oSIST prEN 14972-18:2026

SLOVENSKI STANDARD
01-september-2026
Vgrajeni gasilni sistemi - Sistemi s pršečo vodo - 18. del: Protokol preskušanja
sistemov za lokalno uporabo pri požarih z vnetljivimi tekočinami za sisteme z
odprtimi šobami
Fixed firefighting systems - Water mist systems - Part 18: Test protocol for local
application involving flammable liquid fires for open nozzle systems
Ortsfeste Brandbekämpfungsanlagen - Wassernebelsysteme - Teil18: Prüfprotokoll für
den örtlichen Einsatz bei Bränden mit brennbaren Flüssigkeiten für offene
Düsensysteme
Ta slovenski standard je istoveten z: prEN 14972-18
ICS:
13.220.10 Gašenje požara Fire-fighting
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2026
ICS 13.220.20
English Version
Fixed firefighting systems - Water mist systems - Part 18:
Test protocol for local application involving flammable
liquid fires for open nozzle systems
Ortsfeste Brandbekämpfungsanlagen -
Wassernebelsysteme - Teil18: Prüfprotokoll für den
örtlichen Einsatz bei Bränden mit brennbaren
Flüssigkeiten für offene Düsensysteme
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 191.
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
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 14972-18:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 General requirements . 4
4.1 General. 4
4.2 Requirements . 6
5 Test enclosure requirements . 7
6 Test equipment . 7
6.1 Square pool fires . 7
6.2 Channel pool fires . 8
6.3 Spray fires . 9
7 Instrumentation . 10
8 Fire tests . 10
8.1 General. 10
8.2 Square pool fires . 11
8.3 Channel pool fires . 11
8.4 Spray fires . 12
8.5 Square pool fire (2X × 2X) combined with a 6 MW spray fire (see 6.1 and 6.3) . 14
8.6 Obstructed square pool fire (3X × 3X) . 18
8.7 Offset square pool fire (X × X) . 19
8.8 6 MW spray fire with an external ignition source . 20
9 Test report . 21
Bibliography . 22
European foreword
This document (prEN 14972-18:2026) has been prepared by Technical Committee CEN/TC 191 “Fixed
firefighting systems”, the secretariat of which is held by BSI.
This document is currently submitted to the CEN Enquiry.
EN 14972, Fixed firefighting systems — Water mist systems, consists of the following parts:
— Part 1: Design, installation, inspection and maintenance;
— Part 2: Test protocol for shopping areas for automatic nozzle systems;
— Part 3: Test protocol for office, school class rooms and hotel for automatic nozzle systems;
— Part 4: Test protocol for non-storage occupancies for automatic nozzle systems;
— Part 5: Test protocol for car garages for automatic nozzle systems;
— Part 6: Test protocol for false floors and false ceilings for automatic nozzle systems;
— Part 7: Test protocol for commercial low hazard occupancies for automatic nozzle systems;
— Part 8: Test protocol for machinery in enclosures exceeding 260 m for open nozzle systems;
— Part 9: Test protocol for machinery in enclosures not exceeding 260 m for open nozzle systems;
— Part 10: Test protocol for atrium protection with sidewall nozzles for open nozzle systems;
— Part 11: Test protocol for cable tunnels for open nozzle systems;
— Part 12: Test protocol for commercial deep fat cooking fryers for manually activated open nozzle
systems;
— Part 13: Test protocol for wet benches and other similar processing equipment for open nozzle systems;
— Part 14: Test protocol for combustion turbines in enclosures exceeding 260 m for open nozzle systems;
— Part 15: Test protocol for combustion turbines in enclosures not exceeding 260 m for open nozzle
systems;
— Part 16: Test protocol for industrial oil cookers for open nozzle systems;
— Part 17: Test protocol for residential occupancies for automatic nozzle systems;
— Part 18: Test protocol for local application involving flammable liquid fires for open nozzle systems.
NOTE This list includes standards that are in preparation and other standards might be added. For current
status of published standards refer to www.cencenelec.eu.
