FprEN 12952-1

Water-tube boilers and auxiliary installations - Part 1: General

This document is applicable to water-tube boilers and boiler assemblies with volumes in excess of two litres for the generation of steam and/or hot water at a maximum allowable pressure PS greater than 0,5 bar and with a temperature in excess of 110 °C as well as auxiliary installations (other plant equipment).
The requirements of this document take account of pressure-related hazards, which apply to water tube boilers, including failure of pressure-retaining components due to overheating.
This document does not apply to the following types of boiler plant:
a)   boilers other than stationary boilers;
b)   shell type boilers;
c)   electrical boilers;
d)   nuclear primary circuits, the failure of which can cause an emission of radioactivity.

Wasserrohrkessel und Anlagenkomponenten - Teil 1: Allgemeines

Chaudières à tubes d'eau et installations auxiliaires - Partie 1: Généralités

Vodocevni kotli in pomožne napeljave - 1. del: Splošno

General Information

• Status: Not Published
• Publication Date: 14-Oct-2026
• ICS: 27.040 - Gas and steam turbines. Steam engines
• Technical Committee: CEN/TC 269 - Shell and water tube boilers
• Drafting Committee: CEN/TC 269/WG 1 - Water-tube boilers
• Current Stage: 4599 - Dispatch of FV draft to CMC - Finalization for Vote
• Start Date: 12-May-2026
• Due Date: 08-May-2024
• Completion Date: 12-May-2026
• Directive: Harmonized Standard2014/68/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: oSIST prEN 12952-1:2024 - Water-tube boilers and auxiliary installations - Part 1: General

Relations

• Referred By: CEN/TR 12952-17:2024 - Water-tube boilers and auxiliary installations - Part 17: Guideline for the involvement of an inspection body independent of the manufacturer
• Effective Date: 28-Jan-2026
• Revises: EN 12952-1:2015 - Water-tube boilers and auxiliary installations - Part 1: General
• Effective Date: 19-Jan-2023

Overview

FprEN 12952-1: Water-tube boilers and auxiliary installations - Part 1: General is a draft European Standard developed by the European Committee for Standardization (CEN/TC 269). This document establishes essential requirements and general principles for the design, manufacture, assembly, and commissioning of stationary water-tube boilers and associated auxiliary installations. It applies to assemblies with a volume greater than two litres, for generating steam or hot water at pressures greater than 0.5 bar and temperatures above 110°C.

The primary focus is on safety, particularly addressing pressure-related hazards and the prevention of failures in pressure-retaining components due to overheating. FprEN 12952-1 ensures alignment with the requirements of the EU Pressure Equipment Directive 2014/68/EU, providing a foundation for presumption of conformity and compliance in the European market.

Key Topics

• Scope and Applicability

  • Covers stationary water-tube boilers and assemblies, including all relevant pressure parts and auxiliary installations.
  • Applies to plants generating steam or hot water above defined thresholds.
  • Excludes non-stationary boilers, shell boilers, electrical boilers, and nuclear primary circuits.

• Safety Requirements

  • Emphasizes essential safety features specified in the Pressure Equipment Directive.
  • Requires suitable design, manufacturing, testing, and inspection methods.
  • Addresses hazards from overheating and other pressure-related failures.

• Roles and Responsibilities

  • Defines responsibilities for purchasers, manufacturers, designers, and regulatory authorities.
  • Stipulates that only qualified personnel and approved organizations should undertake design and construction.

• Conformity and Documentation

  • Outlines obligations for technical documentation and records including deviations and safety measures.
  • Mandates a global conformity assessment for the complete boiler assembly.

• Integration with Related Standards

  • Acts as the foundation within the EN 12952 standard series-full compliance often requires reference to multiple parts.

Applications

The standard is widely used in industries where reliable, high-pressure steam or hot water is essential. Typical applications include:

• Power Generation: Water-tube boilers form a critical part of thermal and combined-cycle power plants.
• Industrial Processing: Facilities in the petrochemical, chemical, and food industries employ water-tube boilers for process steam.
• District Heating: Centralized hot water or steam distribution systems, including large-scale municipal heating networks.
• Auxiliary Installations: Covers related equipment such as superheaters, reheaters, economizers, and associated piping and safety accessories.
• Safety and Compliance Management: Ensures organizations meet stringent EU regulations, reducing liability and improving operational safety.

