1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS 750:2012Specification forunderground firehydrants and surfacebox frames and coversPublishing and copyright informationThe BSI copyright notice displayed in this document indic
2、ates when the documentwas last issued. The British Standards Institution 2012Published by BSI Standards Limited 2012ISBN 978 0 580 74714 4ICS 13.220.10The following BSI references relate to the work on this standard:Committee reference FSH/17/8Draft for comment 11/30243193 DCPublication historyFirst
3、 published August 1937First revision, January 1950Second revision, August 1964Third revision, February 1977Fourth revision, January 1984Fifth revision, September 2006Sixth revision (present), September 2012Amendments issued since publicationDate Text affectedBS 750:2012 BRITISH STANDARDContentsForew
4、ord iiIntroduction 11 Scope 12 Normative references 13 Terms and definitions 24 Fire hydrants 35 Outlets 66 Stem drive 77 Draining system 78 Coating 79 Maintenance of water purity (potable water systems only) 910 Type requirements 911 Fire hydrant assembly resistance to internal pressure of the shel
5、l and ofall pressure containing components and resistance of the obturator todifferential pressure 1112 Hydrostatic test certificate 1113 Marking and additional data 1114 Surface box frames and covers 1115 Marking 1516 Type requirements 1517 Production requirements 1618 Test certificate 16AnnexesAnn
6、ex A (normative) Type tests for strength, security and endurance 17Annex B (normative) Type hydrostatic tests for screwed outlets 19Annex C (normative) Air release test 20Annex D (normative) Obturator impact resistance test 21Annex E (normative) Hydrant box cover opening procedure 21Annex F (normati
7、ve) Information to be supplied by the purchaser 22Annex G (normative) Type and production loading tests for surface box framesand covers 22List of figuresFigure 1 Example of type 1 fire hydrant showing required dimensions 4Figure 2 Example of type 2 fire hydrant showing required dimensions 5Figure 3
8、 Screwed outlet (round thread) and outlet cap showing requireddimensions 8Figure 4 Minimum bedding width of surface box frame showing requireddimensions 13Figure 5 Prising bar dimensions 13Figure 6 Geometry of prising slots 14Figure 7 Detail of keyhole and key 15Figure A.1 Load/deflection test appar
9、atus 18Figure C.1 Example arrangement of test apparatus 20List of tablesTable 1 Production test load requirements and acceptance criteria 16Summary of pagesThis document comprises a front cover, an inside front cover, pages i to ii,pages 1 to 24, an inside back cover and a back cover.BRITISH STANDAR
10、D BS 750:2012 The British Standards Institution 2012 iForewordPublishing informationThis British Standard is published by BSI Standards Limited, under licence fromThe British Standards Institution, and came into effect on 30 September 2012. Itwas prepared by Subcommittee FSH/17/8, Hydrants, hoses an
11、d associated waterdelivery equipment, under the authority of Technical Committee FSH/17, Fireand rescue service equipment. A list of organizations represented on thiscommittee can be obtained on request to its secretary.SupersessionThis British Standard supersedes BS 750:2006, which is withdrawn.Inf
12、ormation about this documentThis British Standard includes specific national requirements that are notspecified in BS EN 14339 and BS EN 1074-6.It has been assumed in the drafting of this British Standard that the executionof its provisions is entrusted to appropriately qualified and experienced peo
13、ple,for whose guidance it has been prepared.Presentational conventionsThe provisions of this standard are presented in roman (i.e. upright) type. Itsrequirements are expressed in sentences in which the principal auxiliary verb is“shall”.Commentary, explanation and general informative material is pre
14、sented insmaller italic type, and does not constitute a normative element.Contractual and legal considerationsThis publication does not purport to include all the necessary provisions of acontract. Users are responsible for its correct application.Compliance with a British Standard cannot confer imm
15、unity from legalobligations.BRITISH STANDARDBS 750:2012ii The British Standards Institution 2012IntroductionA fire hydrant is installed primarily for use by the Fire and Rescue Service (FRS)to quickly secure a supply of water to extinguish a fire in the vicinity. A firehydrant may also be installed
16、for other purposes that allow a water supplieraccess to the pressurized water network.NOTE A fire hydrant installed for non-fire fighting purposes is commonly known asa washout.The water supplier is responsible for installing and maintaining fire hydrants forboth purposes.It is advisable to consult
17、the FRS and the water supplier during the developmentof products conforming to this standard. In general terms, the FRS requires quickaccess to a supply of water from a fire hydrant using an operating key/bar and astandpipe. The water supplier does not require such quick access but carries awider ra
