1、BSI Standards PublicationBS 8458:2015Fixed fire protectionsystems Residential anddomestic watermistsystems Code of practicefor design and installationPublishing and copyright informationThe BSI copyright notice displayed in this document indicates when the documentwas last issued. The British Standa
2、rds Institution 2015Published by BSI Standards Limited 2015ISBN 978 0 580 85527 6ICS 13.220.01; 13.220.20The following BSI references relate to the work on this document:Committee reference FSH/18/5Draft for comment 14/30295812 DCPublication historyFirst published as DD 8458-1, October 2010First pub
3、lished as BS 8458, November 2015Amendments issued since publicationDate Text affectedBS 8458:2015 BRITISH STANDARDContentsForeword iiiIntroduction 11 Scope 22 Normative references 23 Terms and definitions 34 Preliminary work and consultation 74.1 Initial considerations 74.2 Consultation 74.3 Categor
4、y of system 74.4 Cylinder-based systems 84.5 Use of watermist systems as a compensatory feature 84.6 Special circumstances 95 System actuation 96 Design 106.1 Fire tests 106.2 Limits of application 116.3 System design 116.4 Extent of watermist system protection 126.5 Hydraulic calculations 126.6 Dis
5、charge performance 136.7 Discharge duration 136.8 Water supplies 136.9 Backflow prevention 186.10 Watermist nozzle coverage and location 186.11 Components 196.12 Electrical design and installation 246.13 Additives 247 Installation, commissioning and documentation 257.1 Installation 257.2 Commissioni
6、ng 267.3 Documentation 277.4 System data label 288 Maintenance 288.1 Inspecting and testing after commissioning and whilst in service 288.2 Reinstatement of the system 298.3 Log book 29AnnexesAnnex A (informative) Elements of a typical watermist fire suppressionsystem 30Annex B (informative) Watermi
7、st performance, reliability and resilience forsystems installed in the homes of vulnerable people 34Annex C (normative) Room fire tests for watermist systems with automaticnozzles 35Annex D (normative) Hydraulic calculations 47Annex E (informative) Example of system data label 52Bibliography 53BRITI
8、SH STANDARD BS 8458:2015 The British Standards Institution 2015 iList of figuresFigure 1 Stored water supply 15Figure 2 Mounting of nozzles within sloping ceilings 19Figure A.1 Fire pump and tank system 31Figure A.2 Fire pump and town mains system 32Figure A.3 Cylinder-based system 33Figure C.1 Corn
9、er test layout showing a two-nozzle arrangement 38Figure C.2 Between two nozzles test layout showing a two-nozzlearrangement 39Figure C.3 Beneath a nozzle test layout showing a two-nozzlearrangement 40Figure C.4 Corner fire test ignition and fuel package 41Figure C.5 Beneath a nozzle and between two
10、 nozzles fire test ignition andfuel package 42Figure C.6 Ventilation test layout showing a two-nozzle arrangement 43Figure C.7 Open room test layout showing a two-nozzle arrangement 44Figure D.1 Example of a square law graduation graph 51Figure D.2 Blank template of a square law graduation graph 51F
11、igure E.1 Example of system data label 52List of tablesTable 1 Category of system 8Table 2 Fire test maximum temperatures 10Table 3 Limits of application based on fire tests 11Table D.1 C values for various type of pipes 47Table D.2a K values for carbon steel tube conforming to BS EN 10255,Medium se
12、ries 48Table D.2b K values for CPVC conforming to ASTM F442 48Table D.2c K values for copper tube conforming to BS EN 1057:2006+A1,half-hard, R250 designation 48Table D.3a Typical equivalent lengths for steel fittings and valves 49Table D.3b Typical equivalent lengths for CPVC fittings and valves 49
13、Table D.3c Typical equivalent lengths for copper fittings and valves 50Summary of pagesThis document comprises a front cover, an inside front cover, pages i to iv,pages 1 to 54, an inside back cover and a back cover.BRITISH STANDARDBS 8458:2015ii The British Standards Institution 2015ForewordPublish
14、ing informationThis British Standard is published by BSI Standards Limited, under licence fromThe British Standards Institution, and came into effect on 30 November 2015.It was prepared by Subcommittee FSH/18/5, Watermist systems, under theauthority of Technical Committee FSH/18, Fixed fire fighting
15、 systems. A list oforganizations represented on these committees can be obtained on request totheir secretary.SupersessionThis British Standard supersedes DD 8458-1:2010, which is withdrawn.Relationship with other publicationsAttention is drawn to the requirements of BS EN 806, with particular regar
16、d tobackflow prevention, and to BS 1710 for guidance on identification and markingof pipework.Guidance on the application of automatic fire suppression systems is given inBS 9991, BS 9999, the Building Regulations 2010, Approved Document B for usein England 1, 2, Wales 3, 4 and its equivalents in Sc
17、otland 5 and NorthernIreland 6.Information about this documentWatermist fire suppression systems for residential and domestic applications aredesigned to provide an additional degree of protection of life and property,above that to be achieved by the installation of smoke and/or fire detectors andsy
