1、BRITISH STANDARD BS 5306-5.2: 1984 Code of practice for Fire extinguishing installations and equipment on premises Part 5: Halon systems Section5.2Halon1211 total flooding systems UDC 614.842.6:614.844.2BS 5306-5.2:1984 This British Standard, having been prepared under the directionof the Fire Stand
2、ards Committee, was published underthe authority ofthe BoardofBSI andcomes into effecton 28September1984 BSI08-1999 The following BSI references relate to the work on this standard: Committee referenceFSM/13 Draft for comment82/11026DC ISBN 0 580 13923 9 Committees responsible for this British Stand
3、ard The preparation of this British Standard was entrusted by the Fire Standards Committee (FSM/-) to Technical CommitteeFSM/13 upon which the following bodies were represented: Association of Metropolitan Authorities British Automatic Sprinkler Association British Fire Protection Systems Associatio
4、n Ltd. British Fire Services Association British Gas Corporation Chief and Assistant Chief Fire Officers Association Confederation of British Industry Department of the Environment (Building Research Establishment, Fire Research Station) Department of the Environment (Property Services Agency) Depar
5、tment of Health and Social Security Department of Transport (Marine Directorate) Electricity Supply Industry in England and Wales Engineering Equipment and Materials Users Association Fire Extinguishing Trades Association Fire Insurers Research and Testing Organization (FIRTO) Fire Offices Committee
6、 Fire Protection Association Greater London Council Health and Safety Executive Home Office Incorporated Association of Architects and Surveyors Institute of Petroleum Institution of Fire Engineers Institution of Gas Engineers Ministry of Defence National Coal Board Royal Institute of British Archit
7、ects Society of Fire Protection Engineers Society of Motor Manufacturers and Traders Limited United Kingdom Atomic Energy Authority Amendments issued since publication Amd. No. Date of issue CommentsBS5306-5.2:1984 BSI 08-1999 i Contents Page Committees responsible Inside front cover Foreword iii 0
8、Introduction 1 1 Scope 1 2 Definitions 1 3 Characteristics of Halon 1211 2 4 Planning 3 5 Contract arrangements 4 6 System design 4 7 System operation 6 8 Enclosure characteristics 7 9 System components 8 10 System design procedure 11 11 Maintenance 12 12 Safety 13 Appendix A Deep-seated fires 15 Ap
9、pendix B Examples of calculation of Halon 1211 quantity where there is natural ventilation 15 Appendix C Examples of calculation of Halon 1211 quantity where there is forced ventilation 17 Appendix D Example of design calculation for balanced system 18 Appendix E Example of design calculation for un
10、balanced system 22 Figure 1 Isometric diagram of Halon 1211 pressurized to25 bar at21 C 30 Figure 2 Isometric diagram of Halon 1211 pressurized to10.5 bar at21 C 31 Figure 3 Pressure drop against mass flow rate for Halon 1211 in galvanized steel pipes 32 Figure 4 Mass flow rate per unit area against
11、 nozzle pressure with Halon 1211/N 2for nozzle type A 33 Figure 5 Mass flow rate per unit area against nozzle pressure with Halon 1211/N 2for nozzle type B 34 Figure 6 Type A nozzle 35 Figure 7 Type B nozzle 35 Figure 8 Example of balanced system 36 Figure 9 Example of Halon 1211 mass flow rate agai
12、nst container pressure for balanced system 37 Figure 10 Example of unbalanced system 38 Figure 11 Example of Halon 1211 mass flow rate against container pressure for unbalanced system 39 Figure 12 Label to be displayed at manual control 40 Figure 13 Label to be displayed at entrances to hazard 41 Fi
13、gure 14 Extended mass flow rate of Halon1211 to maintain constant concentration in enclosures with openings 42 Figure 15 Initial amounts of Halon1211 to produce a2.5% (V/V) residual concentration in enclosures equipped for mechanical mixing 43 Figure 16 Initial amounts of Halon1211 to produce a5% (V
14、/V) residual concentration in enclosures equipped for mechanical mixing 43BS 5306-5.2:1984 ii BSI 08-1999 Page Figure 17 Initial amounts of Halon1211 to produce a7.5% (V/V) residual concentration in enclosures equipped for mechanical mixing 44 Figure 18 Time required for interface between effluxing
15、Halon 1211/air mixtures and influxing air to descend to the centre of enclosures not equipped for mixing 44 Table 1 Physical properties of Halon 1211 24 Table 2 Quality of Halon 1211 24 Table 3 Halon 1211 flame extinguishment concentrations 25 Table 4 Halon 1211 inerting concentrations 26 Table 5 Ha
16、lon 1211 total flooding quantity 27 Table 6 Pipes 27 Table 7 Maximum pipework spans 28 Table 8 Friction loss in screwed pipe fittings and valves 28 Table 9 Friction loss in welded pipe elbows 28 Table 10 Safety clearances to enable operation, inspection, cleaning, repairs, painting and normal mainte
