Explosion suppression systems

This document describes the basic requirements for the design and application of explosion suppression systems. This document also specifies test methods for evaluating the effectiveness and the scale up of explosion suppression systems against defined explosions. This document covers:
— general requirements for explosion suppression system components;
— evaluating the effectiveness of an explosion suppression system;
— evaluating the scale up of an explosion suppression system;
— development and evaluation of design tools for explosion suppression systems;
— installation, operation and maintenance instructions for an explosion suppression system.
This document is applicable only to explosion suppression systems intended for the protection of closed, or essentially closed, enclosures in which an explosion could result as a consequence of ignition of an explosible mixture, e.g. dust-air, gas(vapour)-air, dust-gas(vapour)-air and mist-air.
This document is not applicable for explosions of materials listed below, or for mixtures containing some of those materials:
— unstable materials that are liable to dissociate;
— explosive materials;
— pyrotechnic materials;
— pyrophoric materials.

Explosions-Unterdrückungssysteme

Dieses Dokument Norm beschreibt die Grundanforderungen für die Konstruktion und Anwendung von Explosions-Unterdrückungssystemen. Dieses Dokument legt außerdem Prüfverfahren zur Beurteilung der Wirksamkeit und Reichweite von Explosions-Unterdrückungssystemen bei bestimmten Explosionen fest. Dieses Dokument behandelt:
— allgemeine Anforderungen an Komponenten für Explosions-Unterdrückungssysteme;
— Bewerten des Leistungsvermögens eines Explosions-Unterdrückungssystems;
— Bewerten der Reichweite eines Explosions-Unterdrückungssystems;
— Entwicklung und Bewertung einer Konstruktionsanleitung für Explosions-Unterdrückungssysteme;
— Einbau-, Betriebs- und Instandhaltungsanweisungen für ein Explosions-Unterdrückungssystem.
Dieses Dokument gilt nur für Explosions-Unterdrückungssysteme, die zum Schutz von geschlossenen oder im Wesentlichen geschlossenen Gehäusen vorgesehen sind, in denen eine Explosion durch die Zündung eines explosionsfähigen Gemisches, z. B. Staub/Luft, Gas(Dampf)/Luft, Staub/Gas(Dampf)/Luft und Ne-bel/Luft, entstehen könnte.
Dieses Dokument ist nicht anwendbar bei Explosionen von nachstehend aufgeführten Stoffen oder Ge-mischen, die diese Stoffe enthalten:
— instabile Stoffe, die möglicherweise zerfallen können;
— Explosivstoffe;
— pyrotechnische Materialien;
— pyrophore Stoffe.

Systèmes de suppression d’explosion

Le présent document décrit les exigences minimales de conception et d’application des systèmes de suppression d’explosion. Il spécifie également des méthodes d’essai pour l’évaluation de l’efficacité et de l’extrapolation des systèmes de suppression d’explosion par rapport { des explosions définies. Le présent document couvre les points suivants :
— les exigences générales concernant les composants des systèmes de suppression d’explosion ;
— l’évaluation de l’efficacité d’un système de suppression d’explosion ;
— l’évaluation de l’extrapolation d’un système de suppression d’explosion ;
— le développement et l’évaluation d’outils de conception pour les systèmes de suppression d’explosion ;
— des instructions relatives à l’installation, au fonctionnement et { la maintenance d’un système de suppression d’explosion.
Le présent document s’applique uniquement aux systèmes de suppression d’explosion destinés { protéger des enveloppes fermées ou en majeure partie fermées, dans lesquelles une explosion peut être la conséquence de l’inflammation de mélanges explosibles de type poussière-air, gaz (vapeur)-air, poussière-gaz (vapeur)-air et brouillard-air, par exemple.
Le présent document ne s’applique pas aux explosions des matières énumérées ci-dessous ni aux mélanges contenant certaines de ces matières :
— matières non stables susceptibles de se dissocier ;
— matières explosives ;
— matières pyrotechniques ;
— matières pyrophoriques.

Sistemi za dušenje eksplozij

Ta dokument opisuje osnovne zahteve za projektiranje in uporabo sistemov za dušenje eksplozij. Ta dokument določa tudi preskusne metode za vrednotenje učinkovitosti in nadgradnje sistemov za dušenje eksplozij v primerih navedenih eksplozij. Ta dokument obravnava:
– splošne zahteve za komponente sistemov za dušenje eksplozij;
– vrednotenje učinkovitosti sistema za dušenje eksplozij;
– vrednotenje nadgradnje sistema za dušenje eksplozij;
– razvoj in vrednotenje orodij za projektiranje sistemov za dušenje eksplozij;
– navodila za namestitev, delovanje in vzdrževanje sistema za dušenje eksplozij.
Ta dokument se uporablja samo za sisteme za dušenje eksplozij, namenjene za zaščito zaprtih oziroma v osnovi zaprtih prostorov, v katerih bi lahko prišlo do eksplozije zaradi vžiga eksplozivne mešanice, npr. prah-zrak, plin (hlapi)-zrak, prah-plin (hlapi)-zrak in meglica-zrak.
Ta dokument se ne uporablja za eksplozije spodaj navedenih snovi ali za mešanice, ki vsebujejo nekatere od teh snovi:
– nestabilne snovi, ki se lahko ločijo;
– eksplozivne snovi;
– pirotehnične snovi;
– piroforne snovi.

