BS 1212-4:2016 pdf download – Float operated valves Part 4: Specification for compact type float operated valves for WC flushing cisterns (including floats)
1 Scope This part of BS 1212 specifies requirements for materials, connecting dimensions, overall size limitations and performance of compact float operated valves, incorporating a float designed for use at operating pressures of between 0.1 bar and 10 bar 1 ) and intended for use in WC flushing cisterns.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. BS 21, Specification for pipe threads for tubes and fittings where pressure-tight joints are made on the threads (metric dimensions)
BS 417-2:1987, Specification for galvanized low carbon steel cisterns, cistern lids, tanks and cylinders – Metric units BS 5154, Specification for copper alloy globe, globe stop and check, check and gate valves BS 6100-5:2009, Building and civil engineering – Vocabulary – Civil engineering – Water engineering, environmental engineering and pipe lines
BS 6100-7:2008, Building and civil engineering – Vocabulary – Services BS 6920-1, Suitability of non-metallic materials and products for use in contact with water intended for human consumption with regard to their effect on the quality of the water – Specification
BS EN 1057:2006+A1:2010, Copper and copper alloys – Seamless, round copper tubes for water and gas in sanitary and heating applications
BS EN ISO 7686:2005, Plastics pipes and fittings – Determination of opacity
3 Terms and definitions
For the purposes of this part of BS 1212 the definitions given in BS 6100-5:2009 and BS 6100-7:2008 apply, together with the following.
3.1 float operated valve valve, operated by a float, to control flow into a vessel
3.2 compact type float operated valve float operated valve, incorporating a float, with a suitable inlet connection having an overall space limitation [and having a size not greater than (160 × 145) mm], intended not to foul any outlet device
NOTE 1 The size requirement also applies to combined inlet and outlet flush mechanisms for the inlet aspect of these devices only.
NOTE 2 See Figure 1 for an example of a typical flushing cistern showing size limitations for compact valves.
3.3 combined fill and flush valve
inlet valve that incorporates an integral flushing mechanism
NOTE The combined fill and flush mechanism cannot be separated and the function of the fill and flush are linked.
3.4 datum level
line marked on the product to be used as a reference mark when undertaking backflow prevention tests (see Figure 2)
3.5 delayed action inlet valve
inlet valve designed so that the flow of water into the cistern is delayed on activation of the outlet valve, until all or most of the flush is completed thus preventing or reducing the addition of incoming water to the volume of water
3.6 waterline
level of water at the maximum operational level
NOTE Level achieved with maximum float adjustment.
4 Materials
4.1 Non-metallic materials
When used under the conditions for which they are designed, non-metallic materials in contact with, or likely to come into contact with, wholesome water shall conform to BS 6920-1.
Components subject to direct natural light shall conform to the opacity test specified in BS EN ISO 7686:2005.
4.2 Metals
Components manufactured from metals shall be resistant to corrosion.
5 Design, construction and dimensions
5.1 General dimensional requirements
Valves shall be capable of functioning within a space as indicated in Figure 1.
5.2 Inlet connections
5.2.1 General
Valves shall incorporate an inlet assembly with a connection designed for use with either spigot, compression type connectors or other equally effective methods, e.g. push fit connections.
Where the valve is designed to be connected through the wall of the flush cistern a suitable means shall be provided to secure the valve to the flush cistern to a wall thickness not greater than 12 mm.BS 1212-4 pdf download.