17、nance work to be carried out 29 Publications referred to 46BS 5306-5.2:1984 BSI 08-1999 iii Foreword This Section of this British Standard has been prepared under the direction of the Fire Standards Committee. This British Standard constitutes Part 5-5.2 of the BS5306 series, the main title of which
18、 is: BS5306, Code of practice for fire extinguishing installations and equipment on premises. The other Parts of BS5306 are or will be: Part 1: Hydrant systems, hose reels and foam inlets (formerly CP402.101); Part 2: Sprinkler systems (formerly CP402.201); Part 3: Portable fire extinguishers for bu
19、ildings and plant (formerly CP 402-3); Part 4: Carbon dioxide systems; Part 5: Halon systems; Section5.1: Halon1301 total flooding systems; Section 5.3: Halon 1211 local application systems 1) ; Part 6: Foam systems 1) ; Part 7: Extinguishing powder systems 1) . Halon 1211 total flooding systems, wi
20、th which this Section of the standard is concerned, are designed to provide a piped or otherwise connected supply of Halon1211 for the extinction of fire by achieving a given extinguishing concentration throughout the protected volume. There is a need for dissemination of information on established
21、system design and this code of practice has been prepared to meet this need. Its recommendations are made in the light of the best technical data known to the committee at the time of writing, but since a wide field is covered it has been impracticable to consider every possible factor or circumstan
22、ce that might affect implementation of these recommendations. Accordingly, while the aim has been to give as full and helpful an account as possible of the background knowledge available within the stated scope of the document, the recommendations should be applied in practical situations with discr
23、etion and due regard to local circumstances. This British Standard calls for the use of substances and/or procedures that may be injurious to health if adequate precautions are not taken. It refers only to the technical suitability and does not absolve the user from legal obligations relating to hea
24、lth and safety at any stage. It has been assumed in the drafting of this British Standard that the execution of its provisions is entrusted to appropriately qualified and experienced people. A British Standard does not purport to include all the necessary provisions of a contract. Users of British S
25、tandards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi toiv, pages1to46, an inside back cover and a back cover. This st
26、andard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. 1) In course of preparation.iv blankBS5306-5.2:1984 BSI 08-1999 1 0 Introduction It is important that the fire protection of a building or p
27、lant should be considered as a whole. Halon1211 total flooding systems form only a part, though an important part, of the available facilities, but it should not be assumed that their adoption necessarily removes the need to consider supplementary measures, such as the provision of portable fire ext
28、inguishers or other mobile appliances for first aid or emergency use, or to deal with special hazards. Halon1211 has for many years been a recognized effective medium for the extinction of flammable liquid fires and fires in the presence of electrical risks, but it should not be forgotten, in the pl
29、anning of the comprehensive schemes, that there may be hazards for which this medium is not suitable, or that in certain circumstances or situations there may be dangers in its use, requiring special precautions. Advice on these matters can be obtained from the appropriate fire authority, the Health
30、 and Safety Executive or other enforcing authority under the Health and Safety at Work etc. Act1974, and the insurers. In addition, reference should be made as necessary to other Parts of this code. It is essential that fire extinguishing equipment should be carefully maintained to ensure instant re
31、adiness when required. This routine is liable to be overlooked or given insufficient attention by supervisors. It is, however, neglected at peril to the lives of occupants of the premises and at the risk of crippling financial loss. The importance of maintenance cannot be too highly emphasized. 1 Sc
32、ope This Section of this code gives recommendations for the design, installation, maintenance and safety of Halon1211 total flooding fire extinguishing systems in buildings or plant. Such a system consists of an installation designed to convey Halon 1211 from storage containers for the protection of
33、 particular plant or parts of the premises against possible fire risk. Such systems may be piped or otherwise connected. This code provides factual data on the characteristics of Halon1211 and the types of fire for which it is a suitable extinguishant. The code does not cover the design of explosion
