prEN 15004-4

Fixed firefighting systems - Gas extinguishing systems - Part 4: Physical properties and system design of gas extinguishing systems for HFC 125 extinguishant

This document gives specific requirements for gaseous fire-extinguishing systems, with respect to the HFC 125 extinguishant. It includes details of physical properties, specification, usage and safety aspects and is applicable to systems operating at nominal pressures of 25 bar and 42 bar, superpressurized with nitrogen. This does not preclude the use of other systems.

Ortsfeste Brandbekämpfungsanlagen - Löschanlagen mit gasförmigen Löschmitteln - Teil 4: Physikalische Eigenschaften und Anlagenauslegung für Feuerlöschmittel HFC 125

Installations fixes de lutte contre l’incendie - Installations d’extinction à gaz - Partie 4: Propriétés physiques et conception des systèmes pour agent extincteur HFC 125

Vgrajeni gasilni sistemi - Sistemi za gašenje s plinom - 4. del: Fizikalne lastnosti in načrtovanje sistema za gašenje s plinom za gasilo HFC 125

General Information

• Status: Not Published
• Publication Date: 04-Oct-2016
• Withdrawal Date: 04-Apr-2017
• ICS: 13.220.20 - Fire protection
• Technical Committee: CEN/TC 191 - Fixed firefighting systems
• Drafting Committee: CEN/TC 191/WG 6 - Gas extinguishing Systems and components
• Current Stage: 4098 - Decision to abandon - Enquiry
• Start Date: 08-Jan-2016
• Completion Date: 14-Apr-2025
• Ref Project: oSIST prEN 15004-4:2015 - Fixed firefighting systems - Gas extinguishing systems - Part 4: Physical properties and system design of gas extinguishing systems for HFC 125 extinguishant

Relations

• Revises: EN 15004-4:2008 - Fixed firefighting systems - Gas extinguishing systems - Part 4: Physical properties and system design of gas extinguishing systems for HFC 125 extinguishant (ISO 14520-8:2006, modified)
• Effective Date: 08-Jun-2022

Overview

The prEN 15004-4 standard, developed by CEN (European Committee for Standardization), specifies the requirements for fixed firefighting gas extinguishing systems using HFC 125 (Pentafluoroethane) as the extinguishing agent. This part 4 of the EN 15004 series focuses on the physical properties, specification, system design, and safety aspects of gas extinguishing systems for HFC 125, intended for use at nominal pressures of 25 bar and 42 bar, superpressurized with nitrogen. It provides critical guidelines for designing effective, safe, and environmentally considerate fire suppression systems in various applications.

Key Topics

• Physical Properties of HFC 125

  • Colourless, almost odorless, electrically non-conductive gas
  • Molecular mass: 120.02
  • Boiling point: -48.09 °C
  • Critical temperature: 66.02 °C, critical pressure: 36.18 bar abs
  • Density approx. four times that of air
  • Extinguishes fires mainly by physical interference with combustion

• System Design Requirements

  • Nominal operating pressures: 25 bar and 42 bar with nitrogen superpressurization
  • Maximum fill density: 929 kg/m³ to avoid liquid overfill and pressure spikes
  • Fill densities and container working pressures detailed to maintain container integrity
  • Extinguishant quantity calculations ensure minimum design concentration with a 1.3 safety factor above extinguishment concentration
  • Temperature and pressure relationship guidelines for system stability

• Extinguishant Usage and Concentrations

  • Applicable to total flooding systems for extinguishing Class A (surface fuels) and Class B (flammable liquids/gases) fires
  • Design concentrations specified for various fuels, including heptane, wood crib, ethanol, methanol, propane, and toluene
  • Concentrations designed to ensure effective fire suppression with consideration for hazard classification

