GB50151-1992低倍数泡沫灭火系统设计规范英文版

UDC GB National Standard of the Peoples Republic of China P GB 50151- 92 低倍数泡沫灭火系统设计规范低倍数泡沫灭火系统设计规范 Code of Design for Low Expansion Foam Extinguishing System Issued on: Jan. 10, 1992 Implemented as of: July 01, 1992 Jointly Issued by: State Bureau of Technological Supervision Ministry of Construction of PRC National Standard of the Peoples Republic of China Code of Design for Low Expansion Foam Extinguishing System GB 50151- 92 Compiled and Prepared by: Ministry of Public Security of PRC Approved by: Ministry of Construction of PRC Implemented as of: July 01, 1992 Notice on the issuance of the national standard “Code of Design for Low Expansion Foam Extinguishing System” JB 1992 No.30 In compliance with the requests of Document No. 2630 Jizong 1986 of State Planning Commission, the “Code of Design for Low Expansion Foam Extinguishing System” jointly compiled and prepared by the Ministry of Public Security and other departments concerned has been checked up jointly by the departments concerned. It is approved that GB 50151- 92 “Code of Design for Low Expansion Foam Extinguishing System” be a national standard and take effect as of July 1, 1992. The Code is controlled by the Ministry of Public Security, interpreted by Tianjin Fire Fighting Scientific Research Institute of the Ministry of Public Security and published and distributed by the Standard Quota Research Institute of the Ministry of Construction. Ministry of Construction of PRC Jan. 10, 1992 Explanatory Notes to Compilation and Preparation The Code is prepared jointly by Tianjin Fire Fighting Scientific Research Institute of the Ministry of Public Security and the following units SINOPEC Beijing Design Institute, Luoyang Petrochemical Engineering Corporation, Daqing Petroleum Exploration Design and Research Institute of China Petroleum Natural Gas Corporation and Fire Brigade of Tianjin Public Security Bureau in compliance with Document No. 2630 Jizhong 1986 of the State Planning commission. During compilation and preparation, the draftsmen of the Code made extensive investigations and studies on the current status of the scientific research, design and application of low expansion foam extinguishing system in our country in accordance with relevant national policies and the policy of “Putting Prevention First and Combining Prevention with Fighting” regarding fire fighting work, tested and verified the supply strength of foam solution taking into consideration all previous major tests carried out in China and Sino- Japan Petroleum Fire Fighting Test, especially the availability of ring- pump type proportioning process under self- dumping condition. The Code is checked up and finalized by the departments concerned assimilating the current results of scientific research and engineering practices, referring to the code and information on the design, installation and acceptance of low expansion foam extinguishing system from the US, Japan, Germany, Russian and ISO and soliciting the opinions from scientific and research institutes, design institutes and higher education colleges and universities subordinated to some provinces and cities, departments and commissions concerned as well as large- sized petrochemical enterprises and public security supervision authorities for fire fighting. The Code is divided into four chapters and two appendices, which mainly consist of General Principle, Selection of Foam Liquid and Sizing of the System, System Design, System Assembly, etc. Since the Code is compiled and prepared for the first time, all units are requested to pay attention to the collection of information and summing- up of experience during the execution. If something is found to be modified and supplemented, please mail your comments and relevant materials to Tianjin Fire Fighting Scientific and Research Institute of the Ministry of Public Security (Address: Liqizhuang, Tianjin, Zip Code: 300381) for future reference and modification. Ministry of Public Security of PRC October, 1991 CONTANT Chapter I General Provisions .6 Chapter II Selection of Foam Liquid and Sizing of the System.6 Section I Selection, Storage and Formulation of Foam Solution.6 Section II Sizing of the System6 Chapter III System Design.7 Section I General Provisions of Design for Foam Extinguishing System for Tank Farm7 Section II Design for Injection Foam Extinguishing System for Tank Farm.7 Section III Design for Submerged Injection