General Information

Status
Published
Public Enquiry End Date
21-Apr-2019
Publication Date
24-Jan-2022
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
10-Nov-2021
Due Date
15-Jan-2022
Completion Date
25-Jan-2022

RELATIONS

Buy Standard

Standard
SIST EN 14373:2022
English language
46 pages
sale 10% off
Preview
sale 10% off
Preview
e-Library read for
1 day
Draft
oSIST prEN 14373:2019
English language
41 pages
sale 10% off
Preview
sale 10% off
Preview
e-Library read for
1 day

Standards Content (sample)

SLOVENSKI STANDARD
SIST EN 14373:2022
01-marec-2022
Nadomešča:
SIST EN 14373:2006
Sistemi za dušenje eksplozij
Explosion suppression systems
Explosions-Unterdrückungssysteme
Systèmes de suppression d’explosion
Ta slovenski standard je istoveten z: EN 14373:2021
ICS:
13.230 Varstvo pred eksplozijo Explosion protection
SIST EN 14373:2022 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN 14373:2022
---------------------- Page: 2 ----------------------
SIST EN 14373:2022
EN 14373
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2021
EUROPÄISCHE NORM
ICS 13.230 Supersedes EN 14373:2005
English Version
Explosion suppression systems
Systèmes de suppression d'explosion Explosions-Unterdrückungssysteme
This European Standard was approved by CEN on 27 September 2021.

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, Turkey 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

© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 14373:2021 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN 14373:2022
EN 14373:2021 (E)
Contents Page

European foreword ............................................................................................................................................ 4

1 Scope .......................................................................................................................................................... 5

2 Normative references .......................................................................................................................... 5

3 Terms and definitions ......................................................................................................................... 6

4 Symbols and abbreviations (EN 14373) ....................................................................................... 8

5 Explosion suppression ........................................................................................................................ 9

5.1 Design ........................................................................................................................................................ 9

5.2 General function .................................................................................................................................. 10

5.3 Requirements for explosion suppression systems ................................................................. 11

6 Environmental aspects ..................................................................................................................... 15

6.1 General.................................................................................................................................................... 15

6.2 Suppressant .......................................................................................................................................... 15

6.3 Actuators and other components .................................................................................................. 15

7 Experimental testing of the efficacy of an explosion suppression system ..................... 15

7.1 Information to be submitted prior to testing ........................................................................... 15

7.1.1 General.................................................................................................................................................... 15

7.1.2 Intended use ......................................................................................................................................... 16

7.1.3 Information on the parts of the suppression system ............................................................. 16

7.1.4 Calculation model ............................................................................................................................... 17

7.2 Testing .................................................................................................................................................... 17

7.2.1 General requirements for test setup ........................................................................................... 17

7.2.2 Test program for non metallic dusts ........................................................................................... 17

7.2.3 Test program for metal dust ........................................................................................................... 21

7.2.4 Test program for gas .......................................................................................................................... 21

7.2.5 Test program for hybrid mixtures of non metallic dust and gas ....................................... 22

7.2.6 Test program for mist-air mixtures ............................................................................................. 22

7.3 Parameters to be measured ............................................................................................................ 22

7.4 Test report ............................................................................................................................................. 23

8 Instructions ........................................................................................................................................... 24

8.1 General.................................................................................................................................................... 24

8.2 Installation of cables .......................................................................................................................... 24

8.3 Assembling ............................................................................................................................................ 25

8.3.1 General.................................................................................................................................................... 25

8.3.2 Process information requirements .............................................................................................. 25

8.4 Commissioning .................................................................................................................................... 25

8.4.1 General.................................................................................................................................................... 25

8.4.2 Instructions for hand-over .............................................................................................................. 25

8.4.3 Commissioning report ...................................................................................................................... 25

8.5 Safety ....................................................................................................................................................... 26

8.6 Maintenance ......................................................................................................................................... 26

9 Marking and packaging .................................................................................................................... 26

9.1 General.................................................................................................................................................... 26

9.2 Parts of the explosion suppression system ............................................................................... 26

9.3 Explosion suppression system ....................................................................................................... 28

Annex A (informative) Development of an explosion suppression calculation model ............ 29

---------------------- Page: 4 ----------------------
SIST EN 14373:2022
EN 14373:2021 (E)

A.1 General ................................................................................................................................................... 29

A.2 Extinction............................................................................................................................................... 29

A.3 Functional tests for model development ................................................................................... 30

A.4 Model validation ................................................................................................................................. 31

Annex B (informative) Applications............................................................................................................ 32

B.1 General ................................................................................................................................................... 32

B.2 Hazard definition ................................................................................................................................ 32

B.3 Typical process equipment ............................................................................................................. 33

B.3.1 Spray dryers ......................................................................................................................................... 33

B.3.1.1 Introduction ......................................................................................................................................... 33

B.3.1.2 Definition of elements ....................................................................................................................... 33

B.3.1.3 Dust concentration ............................................................................................................................. 34

B.3.1.4 Protection concept ............................................................................................................................. 35

B.3.1.5 Isolation ................................................................................................................................................. 35

B.3.1.6 Advanced inerting .............................................................................................................................. 35

B.3.1.7 Flame Duration .................................................................................................................................... 35

B.3.1.8 Interlocking .......................................................................................................................................... 35

B.3.2 Clean volumes ...................................................................................................................................... 35

B.3.3 Elevators ................................................................................................................................................ 35

B.3.4 Elongated enclosures ........................................................................................................................ 36

B.3.5 Pipes ........................................................................................................................................................ 36

B.3.6 Occupied spaces .................................................................................................................................. 36

Annex C (informative) Extrapolation to larger volumes ..................................................................... 38

Annex D (informative) Significant changes between this European Standard and

EN 14373:2005 .................................................................................................................................... 42

Annex ZA (informative) Relationship between this European Standard and the essential

requirements of EU Directive 2014/34/EU aimed to be covered ..................................... 44

Bibliography ....................................................................................................................................................... 46

---------------------- Page: 5 ----------------------
SIST EN 14373:2022
EN 14373:2021 (E)
European foreword

This document (EN 14373:2021) 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 May 2022, and conflicting national standards shall be

withdrawn at the latest by November 2022.

