ISO 14520-9:2019

INTERNATIONAL ISO
STANDARD 14520-9
Fourth edition
2019-07
Gaseous fire-extinguishing systems —
Physical properties and system
design —
Part 9:
HFC 227ea extinguishant
Systèmes d'extinction d'incendie utilisant des agents gazeux —
Propriétés physiques et conception des systèmes —
Partie 9: Agent extincteur HFC 227ea
Reference number
©
ISO 2019
© ISO 2019
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ii © ISO 2019 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Characteristics and uses . 1
4.1 General . 1
4.2 Use of HFC 227ea systems . 2
5 Safety of personnel . 5
6 System design . 5
6.1 Fill density. 5
6.2 Superpressurization . 6
6.3 Extinguishant quantity . 6
6.4 Other fill density and superpressurization levels . 9
7 Environmental properties . 9
Bibliography .11
Foreword
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This document was prepared by Technical Committee ISO/TC 21, Equipment for fire protection and fire
fighting, Subcommittee SC 8, Gaseous media and firefighting systems using gas.
This fourth edition cancels and replaces the third edition (ISO 14520-9:2016), which has been
technically revised. The main changes compared to the previous edition are as follows:
— a new subclause 6.4 on fill density and superpressurization levels has been added.
A list of all parts in the ISO 14520 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
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iv © ISO 2019 – All rights reserved

INTERNATIONAL STANDARD ISO 14520-9:2019(E)
Gaseous fire-extinguishing systems — Physical properties
and system design —
Part 9:
HFC 227ea extinguishant
1 Scope
This document contains specific requirements for gaseous fire-extinguishing systems, with respect to
the HFC 227ea extinguishant. It includes details of physical properties, specifications, usage and safety
aspects.
This document is applicable to systems operating at nominal pressures of 25 bar, 42 bar and 50 bar
with nitrogen propellant. This does not preclude the use of other systems.
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.
ISO 14520-1:2015, 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.
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
4 Characteristics and uses
4.1 General
Extinguishant HFC 227ea shall comply with the specification shown in Table 1.
HFC 227ea is a colourless, almost odourless, electrically non-conductive gas, with a density
approximately six times that of air.
The physical properties are shown in Table 2.
HFC 227ea extinguishes fires mainly by physical means, but also by some chemical means.
Table 1 — Specification for HFC 227ea
Property Requirement
Purity 99,6 % by mass, min.
Table 1 (continued)
Property Requirement
–6
Acidity 3 × 10 by mass, max.
–6
Water content 10 × 10 by mass, max.
Non-volatile residue 0,01 % by mass, max.
Suspended matter or sediment None visible
Table 2 — Physical properties of HFC 227ea
Property Units Value
Molecular mass — 170
Boiling point at 1,013 bar (absolute) °C −16,4
Freezing point °C −127
Critical temperature °C 101,7
Critical pressure bar abs 29,26
Critical volume cm /mol 274
Critical density kg/m 573
Vapour pressure 20 °C bar abs 3,90
Liquid density 20 °C kg/m 1 410
Saturated vapour density 20 °C kg/m 31,035
Specific volume of superheated m /kg 0,137 4
vapour at 1,013 bar and 20 °C
Chemical formula CF CHFCF
3 3
Chemical name
Heptafluoropropane
4.2 Use of HFC 227ea systems
HFC 227ea total flooding systems may be used for extinguishing fires of all classes within the limits
specified in ISO 14520-1:2015, 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 14520-1:2015, 7.6.
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 and inerting concentrations
are shown in Table 6.
Table 3 — HFC 227ea total flooding quantity
Temperature Specific HCF 227ea mass requirements per unit volume of protected space, m/V (kg/m )
vapour
T
volume
Design concentration (by volume)
°C
S
m /kg 6 % 7 % 8 % 9 % 10 % 11 % 12 % 13 % 14 % 15 %
–10 0,121 5 0,525 4 0,619 6 0,715 8 0,814 2 0,914 7 1,017 4 1,122 5 1,230 1 1,340 1 1,452 7
–5 0,124 1 0,514 2 0,606 4 0,700 5 0,796 7 0,895 1 0,995 7 1,098 5 1,203 8 1,311 4 1,421 6
0 0,126 8 0,503 4 0,593 6 0,685 8 0,780 0 0,876 3 0,974 8 1,075 5 1,178 5 1,283 9 1,391 8
5 0,129 4 0,493 2 0,581 6 0,671 9 0,764 2 0,858 6 0,955 0 1,053 7 1,154 6 1,257 9 1,363 6
10 0,132 0 0,483 4 0,570 0 0,658 5 0,749 0 0,841 4 0,936 0 1,032 7 1,131 6 1,232 8 1,336 4
15 0,134 7 0,474 0 0,558 9 0,645 7 0,734 4 0,825 1 0,917 8 1,012 6 1,109 6 1,208 9 1,310 5
20 0,137 3 0,465 0 0,548 3 0,633 5 0,720 5 0,809 4 0,900 4 0,993 4 1,088 6 1,185 9 1,285 6
2 © ISO 2019 – All rights reserved

