1、BRITISH STANDARD BS1968:1953 Incorporating Amendment Nos.1and2 Specification for Floats for ballvalves (copper) CONFIRMED DECEMBER 2007BS1968:1953 This British Standard, having been approved by the Sanitary Appliances Industry Standards Committee and endorsed by theChairman of the Building Divisiona
2、l Council, was publishedunder the authority ofthe General Council on 8May1953 BSI 10-1999 ISBN 0580355799 Co-operating organizations The Sanitary Appliances Industry Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Govern
3、ment departments and scientific and industrial organizations: Admiralty Metal Sink Manufacturers Association British Bath Manufacturers Association Ministry of Housing and Local Government* British Ironfounders Association* Ministry of Works* British Plastics Federation National Brassfoundry Associa
4、tion* British Sanitary Earthenware Manufacturers National Federation of Building Trades Association Employers British Sanitary Fireclay Association National General Export Merchants Group British Waterworks Association* Royal Institute of British Architects* D.S.I.R.Building Research Station* Royal
5、Institute of Chartered Surveyors Flushing Cistern Makers Association* Royal Sanitary Institute* Institute of Plumbers* Sanitary Inspectors Association Institution of Municipal Engineers* Scottish Federation of Plumbers and Domestic Institution of Sanitary Engineers Engineers (Employers) Associations
6、 London County Council Water Companies Association* The Government departments and scientific and industrial organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: Assoc
7、iated Master Plumbers and Domestic Crown Agents for the Colonies Engineers Distributors of Builders Supplies Joint Council Association of Heating, Ventilating and Electric Water Heater Manufacturers Domestic Engineering Employers Association British Electrical Development Association Institute of Br
8、itish Foundrymen British Electrical and Allied Manufacturers Institution of Gas Engineers Association Institution of Heating and Ventilating British Non-Ferrous Metals Research Engineers Association Institution of Water Engineers Building Industries National Council London Chamber of Commerce B.W.A.
9、 Licensees Association Metropolitan Water Board Copper Ball Manufacturers Association Society of British Gas Industries Copper Tube Fittings Manufacturers Urban District Councils Association Association Amendments issued since publication Amd. No. Date of issue Comments 3220 November 1958 4667 Septe
10、mber 1962 Indicated by a sideline in the marginBS1968:1953 BSI 10-1999 i Contents Page Co-operating organizations Inside front cover Foreword ii 1 Scope 1 2 Definitions 1 3 General 1 4 Materials 1 5 Jointing of copper floats 1 6 Floats other than spherical 2 7 Bosses and fitments 2 8 Tolerances 2 9
11、Tests 2 10 Marking 2 Appendix Information to be supplied by the purchaser 3 Table 1 Spherical copper floats 4 Table 2 Classification of bosses for use with classes A, B and C floats 5 Table 3a Bosses for classes A and C floats with soldered and brazed joints 6 Table 3b Bosses for class B floats with
12、 solderless joints 7 Table 4 Weight of boss for classes A and C floats and of boss and fitments for class B floats 8 Table 5 Assembled weight of spherical copper floats including solder or other jointing material 8BS1968:1953 ii BSI 10-1999 Foreword This standard makes reference to the following Bri
13、tish Standards: BS84, Screw threads of Whitworth form. BS218, Brass bars and sections (suitable for forging) and drop forgings. BS219, Soft solders. BS427, Tables of diamond pyramid hardness numbers. BS899, Cold rolled copper sheets and strip (half-hard and annealed) for general purposes. BS1212, Ba
14、llvalves (“Portsmouth” type) excluding floats. BS1400, Copper alloy ingots and castings. BS1845, Filler alloys for brazing (silver solders and brazing solders). This British Standard specifies requirements for copper floats for use with ballvalves and has been issued to facilitate the manufactureas
15、separate items, to be purchasable as suchof floats suitable for ballvalves complying with the requirements of BS1212, “Ballvalves (“Portsmouth” type)” and other types of ballvalve requiring floats of this description. Reference should be made to BS1212 for permissible alternative types of float for
16、use with ballvalves complying with that specification. For information regarding the correct size of float to use for a particular size of ballvalve, or range of pressure, where the leverage exerted is not less than that specified in BS1212, reference should be made to Table 2 of this standard and a
17、lso to BS1212. A British Standard does not purport to include all the necessary provisions of a contract. Users of British 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 docu
