SIST EN 12953-2:2026

Shell boilers - Part 2: Materials for pressure parts of boilers and accessories

This European Standard specifies the following materials for the pressure bearing parts of shell boilers and equipment of shell boilers (e.g. valves), subjected to internal and external pressure including integral attachments (non pressure bearing parts):
—   flat products (plate) and parts formed from flat products (e.g. shell, furnace, dished ends);
—   tubes and parts formed from tubes (e.g. bending, elbows, reducers, fittings);
—   forgings and cast products ;
—   bolting materials;
—   welding consumables.

Großwasserraumkessel - Teil 2: Werkstoffe für drucktragende Kesselteile und Zubehör

Dieses Dokument legt die folgenden Werkstoffe für die drucktragenden Teile von Großwasserraumkesseln und die Ausrüstung von Großwasserraumkesseln (z. B. Armaturen) fest, die durch Innen- und Außendruck beansprucht werden sowie für integrale Zubehörteile:
-   Flacherzeugnisse (Bleche) und aus Flacherzeugnissen geformte Teile (z. B. Kesselmantel, Flammrohr, gewölbte Kesselböden);
-   Rohre und aus Rohren geformte Teile (z. B. Rohrbiegung, Bögen, Reduzierstücke, Formstücke);
-   Schmiede- und Gussteile;
-   Werkstoffe für Schrauben und Muttern;
-   Schweißzusätze.

Chaudières à tubes de fumée - Partie 2: Matériaux des parties sous pression des chaudières et des accessoires

Le présent document spécifie les matériaux suivants pour les parties sous pression des chaudières à tubes de fumée et aux équipements de chaudières à tubes de fumée (par exemple, appareils de robinetterie) soumis à pression interne et externe y compris leurs attaches incorporées :
-   produits plats (tôles) et parties formées à partir de produits plats (par exemple, virole, foyer, fonds bombés) ;
-   tubes et parties formées à partir de tubes (par exemple, tubes cintrés, coudes, réducteurs, raccords) ;
-   pièces forgées et produits moulés ;
-   matériaux de boulonnerie ;
-   produits consommables pour le soudage.

Mnogovodni kotli - 2. del: Materiali za tlačno obremenjene dele in opremo kotla

General Information

• Status: Published
• Public Enquiry End Date: 02-Mar-2024
• Publication Date: 08-Dec-2025
• ICS: 27.060.30 - Boilers and heat exchangers
• Technical Committee: TLP - Pressure vessels
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 09-Dec-2025
• Due Date: 13-Feb-2026
• Completion Date: 09-Dec-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
• Mandate: M/071 - Mandate to CEN for standardization in the field of Pressure equipment
• Mandate: M/601 - COMMISSION IMPLEMENTING DECISION of 1.3.2024 on a standardisation request to the European Committee for Standardization and the European Committee for Electrotechnical Standardization as regards pressure equipment and assemblies in support of Directive 2014/68/EU of the European Parliament and of the Council
• Ref Project: EN 12953-2:2025 - Shell boilers - Part 2: Materials for pressure parts of boilers and accessories

Relations

• Replaces: SIST EN 12953-2:2012 - Shell boilers - Part 2: Materials for pressure parts of boilers and accessories
• Effective Date: 01-Jan-2026

Overview - EN 12953-2:2025 (CEN)

EN 12953-2:2025 is the CEN European Standard that specifies materials for pressure parts of shell boilers and accessories. Approved in November 2025, it defines acceptable metallic materials, material selection rules, and documentation/traceability requirements for components subject to internal and external pressure. The scope covers flat products (plates and formed parts), tubes, forgings and castings, bolting materials and welding consumables used in shell boilers.

Key topics and technical requirements

• Scope of materials: Lists permitted steels and tube grades for boiler bodies and smoke tubes (see Table 1 in the standard). Cast iron and cast steel are explicitly not permitted for shell boiler body components.
• Component types covered: Shells, furnaces, dished ends, tube bends, elbows, reducers, fittings, forgings, cast products, valves and bolting.
• Material limits for valves and castings: Grey cast iron and spheroidal graphite cast iron are allowed for certain valve sizes with specified maximum pressure and temperature limits (e.g., grey cast iron: max DN 200, PS max 13 bar, TS max 220 °C; spheroidal: PS max 40 bar, TS max 350 °C). Specific valve uses (e.g., steam outlet stop valves, drain valves, safety valves) forbid grey cast iron.
• Material selection routes: Use of Harmonized European Standards, European Approvals for Materials (EAM), or Particular Material Appraisals (PMA) in accordance with EN 764-4:2014.
• Documentation and traceability: Material certificates per EN 10204:2004, inspection documents, marking and traceability during cutting/forming are required.
• Welding and bolting: Specifies acceptance of welding consumables and bolting selection guidelines (references EN 13479 and EN 1515-4).