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 14373:2005.

The significant changes between this document and EN 14373:2005 are given in Annex D.

This document has been prepared under a Standardization Request given to CEN by the European

Commission and the European Free Trade Association, and supports essential requirements of EU

Directive(s).

For relationship with EU Directive(s), 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, Turkey and the United

Kingdom.
---------------------- Page: 6 ----------------------
SIST EN 14373:2022
EN 14373:2021 (E)
1 Scope

This document describes the basic requirements for the design and application of explosion suppression

systems. This document also specifies test methods for evaluating the effectiveness and the scaling up of

explosion suppression systems against defined explosions. This document covers:
— general requirements for explosion suppression system parts;
— evaluating the effectiveness of an explosion suppression system;

— evaluating the scale up of an explosion suppression system to larger than tested volumes;

— development and evaluation of design tools for explosion suppression systems;

— installation, operation and maintenance instructions for an explosion suppression system.

This document is applicable only to explosion suppression systems intended for the protection of closed,

or essentially closed, enclosures in which an explosion could result as a consequence of ignition of an

explosible mixture, e.g. dust-air, gas(vapour)-air, dust-gas(vapour)-air and mist-air.

This document is not applicable for explosions of materials listed below, or for mixtures containing some

of those materials:
— unstable materials that are liable to dissociate;
— explosive materials;
— pyrotechnic materials;
— pyrophoric materials.
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 1127-1:2019, Explosive atmospheres - Explosion prevention and protection - Part 1: Basic concepts and

methodology

EN 13237:2012, Potentially explosive atmospheres - Terms and definitions for equipment and protective

systems intended for use in potentially explosive atmospheres

EN 15233:2007, Methodology for functional safety assessment of protective systems for potentially

explosive atmospheres

EN 15967:2011, Determination of maximum explosion pressure and the maximum rate of pressure rise of

gases and vapours

EN 14034-1:2004+A1:2011, Determination of explosion characteristics of dust clouds - Part 1:

Determination of the maximum explosion pressure pmax of dust clouds

EN 14034-2:2006+A1:2011, Determination of explosion characteristics of dust clouds - Part 2:

Determination of the maximum rate of explosion pressure rise (dp/dt)max of dust clouds

---------------------- Page: 7 ----------------------
SIST EN 14373:2022
EN 14373:2021 (E)

EN IEC 60079-0:2018, Explosive atmospheres - Part 0: Equipment - General requirements (IEC 60079-

0:2017)

EN 60079-14:2014, Explosive atmospheres - Part 14: Electrical installations design, selection and erection

(IEC 60079-14:2013)

EN 60529:1991, Degrees of protection provided by enclosures (IP Code) (IEC 60529:1989)

EN ISO 80079-36:2016, Explosive atmospheres - Part 36: Non-electrical equipment for explosive

atmospheres - Basic method and requirements (ISO 80079-36:2016)
3 Terms and definitions

For the purposes of this document, the terms and definitions given in EN 1127-1:2019 and

EN 13237:2012 and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
high rate discharge suppressor
HRD-suppressor

vessel with opening mechanism, which upon activation discharges an explosion suppressant at a high

rate
3.2
suppressant

substance contained in the HRD-suppressor which, when dispersed into an enclosure to be protected,

can arrest and mitigate a developing explosion in that enclosure
3.2.1
powder suppressant

powder with recognised flame extinguishing properties such as products based on monoammonium

phosphate, potassium bicarbonate or sodium bicarbonate
3.2.2
liquid suppressant

substance stored as a liquid with recognised flame extinguishing properties such as cold or hot water

3.3
dispersion pressure

pressure in HRD-suppressor to disperse the suppressant, which is provided by gas, chemical reaction or

the application of heat
As impacted by amendments EN 60529:1991/A1:2000 and EN 60529:1991/A2:2013.
---------------------- Page: 8 ----------------------
SIST EN 14373:2022
EN 14373:2021 (E)
3.4
suppressant charge
mass of the suppressant contained within the suppressor
3.5
explosion detector

device that responds to an explosion (e.g. developing pressure and/or radiation) and provides a signal to

the control and indicating equipment
Note 1 to entry: See 3.10.
3.6
activation pressure

pressure at which the control and indicating equipment activates the high rate discharge suppressor(s)

3.7
maximum reduced (suppressed) explosion pressure
red,max

maximum explosion overpressure generated by an explosion of an explosive atmosphere in an enclosure

at optimum fuel concentration, after effective explosion venting or explosion suppression

3.8
explosion suppression

technique limiting and/or avoiding the destructive effect of an explosion by the deployment of

suppressant
3.9
explosion suppression system

arrangement comprising one or more explosion detectors, control and indicating equipment and one or

more high rate discharge suppressors aiming at achieving explosion suppression
3.10
control and indicating equipment
CIE

safety device, which is an electronic system which controls, records and monitors the status of the

explosion protection system and initiates the explosion protection devices upon detection

