Code for Design of Gas Fire Extinguishing Systems

UDC NATIONAL STANDARD ~,~c,c 1:1 OF THE PEOPLE'S REPUBLIC OF CHINA 9=t $A~~ *'1 ffil IE *ijfte p GB 50370-2005 Code for Design of Gas Fire Extinguishing Systems Date of issuing: March 2, 2006 Date of enforcement: May 1, 2006 Jointly issued by: Ministry of Construction of the People's Republic of China General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China

Preface According to the requirement of "Notice on Promulgation of '"Plan for Preparation and Modification of National Standards for Project Construction 2001 ~2002" Document JB [2002] No.26 the \;linistry of Construction of PRC. this Standard is prepared by Tianjin Fire Research Institute of :V1inistry of Public Security, jointly by other relevant units. During the preparation. the editorial group carried out thorough and in-depth investigation and research: carefully summarized achievements of scientific research in the researching. production. design and application and the practical experience of the engineering about the gas fire extinguishing systems in our country, referred to the relevant international standards and the ones of developed countries such as America. Japan and Germany, and employed the fundamental experiments and the experimental research on engineering applications. After extensive opinions have been obtained from departments and units of design, scientific research. manufacturing, construction, universities and colleges, and supervision on fire fighting, the Standard is finalized by relevant depaiiments, under the review of expe1is. This Standard consists of 6 chapters and 7 appendixes, in which the main contents are: general, terms and symbols, design requirements, system components. operation and control and safety requirements. Those clauses in block are mandatory clauses, which must be forced strictly. The Ministry of Construction will be responsible for the management and explanation on the mandatory clauses. The Ministry of Public Security will be responsible for the specific management. Tianjin Fire Research Institute of Ministry of Public Security will be responsible for the explanation on the detailed technical contents. During the implementation. the users of this Standard are kindly required to summarize experience and collect materials, and send any suggestion or comment in this regard to Tianjin Fire Research Institute of Ministry of Public Security (Address: 110 South Road of Weijin of Nankai District Tianjin. Post Code: 300381) at any time for reference in future revision. Chief editorial units. paiiicipating editorial units and major drafters of this Standard: Chief editorial units: Tianjin Fire Research Institute of Ministry of Public Security Participating editorial units: National Quality Supervision & Testing Center on Fixed Fire Extinguishing Systems and Fire-Retarding Components Beijing Urban Engineering Design & Research Institute China Academy of Railway Sciences Shenzhen International Safety Technology Co., Ltd. China Mobile Communications Corporation Shanxi General Fire Brigade of Public Security Fire Administration of Shenzhen Public Security Bureau Guangdong Shengjie Fire Protection Group Zhejiang Lantian Environmental Protection Hi-Tech Co., Ltd. Hangzhou New Epoch Fire Protection Science and Technology Co., Ltd. Xi'an Jianrui Chemical Industry Co., Ltd.

Contents General............................................................... J 7 Terms and Symbols.............................................................. 2 2.1 Terms..................................................................................... 2 2.2 Symbols..................................................................... 3 3 De.sign Require1r 1e.nts..................................................................... 6 3.! Ge neral Provis ions...................................................................... 6 3.2 System Set-up.......................................................... 7 3.3 Extinguishing Systen1s of Hepta-Fluoropropane............................................ 8 3.4 IG541 Mixed Gas Fire-Extinguishing System....................................... 13 3.5 Pre-engineered Syste m of Condensed Fire-Extinguishin g Aerosol....................... 16 4 System Components............................................................ 18 4. 1 General Provi sions....................................................... 18 4.2 Special Requirements on Components of Hepta-Fluoropropane Extinguishing Systems........................................................................... 19 4.3 Special Req uirements 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 Controls................................................................... 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 Eq uivalent 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 satisfying the demands of total f1ood extinguishing system 2.1.2 To ta! flooding extinguishing system The fire extingui shing system in \\'h ich during 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 cettain application 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 regulated 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 from ex~eeding the allowable pressure, in case of the blowing of fire agent. 2.1.11 Course Middle Point During the blowing, the system state when the blowing amount is 50% of the designed use level 2.1.12 NOAEL concentration The maximum concentration of fire agent of which the occurrence of the physiological 2

-Internal pressure of storage vessel at the course middle point Q-- Designed flo\\ of pipe channel Q, Designed flow of single nozzle Qg --Average designed flow of branch pipes Q -Designed flow of pressure-relief orifice plate Q, -Average designed flow of main trunk pipe Q, -Average blowing speed of fire agent in the protected area q, --Blowing rate on unit area of equivalent orifice S -Mass volume of overheated steam or gas of fire agent under circumstances of 101 kpa air pressure and the minimum environmental temperature of protected area T --Minimum environmental temperature of protected area {--Designed blowing time of fire agent V -Net volume of protected area V 0 -Total volume of gas phase in the overall storage vessels before the blowing (total volume of the entire storage vessel for IG541 system) v; -Volume of pipe channel of pipe network before the pressure-relief orifice plate V 2 --Volume of pipe channel of pipe network behind the pressure-relief orifice plate ~,-Capacity of storage vessel VP -Internal volume of pipe channel of pipe network W -Designed use level of fire extinguishing or inerting Vf 7 -Storage amount of fire agent of system 0 TV, -Remaining amount of fire agent of system Y -Pressnre rnefficient at the initiatimi: end of calculated nine section l - - - - --- - - - -.._,..L.J._ 1; -Pressure coefficient at the tail end of calculated pipe section Z 1 -Density coefficient at the initiating end of calculated pipe section Z 2 -Density coefficient at the tail end of calculated pipe section 4