Practical applications and users

Who uses EN 12953-2:2025:

• Boiler manufacturers and fabricators specifying materials for pressure parts.
• Mechanical and pressure vessel designers selecting plate, tube and forging grades.
• Procurement teams and material suppliers ensuring compliant certificates (EN 10204).
• Inspectors, notified bodies and quality managers verifying traceability, welding consumables and bolting.
• Maintenance and operations engineers assessing repair materials and component replacement options.

Practical uses:

• Preparing material specifications for shell boilers and accessories.
• Defining inspection/acceptance criteria and supplier documentation.
• Ensuring compliance with Pressure Equipment Directive interfaces and related parts of the EN 12953 series.

Related standards

Key referenced documents include: EN 12953-1/3/4/5, EN 10204, EN 764-4/5, EN 10028, EN 10216/17, EN 10222-2, EN 10213, EN 1515-4, and EN 13479. These are used together for comprehensive boiler design, manufacture and inspection.

Standards Content (Sample)

SLOVENSKI STANDARD
01-januar-2026
Nadomešča:
SIST EN 12953-2:2012
Mnogovodni kotli - 2. del: Materiali za tlačno obremenjene dele in opremo kotla
Shell boilers - Part 2: Materials for pressure parts of boilers and accessories
Großwasserraumkessel - Teil 2: Werkstoffe für drucktragende Kesselteile und Zubehör
Chaudières à tubes de fumée - Partie 2: Matériaux des parties sous pression des
chaudières et des accessoires
Ta slovenski standard je istoveten z: EN 12953-2:2025
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 12953-2
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2025
EUROPÄISCHE NORM
ICS 27.060.30 Supersedes EN 12953-2:2012
English Version
Shell boilers - Part 2: Materials for pressure parts of
boilers and accessories
Chaudières à tubes de fumée - Partie 2: Matériaux des Großwasserraumkessel - Teil 2: Werkstoffe für
parties pour pression des chaudières et des accessoires drucktragende Kesselteile und Zubehör
This European Standard was approved by CEN on 15 September 2025.

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
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12953-2:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 General requirements for material selection . 7
4.1 General . 7
4.2 Material specification . 7
4.3 European Approvals for Materials (EAM) . 7
4.4 Particular Material Appraisals (PMA) . 7
5 Materials for pressure parts . 8
5.1 Shell boiler body . 8
5.2 Valves and other forged or cast products . 9
5.3 Bolting material . 10
5.4 Flange and fitting material . 10
5.4.1 Flange material . 10
5.4.2 Fitting material . 10
5.5 Welding consumables . 10
5.6 Inspection documents . 10
5.7 Marking and traceability . 11
5.7.1 General . 11
5.7.2 Material supplied from a supplier other than the material manufacturer . 11
5.7.3 Material traceability during cutting and forming . 11
6 Materials for non pressure parts . 11
Annex A (informative) Example for Particular Material Appraisals (PMA). 12
Annex B (informative) Significant technical changes between this document and the
previous edition . 14
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 2014/68/EU aimed to be covered. 15
Bibliography . 16