1 Scope
This document specifies the evaluation of the fire performance of water mist systems used for local
application involving flammable liquid fires.
The tests specified in this document are applicable to the following:
a) flammable liquid pool fires where the liquid release can be confined to a bunded area, where the
entire surface of the bunded area is protected by the water mist system;
b) flammable liquid channel fires in channels not exceeding the maximum specified width of the water
mist system and with no limited channel length;
c) partially obstructed flammable liquid pool fires where the percentage of obstructed surface is limited
to that tested;
d) spray fires up to 6 MW fuelled by flammable liquids;
e) spray and pool fire combinations where confined to a bunded area;
f) flammable liquid residues (ink and paper dust) on printing presses.
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 14972-1:2020+A1:2025, Fixed firefighting systems — Water mist systems — Part 1: Design,
installation, inspection and maintenance
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 14972-1 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/
4 General requirements
4.1 General
The water mist system shall be capable of extinguishing the fire scenarios in this document for the
application for which it is intended to be used. Table 1 shall be used to determine the fire test scenarios
to be tested.
Table 1 — Fire test scenarios
Application type
Fire test description 2D ignitable combination 2D Spray fire – 2D ignitable
liquid pool fire ignitable liquid pool fire point liquid channel
protection and spray fire protection protection
protection
Square pool fire (see 8.2)
(X × X) pool at X X — —
maximum nozzle
height
(2X × 2X) pool at X X — —
maximum nozzle
height
(3X × 3X) pool at
X X — —
maximum nozzle
height
(3X × 3X) pool at X X — —
minimum nozzle
height
Channel pool fire (see 8.3)
(Y × Y) channel at — — — X
maximum nozzle
height
(Y × 2Y) channel at — — — X
maximum nozzle
height
(Y × 3Y) channel at — — — X
maximum nozzle
height
(Y × 3Y) at minimum — — — X
nozzle height
Spray fire (see 8.4)
Horizontal spray at — — X —
maximum nozzle
distance from spray
Horizontal spray at — — X —
minimum nozzle
distance from spray
Vertical spray at
— — X —
maximum nozzle
distance from spray
Vertical spray at — — X —
minimum nozzle
distance from spray
Combined pool and spray fire (see 8.5)
Arrangement — X — —
Figure 4 a) at
Application type
Fire test description 2D ignitable combination 2D Spray fire – 2D ignitable
liquid pool fire ignitable liquid pool fire point liquid channel
protection and spray fire protection protection
protection
maximum nozzle
height
Arrangement — X — —
Figure 4 b) at
maximum nozzle
height
Arrangement — X — —
Figure 4 c) at
maximum nozzle
height
Arrangement — X — —
Figure 4 d) at
maximum nozzle
height
Arrangement — X — —
Figure 4 e) at
maximum nozzle
height
Obstructed pool fire (see 8.6)
(3X × 3X) at maximum X X — —
nozzle height
(3X × 3X) at minimum X X — —
nozzle height
Obstructed pool fire (see 8.7)
Offset (X × Y) at X X — —
maximum nozzle
height
Offset (X × Y) at X X — —
minimum nozzle
height
6 MW spray fire with an external ignition source (see 8.8)
maximum nozzle — X — —
height
minimum nozzle — X — —
height
4.2 Requirements
4.2.1 Up to a maximum of 5 nozzles used in the fire tests shall be kept for later verification.
4.2.2 The water mist system, operating without manual intervention, shall successfully complete all
described performance fire tests for their specific applications.
4.2.3 The fire tests shall be conducted until the fire is extinguished.
4.2.4 System components, component locations, operating conditions and test enclosure details shall
remain unaltered throughout all of the fire tests for a given application.
4.2.5 The test protocol is only applicable to open nozzles.
4.2.6 The water supply shall be capable of supplying a flow rate and pressure at the minimum operating
pressure and flow rate as specified by the manufacturer. These parameters shall be met based on the
actual layout of the pipework installation as used in the test scenario.
