SIST EN 12953-9:2025

Shell boilers - Part 9: Requirements for limiting devices of the boiler and accessories

This European Standard specifies requirements for limiters (or limiting devices) which are incorporated into safety systems for shell boilers as defined in EN 12953-1. A limiter (or limiting device) can be either: - a safety accessory as defined in the Pressure Equipment Directive, Article 1, clause 2.1.3, and needs to include the safety logic and final actuator, or - one element of a safety system, for example, a self-monitoring water level sensor used as part of a safety accessory as defined in the Pressure Equipment Directive, Article 1, clause 2.1.3. The overall boiler protection function needs to be provided in association with additional safety logic (where appropriate) and a final actuator. The design requirements and examination of functional capability for the limiters are covered in this European Standard. For an explanation of the extent of the limiter (or limiting device) see Figure A.1.

Großwasserraumkessel ­ Teil 9: Anforderungen an Begrenzungseinrichtungen an Kessel und Zubehör

Chaudières à tubes de fumée ­ Partie 9: Exigences pour les dispositifs de limitation de lachaudière et de ses accessoires

Le présent document spécifie les exigences pour les limiteurs intégrés dans les systèmes de sécurité des chaudières à tubes de fumée, tel que spécifié dans l'EN 12953 1:2012.
Le présent document couvre les exigences de conception et l'examen des limiteurs.
NOTE   Voir l'Annexe E pour la détermination des données caractéristiques à utiliser dans les circuits de protection avec un niveau d'intégrité de sécurité (SIL). Les exigences relatives aux limiteurs concernant le niveau d'intégrité de sécurité (SIL), par exemple conformément à l'EN 61508, ne sont pas couvertes dans le présent document.

Mnogovodni kotli - 9. del: Zahteve za omejilne naprave kotla in opremo

General Information

• Status: Published
• Public Enquiry End Date: 02-Jul-2023
• Publication Date: 14-Jan-2025
• ICS: 27.060.30 - Boilers and heat exchangers
• Technical Committee: TLP - Pressure vessels
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 08-Jan-2025
• Due Date: 15-Mar-2025
• Completion Date: 15-Jan-2025
• Directive: 2014/68/EU - Directive 2014/68/EU of the European Parliament and of the Council of 15 May 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of pressure equipment
• Directive: 97/23/EC - Directive 97/23/EC of the European Parliament and of the Council of 29 May 1997 on the approximation of the laws of the Member States concerning pressure equipment
• Mandate: M/071 - Mandate to CEN for standardization in the field of Pressure equipment
• Ref Project: EN 12953-9:2024 - Shell boilers - Part 9: Requirements for limiting devices of the boiler and accessories

Relations

• Replaces: SIST EN 12953-9:2007 - Shell boilers - Part 9: Requirements for limiting devices of the boiler and accessories
• Effective Date: 01-Feb-2025

Standards Content (Sample)

SLOVENSKI STANDARD
01-februar-2025
Nadomešča:
SIST EN 12953-9:2007
Mnogovodni kotli - 9. del: Zahteve za omejilne naprave kotla in opremo
Shell boilers - Part 9: Requirements for limiting devices of the boiler and accessories
Großwasserraumkessel ­ Teil 9: Anforderungen an Begrenzungseinrichtungen an Kessel
und Zubehör
Chaudières à tubes de fumée ­ Partie 9: Exigences pour les dispositifs de limitation de
lachaudière et de ses accessoires
Ta slovenski standard je istoveten z: EN 12953-9:2024
ICS:
27.060.30 Grelniki vode in prenosniki Boilers and heat exchangers
toplote
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 12953-9
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2024
EUROPÄISCHE NORM
ICS 27.060.30 Supersedes EN 12953-9:2007
English Version
Shell boilers - Part 9: Requirements for limiting devices of
the boiler and accessories
Chaudières à tubes de fumée - Partie 9: Exigences pour Großwasserraumkessel - Teil 9: Anforderungen an
les dispositifs de limitation de la chaudière et de ses Begrenzungseinrichtungen an Kessel und Zubehör
accessoires
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, Czech Republic, 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 COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12953-9:2024 E
worldwide for CEN national Members.

⁠⁠⁠Contents Page
⁠⁠⁠European foreword . 4
Introduction . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 9
4 Requirements for limiter . 12
4.1 General . 12
4.2 Components . 12
4.3 Materials and design . 13
4.4 Electrical equipment . 14
4.5 Fault assessment . 15
4.5.1 General . 15
4.5.2 Fault models and exclusions . 18
4.6 Marking . 19
4.7 Operating instructions . 20
4.8 Type examination of functional capability . 20
4.9 Routine testing for final assessment . 23
5 Special requirements for water level limiters . 23
5.1 Design . 23
5.1.1 General . 23
5.1.2 Internal protection tubes . 24
5.1.3 External chambers . 24
5.2 Floating devices . 24
5.3 Level electrode devices . 25
5.4 Additional requirements for differential pressure sensors . 27
5.5 Type examination of functional capability . 27
6 Special requirements for pressure limiters . 28
6.1 Design . 28
6.2 Fault exclusion of mechanical failure of moving parts . 30
6.3 Type examination of functional capability . 30
7 Special requirements for temperature limiters . 32
7.1 Design . 32
7.2 Type examination of functional capability . 32
8 Special requirements for water conductivity limiters . 32
8.1 ⁠⁠⁠ Internally mounted transducers . 32
8.2 ⁠⁠⁠ ⁠⁠⁠Externally mounted transducers . 32
8.3 Transducers . 32
8.4 Type examination of functional capability of water conductivity limiter . 32
Annex A (informative) Limiting devices . 34
Annex B (informative) Example of an examination plan . 35
Annex C (informative) Marking of limiters . 37
Annex D (normative) Immunity against electrical and electromagnetic influences —
Requirements and testing . 40
D.1 General . 40
D.2 Immunity against mains voltage variations . 40
D.3 Immunity against short-time voltage interruptions and reductions . 40
D.4 Immunity against mains frequency changes . 41
D.5 Immunity against electrostatic discharge (ESD) . 41
D.6 Immunity against fast transient disturbance variables (burst) . 41
D.7 Immunity against surges . 42
D.8 Immunity against high-frequency electromagnetic fields . 42
D.9 Immunity against conducted disturbances induced by high frequency fields . 43
D.10 Immunity against power frequency magnetic fields . 44
Annex E (informative) Deterministic or probabilistic procedures for limiter safety cases . 45
E.1 General . 45
E.2 Relationships . 45
E.2.1 Type test . 45
E.2.2 Determination of characteristic data for use in protective circuits with SIL
classification (SIL = safety integrity level). 45
Annex F (normative) Requirements and tests of electrical safety . 46
Annex G (informative) Significant technical changes between this document and the
previous edition . 48
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 2014/68/EU aimed to be covered . 49
⁠⁠⁠Bibliography . 50

⁠⁠⁠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
...