BS 2879-1980 Specification for draining taps (screw-down pattern)《排水旋塞(下旋式)规范》.pdf

1、BRITISH STANDARD BS2879:1980 Incorporating Amendment Nos. 1, 2, and 3 Specification for Draining taps (screw-down pattern) UDC 621.646.652 CONFIRMED DECEMBER 2007BS2879:1980 This British Standard, having been prepared under the directionof the Building ServicesStandards Committee, was published unde

2、r the authorityof the Executive Boardand comes into effect on 31January1980 BSI 08-1999 First published July1957 First revision January1980 The following BSI references relate to the work on this standard: Committee reference SEB/2 Draft for comment78/11626 DC ISBN 0580 11137 7 Cooperating organizat

3、ions The Building Services Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: The organizations marked with an asterisk in the above list, together with the

4、following, were directly represented on the committee entrusted with the preparation of this British Standard: Association of District Councils Domestic Solid Fuel Appliances Approval Bath Manufacturers Co-ordinating Committee Scheme British Gas Corporation* Environmental Health Officers Association

5、 British Ironfounders Association Greater London Council British Plastics Federation* Heating and Ventilating Contractors British Plumbing Employers Council Association* British Precast Concrete Federation Ltd Incorporated Association of Architects and Builders Merchants Federation* Surveyors Buildi

6、ng Services Research and Information Institute of Plumbing* Association Institution of Gas Engineers* Chartered Institution of Building Services* Institution of Municipal Engineers Clay Pipe Development Association Limited Institution of Public Health Engineers* Consumer Standards Advisory Committee

7、 Institution of Structural Engineers of BSI* Institution of Water Engineers and Scientists* Convention of Scottish Local Authorities National Brassfoundry Association* Council of British Ceramic Sanitaryware National Coal Board Manufacturers* National Federation of Building Trades Department of Heal

8、th and Social Security Employers Department of the Environment (PSA)* National Water Council* Department of the Environment Building Royal Institute of British Architects* Research Establishment* Royal Institution of Chartered Surveyors Department of the Environment Housing Royal Society of Health a

9、nd Construction Scottish Development Department Department of the Environment Water Trades Union Congress Engineering Division including Water Water Companies Association* Data Unit* Association of Gas Equipment Manufacturers Institution of Production Engineers and Contractors National Association o

10、f Plumbing, Heating and Association of Manufacturers of Domestic Mechanical Services Contractors Electrical Appliances Plastic Bath Manufacturers Association BOF Metals Technology Centre South London Consortium British Bath Manufacturers Association Thames Water Authority Metropolitan Water British

11、Valve Manufacturers Association Ltd Division Copper Tube Fittings Manufacturers Water Research Centre Association Department of Prices and Consumer Protection Metrology Quality Assurance and Standards Division Amendments issued since publication Amd. No. Date of issue Comments 3715 July 1981 4595 Se

12、ptember 1984 5477 June 1988 Indicated by a sideline in the marginBS2879:1980 BSI 08-1999 i Contents Page Cooperating organizations Inside front cover Foreword ii Section 1. General 1 Scope 1 2 References 1 3 Definition 1 4 Materials 1 5 Marking 1 Section 2. Design requirements 6 Nominal size 1 7 Pat

13、tern 1 8 General requirements 2 9 Seating 2 10 Washer plate 2 11 Lockshield 3 12 Keys 3 13 Inlet ends 3 14 Outlet ends 3 Section 3. Materials and dimensions 15 Castings 3 16 Hot pressings 3 17 Dimensions 3 Section 4. Test requirements 18 Hydraulic type tests 5 Figure 1 Screw-down pattern draining ta

14、p: typical design 2 Figure 2 Dimensions of draining tap bodies 3 Figure 3 Dimensions of draining tap spindle, washer plate, washernutandkey 5 Figure 4 Dimensions of draining tap gland and lockshield 6 Table 1 Dimensions of draining tap bodies 3 Table 2 Dimensions of draining tap spindle, washer plat

15、e, washernutandkey 4 Table 3 Dimensions of draining tap gland and lockshield 5 Table 4 Test requirements for ethylene propylene rubber for type 2 washers 6 Publications referred to Inside back coverBS2879:1980 ii BSI 08-1999 Foreword This revision of this British Standard has been prepared under the

16、 direction of the Building Services Standards Committee following a request by the Department of the Environment to conform to impending changes in regulations. Although it is recognised that other types and sizes of draining tap are used, it is thought that the screw-down pattern in1/2 and3/4 nomin

17、al sizes are the most satisfactory in service and this standard is accordingly limited to that pattern and size range. The opportunity has been taken to metricate and up-date where necessary. A British Standard does not purport to include all the necessary provisions of a contract. Users of British