Foam Extinguishing System for Tank Farm.10 Section IV Foam Spraying System12 Section V Foam Pump Station .12 Chapter IV System Assembly 13 Section I General Provisions13 Section II Foam Pump and Foam Proportioner13 Section III Foam Liquid Storage Vessel.14 Section IV Foam Generator14 Section V Valve and Fitting14 Appendix I Terminology15 Appendix II Notes of Wording16 Additional Explanatory Notes:17 Chapter I General Provisions Article 1.0.1 The Code is prepared to design properly the low expansion air foam extinguishing system (hereinafter referred as foam extinguishing system), minimize fire losses and guarantee the safety of personnel and property. Article 1.0.2 The design for foam extinguishing system shall comply with the relevant national principles and policies, be safe and reliable, advanced in technology, rational in economy and easy in management. Article 1.0.3 The Code is applicable to the design for foam extinguishing system for the process, storage , handling and application of Class A (except liquefied hydrocarbons), B and C liquids. The Code is not applicable to the design for foam extinguishing system for ships and offshore oil platforms. Article. 1.0.4 In addition to the specifications of the Code, the design for foam extinguishing system shall conform to the relevant standards and codes in force in the country. Chapter II Selection of Foam Liquid and Sizing of the System Section I Selection, Storage and Formulation of Foam Solution Article 2.1.1 For non- aqueous liquids of Class A, B and C, it is recommended that protein foam liquid, fluoro- protein foam liquid or aqueous film- forming foam liquid shall be selected if injection foam extinguishing system is used while fluoro- protein foam liquid or aqueous film- forming liquid shall be selected if submerged injection foam extinguishing system is used. Article 2.1.2 Alcohol- resistant foam liquid shall be used for aqueous liquids of Class A, B and C. Article 2.1.3 Foam liquids shall be stored at a temperature of 0- 40 0C and in a well- ventilated dry room or shed. Article 2.1.4 The formulation of foam liquid into foam solution shall meet the following requirements: 1. Fresh water or sea water may be used to formulate protein, fluoro- protein and alcohol- resistant fluoro- protein foam liquid into foam solution; 2. Fresh water shall be used to formulate gel- type and metallic soap type foam liquid into foam solution. 3. Water that has an impact on the extinguishing performance of the foam is forbidden to be used to formulate all kinds of foam liquid into foam solution. 4. It is recommended that the temperature of the water used to formulate foam liquid into foam solution be 4- 35 0C. Section II Sizing of the System Article 2.2.1 The system shall be sized according to the compound factors such as the scale of the protected object, fire hazard, general arrangement, difficulty of fire suppression and set up of fire station. Article 2.2.2 It is recommended that fixed foam extinguishing system be selected for one of the following applications 1. Independent tank farm of non- aqueous liquids of Class A, B and C with a total storage capacity 500 m3; 2. Vertical tank farm of aqueous liquids of Class A, B and C with a total storage capacity 200 m3; 3. Tank farm of non- aqueous liquids of Class A, B and C, which is affiliated to enterprises with inadequate mechanical fire fighting facilities. Article 2.2.3 It is recommended that semi- fixed foam extinguishing system be used for one of the following applications: 1. Tank farm of liquids of Class A, B and C affiliated to enterprises with strong mechanical fire fighting facilities; 2. Applications with potential of fire hazard in petrochemical production area. Article 2.2.4 It is recommended that portable foam extinguishing system be used for one of the following applications: 1. Ground vertical tank of non- aqueous liquids of Class A, B and C with a total storage capacity 500 m3, single tank capacity 200 m3 and the height of tank wall 7m; 2. Ground vertical tank of aqueous liquids of Class A, B and C with a total storage capacity 33 3 30 Section II Design for Injection Foam Extinguishing System for Tank Farm Article 3.2.1 The firing area of injection foam extinguishing system for fixed roof tank shall be calculated with the cross section area of tank. The supply strength and continuous supply duration of foam solution shall conform to the following specifications: I. For