Note 1 to entry: The CIE is intended to activate the explosion protection devices and to initiate alarm systems and

process shutdown.
3.11
dispersion nozzle

device fitted on a HRD-suppressor and designed to distribute the suppressant throughout the enclosure

to be protected
3.12
compact enclosure/cubic enclosure
enclosures having a length (height) to diameter ratio of less than 2
---------------------- Page: 9 ----------------------
SIST EN 14373:2022
EN 14373:2021 (E)
3.13
elongated enclosures
enclosures with a length (height) to diameter ratio of 2 to 10
3.14
pipe
construction with a length (height) to diameter ratio greater than 10
3.15
hazard sector

three-dimensional space for which the explosion suppression system is designed to be active

3.16
lowest observable adverse effect level
LOAEL

lowest concentration of the suppressant at which an adverse toxicological or physiological effect has been

observed
3.17
suppression model

mathematical calculation which predicts the course of an explosion, the action of the suppression system

and its interaction with the explosion, in order to enable an accurate design of explosion suppression

systems
3.18
maximum throw

maximum distance from a suppressor at which the concentration of the expelled suppressant is still

sufficiently high to extinguish an explosion flame
3.19
arming
enabling the explosion suppression system for fault free operation
3.20
activation
initiation of the high rate discharge suppressor to discharge
3.21
discharge
opening and consequential emptying of the high rate discharge suppressor
3.22
lock out
mechanical device to prevent discharge of the high rate discharge suppressor
4 Symbols and abbreviations (EN 14373)
CIE control and indicating equipment
C heat capacity at constant pressure
HRD high rate discharge
IP ingress protection
---------------------- Page: 10 ----------------------
SIST EN 14373:2022
EN 14373:2021 (E)
K maximum rate of pressure rise to be applied and determined according to
max

EN 14034-2:2006+A1:2011 for a certain dust and dust concentration normalised to a

1 m volume or according to EN 15967:2011 for a certain gas or vapour and gas or
vapour concentration normalised to a 1 m volume
K minimum rate of pressure rise to be applied and determined according to
min

EN 14034-2:2006+A1:2011 for a certain dust and dust concentration normalised to a

1 m volume or according to EN 15967:2011 for a certain gas or vapour and gas or
vapour concentration normalised to a 1 m volume
K maximum rate of pressure rise of a dust determined according to
EN 14034-2:2006+A1:2011 normalised to a 1 m volume
L/D length-to-diameter ratio
LEL lower explosion limit
LOAEL lowest observable adverse effect level
MIE minimum ignition energy
MIT minimum ignition temperature of a dust cloud
MSDS material safety data sheets
M suppressant charge
activation pressure
p maximum explosion overpressure of a dust determined according to
max
EN 14034-2:2006+A1:2011 or gas or vapour determined according to EN 15967:2011
p reduced (suppressed) overpressure
red
p maximum reduced (suppressed) explosion pressure
red,max
p dispersion pressure
p pressure transducer
S laminar burning velocity
TPED Transportable Pressure Equipment Directive
PED Pressure Equipment Directive
V volume
5 Explosion suppression
5.1 Design

Explosion suppression systems shall be designed to extinguish propagating flames and to reduce the

maximum explosion pressure, p to a reduced explosion pressure (p ), following an ignition in the

max, red

protected enclosure. Successful explosion suppression implies that the p will not exceed the strength

red

of the protected equipment. Explosion suppression systems can be applied to flammable gases, mists,

dusts or hybrid mixtures.
See Annex B for examples of applications of explosion suppression systems.
---------------------- Page: 11 ----------------------
SIST EN 14373:2022
EN 14373:2021 (E)
5.2 General function

Explosion suppression is a protective measure for enclosures, where a gas, mist, dust or hybrid mixture

explosion is detected and arrested during incipient stages (see Figure 1).
Key
1 suppressor
2 explosion detector (D)

a The explosive atmosphere in an enclosure is ignited. The enclosure is provided with one (or more) explosion

detectors (D) and one (or more) suppressors (1).
b The explosion is detected by the explosion detector(s).

c The control and indicating equipment CIE (not shown) has received the signal from the explosion detector(s)

and activated the suppressor(s). The suppressor(s) has (have) started to inject suppressant into the

enclosure.
d The suppressant cloud reaches the explosion flame.
e The flame is extinguished: the explosion is suppressed.
Figure 1 — Stages in explosion suppression of an enclosure
The performance of an explosion suppression system depends on:

— the response time of the system: time until explosion is detected + response time of the various items

+ time required to inject sufficient suppressant into the enclosure;
— the suppressant dispersion: spatial distribution, as a function of time;
— the effectiveness of the suppressant.

Explosion suppression measures shall be designed and installed such that their operational effectiveness

is assured.

The effectiveness of a suppression system is dependent on many factors also related to the application:

— volume and geometry of the component to be protected;
— reactivity of the combustible dust:
• p maximum explosion pressure,
max
• K explosion rate constant,
— process conditions: airflow and turbulence;
---------------------- Page: 12 ----------------------
SIST EN 14373:2022
EN 14373:2021 (E)
— detection pressure threshold value;
— type and efficiency of explosion suppressors;
— number, and geometric distribution of suppressors;
— propellant pressure.
5.3 Requirements for explosion suppression systems

An explosion suppression system consists of at least one: explosion detector, HRD suppressor, complete

with suppressant / dispersion nozzle and connected to control and indicating equipment (CIE).