• Safety Considerations

  • Personnel safety impacts from the gas and combustion by-products must be addressed in system design
  • Toxicological limits such as NOAEL (No Observed Adverse Effect Level) at 7.5% volume concentration, and LOAEL (Lowest Observed Adverse Effect Level) at 10% concentration
  • Compliance with safety guidelines per EN 15004-1 clause 5 is mandatory

• Environmental Impact

  • HFC 125 has zero ozone depletion potential (ODP) because it contains no chlorine, bromine, or iodine
  • Global warming potential (GWP) over 100 years is rated at 3500, important for environmental impact assessments
  • Designers are encouraged to consider environmental factors in system planning

Applications

The prEN 15004-4 standard is essential for engineers, designers, and facility managers involved in the specification and installation of fixed firefighting systems in a variety of environments, including:

• Data centers and server rooms where sensitive electrical equipment requires non-conductive extinguishing agents
• Industrial facilities with flammable liquid or gas hazards requiring rapid total flooding suppression
• Archives, museums, and libraries where clean agent systems are preferred to avoid residue and damage
• Telecommunication facilities and control rooms needing reliable fire protection without harming equipment
• Marine and offshore installations where space and safety are critical, and conventional water-based suppression is unsuitable

This standard ensures that installations using HFC 125 are safe for personnel, effective in fire suppression, and consider environmental performance.

Related Standards

• EN 15004-1: General requirements for design, installation, and maintenance of gas extinguishing systems
• EN 15004-2: For FK-5-1-12 extinguishant system design and physical properties
• EN 15004-3: For HCFC Blend A extinguishing agents
• EN 15004-6 to EN 15004-10: Cover physical properties and system design for other extinguishing agents such as HFC 23, and various IG-series inert gases

These related parts cover different types of extinguishing agents or general system requirements, providing a comprehensive regulatory framework for fixed firefighting gas systems.

---

Keywords: prEN 15004-4, fixed firefighting systems, gas extinguishing systems, HFC 125, pentafluoroethane, system design, physical properties, fire suppression, nitrogen superpressurization, extinguishant concentration, safety, environmental impact, global warming potential, gas fire suppression, CEN standard, fire protection engineering.

Standards Content (Sample)

SLOVENSKI STANDARD
01-marec-2015
9JUDMHQLJDVLOQLVLVWHPL6LVWHPL]DJDãHQMHVSOLQRPGHO)L]LNDOQHODVWQRVWLLQ
QDþUWRYDQMHVLVWHPD]DJDãHQMHVSOLQRP]DJDVLOR+)&
Fixed firefighting systems - Gas extinguishing systems - Part 4: Physical properties and
system design of gas extinguishing systems for HFC 125 extinguishant
Ortsfeste Brandbekämpfungsanlagen - Löschanlagen mit gasförmigen Löschmitteln -
Teil 4: Physikalische Eigenschaften und Anlagenauslegung für Feuerlöschmittel HFC
Installations fixes de lutte contre l’incendie - Installations d’extinction à gaz - Partie 4:
Propriétés physiques et conception des systèmes pour agent extincteur HFC 125
Ta slovenski standard je istoveten z: prEN 15004-4
ICS:
13.220.20 3RåDUQD]DãþLWD Fire protection
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
DRAFT
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2014
ICS 13.220.20 Will supersede EN 15004-4:2008
English Version
Fixed firefighting systems - Gas extinguishing systems - Part 4:
Physical properties and system design of gas extinguishing
systems for HFC 125 extinguishant
Installations fixes de lutte contre l'incendie - Installations Ortsfeste Brandbekämpfungsanlagen - Löschanlagen mit
d'extinction à gaz - Partie 4: Propriétés physiques et gasförmigen Löschmitteln - Teil 4: Physikalische
conception des systèmes pour agent extincteur HFC 125 Eigenschaften und Anlagenauslegung für Feuerlöschmittel
HFC 125
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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, 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: Avenue Marnix 17, B-1000 Brussels
© 2014 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 15004-4:2014 E
worldwide for CEN national Members.