18、Standards 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, pages i and ii, pages1 to 6, an inside back cover and a back cover. Th

19、is standard 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.BS2879:1980 BSI 08-1999 1 Section 1. General 1 Scope This British Standard specifies requirements for copper alloy bodied taps used for

20、draining hot and cold water installations and heating systems. It covers nominal sizes of1/2 and3/4 only for use with water: a) up to70 C with occasional excursions up to90 C max.for period of1h (type1); b) up to a maximum of120 C (type2). 2 References The titles of the publications referred to in t

21、his standard are listed on the inside back cover. 3 Definition 3.1 nominal size the nominal size of the draining tap is the size of the inlet connection 4 Materials The chemical composition of the various copper alloys and materials for component parts shall be not less suitable than those specified

22、 in the following British Standards, and they shall be corrosion resisting, free from toxic substances and shall not foster microbial growth nor give rise to taste, odour, cloudiness or discoloration of the water with which they are or could be in contact. NOTEAttention is drawn to Water Authorities

23、 Association requirements in this respect. a) Brass (cast), excluding diecasting, for bodies and components: alloys SCB1 or SCB3 in accordance with BS1400. b) Brass gravity diecastings for bodies and components: alloy DCB3 in accordance with BS1400. c) Brass pressure diecastings for bodies and compo

24、nents: alloy PCB1 in accordance with BS1400. d) Gunmetal (cast) for bodies and components: alloys LG1- or LG2-in accordance with BS1400. e) Brass for hot pressings for bodies and components: alloy CZ122 in accordance with BS2872. f) Brass rod for spindles, glands, washer plates, nuts etc.: alloy CZ1

25、22 in accordance with BS2872 or alloy CZ121 in accordance with BS2874. g) Dezincification resistant brasses: alloy CZ132 1)in accordance with BS2872. h) Rubber for washers: for type1: in accordance with clause6 of BS3457:1973. for type 2: ethylene propylene suitable for use with water at120 C, compl

26、ying with the minimum requirements given inTable 4. i) Rubber for sealing rings: for type1: ethylene propylene or silicone in accordance with Appendix B of BS2767:1972, or high nitrile. for type2: ethylene propylene in accordance with Appendix B of BS2767:1972. j) Plastics for washer plates: for typ

27、e1 only: acetal copolymer in accordance with9.4 of BS5412/BS5413-5:1976. 5 Marking Every draining tap supplied as being in accordance with this British Standard shall be legibly and permanently marked with the following information: a) nominal size; b) manufacturers name or identification mark; c) t

28、he number of this British Standard followed by the temperature rating type, e.g.BS2879-1, BS2879-2; d) 1/2 taps when fitted with3/8 washer shall be marked with the letter “S” after the size e.g.1/2 S. NOTEMarking BS2879 on or in relation to a product is a claim by the manufacturer that the product h

29、as been manufactured in accordance with the requirements of the standard. The accuracy of such a claim is therefore the manufacturers sole responsibility. Enquiries as to the availability of third party certification to support such claims should be addressed to the Director, British Standards Insti

30、tution, Maylands Avenue, Hemel Hempstead, Herts HP24SQ in the case of certification marks administered by BSI or to the appropriate authority for other certification marks. Section 2. Design requirements 6 Nominal size There shall be two nominal sizes of draining tapsi.e.1/2 and3/4. 7 Pattern Draini

31、ng taps shall be of the screw-down pattern as shown inFigure 1. 1) Incorporated in BS2872 by Amendment No.1 which is in course of preparation.BS2879:1980 2 BSI 08-1999 The1/2 tap shall be fitted with a1/4 washer as defined in columns3 and4 ofTable 1, Table 2 andTable 3 or a3/8 washer as defined in c

32、olumns5 and6 ofTable 1, Table 2 andTable 3. The1/4 washer shall be supplied unless the3/8 washer is specifically ordered. The3/4 tap shall be fitted with a1/2 washer as defined in columns7 and8 ofTable 1, Table 2 andTable 3. An undercut used for securing the washer plate (to lift with the spindle) s

33、hall have a diameter of not less than80% of the minimum diameter of the washer plate stem. 8 General requirements Draining taps manufactured to the requirements of this standard shall be operated by a key located on a square on the top of a screwed spindle. The spindle shall be fitted with a renewab

34、le, non-metallic washer at its lower end which shuts, against the water pressure, on a seating at right angles to the axis of the spindle. Spindles shall be fitted with a toroidal “O” ring for sealing which shall be accessible for maintenance or replacement. All draining taps shall be fitted with a

35、gland or lockshield to prevent the removal of the spindle during normal operation. A sealing device shall be provided between body and gland or lockshield if necessary. The body, spindle and other parts shall be such that when assembled, the parts are coaxial and provide freedom of spindle rotation.