Essential requirements are:

— the overall requirement of the explosion suppression system is to detect an explosion in the incipient

stage and to have a fast response to allow for the dispersion of suppressant and extinguishment of

the flame in order to limit the maximum reduced explosion pressure below the admissible pressure

of the protected equipment - Experimental validation shall be performed as described in Clause 7;

— the system as installed or any of its parts shall not introduce ignition hazards, such as electrostatic

discharge, mechanical friction, electrical sparks, hot surfaces:

• All electrical and non-electrical equipment and components, as parts of explosion suppression

system, intended for use in potentially explosive atmospheres, shall be designed and constructed

in conformity with the required categories for group II equipment to ensure avoidance of any

ignition sources as detailed in EN 1127-1:2019.

• Any electrical equipment as a part of an explosion suppression system installed and located in

hazardous areas shall conform to the requirements of EN 60079-14:2014 through at least

EN IEC 60079-0:2018 and relevant type(s) of protection.

• Any non-electrical equipment as a part of an explosion suppression system installed and located

in hazardous areas shall conform to the requirements of EN ISO 80079-36:2016 and relevant

type(s) of protection.

— the activation of the suppression system shall not result in dangerous ejected parts;

— the explosion suppression system shall have a defined reliability for safety-functions according to

the intended use (see 5.3 h);

— if discharging the suppressant during maintenance or inspection can result in injury, the explosion

suppression system shall have safe provisions in place to prevent an unintended suppressor

discharge prior to performing such operations;

— the supplier shall provide instructions which ensure safe operation of the explosion suppression

system and the system is always armed when explosible atmospheres are present and is disarmed

and locked out before access to be inside protected equipment is granted (see 8.5);

— the explosion suppression system shall avoid operation of the protected process by provision of a

safe signal interface through the CIE so that operation cannot be started or resumed until the

suppression system is armed and fault free;

— relevant parts of the explosion suppression system directly exposed to the explosion shall be capable

of withstanding the expected maximum explosion pressure.
---------------------- Page: 13 ----------------------
SIST EN 14373:2022
EN 14373:2021 (E)
...

SLOVENSKI STANDARD
oSIST prEN 14373:2019
01-april-2019
Sistemi za dušenje eksplozij
Explosion suppression systems
Explosions-Unterdrückungssysteme
Systèmes de suppression d’explosion
Ta slovenski standard je istoveten z: prEN 14373
ICS:
13.230 Varstvo pred eksplozijo Explosion protection
oSIST prEN 14373:2019 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
oSIST prEN 14373:2019
---------------------- Page: 2 ----------------------
oSIST prEN 14373:2019
DRAFT
EUROPEAN STANDARD
prEN 14373
NORME EUROPÉENNE
EUROPÄISCHE NORM
January 2019
ICS 13.230 Will supersede EN 14373:2005
English Version
Explosion suppression systems
Systèmes de suppression d'explosion Explosions-Unterdrückungssysteme

This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee

CEN/TC 305.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,

Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey 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

© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 14373:2019 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
oSIST prEN 14373:2019
prEN 14373:2019 (E)
Contents Page

European foreword ....................................................................................................................................................... 4

1 Scope .................................................................................................................................................................... 5

2 Normative references .................................................................................................................................... 5

3 Terms and definitions ................................................................................................................................... 6

4 Explosion suppression .................................................................................................................................. 9

4.1 Objectives ........................................................................................................................................................... 9

4.2 General function .............................................................................................................................................. 9

4.3 Essential requirements ................................................................................................................................. 9

5 Environmental aspects ............................................................................................................................... 12

5.1 General ............................................................................................................................................................. 12

5.2 Suppressant .................................................................................................................................................... 13

5.3 Actuators and other components ........................................................................................................... 13

6 Experimental testing of the efficacy of an explosion suppression system .............................. 13

6.1 Required information ................................................................................................................................. 13

6.1.1 General ............................................................................................................................................................. 13

6.1.2 Intended use .................................................................................................................................................. 13

6.1.3 Information on the components of the suppression system ........................................................ 13

6.1.4 Calculation model ........................................................................................................................................ 14

6.2 Testing .............................................................................................................................................................. 14

6.2.1 General requirements for test setup ..................................................................................................... 14

6.2.2 Test program for non metallic dusts ..................................................................................................... 15

6.3 Test program for metal dust .................................................................................................................... 17

6.4 Test program for gas ................................................................................................................................... 17

6.5 Test program for hybrid mixtures ......................................................................................................... 18

6.6 Measuring techniques ................................................................................................................................ 18

6.7 Test Report ..................................................................................................................................................... 18

7 Instructions .................................................................................................................................................... 20

7.1 General ............................................................................................................................................................. 20

7.2 User manual ................................................................................................................................................... 20

7.3 Installation of cables ................................................................................................................................... 20

7.4 Assembling ..................................................................................................................................................... 20

7.4.1 General ............................................................................................................................................................. 20

7.4.2 Assembly ......................................................................................................................................................... 20

7.5 Commissioning .............................................................................................................................................. 21

7.5.1 General ............................................................................................................................................................. 21

7.5.2 Instructions for hand-over ....................................................................................................................... 21

7.5.3 Commissioning report ................................................................................................................................ 21

