1、BRITISH STANDARD BS1125:1987 Specification for WC flushing cisterns (including dual flush cisterns and flush pipes) UDC 696.141.1:621.642.34BS1125:1987 This British Standard, having been prepared under the directionof the Building Services Standards Committee, was published under the authority ofthe
2、 Board of BSI and comes intoeffect on 31 March1987 BSI 03-1999 First published July1943 First revision June1945 Second revision June1956 Third revision March1959 Fourth revision April1969 Fifth revision October1973 Sixth revision March1987 The following BSI references relate to the work on this stan
3、dard: Committee referenceSEB/1 Draft for comment85/13284DC ISBN 0 580 15742 3 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Building Services Standards Committee (SEB/-) to Technical CommitteeSEB/1, upon which the following bodies were
4、 represented: British Bath Manufacturers Association British Plastics Federation British Woodworking Federation Builders Merchants Federation Clay Pipe Development Association Limited Consumer Standards Advisory Committee of BSI Council of British Ceramic Sanitaryware Manufacturers Department of Hea
5、lth and Social Security Department of the Environment (Building Research Establishment) Department of the Environment (Housing and Construction Industries) Department of the Environment (Property Services Agency) Greater London Council Institute of Clerks of Works of Great Britain Inc Institute of P
6、lumbing Institute of Vitreous Enamellers Institution of Environmental Health Officers Institution of Public Health Engineers Institution of Water Engineers b) the number of this British Standard, i.e.BS1125 1) ; c) the wording specified in17.2 on dual flush type cisterns. The marks required ina) and
7、b) shall be capable of being seen after the installation of the cistern and before any cover is fitted. NOTEThe mark “BS1125” on a cistern, with or without the certification mark, in no way refers to the suitability or otherwise of any float operated valve or float fitted in the cistern. 1) Marking
8、BS1125 on or in relation to a product is a claim by the manufacturer that the product has been manufactured to the requirements of the standard. The accuracy of such a claim is therefore solely the manufacturers responsibility. Enquiries as to the availability of third party certification should be
9、addressed to the appropriate certification body.BS1125:1987 2 BSI 03-1999 Section 2. Materials and design 4 General requirements Cistern shells, siphons and associated components shall be made from materials which under the conditions of use are one of the following: a) non-corroding e.g.plastics; b
10、) protected against the types of corrosion caused by the action 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 d
11、urability or efficiency of the cistern. Before dissimilar metals are used in the construction of a cistern, the manufacturer shall ensure avoidance of the possibility of electrolytic action. 5 Requirements for particular materials 5.1 Ceramic ware cisterns (seealsoclauses14, 15 and16) 5.1.1 The shel
12、l thickness of ceramic ware cisterns shall comply with either5.1.2, 5.1.3 or5.1.4. 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 china cisterns shall have a minimum thickness
13、 of10mm, except as described in5.1.4. 5.1.4 Vitreous china cisterns with an internal width of less than365mm, designed for use with Water Authority listed float operated valves other than as specified in BS1212, shall have a minimum thickness of6mm. 5.2 Rubber compound and plastics cisterns 5.2.1 Ge
14、neral. Plastics materials and rubber compounds shall be such that, when assembled, the cistern shall comply with5.2.2 to5.2.8. 5.2.2 Appearance. The cistern shall be free from blisters and delamination and reasonably free from flow lines, contamination, streaking or unintended colour variations on s
15、urfaces visible after installation. 5.2.3 Colour fastness to light. The colour fastness to light of the cistern and cover shall be not less than5 when determined in accordance with BS2782:Method540B. 5.2.4 Opacity. When tested in accordance with BS2782:Method530A, the cistern and cover shall not tra
16、nsmit more than0.2% of the visible light falling on them. 5.2.5 Distortion resistance. The cistern, when tested in accordance with Appendix A, shall not bulge more than6mm and the cover shall not be dislodged. 5.2.6 Dead load test. The complete cistern, when installed and filled as described in Appe
17、ndix A and tested by the application of a dead load of23kg for30s, shall not distort to such an extent that any part becomes detached. 5.2.7 Front thrust test for cisterns for use at low levels (including close coupled). The complete cistern, when installed and filled as described in Appendix A and
18、tested by the method described in Appendix B, shall not distort to such an extent that any part becomes detached or inoperable. 5.2.8 Impact test. The complete cistern, when installed and filled as described in Appendix A and tested as described in Appendix C, shall show no defect after one impact,