18、ment comprises a front cover, an inside front cover, pagesi andii, pages1 to8, an inside back cover and a back cover. This 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.BS1968:1953 BSI
19、10-1999 1 1 Scope This British Standard specifies requirements for a range of spherical copper floats of4 1 / 2 ,5,6,7,8,9,10,11 and12inches nominal diameter suitable for attachment to the ballvalves specified in BS1212 and to ballvalves the leverage of which for the same bore of seat is not less th
20、an that specified in BS1212, in the following classes: Class A. Floats of all sizes with soldered joints. Class B. Floats of all sizes with solderless joints. Class C. Floats of all sizes with brazed, welded or silver-soldered joints. Performance requirements relating to floats of a shape other than
21、 spherical are also included. 2 Definitions For the purposes of this British Standard the following definitions shall apply: 2.1 volume the volume of water in cubic inches, taken to the nearest cubic inch, displaced when the shell (floatwith no boss) is completely immersed 2.2 free-floating, volume
22、the volume of water in cubic inches, taken to the nearest cubic inch, displaced when the shell (floatwith no boss) is resting on water 2.3 useful volume half the volume (see definition 2.1 above) less the free-floating volume (see definition 2.2 above) taken to the nearest cubic inch 2.4 lifting eff
23、ort the useful volume (see definition 2.3 above) converted into weight in pounds at the rate of0.036lb. per cubic inch (Shown calculated in Table 1 for the minimum weight of shell.) 2.5 maximum immersed operating depth the point at which the volume (see definition 2.1 above) is equally above and bel
24、ow the surface of the water 2.6 diameter of spherical floats the average outside diameter of the shell measured at two axes at right angles to each other and clear of the jointing seam 3 General The shells of copper floats shall comply with the requirements of Clauses4, 5, 6, 8, 9 and10, and shall b
25、e of the dimensions and weights given in Table 1. They shall be fitted with bosses complying with the requirements of Clause7 and Table 2, Table 3a, Table 3b and Table 4. The complete float shall comply with the weight requirements of Table 5 and shall not be artificially loaded for this purpose. Af
26、ter manufacture, the copper used for floats shall be left in a planished, condition and shall have a minimum Vickers hardness (HV) of70 at any one point when tested with a5kgf load applied in accordance with the requirements of BS427-1 1)Table3. 4 Materials The chemical, composition of the materials
27、 of which the float is made shall be not less suitable than that laid down in the following British Standards: a) Copper for the shell: BS899, “Cold rolled copper sheets and strip for general purposes”. b) Alloy for cast bosses: BS1400, “Copper alloy ingots and castings”. Complying with either Speci
28、fication BS1400-B1-C for brass castings or for Specification BS1400-LG2-C for leaded gunmetal castings. c) Alloy for hot pressed bosses: BS218, “Brass bars and sections (suitable for forging) and drop forgings”. d) Solder: BS219, “Soft solders”, complying with Type F, Table 2, “Non-antimonial solder
29、s” or BS1845, “Filler alloys for brazing”, complying with the requirements for silver bearing brazing alloy, Types4 or5 or with the requirements for brazing brasses, Grades8,9 or10. 5 Jointing of copper floats The jointing of the shells shall be in accordance with one of the methods given below, pro
30、vided that when floats are required for use in water at a temperature exceeding37.8 C. (100 F.) they shall be jointed as specified for Class C. The purchaser shall specify the method of jointing required. The methods of jointing are as follows: Class A floats. An efficient, burnished, lapped and sol
31、dered seam. 1) BS427, “Method for Vickers hardness test”, Part1, “Testing of metals”.BS1968:1953 2 BSI 10-1999 Class B floats. An efficient, solderless, compressed seam with a jointing ring of rubber or other equally suitable material, either extending right through the joint or otherwise arranged t
32、o prevent the joint ring from extruding into the shell and thus unsealing the joint. Class C floats. A brazed, bronze welded or silver-soldered joint. 6 Floats other than spherical Floats of a shape other than spherical shall have a “lifting effort” at least equal to that of a spherical float intend
33、ed for the same duty, as given in Table 1, and shall be not less robust. 7 Bosses and fitments Bosses shall be either: a) Brass (pressed or forged). b) Cast brass (die cast or sand cast). c) Cast gunmetal. Fitments (rivets and washers or like methods of attachment) for Class B floats shall be either
34、: a) Copper for rivets or washers. b) Brass for washers only. Every boss shall comply with one of the classifications set out in Table 2 and shall be in accordance with the appropriate dimensions given in Table 3a or Table 3b. The bottom of the tapped hole shall not extend through the flange. Spheri
