GB 50370-2005Code for design of gas fire extinguishing systems (English PDF)

4.2 Special Requirements on Components of Hepta-Fluoropropane Extinguishing Systems

4.3 Special Requirements on Components of IG54 l Mixed-Gas Extinguishing Systems .. 20

4.4 Special Requirements on Components of Pre-Engineered Systems of Condensed

Fire-Extinguishing Aerosol... 20

5 Operations and Contro ls ... 21

6 Safety Requirements ... 22 Appendix A Concentrations of Extinguishing and Inerting ... 23 Appendix B Modified Coefficients of Height above Sea level ... 25 Appendix C Jetting Rate of Equivalent Orifice Unit Area about Nozzles of Hepta-Fluoropropane Extinguishing System ... 26 Appendix D Nozzle Specifications and Equivalent Orifice Area ... 28 Appendix E Coefficients of Both Pressure and Density on Pipe Channels of IG54 l Mixed Gas Extinguishing Systems ... 29 Appendix F Jetting Rate of Equivalent Orifice Unit Area about Nozzles of IG541 Mixed Gas Extinguishing System ... 3 1 Appendix G Concentrations of No-Toxicity Response (NOAEL) and with Toxicity Response (LOAEL) and Technological Properties of Fire Agent... 33 Word Diction of the Code ... 34

1 General

1.0.1 This Standard has been \\ orked out for the purpose of designing gas fire extinguishing systems reasonably, reducing fire damage. and protecting the safety of human body and properties.

1.0.2 This code applies to the design on total flooding extinguishing of hepta-tluorupropane, mixed gas 1G54 l. and condensed fire extinguishing aerosol.

1.0.3 Design of gas fire extinguishing systems shall comply with the national guiding principles and policies, and be safe, technologically advanced. economic and reasonable .

1.0.4 Products and components of the system applied according to the design must be m accordance with national standards and regulations.

1.0.5 Besides complying \\ith this standard, the design of gas fire extinguishing systems shall also comply with other relevant current national standards.

2 Terms and Symbols

2.1 Terms

2.1. l Protected area the restricted enclosure space sati sfying the demands of total f1ood extinguish ing system

2.1.2 Tota! flooding extinguish ing system the fire extinguishing system in \\'h ich dur ing the regulated time the fire agent with the designed standard use level is ble\\ towa1·cls the protected area w hi ch is filled with the agent evenly.

2.1.3 Piping extinguishing system the fire extinguishing system in which the fire agent transported from storage device to blowing components via main and branch pipes is blew based on the design and calculation according to cetta in appl ication conditions.

2.1.4 Pre-engineered system the fire extinguishing system in which the storage device and blowing components of fire agent are pre-designed and assembled to be a whole set with functions of gang control

2.1.5 Combined distribution systems the fire extinguishing system in which a set of storage devices of gas extinguishing agent is applied through the selection distribution of pipe network to protect two or more than two protected areas.

2.1.6 Flame extinguishing concentration the mi nimum volume percent of the gas extinguishing agent in the air needed fo r putting out ce1tain fire under circumstances of l 0 1 kPa air pressure and regulated temperature.

2.1. 7 Flame extinguishing density the mass of solid condensed-fire -extinguishing-aerosol generate needed for putting out certain fire in the unit volume, under circumstances of 101 kPa air pressure and regu lated temperature.

2.1.8 Inerting concentration the minimum volume percent of the gas extinguishing agent in the air needed fo r restraining the occurrence of burning rising from the f1ammable and combustible gas or liquid steam with any concentration in the air, under circumstances of l 01 kPa air pressure and regulated temperature, in case of the fire source.

2.1.9 Soaking time

The time that the designed concentration of fire agent is maintained in the protected areas to put out the fire completely

2.1.10 Pressure re lief opening the opening where the pressure is released to prevent the internal pressure of protected areas fro m ex~eeding the allowable pressure, in case of the blowing of fire agent.