18、nge of tools and equipment for operation and maintenance.1 ScopeThis British Standard specifies the operational and health and safetyrequirements for underground fire hydrants conforming to the dimensional,material and performance requirements of BS EN 14339 and BS EN 1074-6. Italso includes specifi
19、c national requirements not included in BS EN 14339 andBS EN 1074-6.This British Standard applies to underground fire hydrants:a) to be installed in a water supply system;b) size DN80;c) suitable for a maximum allowable operating pressure (PFA) of 1.6 MPaor 2.5 MPa (16 bar or 25 bar);d) with operati
20、ng valves; ande) with one outlet.It also specifies requirements for their surface box frames and covers.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in thisdocument and are indispensable for its application. For dated references, onlythe edition cite
21、d applies. For undated references, the latest edition of thereferenced document (including any amendments) applies.Standards publicationsBS 336:1989, Specification for fire hose couplings and ancillary equipmentBS 5163-1, Valves for waterworks purposes Part 1: Predominantly key-operatedcast iron gat
22、e valves Code of practiceBS 5163-2, Valves for waterworks purposes Part 2: Stem caps for use onisolating valves and associated water control apparatus SpecificationBS 5834-2:2011, Surface boxes, guards and underground chambers for thepurposes of utilities Part 2: Specification for surface boxesBS 60
23、01-3, Sampling procedures for inspection by attributes Part 3: Skip-lotsampling proceduresBRITISH STANDARD BS 750:2012 The British Standards Institution 2012 1BS 6920-1, Suitability of non-metallic products for use in contact with waterintended for human consumption with regard to their effect on th
24、e quality ofthe water Part 1: SpecificationBS EN 736 (all parts), Valves TerminologyBS EN 1074-1:2000, Valves for water supply Fitness for purpose requirementsand appropriate verification tests Part 1: General requirementsBS EN 1074-2, Valves for water supply Fitness for purpose requirements andappr
25、opriate verification tests Part 2: Isolating valvesBS EN 1074-6:2008, Valves for water supply Fitness for purpose requirementsand appropriate verification tests Part 6: HydrantsBS EN 1092-2, Flanges and their joints Circular flanges for pipes, valves, fittingsand accessories, PN designated Part 2: C
26、ast iron flangesBS EN 1092-3, Flanges and their joints Circular flanges for pipes, valves, fittingsand accessories, PN designated Part 3: Copper alloy flangesBS EN 1561, Founding Grey cast ironsBS EN 1563, Founding Spheroidal graphite cast ironBS EN 1982, Copper and copper alloys Ingots and castings
27、BS EN 10088-1, Stainless steels Part 1: List of stainless steelsBS EN 12163, Copper and copper alloys Rod for general purposesBS EN 12164, Copper and copper alloys Rod for free machining purposesBS EN 12165, Copper and copper alloys Wrought and unwrought forging stockBS EN 12167, Copper and copper a
28、lloys Profiles and bars for general purposesBS EN 12168, Copper and copper alloys Hollow rod for free machiningpurposesBS EN 14339:2005, Underground fire hydrantsBS EN ISO 7500-1, Metallic materials Verification of static uniaxial testingmachines Part 1: Tension/compression testing and machines Veri
29、fication andcalibration of the force-measuring systemOther publicationsN1 WATER UK. WIS 04-52-01, Specification for polymeric anti-corrosion (barrier)coatings (as amended). Swindon: WRc plc, 1994. ISSN 1353-2510.1)N2 WATER UK. WIS 04-52-02, The use of polymeric anti-corrosion (barrier)coatings. Swin
30、don: WRc plc, 1993. ISSN 0267-0305.1)N3 WATER UK. WIS 04-52-03, Specification for anti-corrosion coatings onthreaded fasteners (as amended). Swindon: WRc plc, 1995. ISSN 1353-2510.1)3 Terms and definitionsFor the purposes of this British Standard, the terms and definitions given inBS EN 14339 and BS
31、 EN 736 (all parts) apply.1)Available from http:/www.water.org.uk/BRITISH STANDARDBS 750:20122 The British Standards Institution 20124 Fire hydrants4.1 GeneralAs a minimum, fire hydrants conforming to this British Standard shall conformto BS EN 14339.Fire hydrants shall have a design life of a minim
32、um of 50 years. This shall bedetermined by reference to:a) the properties of the materials used in the construction;b) the engineering design of the fire hydrant;c) the normal situation of installation; andd) the conditions of use.Where materials have time-dependent properties, these shall be select
33、ed withreference to the manufacturers data on such properties to determine theirsuitability for the function and life span.Where components of the fire hydrant are designed to be serviceable, this shallnot be regarded as a reason to design for a shorter operating life.Serviceable components shall in
