National foreword

This British Standard is the UK implementation of EN 14986:2024. It supersedes BS EN 14986:2017, which is withdrawn.

The UK participation in its preparation was entrusted to Technical Committee EXL/23/-/3, Design of fans working in potentially explosive atmospheres.

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 May 2024.

This European Standard was approved by CEN on 16 March 2024.

This European Standard was corrected and reissued by the CEN-CENELEC Management Centre on 8 May 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 foreword

This document (EN 14986:2024) has been prepared by Technical Committee CEN/TC 305 “Potentially explosive atmospheres — Explosion prevention and protection”, 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 October 2024, and conflicting national standards shall be withdrawn at the latest by October 2024.

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 14986:2017.

The significant changes with respect to EN 14986:2017 are listed in Annex F.

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.

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.

Introduction

This document is a type C standard as stated in EN ISO 12100:2010.

The machinery concerned and the extent to which hazards, hazardous situations and events are covered and indicated in the scope of this document.

When provisions of this type C standard are different from those which are stated in type A or B standards, the provisions of this type C standard take precedence over the provisions of the other standards, for machines that have been designed and built according to the provisions of this type C standard.

1 Scope

1.1

This document specifies the constructional requirements for fans constructed to Group II G (of explosion groups IIA, IIB and hydrogen) categories 1, 2 and 3, and Group II D categories 2 and 3, intended for use in explosive atmospheres.

NOTE Operation conditions for the different categories of fans used in this document are defined in Clause 4.

1.3

This document specifies requirements for design, construction, testing and marking of complete fan units intended for use in potentially explosive atmospheres in air containing gas, vapour, mist and/or dusts. Such atmospheres can exist inside (the conveyed atmosphere (flammable or not)), outside, or inside and outside of the fan.

This document covers mechanical equipment, in particular fans. The “type of protection” as specified in EN ISO 80079‑37:2016 is constructional safety.

1.4

This document is applicable to fans working in ambient atmospheres and with normal atmospheric conditions at the inlet, having

absolute pressures ranging from 0,8 bar to 1,1 bar,
and temperatures ranging from −20 °C to +60 °C,
and maximum volume fraction of 21 % oxygen content,
and an aerodynamic energy increase of less than 25 kJ/kg.

NOTE 1 25 kJ/kg is equivalent to 30 kPa at inlet density of 1,2 kg/m³.

This document can also be helpful for the design, construction, testing and marking of fans intended for use in atmospheres outside the validity range stated above or in cases where other material pairings need to be used. In this case, the ignition risk assessment, ignition protection provided, additional testing (if necessary), manufacturer's marking, technical documentation and instructions to the user, clearly demonstrate and indicate the equipment's suitability for the conditions the fan can encounter.

NOTE 2 Temperatures below −20 °C can be considered. Material suitability can require specific evaluation for these temperatures. With lower temperature the explosion pressure increases, which leads to increased test pressures (see A.3) and can require specific testing. Although the standard atmospheric conditions in EN ISO 80079‑36:2016 give a temperature range for the atmosphere of −20 °C to +60 °C the normal ambient temperature range for the equipment is −20 °C to +40 °C unless otherwise specified and marked.

1.5

This document does not apply to:

group I fans (fans for mining);
explosion group IIC (other than hydrogen);
category 1D fans;
cooling fans or impellers on rotating electrical machines;
cooling fans or impellers on internal combustion engines, vehicles or electric motors.

NOTE 1 Measures for category 1D fans are given in EN 1127‑1:2019.

NOTE 2 Measures for explosion group IIC (other than hydrogen) are given in EN 1127‑1:2019.

NOTE 3 Measures for explosion group I are given in EN ISO/IEC 80079‑38:2016 and EN 1127‑2:2014.

2 Normative references

3 Terms and definitions

4 Requirements for all fans

4.1 Ignition hazard assessment

4.2 Assignment of categories

4.3 Temperatures

4.4 Mechanical design criteria

4.5 Casing

4.6 Impellers

4.7 Materials for rotating and stationary parts of fans

4.8 Linings and tip extensions

4.9 Vibration

4.10 Earthing conducting parts

4.11 Electrostatic charges

4.12 Electrical equipment

4.13 Prevention of deposits inside the fan

4.14 Shaft seals

4.15 Bearings

4.16 Power transmission systems

4.17 Clutches and couplings

4.18 Brakes and braking systems

4.19 Impeller-shaft attachment

4.20 Corrosion of fan components

4.21 Fire resistance

4.22 Protection against foreign particles

5 Additional requirements for category 2

5.1 General

5.2 Impeller-shaft attachment

5.3 Vibration

5.4 Material pairings

6 Category 1G fans for specific use with a gaseous explosive atmosphere as a conveyed atmosphere (flammable or not)

6.1 General requirements

6.2 Flame arresters

6.3 Casings

7 Information for use

7.1 General

7.2 Accompanying documentation

7.3 Markings

Bibliography

BS EN 14986:2024

Design of fans working in potentially explosive atmospheres

Current

Published:

31 Jul 2025