1、BRITISH STANDARD BS7357:1990 Specification for 7.5 L WC flushing cisternsBS7357:1990 This British Standard, having been prepared under the directionof the Building ServicesStandards Policy Committee, was published underthe authority of the BoardofBSI and comes into effect on 31 October1990 BSI 04-19
2、99 The following BSI references relate to the work on this standard: Committee reference SEB/1 Draft for comment88/14136DC ISBN 0 580 18948 1 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Building Services Standards Policy Committee (S
3、EB/-) to Technical Committee SEB/1, upon which the following bodies were represented: British Bathroom Council British Plastics Federation Clay Pipe Development Association Limited Consumer Policy Committee of BSI Department of Health Department of the Environment (Building Research Establishment) D
4、epartment of the Environment for Northern Ireland Department of the Environment (Property Services Agency) Institute of Clerks of Works of Great Britain Inc. Institute of Plumbing Institute of Vitreous Enamellers Institution of Environmental Health Officers Institution of Water and Environmental Man
5、agement Metal Sink Manufacturers Association Royal Institute of British Architects Vitreous Enamel Development Council Water Services Association of England and Wales Amendments issued since publication Amd. No. Date CommentsBS7357:1990 BSI 04-1999 i Contents Page Committees responsible Inside front
6、 cover Foreword ii Section 1. General 1 Scope 1 2 Definitions 1 3 Marking 1 Section 2. Materials and design 4 General corrosion resistance for components 2 5 Cistern shells 2 6 Soft solder 2 7 Hard solder 2 8 Flushing apparatus 2 9 Volume of discharge per flush 3 10 Rate of flush discharge 3 11 Wate
7、r line 3 12 Spill-over level 3 13 Warning pipe connections 3 14 Float operated valves 3 15 Covers 4 Section 3. Construction 16 Shell 5 17 Operating mechanism 5 18 Flush pipe connection 5 Section 4. Flush pipes 19 Materials, construction and ends 6 20 Flush pipes for use with cisterns at high level 6
8、 21 Flush pipes for use with cisterns at low level 6 Appendix A Options: information to be supplied by the purchaser 7 Appendix B Distortion test 7 Appendix C Front thrust test 7 Appendix D Flushing apparatus torque test 7 Appendix E Volume of discharge test 7 Appendix F Rate of discharge test 8 App
9、endix G Warning pipe connection test 9 Appendix H Dead load test on operating mechanism 9 Figure 1 Illustration of effective warning water level 10 Figure 2 High level flush pipes 11 Figure 3 Front thrust test apparatus 12 Figure 4 Flushing apparatus stainless steel test spacer 13 Figure 5 Test flus
10、h pipe for low level cistern 14 Figure 6 Fluid level sensing device 14 Figure 7 Warning pipe stainless steel test spacer 15 Publications referred to Inside back coverBS7357:1990 ii BSI 04-1999 Foreword This British Standard has been prepared under the direction of the Building Services Standards Pol
11、icy Committee and is complementary to BS1125, which specifies requirements for flushing cisterns designed to have a9L flushing capacity. 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
12、. 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 and ii, pages1 to16, an inside back cover and a back cover. This standard has been updated (see copyright date) and ma
13、y have had amendments incorporated. This will be indicated in the amendment table on theinside front cover.BS7357:1990 BSI 04-1999 1 Section 1. General 1 Scope This British Standard specifies requirements for7.5L maximum single flush, exposed and concealed WC flushing cisterns with a side inlet or b
14、ottom inlet supplied with a float operated valve, a valveless siphon for high level, low level, and close coupled applications together with the necessary flush pipes. Information to be supplied by the purchaser at the time of enquiry and/or order is listed in Appendix A. Requirements for float oper
15、ated valve assemblies and methods of fixing cisterns are not specified in this standard. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2 Definitions For the purposes of this British Standard the following definitions apply. 2.1 spill-over level
16、the level at which water in the flushing cisterns will first spill over if the rate of inflow exceeds the rate of outflow through the warning pipe 2.2 warning pipe an overflow pipe with its outlet, whether inside or outside a building, in a conspicuous position where the discharge of water can be re
17、adily seen 2.3 water line a level marked inside the cistern to indicate the highest water level at which the float operated valve is adjusted to shut off 2.4 effective warning water level the level when water reaches10mm above the invert of a side entry connection warning pipe or10mm above the overf
