ISO 14520-15:2015

INTERNATIONAL ISO
STANDARD 14520-15
Third edition
2015-02-15
Gaseous fire-extinguishing
systems — Physical properties and
system design —
Part 15:
IG-541 extinguishant
Systèmes d’extinction d’incendie utilisant des agents gazeux —
Propriétés physiques et conception des systèmes —
Partie 15: Agent extincteur IG-541
Reference number
©
ISO 2015
© ISO 2015
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ii © ISO 2015 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative reference . 1
3 Terms and definitions . 1
4 Characteristics and uses . 1
4.1 General . 1
4.2 Use of IG-541 systems . 2
5 Safety of personnel . 6
6 System design . 7
6.1 Fill pressure . 7
6.2 Superpressurization . 7
6.3 Extinguishant quantity . 8
7 Environmental Properties . 8
Foreword
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to Trade (TBT), see the following URL: Foreword — Supplementary information.
The committee responsible for this document is ISO/TC 21, Equipment for fire protection and fire fighting,
Subcommittee SC 8, Gaseous media firefighting systems using gas.
This third edition cancels and replaces the second edition (ISO 14520-15:2005), which has been
technically revised.
ISO 14520 consists of the following parts, under the general title Gaseous fire-extinguishing systems —
Physical properties and system design:
— Part 1: General requirements
— Part 2: CF I extinguishant
— Part 5: FK-5-1-12 extinguishant
— Part 6: HCFC Blend A extinguishant
— Part 8: HFC 125 extinguishant
— Part 9: HFC 227ea extinguishant
— Part 10: HFC 23 extinguishant
— Part 11: HFC 236fa extinguishant
— Part 12: IG-01 extinguishant
— Part 13: IG-100 extinguishant
— Part 14: IG-55 extinguishant
— Part 15: IG-541 extinguishant
Parts 3, 4, and 7, which dealt with FC-2-1-8, FC-3-1-10, and HCFC 124 extinguishants, respectively, have
been withdrawn, as these types are no longer manufactured.
iv © ISO 2015 – All rights reserved

INTERNATIONAL STANDARD ISO 14520-15:2015(E)
Gaseous fire-extinguishing systems — Physical properties
and system design —
Part 15:
IG-541 extinguishant
1 Scope
This part of ISO 14520 contains specific requirements for gaseous fire-extinguishing systems, with
respect to the IG-541 extinguishant. It includes details of physical properties, specification, usage, and
safety aspects.
This part of ISO 14520 covers systems operating at nominal pressures of 150 bar, 200 bar, and 300 bar
at 15 °C. This does not preclude the use of other systems, although design data for other pressures are
not available at this time.
2 Normative reference
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.
ISO 14520-1:2006, Gaseous fire-extinguishing systems — Physical properties and system design —
Part 1: General requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 14520-1 apply.
4 Characteristics and uses
4.1 General
IG-541 is a colourless, odourless, electrically non-conductive gas with a density approximately the same
as that of air.
It is an inert gas mixture consisting nominally of 52 % nitrogen, 40 % argon, and 8 % carbon dioxide.
The mixture specification for IG-541 (based on 8 % carbon dioxide with tolerance of ± 5 %) is as follows:
a) carbon dioxide percentage range 7,6 % to 8,4 %;
b) argon percentage range 37,2 % to 42,8 %;
c) nitrogen percentage range 48,8 % to 55,2 %.
Individual container or batch analysis is based on carbon dioxide measurement only.
Extinguishant IG-541 shall comply with the specification shown in Table 1.
The physical properties are shown in Table 2.
IG-541 extinguishes fires mainly by a reduction of oxygen concentration in the atmosphere of the
hazard enclosure.
Table 1 — Component gas specification for IG-541
Argon Nitrogen Carbon dioxide
Purity 99,997 % by volume, 99,99 % by volume, 99,5 % by volume,
min. min. min.
−6 −6 −6
Moisture 4 × 10 by mass, 5 × 10 by mass, 10 × 10 by mass,
max. max. max.
−6 −6 −6
Oxygen 3 × 10 by mass, 3 × 10 by mass, 10 × 10 by mass,
max. max. max.
NOTE Only principal contaminants are shown. Other measurements can include
hydrocarbons, CO, NO, NO . Most are < 20 × 10–6.
Table 2 — Physical properties of IG-541
Property Units Value
Molecular mass — 34,0
Boiling point at 1,013 bar (absolute) °C –196
Freezing point °C –78,5
Critical temperature °C —
Critical pressure bar abs —
Critical volume cm /mol —
Critical density kg/m —
Vapour pressure 20 °C bar abs 152
Liquid density 20 °C kg/m —
Saturated vapour density 20 °C kg/m —
Specific volume of superheated vapour m /kg 0,706
at 1,013 bar and 20 °C
Components N 52 % by volume
Ar 40 % by volume
CO 8 % by volume
Chemical name Nitrogen/argon/carbon dioxide
4.2 Use of IG-541 systems
IG-541 total flooding systems can be used for extinguishing fires of all classes within the limits specified
in ISO 14520-1:2006, Clause 4.
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 ISO 14520-1:2006, 7.6.
The extinguishing concentrations and design concentrations for heptane and surface class A hazards a
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