National foreword

This British Standard is the UK implementation of EN 12953‑9:2024. It supersedes BS EN 12953‑9:2007, which is withdrawn.

The UK participation in its preparation was entrusted to Technical Committee PVE/2, Water Tube And Shell Boilers.

A list of organizations represented on this committee can be obtained on request to its committee manager.

Contractual and legal considerations

This publication has been prepared in good faith, however no representation, warranty, assurance or undertaking (express or implied) is or will be made, and no responsibility or liability is or will be accepted by BSI in relation to the adequacy, accuracy, completeness or reasonableness of this publication. All and any such responsibility and liability is expressly disclaimed to the full extent permitted by the law.

This publication is provided as is, and is to be used at the recipient’s own risk.

The recipient is advised to consider seeking professional guidance with respect to its use of this publication.

This publication is not intended to constitute a contract. Users are responsible for its correct application.

This publication has been prepared under a mandate given to the European Standards Organizations by the European Commission and the European Free Trade Association. It is intended to support requirements of the EU legislation detailed in the European Foreword. A European Annex, usually Annex ZA or ZZ, describes how this publication relates to that EU legislation.

For the Great Britain market (England, Scotland and Wales), if UK Government has designated this publication for conformity with UKCA marking (or similar) legislation, it may contain an additional National Annex. Where such a National Annex exists, it shows the correlation between this publication and the relevant UK legislation. If there is no National Annex of this kind, the relevant Annex ZA or ZZ in the body of the European text will indicate the relationship to UK regulation applicable in Great Britain. References to EU legislation may need to be read in accordance with the UK designation and the applicable UK law. Further information on designated standards can be found at www.bsigroup.com/standardsandregulation.

For the Northern Ireland market, UK law will continue to implement relevant EU law subject to periodic confirmation. Therefore Annex ZA/ZZ in the European text, and references to EU legislation, are still valid for this market.

UK Government is responsible for legislation. For information on legislation and policies relating to that legislation, consult the relevant pages of www.gov.uk.

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 December 2024.

This European Standard was approved by CEN on 20 October 2024.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czechia, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and United Kingdom.

⁠⁠⁠European foreword

This document (EN 12953‑9:2024) has been prepared by Technical Committee CEN/TC 269 “Shell and water-tube boilers”, the secretariat of which is held by DIN.

This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by June 2025, and conflicting national standards shall be withdrawn at the latest by June 2025.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights

This document supersedes EN 12953‑9:2007.

This document has been prepared under a standardization request addressed to CEN by the European Commission. The Standing Committee of the EFTA States subsequently approves these requests for its Member States.

For the relationship with EU Legislation, see informative Annex ZA, which is an integral part of this document.

Annex G provides details of significant technical changes between this European Standard and the previous edition.

The European Standard series EN 12953 concerning shell boilers consists of the following Parts:

Part 1: General
Part 2: Materials for pressure parts of boilers and accessories
Part 3: Design and calculation for pressure parts
Part 4: Workmanship and construction of pressure parts of the boiler
Part 5: Inspection during construction, documentation and marking of pressure parts of the boiler
Part 6: Requirements for equipment for the boiler
Part 7: Requirements for firing systems for liquid and gaseous fuels for the boiler
Part 8: Requirements for safeguards against excessive pressure
Part 9: Requirements for limiting devices of the boiler and accessories
Part 10: Requirements for feedwater and boiler water quality
Part 11: Acceptance tests
Part 12: Requirements for grate firing systems for solid fuels for the boiler
Part 13: Operating instructions

Although these parts may be obtained separately, it should be recognized that the parts are interdependent. As such, the design and manufacture of shell boilers requires the application of more than one part in order for the requirements of the European Standard to be satisfactorily fulfilled.

NOTE A “Boiler Helpdesk” has been established in CEN/TC 269 which can be contacted for any questions regarding the application of the European Standards series EN 12952 and EN 12953 see the following website: http://www.boiler-helpdesk.din.de.

Any feedback and questions on this document should be directed to the users’national standards body. A complete listing of these bodies can be found on the CENwebsite.

According to the CEN-CENELEC Internal Regulations, the national standardsorganisations of the following countries are bound to implement this EuropeanStandard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark,Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic ofNorth Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,Türkiye and the United Kingdom.

Introduction

The types of limiters which are to be fitted to boilers are specified in EN 12953‑6:2024 and the design of the safety systems are specified in EN 50156‑1:2015.

In order to provide the necessary safety function, for example, to cut off the energy supply to the boiler in the event of a low water fault, the limiter is connected to other elements in the safety system.

1 Scope

This document specifies requirements for limiters which are incorporated into safety systems for shell boilers as specified in EN 12953‑1:2012.

The design requirements and examination of the limiters are covered in this document.

NOTE See Annex E for determination of the characteristic data for use in protective circuits with a safety integrity level (SIL) rating. The requirements for limiters with regard to the safety integrity level (SIL), for example, in accordance with EN 61508 are not covered in this document.

2 Normative references

3 Terms and definitions

4 Requirements for limiter

4.1 General

4.2 Components

4.3 Materials and design

4.4 Electrical equipment

4.5 Fault assessment

4.6 Marking

4.7 Operating instructions

4.8 Type examination of functional capability

4.9 Routine testing for final assessment

5 Special requirements for water level limiters

5.1 Design

5.2 Floating devices

5.3 Level electrode devices

5.4 Additional requirements for differential pressure sensors

5.5 Type examination of functional capability

6 Special requirements for pressure limiters

6.1 Design

6.2 Fault exclusion of mechanical failure of moving parts

6.3 Type examination of functional capability

7 Special requirements for temperature limiters

7.1 Design

7.2 Type examination of functional capability

8 Special requirements for water conductivity limiters

8.1 ⁠⁠⁠ Internally mounted transducers

8.2 ⁠⁠⁠ ⁠⁠⁠Externally mounted transducers

8.3 Transducers

8.4 Type examination of functional capability of water conductivity limiter

⁠⁠⁠Bibliography

BS EN 12953-9:2024

Shell boilers - Requirements for limiting devices of the boiler and accessories

Current

Published:

31 Dec 2024