18、stems.This British Standard presumes that the watermist fire suppression system willform part of an integrated fire safety system as part of the building design.This document converts DD 8458-1 into a full British Standard. It is a full revisionof the Draft for Development, and incorporates the foll
19、owing principal changes: clarification of the application of residential and domestic buildingcategorizations based on occupancy and risk; change to building height limit (from 20 m to 45 m); changes to fire test protocols: removal of one ventilation fire test; addition of two optional “open room” f
20、ire tests; changes to the limits of application dependent on fire tests successfullycompleted; increase in maximum nozzle spacing; expanded guidance on water supplies; additional measures for vulnerable people; additional recommendations for components.Product certification/inspection/testing. Users
21、 of this British Standard are advisedto consider the desirability of third-party certification/inspection/testing ofproduct conformity with this British Standard. Users seeking assistance inidentifying appropriate conformity assessment bodies or schemes may ask BSI toforward their enquiries to the r
22、elevant association.BRITISH STANDARD BS 8458:2015 The British Standards Institution 2015 iiiUse of this documentAs a code of practice, this British Standard takes the form of guidance andrecommendations. It should not be quoted as if it were a specification andparticular care should be taken to ensu
23、re that claims of compliance are notmisleading.Any user claiming compliance with this British Standard is expected to be able tojustify any course of action that deviates from its recommendations.This British Standard is intended for the use of designers, engineers, architects,surveyors, contractors
24、, installers and authorities having jurisdiction.It has been assumed in the preparation of this British Standard that theexecution of its provisions will be entrusted to appropriately qualified andexperienced people, for whose use it has been produced.Presentational conventionsThe provisions in this
25、 British Standard are presented in roman (i.e. upright) type.Its recommendations are expressed in sentences in which the principal auxiliaryverb is “should”.Commentary, explanation and general informative material is presented insmaller italic type, and does not constitute a normative element.Where
26、words have alternative spellings, the preferred spelling of the ShorterOxford English Dictionary is used (e.g. “organization” rather than“organisation”).Contractual and legal considerationsThis publication does not purport to include all the necessary provisions of acontract. Users are responsible f
27、or its correct application.Compliance with a British Standard cannot confer immunity from legalobligations.Particular attention is drawn to the Water Supply (Water Fittings)Regulations 1999 7, the Water Supply (Water Fittings) (Scotland)Byelaws 2014 8 and the Water Supply (Water Fittings) Regulation
28、s(Northern Ireland) 2009 9 in respect of requirements for any fire suppressionsystem which conveys, or is likely to convey, water supplied by a waterundertaker or licensed water supplier.BRITISH STANDARDBS 8458:2015iv The British Standards Institution 2015IntroductionWatermist fire suppression syste
29、ms have demonstrated their value in assistingthe protection of life and property in industrial and commercial applications formany years. The advent of watermist nozzles that operate at an earlier stage inthe development of a fire, together with the recognition that the largestnumbers of deaths from
30、 fire occur in the home, have led to the introduction ofwatermist fire suppression systems specifically designed for residential anddomestic occupancies.A correctly designed, installed and properly maintained watermist firesuppression system can detect, suppress and control a fire at an early stage
31、ofdevelopment, and activate an alarm. Operation of the system rapidly reducesthe rate of production of heat and smoke, allowing more time for the occupantsto escape to safety or be rescued.This British Standard accordingly covers design, installation, water supplies,maintenance and testing of reside
32、ntial and domestic watermist fire suppressionsystems installed to reduce the risk to life.However, fire-fighting and life protection encompasses a wide field ofendeavour and as such it is impracticable to cover every possible factor orcircumstance that might affect implementation of this British Sta
33、ndard.Residential and domestic watermist systems are seen as emerging technology inthe market and their performance can be more sensitive than traditionalsprinkler systems to small design changes, which can compromise theireffectiveness. They can have features such as smaller bore waterways and they