non- aqueous liquids of Class A, B and C, the strength and duration shall not be less than those in Table 3.2.1- 1. Supply Strength and Continuous Supply Duration Table 3.2.1- 1 Supply Strength (L/min.m2) Class of liquid Fixed and semi- fixed type Portable type Continuous supply duration (min) Class A II. The distance from foam weir plate to the tank wall shall be 1.0m. If mechanical seal is used, the height of the weir plate shall be 0.25m; If soft seal is used, the height of the weir plate shall be 0.9m. Water discharge holes shall be provided at the lowest part of the weir plate, the opening area shall be calculated based on the assumption that two 12mm x 8mm rectangular openings are provided for every square meter of annular area. Supply Strength of Foam Solution, Protection Perimeter of Foam Generator and Continuous Supply Duration Table 3.2.2 Foam Generator Supply Strength Protection Perimeter Continuous Duration Type Flow of Solution (L/min) (L/min.m2) (m) (min) PC4 240 12.5 18 30 PC8 480 12.5 36 30 Article 3.2.3 The design for foam extinguishing system for inner floating roof tank shall conform to the following specifications: I. For shallow- pan type inner floating roof tanks and the inner floating roof tanks with the floating pan made of fusible material, the firing area, supply strength and continuous supply duration shall conform to the specifications in Article 3.2.1 of the Code. III. For single- and double- pan type inner floating roof tanks, the firing area, supply strength and continuous supply duration of foam solution shall conform to the specifications of item 1 of Article 3.2.2 of the Code, the distance from foam weir plate to tank wall shall be 0.55m, and the height of the plate shall be 0.5m. Article 3.2.4 The foam generator for injection foam extinguishing system shall be provided according to the following specifications: I. For fixed roof tank, inner floating roof tank of shallow- pan type and with the floating roof made of fusible material, the type and number of foam generator shall be determined by the flow of foam solution calculated, and the number provided shall not be less than those specified in Table 3.2.4. Number of Foam Generator Provided Table 3.2.4 Diameter of Tank (m) Number of Foam Generator Provided (set) 33 3 Article 3.3.3 The high back- pressure foam generator for submerged injection foam extinguishing system shall be provided as follows: I. The number of generators provided shall be determined according to the foam solution flow calculated in Article 3.2.2; II. The outlet pressure shall be greater than the sum of pipe resistance and hydraustatic pressure inside the tank; III. The inlet pressure shall be 0.6- 1.0 Mpa, the corresponding flow of foam solution shall be calculated with the following equation: Where qthe flow of foam solution (L/min); K2the flow characteristic coefficient of high back- pressure foam generator; pthe inlet pressure of high back- pressure foam generator(Mpa). Article 3.3.4 The foam pipe of submerged injection foam extinguishing system shall be routed according to the following specifications: I. The foam pipe inside the fire- proof embankment shall be routed according to Article 3.2.6 of the Code. II. Vent valves shall be provided in the foam pipe out of the fire- proof embankment, and with 2% slope to vent valves; no hydrants and gas valves shall be provided. Article 3.3.5 The hydraulic calculations shall conform to the following specifications: I. The hydraulic calculations shall be based on the following equation: H = CQ1.72 (3.3.5) Where hResistance loss of unit length of foam pipe (Pa/10m); CCoefficient of pipe resistance loss QFoam flow (L/S) II. The coefficient of pipe resistance loss shall be selected from Table 3.3.5- 1. Coefficient of pipe resistance loss Table 3.3.5- 1 Pipe Diameter (mm) Coefficient of Pipe Resistance Loss 100 12.920 150 2.140 200 0.555 250 0.210 300 0.111 )3 . 3 . 