34、clude those having potential for accidentaldamage and wear from abnormal use.The manufacturer shall ensure that parts that are considered to be subject towear shall be available for the lifetime of the valve.Fire hydrants shall be one of the following two types:1) type 1 (see 4.2 and Figure 1);2) ty
35、pe 2 (see 4.3 and Figure 2).4.2 Type 1 fire hydrantType 1 fire hydrants shall conform to the dimensions shown in Figure 1.The operating valve shall conform to BS EN 1074-1,BS EN 1074-2, BS 5163-1 and BS 5163-2 for PFA 16 or PFA 25 valves.Materials for duckfoot bends shall conform to BS EN 1561 or BS
36、 EN 1563.The Y and Z flanges DN50, PN 16 or PN 25, as shown in Figure 1, shall becompatible with the mating dimensions given in BS EN 1092-2 andBS EN 1092-3 as appropriate, using the bolts, studs or set screws specified.NOTE 1 They are not required to be circular and are not required to have raisedf
37、aces.NOTE 2 Y or Z flanges may have a groove in the face to accommodate an “O” ring.The bolt holes may be slotted and the slots may extend to the periphery of theflange.4.3 Type 2 fire hydrant4.3.1 ClassificationType 2 fire hydrants shall conform to one of the following patterns.a) Type 2a: The bonn
38、ets and/or outlets of this pattern shall be secured in sucha manner that they cannot be removed when installed in a pipeline. Withthe exception of stem sealings, it shall be made clear in the manufacturersliterature that the fire hydrant cannot be maintained while in situ.BRITISH STANDARD BS 750:201
39、2 The British Standards Institution 2012 3b) Type 2b: This shall be designed to facilitate maintenance of the obturator,stem, outlet and their seals, in situ, while mounted in a chamber with asurface box frame and cover in accordance with Clause 14. They shall have:1) Y and Z flanges DN50, PN 16 or
40、PN 25, compatible with the matingdimensions given in BS EN 1092-2 and BS EN 1092-3 as appropriate,using bolts, studs or set screws specified; andNOTE 1 They are not required to be circular and are not required to haveraised faces.NOTE 2 Y or Z flanges may have a groove in the face to accommodate an
41、“O”ring. The bolt holes may be slotted and the slots may extend to the periphery ofthe flange.2) a bolted connection at the body/bonnet joint with a minimum of threebolts.c) Type 2c: This shall be designed to facilitate maintenance as type 2b. Theyshall have bolted connections between both the outle
42、t and body, and thebonnet and body. These connections shall each have a minimum of threebolts.Figure 1 Example of type 1 fire hydrant showing required dimensionsDimensions in millimetresKey1 Stem cap 4 Wedge-gate or other operating valve2 Outlet cap 5 65 nominal bore3 Outlet (for detailssee Figure 3
43、)6 Duckfoot bendX, Y, Z flangeBRITISH STANDARDBS 750:20124 The British Standards Institution 2012d) Type 2d: This shall be designed to facilitate maintenance as type 2b, butshall have a means of connection of the outlet and/or bonnet to the firehydrant body other than type 2c (see 5.4, 5.5 and 4.3.5
44、).Type 2b, type 2c and type 2d fire hydrants shall be capable of being dismantledin situ using standard, readily available tools.4.3.2 DimensionsType 2 fire hydrants shall conform to the dimensions shown in Figure 2.The clearance between the back of flange X (where used), see Figure 2, and thebody s
45、hall be not less than 17 mm at the position of any bolt hole.The mating dimensions of flange X (where used), see Figure 2, shall be inaccordance with BS EN 1092-2, DN80 and PN 16 or PN 25.NOTE It is not required to be circular or full-form and may be provided withadditional holes, which may be slott
46、ed, to suit other flange designs.Figure 2 Example of type 2 fire hydrant showing required dimensionsDimensions in millimetresKey1 Stem cap 3 Outlet (for details see Figure 3)2 Outlet cap 4 65 nominal boreX, Y, Z flangeBRITISH STANDARD BS 750:2012 The British Standards Institution 2012 54.3.3 Materia
47、ls4.3.3.1 All copper alloy materials used in the construction of fire hydrants shallconform to BS EN 1982, BS EN 12163, BS EN 12164, BS EN 12165, BS EN 12167 orBS EN 12168.4.3.3.2 The threaded part of the valve that engages with the stem shall becopper alloy.4.3.3.3 All components of the valve opera
48、ting mechanism shall consist ofmaterials that avoid the risk of corrosion or galling resulting in seizure ormechanical failure.4.3.3.4 Stems of type 2 fire hydrants shall be manufactured from stainless steelconforming to BS EN 10088-1 with a minimum chromium content of 13%, orcopper alloy (see 4.3.3
49、.1).4.3.3.5 Stainless steel outlets shall be manufactured from grades conforming toBS EN 10088-1 with a minimum chromium content of 13%.4.3.4 SealingsStem sealings shall be of one of the following two types:a) toroidal sealing ring (“O” ring) type; orb) other pressure actuated types of seal.Stem seals located within the pressure retaining body of the valve shall bemaintainable, in situ, while mounted in a chamber with a surface box frame andcover in accordance with Clause 14, an