34、 suppression systems. Two methods of operation, viz. manual and automatic, are described Advice is given on the selection of a system and on the operational method; also included are detailed recommendations on the design, maintenance and efficient operation of installations. Reference is also made
35、to the part which Halon1211 systems should play in general schemes of fire protection of premises, having regard to safety as well as efficiency. NOTE 1Unless otherwise stated, all pressures are gauge pressures (in bar). 1bar=10 5 N/m 2 =10 5 Pa. NOTE 2The titles of the publications referred to in t
36、his code are listed on the inside back cover. 2 Definitions For the purposes of this Section of this code, the definitions given in BS4422-4 apply, together with the following. 2.1 authority an organization, office or individual responsible for approving equipment, installations or procedures 2.2 au
37、tomatic system a fire extinguishing system that, under specified conditions, functions without intervention by a human operator 2.3 filling density the mass of Halon charge in a container per unit nett container volume 2.4 manual system a fire extinguishing system that, under specified conditions, f
38、unctions by means of the intervention of a human operator 2.5 normally occupied area an area that is occupied by people during working hours 2.6 normally unoccupied area an area that is not occupied by people during working hours but that may be entered into occasionally for brief periods 2.7 total
39、flooding system an automatic or manual Halon 1211 fire extinguishing system consisting of a supply of Halon1211 arranged to discharge and fill an enclosed space to the proper concentrationBS 5306-5.2:1984 2 BSI 08-1999 3 Characteristics of Halon 1211 3.1 General. The chemical name of Halon 1211 is b
40、romochlorodifluoromethane (CF 2ClBr), which is sometimes abbreviated to BCF. Under normal conditions Halon 1211 is a colourless, odourless, electrically non-conductive gas with a density approximately five times that of air. A list of important physical properties of Halon 1211 is given in Table 1.
41、According to present knowledge Halon 1211 extinguishes fires by inhibiting the chemical reaction of fuel and oxygen. The extinguishing effect due to cooling, dilution of oxygen or fuel vapour is minor. 3.2 Quality. Halon 1211 should be in accordance with Table 2. NOTEA British Standard specifying re
42、quirements for Halon media is in course of preparation. 3.3 Halon numbering system. This four-digit number is a convenient method of identifying halogenated hydrocarbon compounds such as Halon1211, Halon1301, etc. Reading from left to right, each digit represents the number of particular atoms in th
43、e compound molecule, thus: number of carbon atoms number of fluorine atoms number of chlorine atoms number of bromine atoms For example, bromochlorodifluoromethane (CF 2 ClBr) is referred to as Halon1211 because the chemical formula shows: one carbon atom; two fluorine atoms; one chlorine atom; one
44、bromine atom. NOTEIf the fourth digit is zero, then this is omitted from the Halon number. 3.4 Use of Halon 1211. Halon 1211 total flooding systems may be used to fight fires of classes A, B or C as defined in BS4547. In the case of class C fires, the risk of explosion after extinction of the fire d
45、ue to the continued presence of flammable gases should be carefully considered. Flammable liquid and gas fires are promptly extinguished when Halon1211 is injected quickly into the enclosure in sufficient quantities to provide an extinguishing concentration for the materials involved. Surface fires
46、and embers associated with the burning of solid materials are also quickly extinguished with Halon1211, provided the fire is detected quickly and the Halon1211 is injected promptly, and that the concentration is maintained for an adequate period of time. Halon1211 should not be used to fight fires i
47、nvolving the following: a) chemicals containing their own supply of oxygen, such as cellulose nitrate or mixtures containing oxidizing agents, such as sodium chlorate or sodium nitrate; b) reactive metals, such as sodium, potassium, magnesium, titanium and zirconium; c) metal hydrides or metal amide
48、s; d) chemicals capable of undergoing autothermal decomposition, such as certain organic peroxides; e) solid materials in which fires quickly become deep-seated (see Appendix A). Halon1211 is suitable for use on fires involving live electrical apparatus. 3.5 Hazard to personnel 3.5.1 The discharge o
49、f Halon 1211 from a total flooding system to extinguish a fire may create a hazard to personnel both from the Halon 1211 itselfand from the products of decomposition that result from exposure of the Halon vapour to the fireor other hot surfaces. Exposure of personnel tohigh concentrations of Halon 1211 (see3.5.2) used in total flooding systems should be avoided asshould unnecessary exposure to the decomposition products. Once discharged into an enclosure, it is difficult to detect its presence through