4.2.7 The tests with the water mist system shall be conducted at maximum spacing and minimum
discharge conditions regarding water flow and pressure as specified by the manufacturer for this
application. The system shall be installed to achieve the maximum allowed time delay of water pressure
build up of the system.
4.2.8 All fire tests shall be conducted using the specifications from the manufacturer’s DIOM manual
(design, installation, operation and maintenance manual) in regard to nozzle placement, spray flux, and
spray duration. Sprays may be continuous or intermittent in time. In the case of intermittent, or cycled,
sprays, the time period during which the system is not discharging shall not be greater than 50 % of one
complete on/off cycle. The system off period shall not exceed 1 min.
4.2.9 The tests can be carried out in accordance with EN ISO/IEC 17025.
5 Test enclosure requirements
The fire tests should be conducted in a large open test hall, greater than 500 m in volume, with a
minimum ceiling height of 5,0 m. Ventilation for between tests and cooling of the enclosure shall be
provided.
The test hall shall be at an ambient temperature of (20 ± 10) °C prior to the start of the test. The test hall
shall be at as uniform an ambient temperature as reasonably possible.
6 Test equipment
6.1 Square pool fires
Three test pools, of sizes (X × X), (2X × 2X) and (3X × 3X), as specified by the manufacturer, shall be used.
Each test pool shall be comprised of a square pan or tray, of steel construction, with wall thickness
between 1,73 mm and 3,0 mm and wall height of 100 mm without lip, with smooth surfaces and edges
that are free from imperfections.
Each test pool shall contain a water base of 50 mm in height, with a fuel load of at least 20 mm above the
water surface. Freeboard should be 30 mm. Freeboard may be greater than 30 mm high, if a constant
freeboard height is used for all fire tests.
The test pools shall be configured according to Figure 1.
For hazards with diesel fuels, the test pools shall contain diesel. Where it is intended to use flammable
liquids with volatilities greater than those of diesel, but not greater than those of heptane, the tests shall
be conducted using heptane.
a) (X × X) pool fire
b) (2X × 2X) pool fire
c) (3X × 3X) pool fire
Key
S Maximum nozzle spacing (manufacturer’s specification)
1 Nozzle
Figure 1 — Configuration for square pool
6.2 Channel pool fires
Three test pools of sizes (Y × Y), (Y × 2Y) and (Y × 3Y), as specified by the manufacturer, shall be used.
Each test pool shall be comprised of pan or tray, of steel construction, with wall thickness between
1,73 mm and 3,0 mm thick and wall height of 100 mm high without lip, with smooth surfaces and edges
that are free from imperfections.
Each test pool shall contain a water base of 50 mm in height, with a fuel load of at least 20 mm above the
water surface. Freeboard should be 30 mm. Freeboard may be greater than 30 mm high, if a constant
freeboard height is used for all fire tests.
The test pools shall be configured according to Figure 2.
For hazards with diesel fuels, the test pools shall contain diesel. Where it is intended to use flammable
liquids with volatilities greater than those of diesel, but not greater than those of heptane, then the tests
shall be conducted using heptane.

Key
1 Nozzle
X Maximum latitudinal nozzle spacing (manufacturer’s specification)
Y Maximum channel width (manufacturer’s specification)
Z Maximum nozzle spacing (manufacturer’s specification)
Figure 2 — Configuration for channel pool
6.3 Spray fires
For the spray fire tests, conventional oil burner nozzles according to Table 2 shall be used.
Table 2 — Characteristics of oil burners for tests involving spray fires
Fire type Spray Fuel type Nominal oil Fuel flow Fuel Nominal
a
nozzles pressure temperature heat release
rate
bar kg/s °C MW
Low Lechler Light diesel 8,2 0,16 ± 0,01 20 ± 10 5,8 ± 0,6
pressure model
Heptane 8,2 0,14 ± 0,01 20 ± 10 5,8 ± 0,6
490.728
or
460.728
a
Lechler model 460.728 and Lechler model 490.728 is the trademark of a product supplied by Lechler GmbH,
Ulmer Straße
...