7.6 Safety ................................................................................................................................................................ 21

7.7 Maintenance ................................................................................................................................................... 22

8 Marking and packaging .............................................................................................................................. 22

8.1 General ............................................................................................................................................................. 22

8.2 Explosion suppression system components....................................................................................... 22

8.3 Explosion suppression system ................................................................................................................ 23

8.4 Omission of markings ................................................................................................................................. 23

---------------------- Page: 4 ----------------------
oSIST prEN 14373:2019
prEN 14373:2019 (E)

Annex A (informative) Development of an explosion suppression calculation model .................... 24

Annex B (informative) Applications ................................................................................................................... 27

Annex C (informative) Extrapolation to larger volumes ............................................................................. 33

Annex D (informative) Significant changes between this European Standard and

EN 14373:2005 .............................................................................................................................................. 37

ANNEX ZA (informative) Relationship between this European Standard and the essential

requirements of EU Directive 2014/34/EU aimed to be covered ............................................... 39

Bibliography ................................................................................................................................................................. 41

---------------------- Page: 5 ----------------------
oSIST prEN 14373:2019
prEN 14373:2019 (E)
European foreword

This document (prEN 14373:2019) 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 document is currently submitted to the CEN Enquiry.
This document will supersede EN 14373:2005.

This document has been prepared under a standardization request given to CEN by the European

Commission and the European Free Trade Association, and supports essential requirements of

EU Directive(s).

For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this

document.
---------------------- Page: 6 ----------------------
oSIST prEN 14373:2019
prEN 14373:2019 (E)
1 Scope

This document describes the basic requirements for the design and application of explosion

suppression systems. This document also specifies test methods for evaluating the effectiveness and the

scale up of explosion suppression systems against defined explosions. This document covers:

— general requirements for explosion suppression system components;
— evaluating the effectiveness of an explosion suppression system;
— evaluating the scale up of an explosion suppression system;
— development and evaluation of design tools for explosion suppression systems;

— installation, operation and maintenance instructions for an explosion suppression system.

This document is applicable only to explosion suppression systems intended for the protection of

closed, or essentially closed, enclosures in which an explosion could result as a consequence of ignition

of an explosible mixture, e.g. dust-air, gas(vapour)-air, dust-gas(vapour)-air and mist-air.

This document is not applicable for explosions of materials listed below, or for mixtures containing

some of those materials:
— unstable materials that are liable to dissociate;
— explosive materials;
— pyrotechnic materials;
— pyrophoric materials.
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.

prEN 1127-1:2018, Explosive atmospheres — Explosion prevention and protection — Part 1: Basic

concepts and methodology

EN 13237:2012, Potentially explosive atmospheres — Terms and definitions for equipment and protective

systems intended for use in potentially explosive atmospheres

EN 15233:2007, Methodology for functional safety assessment of protective systems for potentially

explosive atmospheres

EN 15967:2011, Determination of the maximum explosion pressure and the maximum rate of pressure

rise of gases and vapours

EN 14034-1:2004+A1:2011, Determination of explosion characteristics of dust clouds — Part 1:

Determination of the maximum explosion pressure pmax of dust clouds

EN 14034-2:2006+A1:2011, Determination of explosion characteristics of dust clouds — Part 2:

Determination of the maximum rate of explosion pressure rise (dp/dt)max of dust clouds

---------------------- Page: 7 ----------------------
oSIST prEN 14373:2019
prEN 14373:2019 (E)

EN 61508-1:2010, Functional safety of electrical/electronic/programmable electronic safety-related

systems — Part 1: General requirements

EN 61508-2:2010, Functional safety of electrical/electronic/programmable electronic safety-related

systems — Part 2: Requirements for electrical/electronic/programmable electronic safety-related systems

EN 61508-3:2010, Functional safety of electrical/electronic/programmable electronic safety-related

systems — Part 3: Software requirements

EN 61508-4:2010, Functional safety of electrical/electronic/programmable electronic safety-related

systems — Part 4: Definitions and abbreviations

EN 61508-5:2010, Functional safety of electrical/electronic/programmable electronic safety-related

systems — Part 5: Examples of methods for the determination of safety integrity levels

EN 61508-6:2010, Functional safety of electrical/electronic/programmable electronic safety-related

systems — Part 6: Guidelines on the application of IEC 61508-2 and IEC 61508-3

EN 61508-7:2010, Functional safety of electrical/electronic/programmable electronic safety-related

systems — Part 7: Overview of techniques and measures
3 Terms and definitions

For the purposes of this document, the terms and definitions given in prEN 1127-1:2018,

EN 13237:2012 and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
HRD-suppressor

vessel with opening mechanism, which upon activation discharges an explosion suppressant at a high

rate
Note 1 to entry: HRD is the abbreviation of High Rate Discharge.
3.2
suppressant

substance contained in the HRD-suppressor which, when dispersed into an enclosure to be protected,

can arrest and mitigate a developing explosion in that enclosure

Note 1 to entry: Two categories of suppressants are in general use, separately or in combination:

— powder suppressant;
— liquid suppressant.
---------------------- Page: 8 ----------------------
oSIST prEN 14373:2019
prEN 14373:2019 (E)
3.2.1
powder suppressant

powder with recognised flame extinguishing properties such as products based on monoammonium

phosphate, potassium bicarbonate or sodium bicarbonate

Note 1 to entry: Such suppressants can contain additives to improve their flow properties and their

effectiveness
3.2.2
liquid suppressant

substance stored as a liquid with recognised flame extinguishing properties such as water and

halogenated alkanes, cold or hot

Note 1 to entry: Additives can be included to provide frost protection, and/or to improve the suppressant

effectiveness.
3.3
dispersion pressure

pressure in HRD-suppressor to disperse the suppressant, which is provided by gas, chemical reaction or

the application of heat
3.4
suppressant charge
mass of the suppressant contained within the suppressor
3.5
explosion detector

device that responds to an explosion (e.g. developing pressure and/or radiation) and provides a signal

to the control and indicating equipment
Note 1 to entry: See 3.10.
3.6
activation pressure
pressure at which the CIE activates the HRD-suppressor(s)
3.7
maximum reduced (suppressed) explosion pressure
red,max

maximum explosion overpressure generated by an explosion of an explosive atmosphere in an

enclosure at optimum fuel concentration, after effective explosion venting or explosion suppression

3.8
explosion suppression

technique limiting and/or avoiding the destructive effect of an explosion by the deployment of

suppressant
---------------------- Page: 9 ----------------------
oSIST prEN 14373:2019
prEN 14373:2019 (E)
3.9
explosion suppression system

arrangement comprising one or more explosion detectors, CIE and one or more HRD-suppressors

aiming at achieving explosion suppression
3.10
control and indicating equipment
CIE

electronic system which controls, records and monitors the status of the explosion protection system

and initiates the explosion protection devices upon detection

Note 1 to entry: On detection of an incipient explosion, the CIE activates the explosion protection devices and

initiates alarm systems and process shutdown.
3.11
dispersion nozzle

device fitted on a HRD-suppressor and designed to distribute the suppressant throughout the enclosure

to be protected
3.12
compact enclosure/cubic enclosure
enclosures having a length (height) to diameter ratio of less than 2
3.13
elongated enclosures
enclosures with a length (height) to diameter ratio of 2 to 10
3.14
pipe
construction with a length (height) to diameter ratio greater than 10
3.15
hazard sector

three-dimensional space for which the explosion suppression system is designed to be active

3.16
LOAEL

lowest concentration of the suppressant at which an adverse toxicological or physiological effect has

been observed

Note 1 to entry: LOAEL is the abbreviation of Lowest Observable Adverse Effect Level.

3.17
suppression model

mathematical calculation which predicts the course of an explosion, the action of the suppression

system and its interaction with the explosion, in order to enable an accurate design of explosion

suppression systems
3.18
maximum throw

maximum distance from a suppressor at which the concentration of the expelled suppressant is still

sufficiently high to extinguish an explosion flame
---------------------- Page: 10 ----------------------
oSIST prEN 14373:2019
prEN 14373:2019 (E)
4 Explosion suppression
4.1 Objectives

Explosion suppression systems shall be designed to extinguish propagating flames and to reduce the

maximum explosion pressure, P to a reduced explosion pressure (P ), following an ignition in

max, red

the protected enclosure. In general, successful explosion suppression implies that the P will not

red

exceed the strength of the protected equipment. Explosion suppression systems can be applied to

flammable gases, mists, dusts or hybrid mixtures.
4.2 General function

Explosion suppression is a protective measure for enclosures, where a gas, mist, dust or hybrid mixture

explosion is detected and arrested during incipient stages (see Figure 1).
Key
1 supressor

a The explosive atmosphere in an enclosure is ignited. The enclosure is provided with one (or more)

explosion detectors (D) and one (or more) suppressors (1).
b The explosion is detected by the explosion detector(s).

c The control and indicating equipment CIE (not shown) has received the signal from the explosion

detector(s) and activated the suppressor(s). The suppressor(s) have started to inject suppressant into

the enclosure.
d The suppressant cloud reaches the explosion flame.
e The flame is extinguished: the explosion is suppressed.
Figure 1 — Stages in explosion suppression of an enclosure
The performance of an explosion suppression system depends on:

— the response time of the system: time until explosion is detected + response time of the various

components + time required to inject sufficient suppressant into the enclosure;
— the suppressant dispersion: spatial distribution, as a function of time;
— the effectiveness of the suppressant.
4.3 Essential requirements

An explosion suppression system consists of at least one: explosion detector, HRD suppressor, complete

with suppressant / dispersion nozzle and connected to control and indicating equipment (CIE).

---------------------- Page: 11 ----------------------
oSIST prEN 14373:2019
prEN 14373:2019 (E)
Essential requirements are:

— the overall requirement of the explosion suppression system is to detect an explosion in the

incipient stage and to have a fast response to allow for the dispersion of suppressant and

extinguishment of the flame in order to limit the maximum reduced explosion pressure below the

admissible pressure of the protected equipment - Experimental validation shall be performed as

described in Clause 6;

— the system as installed or any of its components shall not introduce ignition hazards, such as

electrostatic discharge, mechanical friction, electrical sparks, hot surfaces;

— the activation of the suppression system shall not result in dangerous ejected parts;

— the explosion suppression system shall have a defined reliability for safety-functions according to

the intended use (see 4.3 d);

— if discharging the suppressant during maintenance or inspection can result in injury, the explosion

suppression system shall have provisions in place to prevent an unintended suppressor discharge

prior to performing such operations;
— the suppression system shall be configured to prevent unintended arming;

— the supplier shall provide instructions which ensure safe operation of the explosion suppression

system and the system is always activated when explosible atmospheres are present and is

disarmed before access to be inside protected equipment is granted (see 7.6);