19、and after being emptied shall show no defect after one more impact. 6 Soft solder Any soft solder used in the construction of cistern shells, siphons or associated components shall comply with the requirements of BS219, and shall be of type F or type J as given in Table 1 of BS219:1977. 7 Hard solde
20、r Any hard solder or filler alloy used in the construction of cistern shells, siphons or associated components shall be of copper-silver-phosphorus or other corrosion resistant alloy, in accordance with type CP 2 or CP3 of BS1845. 8 Flushing apparatus Cisterns shall have an efficient flushing appara
21、tus of the valveless siphonic type which prevents the waste of water. The apparatus shall be capable of flushing directly the mechanism is operated when the water is at the water line, and shall be so constructed that water cannot flow down the flush pipe except while a flush is being properly deliv
22、ered. Flushing apparatus shall be detachable from the shell and suitable means shall be provided for ensuring and maintaining a watertight joint. The underside of the bend in the siphon pipe (the siphon invert) or, in the dome pattern, the top of the straight discharge pipe, shall be at such a heigh
23、t that no water runs down the flush pipe when, after temporarily closing the warning pipe, the water level is raised to the spill-over level. Any joint in a siphon assembly shall be watertight.BS1125:1987 BSI 03-1999 3 Cisterns of the dual flush type shall be provided with an air inlet device for br
24、eaking the siphonic action so as to enable the cistern to discharge a short flush instead of a full flush at the will of the user. The device shall come into action on the release by the user of the operating pull or handle. Where flushing apparatus of the single flush type is provided with means fo
25、r converting it to dual flush operation, the conversion shall be by the removal of a component. 9 Volume of discharge per flush When tested in accordance with the procedure described in Appendix D, all cisterns, when required to give a full flush, shall discharge L. Dual flush type cisterns shall di
26、scharge alternatively a short flush of L. 10 Rate of discharge 10.1 When tested in accordance with the procedure described in Appendix E, cisterns intended for use with WC pans complying with BS5503 and BS5504 shall discharge the full flush at the rate of9L in not more than5s when fitted with a high
27、 level type flush pipe, and at the rate of9L in not more than6.5s when fitted with a low level type flush pipe. NOTEFor dual flush type cisterns there is no specified rate of discharge for the short flush. 10.2 For cisterns intended for use with WC pans other than those complying with BS5503 and BS5
28、504, and with pans of the double-trap siphonic type, either: a) the cistern shall discharge at the rates specified in10.1; or b) the cistern shall discharge at some slower rate providing it complies with the requirements of Appendix A of BS5503-2:1977. 11 Water line The water line shall be marked pe
29、rmanently 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. 13 Warning pipes 13.1 General Each cistern shall be provided with a warning pipe c
30、onnection so arranged that the invert of a side connection type or the overflowing level of a bottom connection type is not less than25mm or more than32mm above the water line. 13.2 Side connection warning pipes Side connection cisterns shall be supplied with a union, for the connection of a warning
31、 pipe, of not less than19mm internal diameter, complete with a backnut. The union shall be manufactured from copper, copper alloy or plastics materials. Cup overflows shall not be fitted. NOTEFor frost precaution recommendations, see4.5 of CP99:1972 2) . 13.3 Bottom connection warning pipes 13.3.1 G
32、eneral. Bottom connection cisterns shall be supplied with a warning pipe of not less than19mm internal diameter throughout. 13.3.2 Metal warning pipes. Bottom connection warning pipes of metal shall be of either copper or copper alloy. If of copper, they shall comply with Tables X or Z of BS2871-1:1
33、971. If of copper alloy, they shall have a minimum thickness of1mm. They shall be brazed or hard soldered at the lower end into a flanged nipple and shall be provided with a backnut and washer. 13.3.3 Plastics warning pipes. Bottom connection warning pipes of plastics material shall be either integr
34、al with or welded to a flanged nipple at the lower 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 m
35、inimum thickness of0.9mm is necessary because of the small difference between the outside diameter of22mm pipe and the root diameter of the in thread. 13.4 Torque testing When assembled on the appropriate warning pipe, and fitted into a cistern complying with BS1125, backnuts shall be such that when
36、 a torque of10Nm is applied in tightening the backnut on the warning pipe, there shall be no sign of distortion of the threads or of the backnut. 14 Float operated valves 14.1 Float operated valves do not form part of BS1125, but every cistern shall be constructed to comply with14.2, 14.3 and14.4. 9 + 0.5 1.0 4.5 + 1.0 0.5 2) Being revised as BS6700.