18、low level of a bottom connecting warning pipe (see Figure 1) 2.5 concealed cistern a cistern that is not normally visible after installation 3 Marking 3.1 Cisterns shall be permanently marked with the following: a) the manufacturers name or identification mark; b) the number of this British Standard
19、, i.e.BS7357 1) . NOTEFor the purposes of this standard, marking by means of a label complying with BS4781 is considered to be permanent. 3.2 Cisterns intended only for concealed use shall be marked: “For concealed use only”. NOTEThe purchaser should state at the time of enquiry and/or order the typ
20、e of cistern required (see Appendix A). Marking shall be capable of being seen after the installation of the cistern and before any cover is fitted. 1) Marking BS7357 on or in relation to a product represents a manufacturers declaration of conformity, i.e.a claim by or on behalf of the manufacturer
21、that the product meets the requirements of the standard. The accuracy of the claim is therefore solely the responsibility of the person making the claim. Such a declaration is not to be confused with third party certification of conformity, which may also be desirable.BS7357:1990 2 BSI 04-1999 Secti
22、on 2. Materials and design 4 General corrosion resistance for components Cistern shells, siphons and associated components shall be manufactured from materials which under the conditions of use are either: a) non-corroding, e.g.plastics; b) protected against the types of corrosion caused by the acti
23、on on them of the water with which the cistern is to be used; c) highly resistant to corrosion by the action of the water with which the cistern is to be used, i.e.they corrode only at a rate which is insufficient to affect adversely the durability or efficiency of the cistern. NOTEThe purchaser sho
24、uld state at the time of enquiry and/or order the materials of manufacture (see Appendix A). Before dissimilar metals are used in the construction of a cistern, the manufacturer shall ensure the avoidance of possible electrolytic action. 5 Cistern shells 5.1 Ceramic ware cisterns NOTESee also clause
25、s14, 15 and16. 5.1.1 The shell thickness of ceramic ware cisterns shall comply with either5.1.2, 5.1.3 or5.1.4 as appropriate; in addition vitreous china cisterns shall comply with BS3402. 5.1.2 All ceramic ware cisterns, except vitreous china, shall have a minimum thickness of12mm. 5.1.3 Vitreous c
26、hina cisterns shall have a minimum thickness of10mm, except as described in5.1.4. 5.1.4 Vitreous china cisterns with an internal width of less than365mm, measured at the effective warning water level, shall have a minimum thickness of6min. 5.2 Stainless steel cisterns NOTESee also clauses14, 15 and1
27、6. 5.2.1 Stainless steel cisterns shall be manufactured from one of the following grades of austenitic steel:304S11,304S15,304S16 or304S31, selected from BS1449-2, having a minimum thickness of1.2mm before forming. 5.2.2 Steel cisterns shall have no sharp edges. 5.2.3 Steel cisterns shall have all j
28、oints continuously welded. 5.3 Rubber compound and plastics cisterns NOTESee also clauses14, 15 and16 5.3.1 General Plastics materials and rubber compounds shall be such that, when assembled, the cistern shall comply with5.3.2 to5.3.4. 5.3.2 Appearance 5.3.2.1 Cisterns shall be free from blisters an
29、d delaminations. 5.3.2.2 Exposed cisterns shall be reasonably free from flow lines, streaking or unintended colour variations on surfaces visible after installation. 5.3.3 Distortion resistance When tested in accordance with Appendix B, cisterns shall not distort outwards by more than6mm and the cov
30、er shall not be dislodged. 5.3.4 Exposed cisterns only 5.3.4.1 Colour fastness to light When tested in accordance with BS2782:Method540B the colour fastness to light of the cistern and cover shall be not less than No.5. 5.3.4.2 Opacity When tested in accordance with BS2782:Method1104A, the cistern a
31、nd cover shall not transmit more than10% of the visible light falling on them. 5.3.4.3 Front thrust test for low level and close coupled suite cisterns When tested as described in Appendix C, the complete cistern shall not distort to such an extent that any part becomes detached or inoperative. 6 So
32、ft solder Any soft solder used in the construction of siphons or associated components shall be of grade F or J as given in Table1 of BS219:1977. 7 Hard solder Any hard solder or filler alloy used in the construction of siphons or associated components shall be of copper-silver-phosphorus or other c
33、orrosion resistant alloy, in accordance with type CP2 or CP3 of BS1845. 8 Flushing apparatus Cisterns shall be supplied with an efficient flushing apparatus of valveless siphonic type which prevents the waste of water. The apparatus shall be capable of flushing directly the mechanism is operated, wh
34、en the water is at the water line, and shall be so constructed that water cannot flow down the flush pipe other than while a flush is being properly delivered. Flushing apparatus shall be detachable from the shell and suitable means shall be provided for ensuring and maintaining a watertight joint.B