3( 2 pkq = 350 0.070 III. The valve in foam pipe and equivalent length of some pipe fittings shall be determined according to Table 3.3.5- 2. Valve in Foam Pipe and Equivalent Length of Some Pipe Fittings Table 3.3.5- 2 Nominal diameter (mm) category of pipe fitting 150 200 250 300 Gate valve 1.25 1.50 1.75 2.0 900 elbow 4.25 5.00 6.75 8.00 Swing check valve 12.00 15.25 20.50 24.50 Article 3.3.6 For submerged injection foam extinguishing system, the routing of foam solution pipe and hydraulic calculations shall be determined according to Article 3.2.7 if it is beyond this range, it shall be determined by tests. Article 3.4.5 Automatic fire alarms shall be provided for foam spraying system. They shall be in auto control mode, but also provided with manual control device. Section V Foam Pump Station Article 3.5.1 It is recommended that foam pump station be constructed combining with fire fighting water pump house, with a fire resistant grade not lower than II. The distance from pump station to the protected object shall not be less than 30m, and it shall not take longer than 5 min. to delivery foam or foam solution to the farthest protected object after the start- up of foam pump . Article 3.5.2 It is recommended that foam pump be started by self dumping, no less than two suction lines shall be provided for each group of foam pumps, when one line fails, the other one can handle all the water consumption. Article 3.5.3 It is recommended that hydrants be provided in foam solution pipe in and out of the foam pump station; and foam nozzles be provided in foam pump station. Article 3.5.4 Standby pump shall be provided for foam pump , its capacity shall not be less than the maximum capacity of one pump. No standby pump shall be provided if one of the followings is met: I. The total storage capacity of non- aqueous liquids of Class A, B and C is less than 2500m3 and the capacity of single tank is less than 500m3. II. The total storage capacity of aqueous liquids of Class A, B and C is less than 1000m3 and the capacity of single tank is less than 100m3. Article 3.5.5 Backup power shall be provided for foam pump station, combustion engine can be used as power source if it is difficult to supply by double power supplies or double circuits. For foam pump station without standby pump, no backup power is necessary. Article 3.5.6 Water level indicator shall be provided for the water pond in the pump station. The pump station shall be provided with communication devices which can communicate directly with the fire station or fire security department of the unit. Chapter IV System Assembly Section I General Rules Article 4.1.1 The system assemblies such as foam pump, foam proportioner, foam solution pressure vessel, foam generator, valves and piping, shall be the acceptable products inspected and tested by the fire product quality monitoring and testing center of national grade. Article 4.1.2 The painting of major system assemblies shall conform to the following specifications: I. Foam solution pipe, foam pipe, foam liquid tank, foam proportioner and foam generator shall be painted red; II. Foam pump and feedwater pipe shall be painted green. Note: If there are many kinds of pipe and their paintings are in contradiction to those of process pipes, corresponding color belts or color rings can be applied. Section II Foam Pump and Foam Proportioner Article 4.2.1 It is recommended that centrifugal pump with smooth performance curve be selected for foam pump. If ring pump type proportioner is used, the design flow of pump shall be 1.1 times that of calculated flow. Article 4.2.2 Vacuum pressure gauges or vacuum meters shall be provided in the feed line of foam pump. Pressure gauge, check valve or return line with control valve shall be provided in the discharge line of foam pump. Article 4.2.3 If ring pump type proportioner is used, the following specifications shall be satisfied: I. It is recommended that discharge back pressure be zero or negative, when the suction pressure is 0.70.9Mpa, its discharge back pressure may be 0.020.03Mpa; II. The suction shall not be 1m higher than the lowest level of foam liquid in the tank. III. If the discharge back pressure is greater than zero, precautions against the back feeding of water into foam liquid tank shall be taken in the suction pipe; IV. It is recommended that no less than one back up proportioner be provided for foam proportioner. Article 4.2.4 If pressure type foam proportioner is used, the following specifications shall be satisfied: I. The inlet pressure shall be 0.61.0 Mpa; II. The pressure loss shall be calculated as 0.1 Mpa. Article 4.2.5 If pressure balanced type proportioner is used, the following specifications shall be satisfied: I. The water inlet pressure shall be 0.51.0 Mpa; II. The inlet pressure of foam liquid shall be greater than that of water, however the pressure difference shall not be greater than 0.2 Mpa; Article 4.2.6 When foam eductor is used, it shall be connecte