Related Standards

FprEN 12952-1 is part of an integrated series of European standards for water-tube boilers and associated equipment. Key related standards include:

• EN 12952-2: Materials for pressure parts of boilers and accessories.
• EN 12952-3: Design and calculation for pressure parts.
• EN 12952-5/6: Workmanship, construction, inspection, documentation, and marking.
• EN 12952-7–11: Equipment, firing systems, safety devices, and limiting devices requirements.
• EN 12952-12: Boiler feedwater and boiler water quality.
• EN 12952-15: Acceptance tests for boiler assemblies.
• EN 764-1: Pressure equipment vocabulary and general guidance.

Additional procurement guides and technical reports, such as EN 45510-3-1 and EN 45510-3-3, support equipment selection and specification.

---

By following FprEN 12952-1 and its related standards, engineers, manufacturers, and plant operators ensure safe design, installation, and operation of water-tube boiler systems, maintain compliance with European regulations, and foster best practices in industrial boiler management.

Standards Content (Sample)

SLOVENSKI STANDARD
01-julij-2024
Vodocevni kotli in pomožne napeljave - 1. del: Splošno
Water-tube boilers and auxiliary installations - Part 1: General
Wasserrohrkessel und Anlagenkomponenten - Teil 1: Allgemeines
Chaudières à tubes d'eau et installations auxiliaires - Partie 1: Généralités
Ta slovenski standard je istoveten z: prEN 12952-1
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.

DRAFT
EUROPEAN STANDARD
prEN 12952-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2024
ICS Will supersede EN 12952-1:2015
English Version
Water-tube boilers and auxiliary installations - Part 1:
General
Chaudières à tubes d'eau et installations auxiliaires - Wasserrohrkessel und Anlagenkomponenten - Teil 1:
Partie 1: Généralités Allgemeines
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 269.
If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

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. prEN 12952-1:2024 E
worldwide for CEN national Members.

prEN 12952-1:2024 (E)
Contents Page
European foreword . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Interdependency of the parts of the series . 7
5 Symbols and abbreviations . 7
6 Equipment and components of water tube boiler . 11
6.1 Boiler assembly . 11
6.2 Other plant equipment . 12
7 Responsibilities . 12
7.1 Purchaser . 12
7.2 Manufacturer . 12
7.2.1 Qualification . 12
7.2.2 Demonstration of qualification . 12
8 Design/type appraisal of pressure parts . 12
Annex A (informative) Significant technical changes between this document and the
previous edition . 13
Annex ZA (informative) Relationship between this European Standard and the essential
requirements of Directive 2014/68/EU aimed to be covered . 14