36、 The surfaces shall be smoothly finished within the limits of size specified. When the valve is fully open it shall provide a minimum lift to the washer of4.5mm and6mm for the1/2 and3/4 nominal sizes respectively (thereby giving an unrestricted waterway). When the tap is in the normally closed posit

37、ion, the whole of the square section on top of the spindle shall be above the top of the gland, or the base of the lockshield recess if fitted 9 Seating The body of the tap shall have a machined integral seating, which may be flat or raised at the option of the manufacturer. The arris or arrises of

38、the seating shall be rounded as shown inFigure 2. 10 Washer plate The washer plate with its stem and stud for the attachment of the washer shall be made in one piece. The stud shall either be screwed and provided with a locknut, or, if not screwed, shall be of such shape and size as will prevent the

39、 washer from becoming detached under working conditions. The washer plate shall be free to rotate in the hole in the spindle and shall be so secured as to lift with the spindle. The washer plate shall be true all over and if a casting, it shall be machined all over. If the seating of the tap is rais

40、ed (see clause9) the washer plate shall be of either the shrouded or unshrouded type. The depth of shrouding shall not exceed the minimum thickness of the washer when new as specified inTable 2, line Q. With the washer resting on the seating the clearance between the leading edge of the shroud and t

41、he seat recess shall not be less than the minimum washer thickness. Figure 1 Screw-down pattern draining tap: typical designBS2879:1980 BSI 08-1999 3 11 Lockshield Where a lockshield is provided, it shall be designed so that the top of the spindle, when in the closed position, does not protrude abov

42、e the shield. 12 Keys Lockshield, spindle squares and keys when supplied shall comply with the dimensions specified in Table 2 andTable 3. 13 Inlet ends The inlet end of the draining tap shall be screwed externally either with a thread complying with the requirements of BS2779, class B, or, when so

43、ordered, with a taper thread complying with the requirements of BS21. Either a hexagonal or octagonal shoulder shall be provided on the body adjacent to the screwed portion (seeTable 1), or compression or capillary ends complying with the requirements of BS864-2 shall be fitted. 14 Outlet ends The o

44、utlet end of the draining tap shall be formed with external serrations or other means of affording a grip for attachment of a hose of the same nominal size bore. In all other respects the taps shall comply with the relevant dimensions specified inTable 1. Section 3. Materials and dimensions 15 Casti

45、ngs Castings shall be in all respects sound, free from laps, blow holes and pitting. Both the external and internal surfaces shall be clean, smooth and free from sand. Castings shall be neatly dressed and shall not be burned, plugged, stopped or patched. 16 Hot pressings All hot-pressed components s

46、hall be sound and solid, without laminations, and shall be smooth and well finished. 17 Dimensions The dimensions of draining taps shall be as given inFigure 2, Figure 3 andFigure 4 andTable 1, Table 2 andTable 3. Table 1 Dimensions of draining tap bodies (seeFigure 2) Figure 2 Dimensions of drainin

47、g tap bodies(see Table 1) All dimensions are in millimetres unless otherwise stated. Reference letter Dimension Nominal size of tap 1/2 3/4 1/4 washer 3/8 washer 1/2 washer max. min. max. min. max. min. A Bore of seating 9.6 9.4 11.4 9.6 14.4 14.1 B Wall thickness (minor diameter to bore) 3.0 2.0 3.

48、0 2.0 3.0 2.0 C Size across flats of hexagon or octagon 24.0 24.0 32.0 D Radius of arris on flat or raised seat 0.8 0.2 0.8 0.2 0.8 0.2 E Inlet thread length (for parallel thread only) 12.0 12.0 15.0 F Length of outlet nose 35.0 35.0 50.0 G Length of serration 15.0 15.0 18.0 H Outlet outside diamete

49、r 14.0 14.0 20.5 J Outlet bore 9.8 9.3 9.8 9.3 14.5 14.0BS2879:1980 4 BSI 08-1999 Table 2 Dimensions of draining tap spindle, washer plate, washer nut and key (seeFigure 3) All dimensions are in millimetres unless otherwise stated. Reference letter Dimension Nominal size of tap 1/2 3/4 1/4 washer 3/8 washer 1/2 washer max. min. max. min. max. min. A Bore for washer plate stem 4.22 4.01 5.13 4.93 5.94 5.74 B Depth of hole for washer plate stem 14.8 13.7 18.8 17.2 18.8 17.2 C Washer plate clearance 0.8 0.8 0.8 D Length of spindle thread