35、S7357:1990 BSI 04-1999 3 When tested as described in Appendix D the assembly shall be capable of being dismantled and reassembled. The underside of the bend in the siphon pipe (the siphon invert) or, in the case of the dome pattern, the top of the straight discharge pipe, shall be at such a height t
36、hat no water runs down the flush pipe when the water level is raised to the spill-over level after temporarily closing the warning pipe connection. Any servicing joint in the down leg of a siphon shall be above the effective warning water level. 9 Volume of discharge per flush When tested as describ
37、ed in Appendix E, cisterns shall discharge7.5+0.0,1.0L. 10 Rate of flush discharge When tested as described in Appendix F cisterns shall discharge the flush at the following rate: NOTECisterns intended for close coupled use will be tested as for low level. 11 Water line The water level shall be mark
38、ed permanently inside the cistern in such a position that it is easily visible to a person adjusting the water level. 12 Spill-over level The spill-over level of the cistern shall be not less than60mm above the water line (see Figure 1). 13 Warning pipe connections 13.1 General Each cistern shall be
39、 provided with a warning pipe connection so arranged that the invert of a side connection type or the overflowing level of a bottom connection type is not less than25mm or not more than32mm above the water line. NOTEThe purchaser should state at the time of enquiry and/or order whether the warning p
40、ipe and the inlet are to have a side or bottom connection (see Appendix A). Each cistern shall be supplied with a warning pipe connection or a warning stand pipe of not less than19mm internal diameter throughout. 13.2 Bottom warning pipe connection 13.2.1 Metal warning stand pipes Warning stand pipe
41、s of metal shall be of either copper, copper alloy or stainless steel. If made of copper, they shall comply with Tables X or Z of BS2871-1:1971. If made of copper alloy, they shall have a minimum thickness of1mm, if made of stainless steel they shall have a minimum thickness of0.5mm. They shall be b
42、razed, hard soldered or welded at the lower end to a flanged nipple of not less than35mm diameter, and shall be provided with a backnut and washer. 13.2.2 Plastics warning stand pipes Warning stand pipes of plastics material shall be either integral with, or welded to, a flanged nipple at the lower
43、end and shall be provided with a backnut and washer. They shall have a minimum thickness of1.2mm except at the counterbore at the threaded outlet end of the pipe where the thickness under the root of the thread shall be not less than0.9mm. NOTEThe minimum thickness of0.9mm is necessary because of th
44、e small difference between the outside diameter of22mm pipe and the root diameter of the G# thread as specified in BS2779. 13.3 Side warning pipe connection Side connection cisterns shall be supplied with a union, for the connection of a warning pipe complete with a backnut. The union shall be manuf
45、actured from copper, copper alloy, stainless steel or plastics materials. NOTEFor frost precaution recommendations see the commentary and recommendations of10.3.4 of BS6700:1987. 13.4 Torque testing When tested in accordance with Appendix G, the assembly shall be capable of being dismantled and reas
46、sembled. 14 Float operated valves 14.1 Every cistern shall be supplied with a nominal size float operated valve complying with BS1212- 2 or BS1212-3 2)fitted with a type114S or114NS float complying with either BS2456 or a valve listed under the UK Water Fittings Byelaws Scheme. 14.2 The float operat
47、ed valve assembly supplied shall be such that the function of any part is not impaired by the cistern shell or any internal components. a) low level or close coupled : 1.6L/s minimum; b) high level : 2.0L/s minimum. 2) BS1212-4 specifying compact type float operated valves is in preparation.BS7357:1
48、990 4 BSI 04-1999 15 Covers Cisterns shall be provided with a removable cover. The cover and any screws, bolts or other component parts for fixing it shall comply, whether fitted internally or externally, with the corrosion resistance specified in clause4.BS7357:1990 BSI 04-1999 5 Section 3. Constru
49、ction 16 Shell 16.1 Each shell shall be provided with holes of28+2,1mm diameter to accommodate a warning pipe connection and a float operated valve positioned to comply with clauses13 and14 (seeFigure 1). a) side connections: the centre line of the holes shall be positioned between35mm and42mm above the marked water level; b) bottom connections: positioned to comply with clauses13 and14. 16.2 Any aperture in the shell for the operating lever or chain pull shall be not lower than the effective warning water level. 16.3 A means shall be provided for ensuring a