Contents
Page
Foreword .3
1 Scope .4
2 Normative references .4
3 Terms and definitions .4
4 Characteristics and uses .4
4.1 General .4
4.2 Use of HFC 125 systems .5
5 Safety of personnel.9
6 System design . 10
6.1 Fill density . 10
6.2 Superpressurization . 10
6.3 Extinguishant quantity . 10
7 Environmental properties . 12

Foreword
This document (prEN 15004-4:2014) 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.
This document will supersede EN 15004-4:2008.
EN 15004 consists of the following parts, under the general title Fixed firefighting systems – Gas extinguishing
systems:
 Part 1: Design, installation and maintenance”
 Part 2: Physical properties and system design of gas extinguishing systems for FK-5-1-12 extinguishant”
 Part 3: Physical properties and system design of gas extinguishing systems for HCFC Blend A
extinguishant”
 Part 4: Physical properties and system design of gas extinguishing systems for HFC 125 extinguishant”
 Part 6: Physical properties and system design of gas extinguishing systems for HFC 23 extinguishant”
 Part 7: Physical properties and system design of gas extinguishing systems for IG-01 extinguishant “
 Part 8: Physical properties and system design of gas extinguishing systems for IG-100 extinguishant”
 Part 9: Physical properties and system design of gas extinguishing systems for IG-55 extinguishant”
 Part 10: Physical properties and system design of gas extinguishing systems for IG-541 extinguishant”
1 Scope
1.1 This part of EN 15004 contains specific requirements for gaseous fire-extinguishing systems, with
respect to the HFC 125 extinguishant. It includes details of physical properties, specification, usage and safety
aspects.
1.2 This part of EN 15004 covers systems operating at nominal pressures of 25 bars and 42 bar,
superpressurized with nitrogen. This does not preclude the use of other systems.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
EN 15004-1, Gaseous fire-extinguishing systems — Physical properties and system design — Part 1: General
requirements.
3 Terms and definitions
For the purposes of this part of EN 15004, the terms and definitions given in EN 15004-1 apply.
4 Characteristics and uses
4.1 General
Extinguishant HFC 125 shall comply with the specification shown in Table 1.
HFC 125 is a colourless, almost odourless, electrically non-conductive gas, with a density approximately four
times that of air.
The physical properties are shown in Table 2.
HFC 125 extinguishes fires mainly by physical means, but also by some chemical means
Table 1 — Specification for HFC 125
Property Requirement
Purity 99,6 % by mass,
min.
–4
Acidity
3 × 10 % by
mass (3 ppm),
max.
–4
Water content
10 × 10 % by
mass (10 ppm),
max.
Non-volatile 0,01 % by mass,
residue max.
Suspended matter None visible
or sediment
Table 2 — Physical properties of HFC 125
Property Units Value
Molecular mass — 120,02
Boiling point at 1,013 bar (absolute) -48,09
°C
Freezing point °C -101
Critical temperature 66,02
°C
Critical pressure bar abs 36,18
Critical volume cm /mol 210
Critical density kg/m 573,6
Vapour pressure 20 °C bar abs 12,05
Liquid density 20 °C kg/m 1 218,0
Saturated vapour density 20 °C kg/m 77,97
Specific volume of superheated vapour m /kg 0,1972
at 1,013 bar and 20 °C
Chemical formula CF CHF
3 2
Chemical name
Pentafluoroethane
4.2 Use of HFC 125 systems
HFC 125 total flooding systems may be used for extinguishing fires of all classes within the limits specified in
Clause 4 of EN 15004-1.
The extinguishant requirements per volume of protected space are shown in Table 3 for various levels of
concentration. These are based on methods shown in 7.6 of EN 15004-1.
The extinguishing concentrations and design concentrations for n-heptane and surface class A hazards are
shown in Table 4. Concentrations for other fuels are shown in Table 5
oSIST prEN 1
...