prEN 12952-1:2024 (E)
European foreword
This document (prEN 12952-1:2024) has been prepared by Technical Committee CEN/TC 269 “Shell and
water-tube boilers”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
This document supersedes EN 12952-1:2015.
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 relationship with EU legislation(s), see informative Annex ZA which is an integral part of this
document.
The informative Annex A lists the significant technical changes between this document and the previous
edition.
EN 12952, Water-tube boilers and auxiliary installations 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 of the boiler;
— Part 4: In-service boiler life expectancy calculations;
— Part 5: Workmanship and construction of pressure parts of the boiler;
— Part 6: Inspection during construction; documentation and marking of pressure parts of the boiler;
— Part 7: Requirements for equipment for the boiler;
— Part 8: Requirements for firing systems for liquid and gaseous fuels for the boiler;
— Part 9: Requirements for firing systems for pulverized solid fuels for the boiler;
— Part 10: Requirements for safeguards against excessive pressure;
— Part 11: Requirements for limiting devices of the boiler and accessories;
— Part 12: Requirements for boiler feedwater and boiler water quality;
—
— Part 14: Requirements for flue gas DENOX-systems using liquefied pressurized ammonia and ammonia
water solution;
— Part 15: Acceptance tests;
— Part 16: Requirements for grate and fluidized-bed firing systems for solid fuels for the boiler;
prEN 12952-1:2024 (E)
— CEN/TR 12952 Part 17 Part 17: Guideline for the involvement of an inspection body independent of
the manufacturer;
— Part 18: Operating instructions.
Although these parts can be obtained separately, it is recognized that the parts are inter-dependent. As
such, the design and manufacture of water-tube boilers requires the application of more than one part in
order for the requirements of the document 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
prEN 12952-1:2024 (E)
1 Scope
This document applies to water-tube boilers and boiler assemblies with volumes in excess of two litres
for the generation of steam and/or hot water at a maximum allowable pressure PS greater than 0,5 bar
and with a temperature in excess of 110 °C as well as auxiliary installations (other plant equipment).
The purpose of this document is to ensure that the necessary essential safety requirements according to
Annex I of the Pressure Equipment Directive are fulfilled in order to guarantee the safety of water tube
boilers.
This aim will be achieved by:
— the proper application of the design, manufacturing, testing and inspection methods and techniques,
— the provision of protective measures against hazards, which cannot be eliminated, and
— the provision of information on residual hazards and other measures to reduce risk,
which are incorporated in the various parts of this document.
The requirements of this document take account of pressure-related hazards, which apply to water tube
boilers, including failure of pressure-retaining components due to overheating.
This standard recognizes that it is not possible to cover all the combinations of situations that might arise.
This document does not apply to the following types of boiler plant:
a) boilers other than stationary boilers;
b) shell type boilers;
c) electrical boilers;
d) nuclear primary circuits, the failure of which can cause an emission of radioactivity.
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 764-1:2016, Pressure equipment — Part 1: Vocabulary
EN 12952-5:2021, Water-tube boilers and auxiliary installations - Part 5: Workmanship and construction
of pressure parts of the boiler
EN 12952-6:2021, Water-tube boilers and auxiliary installations - Part 6: Inspection during construction,
documentation and marking of pressure parts of the boiler
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 764-1 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
ISO Online browsing platform: available at https://www.iso.org/obp/
IEC Electropedia: available at https://www.electropedia.org/
prEN 12952-1:2024 (E)
3.1
purchaser
individual or organization that buys the boiler or a part thereof
3.2
manufacturer
individual or organization responsible for the design, fabrication, testing, installation where relevant, and
compliance with the requirements of the relevant product standard, whether executed by him or a
subcontractor
Note 1 to entry: The manufacturer can subcontract one or more of the abovementioned tasks under their
responsibility.
[SOURCE: EN 764-1:2016, 3.5.5, modified – Note 1 complete and Note 2 deleted.]
3.3
designer
individual or organization that, on behalf of the manufacturer, carries out the design of the boiler plant
Note 1 to entry: The designer determines the shape, dimensions and thicknesses of the boiler plant components,
selects the materials and details the methods of construction and testing.
3.4
material supplier
individual or organization, not being a material manufacturer, that supplies material or prefabricated
parts to be used in the construction of pressure components
[SOURCE: EN 764-1:2016, 3.5.7]
3.5
material manufacturer
individual or organization that produces material in the basic product form used in the manufacture of
pressure equipment
[SOURCE: EN 764-1:2016, 3.5.6]
3.6
responsible authority
competent organizations which are independent of the manufacturer
Note 1 to entry: This standard identifies responsible authorities. Such organizations may be notified bodies,
recognized third-party organizations or user inspectorates. For the purpose of this standard, these organizations
have been collectively termed responsible authorities (RA).
Note 2 to entry: The definition of a notified body and the criteria controlling its operation are given in Article 24 of
the Pressure Equipment Directive 2014/68/EU.
Note 3 to entry: The definition of a recognized third-party organization and the criteria controlling its operation are
given in Article 24 of the Pressure Equipment Directive 2014/68/EU.
Note 4 to entry: The definition of a user inspectorate and the criteria controlling its operation are given in Article 25
of the Pressure Equipment Directive 2014/68/EU.
Note 5 to entry: The responsibility of the manufacturer is described in 3.2.
prEN 12952-1:2024 (E)
4 Interdependency of the parts of the series
EN 12952-1 to EN 12952-18 form a consistent set of specifications to be followed.
NOTE 1 Parts 4, 12, 13 and 15 of the series are published as supporting European Standards.
NOTE 2 Part 17 of the series is published as a CEN Report. It is not a European Standard.
5 Symbols and abbreviations
For the purposes of this document, the general symbols and abbreviations given in Table 1 shall apply.
Table 1 — Symbols
Symbol Description Unit
A area mm
Af effective cross-sectional area without allowances mm
A effective cross-sectional area of branch mm
fb
A effective cross-sectional area of reinforcing pad mm
fp
Afs effective cross-sectional area of main body mm
Ap pressurized area without allowances mm
A pressurized area referred to branch mm
pb
A pressurized area referred to main body mm
ps
As shell cross-sectional area referred to main body mm
C shape factor —
C1 shape factor for unstayed ends or plates —
c allowance to consider the minus tolerance of wall thickness mm
C shape factor for rectangular and elliptical plates —
c2 allowance for metal wastage mm
C3 shape factor for flat plates with openings —
d diameter of tube hole (if applicable in the condition after metal wastage) mm
d diameter of counter boring for expanded tubes mm
di inside diameter mm
dib inside diameter of branch without allowances mm
d inside diameter of main body (cylindrical shell, sph
...