnel are appropriate.

-

Check that the WPSs are based on appropriate WQPRs 16 .

-

During an inspection tour through the plant, check that suitable equipment is available for joint preparation, welding, heat treatment (if necessary) and treatment after welding, and that the equipment is suitably maintained.

-

Check that the quality of welding works is being monitored in accordance with the specified requirements.

-

Check that relevant standards, regulations and specifications, necessary for the production are available.

2 Continuous Surveillance, Assessment and Approval of the FPC 2.1 The frequency of surveillance visits shall be in accordance with B.4 of EN 1090-1. The FPC system in every unit, line and department covered by a single FPC system shall be included in a surveillance visit at least once every three years. Subject to inspection of non-conformance reports or irregularities identified during the NB audit, the NB may request more frequent visits from that given in B.4 of EN1090-1. The issues to be considered include: -

15

irregularities in the performance and evaluation of welder, welding operator or welding procedure qualification tests;

-

irregularities in welding procedure specifications and production weld tests;

-

incomplete or wrong material inspection documents;

-

incomplete necessary standards, specifications and regulations for the production;

-

incomplete technical knowledge of the welding coordinator;

EA 6/02 gives guidelines for certification to EN ISO 3834.

WPQRs and associated WPSs are the equivalent of Initial Type Tests for welds executed within the “family” defined by the range of qualification given in the WPQR. In this context, the process control of welding defined in EN 1090-2/-3 may be seen as suitable for series production. 16

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Guide to the CE Marking of Structural Steelwork -

significant defects in products.

An additional surveillance audit may be required due to one of the following reasons: -

new or changed essential facilities;

-

change of Responsible Welding Coordinator;

-

new welding processes, parent materials and associated WPQRs;

-

new essential equipment.

If the NB becomes aware that one of the above reasons applies but the manufacturer has not informed the NB promptly, then an additional surveillance visit shall be undertaken. 2.2 The tasks of the NB during the surveillance audit are given in Table B.2 of EN 1090-1. 2.3 The audit of special process “welding” shall check the following in accordance with the requirements of EN 1090-2/-3: -

the commissioning of new WPSs into production;

-

plans for the control of production welding are being properly implemented;

-

the methods and frequency of inspection and testing being undertaken.

69

APPENDIX E : ABBREVIATIONS

APPENDIX E – ABBREVIATIONS BCSA

The British Constructional Steelwork Association Ltd

CC

Consequences class

CEN

European Committee for Standardization

CEV

Carbon equivalent value

CPD

Construction Products Directive

CPR

Construction Products Regulations

CSWIP

Certification Scheme for Welding and Inspection Personnel

CVN

Charpy V-notch

DCLG

Department for Communities and Local Government

ETA

European technical approval

EXC

Execution class

FPC

Factory production control

HA

Highways Agency

HAZ

Heat affected zone

IIW

International Institute of Welding

ITC

Initial type calculation

ITT

Initial type testing

IWE

International welding engineer

IWS

International welding specialist

IWT

International welding technologist

MPCS

Manufacturer provided component specification

NB

Notified body

NDT

Non destructive testing

NHSS 20

National Highways Sector Scheme 20

NPD

No performance determined

NSSS

National Structural Steelwork Specification for Building Construction

OJ

Official Journal

PC

Production category

PPCS

Purchaser provided component specification

pWPS

Preliminary welding procedure specification

RWC

Responsible welding coordinator

SC

Service category

SCCS

Steel Construction Certification Scheme

SCI

The Steel Construction Institute

TWI

The Welding Institute

UKAS

United Kingdom Accreditation Service

WPQR

Welding procedure qualification record

WPS

Welding procedure specification

WQMS

Welding quality management system

WQT

Welder qualification tests

70


REFERENCES BCSA Publications: National Structural Steelwork Specification for Building Construction (CE Marking Edition) (In preparation title subject to confirmation) Commentary on the Fourth Edition of the National Structural Steelwork Specification for Building Construction BSI Publications: BS EN 5400-6 Steel, concrete and composite bridges - Part 6: Specification for materials and workmanship, steel BS EN 1011 Welding - Recommendations for welding of metallic materials BS EN 1090-1 Execution of steel structures and aluminium structures - Part 1: Requirements for conformity assessment of structural components BS EN 1090-2 Execution of steel structures and aluminium structures - Part 2: Technical requirements for steel structures BS EN 1990 Eurocode - Basis of structural design BS EN 10025-1 Hot-rolled products of structural steels - Part 1: General technical delivery conditions BS EN 10045-1 Charpy impact test on metallic materials - Part 1: Test method (V-and U-notches) BS EN 10210-1 Hot finished structural hollow sections of non-alloy and fine grain steels - Part 1 Technical delivery conditions BS EN 10219-1 Cold form welded structural hollow sections of non-alloy and fine grain steels Part 1 Technical delivery conditions BS EN 14399-1 High strength structural bolting assemblies for preloading - Part 1: General requirements BS EN 15048-1 Non-preloaded structural bolting assemblies - Part 1: General requirements BS EN ISO 3834 Quality requirements for fusion welding of metallic materials Part 1: Criteria for the selection of the appropriate level of quality requirements Part 2: Comprehensive quality requirements Part 3: Standard quality requirements Part 4: Elementary quality requirements PD CEN ISO/TR Quality requirements for fusion welding of metallic materials - Part 6: Guidelines on implementing ISO 3834 BS EN ISO 9001 Quality management systems - Requirements BS EN ISO/IEC 17021 Conformity assessment - Requirements for bodies providing audit and certification of management systems BS EN ISO/IEC 17025 General requirements for the competence of testing and calibration laboratories BS EN ISO 14731 Welding coordination - Tasks and responsibilities BS ISO 10005 Quality management - Guidelines for quality plans

71

REFERENCES Other publications: CE marking under the Construction Products Directive published by DCLG available at http://www.communities.gov.uk/documents/planningandbuilding/pdf/156006.pdf The Construction Products Directive - A practical guide to implementation and CE marking, Adam A. Pinney and Stephen J. Rein, published by AuthorHouse, Milton Keynes, 2007. Certification Scheme for Welding and Inspection Personnel (CSWIP), Requirements for the Certification of Welding Coordinators in accordance with BS EN ISO 14731: 2006, Document No. CSWIP-WCO-18-06, Administered by TWO Certification Ltd. Guidance Paper 'L' Application and use of Eurocodes. NB-CPD/SG17 Guidance for the FPC assessment according to Annex B of EN 1090-1 NHSS 20 Sector Scheme Document for the Execution of Steelwork in Transportation Infrastructure Assets published by the Highways Agency P185 Steel Bridge Group: Guidance Notes on Best Practice in Steel Bridge Construction published by the Steel Construction Institute P382 Model Project Specification for the Execution of Steelwork in Bridge Structures published by the Steel Construction Institute

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Guide to CE Marking of Structural Steelwork

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