This Part of BS 1212 specifies the performance requirements, materials, certain dimensions and tolerances of diaphragm type float operated valves (plastics bodied) of nominal size ½ for cold water services only, capable of accepting interchangeable low or high pressure renewable seats for use at pressure up to and including 3 bar1) and up to and including 14 bar respectively (see 9.1) and intended for use with 114 S or 114 NS floats (plastics) conforming to BS 2456.
NOTE 1 The nominal size is that corresponding with the Class G ½ B pipe thread specified in BS 2779.
NOTE 2 The titles of the publications referred to in this standard are listed on the inside back cover.