GB 25972-2024Gas fire extinguishing systems and components (English PDF)

3 Terms and definitions

4 Method for the model designation

5 Requirements

6 Test methods

7 Inspection rules

8 Instructions for use

9 Filling with the extinguishing agent

10 Packaging, transport and storage

Foreword

This document is drafted in accordance with the rules given in GB/T 1.1-2020 "Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents".

This document replaces GB 25972-2010 "Gas fire extinguishing systems and components". Compared with GB 25972-2010, apart from structural adjustments and editorial changes, the main technical changes are as follows:

a) the scope of application has been changed (see Clause 1; Clause 1 of the 2010 edition);

b) the definitions of "fire system maximum working pressure" and "discharge time" have been changed (see 3.4 and 3.9; 3.1 and 3.8 of the 2010 edition);

c) the terms and definitions of "external stored pressure gas fire extinguishing system", "container assemblies storage pressure", "container assemblies maximum working pressure", "container assemblies minimum working pressure", "noise-reducing nozzle", "status sensor unit (SSU)", "data transfer unit (DTU)", "pressure relief device in protected area", "effective pressure relief area", "actuating devices" and "pressure relief device action pressure" have been added (see 3.2, 3.6, 3.7, 3.8, 3.11, 3.12, 3.13, 3.14, 3.15, 3.16 and 3.17);

d) the "model designation method for fire extinguishing systems" and the "model designation method for components" have been changed (see 4.1 and 4.2; 4.1 and 4.2 of the 2010 edition);

e) the working temperature range and working pressure requirements of the fire extinguishing system have been changed (see 5.2.1.1 and 5.2.1.3; 5.1.1.1 and 5.1.1.2 of the 2010 edition);

f) the composition requirements for external stored pressure fire extinguishing systems have been added (see 5.2.2.2);

g) the functional requirements and test methods for status monitoring of the fire extinguishing system and for the data application platform have been added (see 5.2.6, 6.12, 6.13 and 6.14);

h) the requirements for the composition of container assemblies (see 5.3.1.1; 5.2.1 and 5.3.1 of the 2010 edition), for the fill density of container assemblies (see 5.3.3; 5.2.3 of the 2010 edition) and for the accidental discharge protection device (see 5.3.9; 5.2.10 of the 2010 edition) have been changed;

i) the structural requirements for container assemblies (see 5.3.1.2), the container assembly characteristics of external stored pressure extinguishing agent container assemblies and their test method (see 5.3.12 and 6.21), the test method for fill density and fill pressure of container assemblies (see 6.15) and the impact test method for the accidental discharge protection device (see 6.19) have been added;

j) the requirements for containers and cylinders have been changed (see 5.3.14; 5.4 of the 2010 edition);

k) the requirements for operational reliability and local resistance loss of container valves (see 5.3.15.4 and 5.3.15.6; 5.5.8 and 5.5.9 of the 2010 edition) and the operation test method at maximum and minimum working pressure (see 6.24; 6.7 of the 2010 edition) have been changed;

l) the requirements and test method for container valves with a pressure reducing function have been added (see 5.3.15.8 and 6.26);

m) the general requirements for pressure indicators have been changed (see 5.3.16.2.1; 5.14.2.1 of the 2010 edition);

n) the display screen requirements (see 5.3.16.2.3) and power supply requirements (see 5.3.16.2.9) for digital pressure indicators have been added;

o) the requirements for the relief operating pressure of safety relief devices (see 5.3.17.1; 5.11.1 of the 2010 edition) and the operation test method of safety relief devices (see 6.39; 6.15 of the 2010 edition) have been changed;

p) the requirements and test method for the relief capacity of safety relief devices have been added (see 5.3.17.4 and 6.40);

q) the nozzle size requirements (see 5.4.1; 5.6.2 of the 2010 edition) and the discharge characteristics test method for total flooding nozzles (see 6.46; 6.21 of the 2010 edition) have been changed;

r) the discharge noise requirements for noise-reducing nozzles and their test method have been added (see 5.4.8 and 6.47);

s) the operational reliability requirements for selector valves have been changed (see 5.5.3; 5.7.6 of the 2010 edition);

t) the requirement for signal feedback of the open/closed state of selector valves has been added (see 5.5.7);

u) the signal feedback requirements and test method for actuating devices have been added (see 5.9.2 and 6.52);

v) the anti-accidental-discharge function (see 5.10.2) and the fault alarm and self-test function requirements (see 5.10.3) of control devices have been added;

w) the operating pressure requirements for signal feedback devices have been changed (see 5.11.2; 5.15.2 of the 2010 edition);

x) the high pressure impact resistance (see 5.12.4) and corrosion resistance requirements (see 5.12.5) of pressure reducing devices and the high pressure impact resistance test method (see 6.56) have been added;

y) the test method for the pressure reducing performance of pressure reducing devices has been changed (see 6.55; 6.38 of the 2010 edition);

z) the installation requirements (see 5.13.1; 5.17.1 of the 2010 edition) and the nominal working pressure requirements (see 5.13.2; 5.17.3 of the 2010 edition) for low venting high close valves have been changed;

aa) the requirements and test methods for seismic supports and hangers have been added (see 5.15.3 to 5.15.5 and 6.59 to 6.61);

ab) flow design calculation and verification have been added (see 5.16);

ac) the requirements and test methods for pressure relief devices in protected area have been added (see 5.17, 6.2, 6.5, 6.16.3, 6.23.5 and 6.62 to 6.68);

ad) the type inspection items and factory inspection items have been changed (see Table 9; Table 4 of the 2010 edition);

ae) requirements for packaging, transport and storage have been added (see Clause 10);

af) the method for determining the maximum and minimum working pressure at different fill densities has been added (see Annex B);

ag) the test sequence and sample quantity for pressure relief devices in protected area have been added (see Annex AA).

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.

This document was proposed by and is under the jurisdiction of the National Fire and Rescue Administration.

The previous editions of this document and of the document it replaces are as follows:

- first issued in 2011 as GB 25972;

- this is the first revision.