3 Design Requirements 3.1 General Provisions 3.1. 1 For the protected area where the gas fire extinguishing systems are applied for the protection. the designed use level of extinguishing or inerting shall be determined by calculations based on the corresponding designed concentration of extinguishing or ineiting about the corn bustible substances in the protected area. 3.1.2 The designed inetiing concentration shall be applied for the gas with explosive ri sks and protected areas with the risks of liquid fire; the designed extinguishing concentration for the gas with no danger of explosions and protected areas with no liquid and solid fire. 3.1.3 In case of co-existence or the mixing of several combustible substances, the designed concentration of extinguishing or inerting shall be detennined according to the maximum designed concentration of extinguishing or inerting among them. 3.1.4 If the combined distribution system is employed for two or more than two protected areas, protected areas protected by one combined distribution system shall not be greater than 8. 3.1.5 The storage amount of fire agent about the combined distribution system shall be confirmed according to the protected areas of maximum storage amount. 3.1.6 The storage amount of fire agent about the extinguishing systems shall be the sum of designed extinguishing use level of protected areas, the remaining amount of fire agent in the storage vessel. and the remaining amount of fire agent in the pipe network. 3.1. 7 For those storage devices of extinguishing systems cannot be refilled for the work recovery within 72 hours, the spare amount shall be set according to 100% of the former storage amount. 3.1.8 The designed temperature of extinguishing systems shall be 20 C o 3.1.9 The same shall be the specifications, filling pressure and filling amount of storage vessels on the same collecting pipe. 3.1.10 If two or three sets of pipe networks are designed in the same protected area, collecting pipe can be set up respectively, but the starting devices of system must be commonly used. Flovv rate of nozzles on each pipe network shall be designed according to the same designed extinguishing concentration and the same blowing time. 3.1.11 Four-way pipe fittings shall not be used for the distribution on the pipe network. 3.1.12 The protective height and radius of nozzles shall comply with the following provisions: 1 The maximum protective height may not be larger than 6.5 m; 2 The minimum protective height shall not be less than 0.3 m; 3 If the installation height of nozzles is smaller than l.srn, the protective radius may not be greater than 4.5 m; 4 If the installation height of nozzles is not smaller than I.Sm, the protective radius shall not be greater than 7.5 m; 3.1.13 The nozzle may be close to the top surface of protected areas for installation. Its maximum distance to the top surface may not be larger than O.Srn. 3.1.14 Numbers of pre-engineered systems to be installed in one protected area may not be larger than 10. 6

3.1.15 If there is more than one set of devices of pre-engineered systems within the same protected area, these systems deyices must be able to be started simultaneously and the responding time of action shall not be larger than 2s. 3.1.16 The protective Yolume of a single-set device of pre-engineered system about condensed fire extinguishing aerosol shall not exceed 160m 3 ; If several devices are installed, the distance between each other shall not be larger than lom. 3.1.17 The height of the protected area. where the pre-engineered systems of condensed fire extinguishing aerosol are used. may not be greater than 6.0 m. 3.1.18 Nozzles of the device of the pre-engineered systems about condensed fire extinguishing aerosol may be 2.0 meters higher than the ground of protected areas. 3.2 System Set-up 3.2.1 Gas fire extinguishing systems apply to the fighting of the following fire: 1 Electric fire 2 Fire of solid surface 3 Liquid fires 4 Gas fire in which the gas source can be cut off before the fire is put out. Note: Except cable tunnels (mezzanines and wells) and self-contained generator houses. pre-engineered systems of condensed fire extinguishing aerosol in type K and other types shall not be applied for other electric fire. 3.2.2 Gas fire extinguishing systems do not apply to the following fire: 1 Fire of chemical products of oxidants or containing oxidants like nitrocellulose and sodium nitrate uranium 2 Fire of active metals such as kalium. magnesium. natrium, titanium. z1rcomum. and 3 Fire of metal hydrides like potassium and sodium hydrides 4 Fire of chemical substances which can be of spontaneous decomposition like hydrogen peroxide and diammonium 5 Deep-seated fires of combustible solid substances 3.2.3 Pre-engineered systems of condensed fire extinguishing aerosol shall not be set up in places crowded with people, the ones of explosive risks, and the ones with ultra-clean requirements. Pre-engineered systems of condensed fire extinguishing aerosol in type K and other types shall not be applied in places like computer rooms and communication rooms. 3.2.4 The division on protected areas shall comply with the following provisions: 1 The protected areas may be divided based on the single enclosed space; if the suspended ceilings and floors of the same zone need protecting at the same time, they can be combined into one protected area. 2 In case of the application on extinguishing systems of pipe netvvork, the area of one protected area may not be larger than 800 m 2 and the volume may not be greater than 3600m 3. 3 If the pre-engineered systems are used, the area of one protected area may not be larger ) 0 than 500 m- and the volume may not be greater than l 600m). 3.2.5 The fire endurance of both building enclosures and doors and windows in protected areas may not be lower than 0.5h; the one of suspended ceiling may not be smaller than 0.25h. 3.2.6 The allowable pressure strength of internal pressure endured by the building enclosures in 7