European foreword
This document (EN 12953-2:2025) 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 May 2026, and conflicting national standards shall be
withdrawn at the latest by May 2026.
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 12953-2:2012.
Annex B provides details of significant technical changes between this document and the previous
edition.
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.
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 boiler feed water 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 can be obtained separately, it should be recognized that the parts are inter-
dependent. As such, the design and manufacture of shell boilers requires the application of more than
one part in order for the requirements of the standard to be satisfactorily fulfilled.
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 CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: 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 the United
Kingdom.
1 Scope
This document specifies the following materials for the pressure parts of shell boilers and equipment of
shell boilers (e.g. valves), subjected to internal and external pressure including integral attachments:
— flat products (plate) and parts formed from flat products (e.g. shell, furnace, dished ends);
— tubes and parts formed from tubes (e.g. tube bends, elbows, reducers, fittings);
— forgings and cast products;
— bolting materials;
— welding consumables.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 764-4:2014, Pressure equipment - Part 4: Establishment of technical delivery conditions for metallic
materials
EN 764-5:2014, Pressure equipment - Part 5: Inspection documentation of metallic materials and
compliance with the material specification
EN 1092-1:2018, Flanges and their joints - Circular flanges for pipes, valves, fittings and accessories, PN
designated - Part 1: Steel flanges
EN 1092-2:2023, Flanges and their joints - Circular flanges for pipes, valves, fittings and accessories, PN
designated - Part 2: Cast iron flanges
EN 1515-4:2021, Flanges and their joints - Bolting - Part 4: Selection of bolting for equipment subject to the
Pressure Equipment Directive 2014/68/EU
EN 1561:2023, Founding - Grey cast irons
EN 1563:2018, Founding - Spheroidal graphite cast irons
EN 1759-1:2004, Flanges and their joint - Circular flanges for pipes, valves, fittings and accessories, Class
designated - Part 1: Steel flanges, NPS 1/2 to 24
EN 10028-2:2017, Flat products made of steels for pressure purposes - Part 2: Non-alloy and alloy steels
with specified elevated temperature properties
EN 10028-3:2017, Flat products made of steels for pressure purposes - Part 3: Weldable fine grain steels,
normalized
EN 10204:2004, Metallic products - Types of inspection documents
EN 10213:2007+A1:2016, Steel castings for pressure purposes
EN 10216-1:2013, Seamless steel tubes for pressure purposes - Technical delivery conditions - Part 1: Non-
alloy steel tubes with specified room temperature properties
EN 10216-2:2024, Seamless steel tubes for pressure purposes — Technical delivery conditions — Part 2:
Non-alloy and alloy steel tubes with specified elevated temperature properties
EN 10217-1:2019, Welded steel tubes for pressure purposes - Technical delivery conditions - Part 1: Electric
welded and submerged arc welded non-alloy steel tubes with specified room temperature properties
EN 10217-2:2019, Welded steel tubes for pressure purposes - Technical delivery conditions - Part 2: Electric
welded non-alloy and alloy steel tubes with specified elevated temperature properties
EN 10217-5:2019, Welded steel tubes for pressure purposes - Technical delivery conditions - Part 5:
Submerged arc welded non-alloy and alloy steel tubes with specified elevated temperature properties
EN 10222-2:2017+A1:2021, Steel forgings for pressure purposes - Part 2: Ferritic and martensitic steels
with specified elevated temperatures properties
EN 10253-2:2021, Butt-welding pipe fittings - Part 2: Non alloy and ferritic alloy steels with specific
inspection requirements
EN 12953-1:2025, Shell boilers - Part 1: General
EN 12953-4:2018, Shell boilers - Part 4: Workmanship and construction of pressure parts of the boiler
EN 12953-5:2020, Shell boilers - Part 5: Inspection during construction, documentation and marking of
pressure parts of the boiler
EN 13479:2017, Welding consumables - General product standard for filler metals and fluxes for fusion
welding of metallic materials
EN 14394:2005+A1:2008, Heating boilers - Heating boilers with forced draught burners - Nominal heat
output not exceeding 10 MW and maximum operating temperature of 110 °C
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 12953-1:2025 and
EN 12953-5:2020 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
4 General requirements for material selection
4.1 General
The materials for the boiler and the parts of the boiler shall fulfil requirements specified in the order and
the requirements of this document.
4.2 Material specification
The selection of materials for pressure parts shall be in accordance with:
a) Harmonized European Standards (see Clause 5 with the exceptions in Table ZA.1);
b) European Approvals for Materials (see 4.3);
c) Particular Material Appraisals (see 4.4).
NOTE If relevant, a technical specification can be issued with additional requirements such as tolerances, non-
destructive examinations (NDE), etc.
For material, it shall be specified:
— the type of inspection document (material certificate) according to EN 10204:2004 (see also 5.6);
— any additional inspection requirements (e.g. second party/customer inspection).
4.3 European Approvals for Materials (EAM)
European Approvals for Materials are intended for repeated use.
EAM shall be established in accordance with EN 764-4:2014.
NOTE References of available EAM are published in the Official Journal of the European Union.
4.4 Particular Material Appraisals (PMA)
Particular Material Appraisals shall be applied for materials:
— used in special cases not covered in 4.2 a) and b),
— not intended for frequent use.
PMA shall be established in accordance with EN 764-4:2014.
NOTE  Examples for PMA, see Annex A and/or EN 764-4:2014, Annex F.
5 Materials for pressure parts
5.1 Shell boiler body
For typical components of the shell boiler body manufactured from flat products and tubes, see
EN 12953-1:2025, Figur
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