Table 3 (continued)
Temperature Specific HCF 227ea mass requirements per unit volume of protected space, m/V (kg/m )
vapour
T
volume
Design concentration (by volume)
°C
S
m /kg 6 % 7 % 8 % 9 % 10 % 11 % 12 % 13 % 14 % 15 %
25 0,139 9 0,456 4 0,538 2 0,621 7 0,707 1 0,794 4 0,883 7 0,975 0 1,068 4 1,164 0 1,261 8
30 0,142 5 0,448 1 0,528 4 0,610 4 0,694 3 0,780 0 0,867 6 0,957 3 1,049 0 1,142 8 1,238 8
35 0,145 0 0,440 1 0,519 0 0,599 6 0,681 9 0,766 1 0,852 2 0,940 2 1,030 3 1,122 4 1,216 8
40 0,147 6 0,432 4 0,509 9 0,589 1 0,670 1 0,752 8 0,837 4 0,923 9 1,012 4 1,102 9 1,195 6
45 0,150 2 0,425 0 0,501 2 0,579 0 0,658 6 0,739 9 0,823 0 0,908 0 0,995 0 1,084 0 1,175 1
50 0,152 7 0,418 0 0,492 9 0,569 4 0,647 6 0,727 6 0,809 3 0,892 9 0,978 4 1,066 0 1,155 5
55 0,155 3 0,411 1 0,484 7 0,560 0 0,636 9 0,715 6 0,796 0 0,878 2 0,962 3 1,048 4 1,136 5
60 0,157 8 0,404 5 0,477 0 0,551 0 0,626 7 0,704 1 0,783 2 0,864 1 0,946 9 1,031 6 1,118 3
65 0,160 4 0,398 0 0,469 4 0,542 3 0,616 7 0,692 9 0,770 7 0,850 4 0,931 8 1,015 2 1,100 5
70 0,162 9 0,391 9 0,462 1 0,533 8 0,607 2 0,682 1 0,758 8 0,837 1 0,917 3 0,999 4 1,083 4
75 0,165 4 0,385 9 0,455 0 0,525 7 0,597 9 0,671 7 0,747 1 0,824 3 0,903 3 0,984 1 1,066 8
80 0,167 9 0,380 1 0,448 2 0,517 8 0,589 0 0,661 7 0,736 0 0,812 0 0,889 8 0,969 4 1,050 9
85 0,170 4 0,374 5 0,441 6 0,510 2 0,580 3 0,651 9 0,725 1 0,800 0 0,876 7 0,955 1 1,035 4
90 0,173 0 0,369 0 0,435 1 0,502 7 0,571 7 0,642 3 0,714 5 0,788 3 0,863 8 0,941 1 1,020 2
95 0,175 5 0,363 8 0,429 0 0,495 6 0,563 6 0,633 2 0,704 4 0,777 1 0,851 6 0,927 7 1,005 7
100 0,178 0 0,358 7 0,422 9 0,488 6 0,555 7 0,624 3 0,694 5 0,766 2 0,839 6 0,914 7 0,991 6
NOTE  This information refers only to the product HFC-227ea and does not represent any other products containing
1,1,1,2,3,3,3-heptafluoropropane as a component.
Symbols:
m/V is the agent mass requirements (kg/m ), i.e. mass, m, in kilograms of agent required per cubic metre of protected volume,
V, to produce the indicated concentration at the temperature specified;
V is the net volume of hazard (m ), i.e. the enclosed volume minus the fixed structures impervious to extinguishant
 
c V
m=
 
100−c S
 
T is the temperature (°C), i.e. the design temperature in the hazard area;
S is the specific volume (m /kg), the specific volume of superheated HFC 227ea vapour at a pressure of 1,013 bar may be
approximated by the formula
S = k + k T
1 2
where
k = 0,126 9;
k = 0,000 513.
c is the concentration (%), i.e. the volumetric concentration of HFC 227ea in air at the temperature indicated and a pressure
of 1,013 bar absolute.
Table 4 — HFC 227ea reference extinguishing and design concentrations
Fuel Extinguishment Minimum design
% by volume % by volume
Class B
Heptane (cup burner) 6,7 9,0
Heptane (room test) 6,9
Surface Class A
Wood Crib 4,9 7,9
PMMA 6,1
PP 6,1
ABS 6,1
Higher Hazard Class A See NOTE 4 8,5
NOTE 1  The extinguishment values for the Class B and the Surface Class A fuels are
determined by testing in accordance with ISO 14520-1:2015, Annexes B and C.
NOTE 2  The minimum design concentration for the Class B fuel is the higher value of the
heptane cup burner or room test heptane extinguishment concentration multiplied by 1,3.
NOTE 3  The minimum design concentration for Surface Class A fuel is the highest value
of the wood crib, PMMA, PP or ABS extinguishment concentrations multiplied by 1,3. In
...