— the explosion suppression system shall avoid operation of the protected process by provision of a

safe signal interface through the CIE so that operation cannot be resumed until the suppression

system is armed and fault free.
Other essential requirements are:
a) Explosion Detector

An explosion detector shall detect the onset of the explosion in time to allow for achieving

successful suppression.
b) Control and Indication Equipment (CIE)

The components and software used in the Control and Indication Equipment (CIE) shall ensure

explosion suppression system functionality by undertaking the following:
— process detection signals;
— initiate the suppressors;
— initiate interlocks/alarms;
— enable safe isolation;

— enable an automatic and orderly safe-mode of the protected process upon activation,

fault/trouble condition.
c) Emergency power
---------------------- Page: 12 ----------------------
oSIST prEN 14373:2019
prEN 14373:2019 (E)

Emergency power shall be specified and facilitated such that full uninterrupted unchanged

explosion protection functionality is ensured at least 4 h after a mains power failure.

d) Explosion Suppressors

Explosion suppressors shall inject sufficient suppressant into the protected enclosure in the

required time. Either monitored mechanical blocking or other monitored provisions to prevent

unintended activation shall be present.
NOTE 1 The performance of suppressors depends upon at least:
— volume, shape and outlet diameter of the suppressor;
— filling ratio and pressure inside the suppressor;
— opening time of the suppressor;
— characteristics of the dispersion nozzle and the suppressant.
e) Dispersion nozzle

The dispersion nozzle shall spread the suppressant into the protected enclosure to achieve both

required throw and spatial distribution / concentration.
NOTE 2 The performance of a dispersion nozzle depends upon at least:
— design of the nozzle;
— characteristics of the suppressor and the suppressant.

Depending on the intended use specific dispersion nozzles can be applied, with special

performances, for example to obtain strong directional effects.
f) Suppressant

The suppressant shall have dispersion characteristics and extinguishing properties allowing for

extinguishing an explosion flame for a given fuel type.
NOTE 3 The properties influencing these characteristics include:
— the particle/droplet size distribution;
— chemical and thermal properties.

Apart from the effectiveness in explosion suppression of the suppressant applied, also the

compatibility of the suppressant with the process shall be considered:
— temperature stability;
— any adverse reaction with the process products;
— toxicity levels of the suppressant.
g) Installation, commissioning, service and maintenance
---------------------- Page: 13 ----------------------
oSIST prEN 14373:2019
prEN 14373:2019 (E)

Installation instructions, service and maintenance requirements and intervals shall be specified in

the system documentation (see Clause 7).
h) Reliability and functional safety

The functional safety of the suppression system shall be quantified by the manufacturer according

to EN 61508-1:2010, EN 61508-2:2010, EN 61508-3:2010, EN 61508-4:2010, EN 61508-5:2010,

EN 61508-6:2010, EN 61508-7:2010 and EN 15233:2007.

The reliability of the system shall be ensured by monitoring of as a minimum the following:

1) wiring circuits for continuity, earth faults and open circuits;
2) mains power supply;
3) emergency power supply;
4) system safety interlock circuitry;
5) system-disabling interlock circuitry;
6) electrically operated actuating devices;
7) detection devices;
8) health monitoring of HRD Suppressors (e.g. pressure).

In addition one shall assess the functional safety. As a minimum the following aspects shall be

addressed:
a) design faults in the hardware;
b) adverse environmental conditions, including electromagnetic disturbance;
c) design faults in the software.

In case of an identifiable fault such that the safety function of the system cannot be guaranteed to

the agreed level of safety integrity, the suppression system shall provide a fail-safe means to place

the installation into a safe condition.
5 Environmental aspects
5.1 General

Dispositions shall be taken to limit the impact of the explosion suppression devices on the environment.

Materials shall be selected to optimize product durability and lifetime and consideration shall be made

to avoiding the selection of rare or hazardous materials. Consideration shall be made to using recycled

or reused materials, and to the selection of materials which can then be subsequently recycled.

Packaging design shall consider using recycled materials, and materials that need little energy for their

manufacture, and shall minimize waste.

It shall be taken into account that each combustion process can generate toxic decomposition products.

---------------------- Page: 14 ----------------------
oSIST prEN 14373:2019
prEN 14373:2019 (E)

After activation of a suppression system the installation shall be cleaned up properly with duly

precautions regarding toxicity of the suppressant. Also the combustible material may have been

affected by the suppressant and by the combustion and may exhibit toxic properties. Waste and

cleaning materials shall be disposed according to the manufacturer instructions and to the enforced law

in respect of environmental protection to limit any risk of water and soil pollution.

5.2 Suppressant

During explosion suppression a large quantity of the suppressant is released into the process. The

manufacturer’s instructions shall address the following items:
— food compatibility;
— toxicity of the suppressant;
— corrosion of equipment.

Depending on the application, non-toxic, non-corrosive and food compatible suppressants should be

preferred.
5.3 Actuators and other components

Other components including actuators (after activation) can affect the environment and shall be

handled accordingly.
6 Experimental testing of the efficacy of an explosion suppression system
6.1 Required information
6.1.1 General

Before testing the manufacturer shall describe the intended use and shall provide detailed information

on the suppression system.
As a minimum, the following information shall be provided prior to testing.
6.1.2 Intended use

The manufacturer shall provide limits of applications. The minimum requirements are listed below:

a) explosive atmosphere type including fuel type (K , p ,
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.