34、generally operate at higher pressures, which poses a number of design andmaintenance challenges. They produce smaller droplets of water, which can beprone to being adversely affected by compartment geometry and fire plumes.Smaller bore waterways and small orifice size in nozzles can be prone to bein
35、gblocked by particles and debris. Attention to good quality installation andcommissioning practices coupled with adequately maintained filtration by meansof strainers is therefore essential. Subsequent contamination or deterioration ofwater supply quality, through ingress of matter, corrosion or mic
36、robial activity,could compromise system effectiveness.The use of components that have been tested and approved in accordance withappropriate component specifications for fire protection applications is alsoimportant for system performance and reliability. At the time of writing of thisBritish Standa
37、rd, the testing and approval of watermist system components forresidential and domestic applications is a developing area. In some cases it mightbe appropriate to select components that have been approved for use insprinkler or commercial watermist systems.The fire tests detailed in this British Sta
38、ndard are an important method ofdemonstrating that the water spray pattern and smaller droplet sizes producedby each specific system are capable of suppressing the test fires and reducingtemperatures in the fire test room. The ventilation fire test also provides anassessment of the effect of air flo
39、ws on the watermist droplets. However, itneeds to be recognized that these tests represent a limited range of firescenarios and there are limits to their applicability to all scenarios that might beencountered in application. The scope of application of this British Standard istherefore limited, as
40、detailed in 6.2. Attention is also drawn to 4.5 whichcontains guidance about circumstances when enhanced performance, reliabilityand resilience measures are to be provided.Residential and domestic watermist fire suppression systems consist of a watersupply, filter, non-return valve, stop valve, prio
41、rity demand valve (whererequired), automatic alarm system and pipework to automatic watermistnozzles.BRITISH STANDARD BS 8458:2015 The British Standards Institution 2015 1The watermist nozzles are fitted at specified locations, the appropriatewatermist nozzle type being used for each location.The ma
42、in elements of a typical watermist fire suppression system are shown inAnnex A. Automatic watermist nozzles operate at a pre-determinedtemperature to discharge water over a known area below. The flow of waterthus initiated causes the sounding of an alarm. Only those watermist nozzlesoperate which ar
43、e individually heated above their operating temperature by theheat from the fire.The provision of a watermist fire suppression system does not negate the needfor other fire precautions or practical measures, which can include structural fireresistance, escape routes, smoke or fire detectors and safe
44、 housekeepingpractices. Even with the installation of a watermist fire suppression system,normal actions on the discovery of a fire need to be taken, such as immediateevacuation and the calling of the fire and rescue service.Watermist fire suppression system maintenance is not complex but is essenti
45、al(see Clause 8). It is important that owners and occupiers pay particular attentionto precautions issued by the watermist system supplier, such as the avoidance ofobstructions to the watermist nozzle, or not painting the watermist nozzle or itsmounting.1 ScopeThis British Standard gives recommendat
46、ions for the design, installation, watersupplies, commissioning, maintenance and testing of watermist systems withautomatic nozzles installed in residential and domestic occupancies up to amaximum ceiling height of 5.5 m. It primarily covers watermist systems used forlife safety, but might also prov
47、ide property protection.The recommendations of this British Standard are also applicable to anyaddition, extension, repair or other modification to a residential or domesticwatermist system.The British Standard does not cover watermist systems in industrial andcommercial buildings. Recommendations f
48、or these systems are givenin DD 8489-11).2 Normative referencesStandards publicationsThe following documents, in whole or in part, are normatively referenced in thisdocument and are indispensable for its application. For dated references, onlythe edition cited applies. For undated references, the la
49、test edition of thereferenced document (including any amendments) applies.ASTM A269-10, Standard specification for seamless and welded austeniticstainless steel tubing for general serviceASTM A312, Standard specification for seamless, welded, and heavily coldworked austenitic stainless steel pipesASTM F442, Standard specification for chlorinated poly(vinyl chloride) (CPVC)plastic pipe (SDRPR)BS 5839 (all parts), Fire detection and fire alarm systems for buildingsBS 7671, Requirements for electri