35、cal floats of all diameters shall be fitted with the appropriate size of tapped boss set out in Table 2, except that when so ordered the size of the tapping may be varied to suit special conditions. The boss shall be fitted to the shell in the following manner: Class A floats. The boss shall be loca
36、ted centrally astride the seam and shall be properly soldered to the shell. The soldering shall extend across the full width (see Dimension “H”, Table 3a) of the edge of the flange. A slot shall be cut in the flange of the boss to accommodate the seam of the shell. Class B floats. The boss shall be
37、in accordance with Table 2 and Table 3b. The flange shall be non-recessed; it shall be shaped to suit the curved face of the shell, to which it shall be securely fixed, on an axis at right angles to the plane of the seam, by riveting or other equally efficient method. Class C floats. The alloy of wh
38、ich the boss is made shall be suitable for brazing. The boss shall be located centrally astride the seam and properly brazed to the shell. The brazing shall extend across the full width (see Dimension “H”, Table 3a) of the edge of the flange. A slot shall be cut in the flange of the boss to accommod
39、ate the seam of the shell. 8 Tolerances a) The volume of the shell shall be as given in Table 1, for each size, with a tolerance of5percent. b) The minimum weights of copper shells of Classes A, B and C shall be as set out in Table 1. c) The weight and dimensions (excluding Dimension A) of bosses sh
40、all be as set out in Table 3a, Table 3b and Table 4 with a tolerance of5percent. Dimension A shall be in accordance with the requirements of BS84, “Screw threads of Whitworth form”. d) The minimum assembled weight of completed spherical floats, including solder or other jointing material, shall be a
41、s set out in Table 5, subject to the tolerances permitted under a), b) and c) above. 9 Tests Every finished float shall be tested by immersion for not less than two minutes, in water having a temperature of not less than17 C. (30 F.) above the temperature of the surrounding air. There shall be no le
42、akage of air from the float when so immersed. 10 Marking 2) Every float supplied as being in accordance with this British Standard shall be legibly and permanently marked with the information indicated below, in such a manner as not to damage or distort the float: a) Manufacturers name or trade mark
43、. b) The number of this British Standard, i.e.BS1968. 2) A joint arrangement has been made between the British Waterworks Association and the BSI under which ballvalve floats made to this specification may be certified as complying with its provisions. Details of the conditions under which licences
44、are issued for the use of the appropriate certification marks may be obtained from the Association, at34 Park Street London, W.1. and from the British Standards Institution, at2 Park Street, London, W.1.BS1968:1953 BSI 10-1999 3 Appendix Information to be supplied by the purchaser The purchaser shal
45、l supply the following information when making an enquiry, or placing an order: a) Size and class of floats required. b) The material for jointing, if Class C floats are required. c) The appropriate tapping of boss required (seeTable 2 and Clause7).BS 1968:1953 4 BSI 10-1999 Table 1 Spherical copper
46、 floats Nominal outside diameter of float Volume of sphere Class A Class B Class C Weight of shell (min.) Free floating volume Useful volume Lifting effort Weight of shell (min.) Free- floating volume Useful volume Lifting effort Weight of shell (min.) Free floating volume Useful volume Lifting effo
47、rt in. 4 1 / 2 5 6 7 8 9 10 11 12 cu. in. 48 65 113 180 268 382 524 697 905 lb. 0.25 0.328 0.476 1.074 1.425 1.782 2.197 2.755 3.207 cu. in. 7 9 13 30 40 50 61 77 89 cu. in. 17 23 43 60 94 141 201 271 363 lb. 0.61 0.84 1.56 2.16 3.38 5.07 7.23 9.75 13.06 lb. 0.25 0.328 0.476 1.074 1.425 1.782 2.197
48、2.755 3.207 cu. in. 7 9 13 30 40 50 61 77 89 cu. in. 17 23 43 60 94 141 201 271 363 lb. 0.61 0.84 1.56 2.16 3.38 5.07 7.23 9.75 13.06 lb. 0.39 0.515 0.843 1.187 1.875 2.06 3.62 4.21 4.85 cu. in. 11 14 23 53 52 57 100 117 135 cu. in. 13 18 33 57 82 134 162 231 317 lb. 0.46 0.65 1.19 2.05 2.95 4.82 5.
49、83 8.31 11.41 NOTEThe lifting effort figures are calculated for the minimum weight of shell in each class.BS1968:1953 BSI 10-1999 5 Table 2 Classification of bosses for use with classes A, B and C floats Classification No. of boss Dia. of flange BS Whit. tapping Appropriate float diameter (ifspherical) Sizes of BS1212 aballvalve bodies with which floats are to be used 1 2 3 in. 1min. 1 7 / 16 1 3 / 4 in. 5 / 16 5 / 16 5 / 16 in. 4 1 / 2and5 6 7 in. 3 / 8 , 1 / 2and 3 / 4 3A 4 1 3 / 4 2 1 / 4 7 / 16 7 / 16 6 and7 8 and9 1 4A 5
