ISO 14520-14:2015

INTERNATIONAL ISO
STANDARD 14520-14
Third edition
2015-02-15
Gaseous fire-extinguishing
systems — Physical properties and
system design —
Part 14:
IG-55 extinguishant
Systèmes d’extinction d’incendie utilisant des agents gazeux —
Propriétés physiques et conception des systèmes —
Partie 14: Agent extincteur IG-55
Reference number
ISO 14520-14:2015(E)
©
ISO 2015

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ISO 14520-14:2015(E)

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ii © ISO 2015 – All rights reserved

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ISO 14520-14:2015(E)

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-55 systems . 2
5 Safety of personnel . 5
6 System design . 6
6.1 Fill pressure . 6
6.2 Superpressurization . 6
6.3 Extinguishant quantity . 6
7 Environmental properties . 7
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ISO 14520-14:2015(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
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electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
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 14520-14:2005), 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
3
— 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.
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INTERNATIONAL STANDARD ISO 14520-14:2015(E)
Gaseous fire-extinguishing systems — Physical properties
and system design —
Part 14:
IG-55 extinguishant
1 Scope
This part of ISO 14520 contains specific requirements for gaseous fire-extinguishing systems, with
respect to the IG-55 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 at 15 °C, 200 bar at
15 °C, 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-55 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 50 % argon and 50 % nitrogen. The mixture specification
for IG-55 is as follows:
a) argon percentage range (50 ± 5) %
b) nitrogen percentage range (50 ± 5) %
Extinguishant IG-55 shall comply with the specification shown in Table 1. The physical properties are
shown in Table 2. IG-55 extinguishes fires by reduction of the oxygen concentration in the atmosphere
of the hazard enclosure.
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ISO 14520-14:2015(E)

Table 1 — Specification for IG-55
Component Argon Nitrogen
Purity > 99,9 % > 99,9 %
−6 −6
Moisture < 15 × 10 < 10 × 10
NOTE Only principal contaminants are shown. Other measurements can include
hydrocarbons, CO, NO, NO , CO , O , etc. Most are < 20 × 10–6.
2 2 2
Table 2 — Physical properties of IG-55
Property Units Value
Molecular mass — 33,98
Boiling point at 1,013 bar (absolute) °C —
Freezing point °C —
Critical temperature °C —
Critical pressure bar abs —
3
Critical volume cm
/mol —
3
Critical density kg/m —
Vapour pressure 20 °C bar abs —
3
Liquid density 20 °C kg/m —
3
Saturated vapour density 20 °C kg/m —
3
Specific volume of superheated vapour at m /kg 0,708
1,013 bar and 20 °C
N 50 % by volume
2
Components
Ar 50 % by volume
NOTE IG-55 is a mixture of two gases. For further details on its physical properties, refer
to ISO standards for the individual gases.
4.2 Use of IG-55 systems
IG-55 total flooding systems
...