BS 2456:1990

Committees responsible
Foreword
Specification
Section 1. General
1.1 Scope
1.2 Definitions
1.3 Marking
1.4 Colour coding
Section 2. Materials
2.1 Effect of materials on water quality
2.2 Plastics materials
2.3 Copper alloy for boss insert
Section 3. Design and construction
3.1 Lifting efforts
3.2 Bosses
Section 4. Test requirements
4.1 Leakage and hot water test
4.2 Deflection test
4.3 Impact test
4.4 Cold embrittlement test
4.5 Boss distortion test
Appendices
A. Information to be supplied by the purchaser
B. Calculation of lifting effort
C. Method of test for leakage and determination of
     resistance to hot water
D. Method of determining deflection
E. Method of determining resistance to cold embrittle-
     ment
F. Method of determining resistance of the boss to
     distortion
Tables
1. Minimum lifting efforts
2. Bosses
Figures
1. Deflection test rig
2. Example of test bolt

Requirements for two grades of plastic floats specified in BS 1212.

This British Standard specifies requirements for two grades of float, with or without boss inserts. Grade C for use in cold water cisterns only, where they may be exposed to temperatures not exceeding 38 °C. Grade H for use in cold water cisterns or systems that may subject the float to hot water not exceeding 93 °C for a limited period, e.g. from a vent pipe arrangement in a feed and expansion cistern. The standard specifies plastics spherical floats of 102 mm, 114 mm, 127 mm and 152 mm diameter, and non-spherical floats having equivalent lifting efforts, suitable for attachment to the float operated valves specified in BS 1212-1, BS 1212-2 and BS 1212-3, except when otherwise specified by the purchaser in accordance with Appendix A of this standard.

Appendix A lists the information to be provided by the purchaser at the time of enquiry or order.

NOTE The titles of the publications referred to in this standard are listed on the inside back cover.