BS1212 Part 3 Float Valves
BS 1361 part 3 is the British Standard for diaphragm type plastic float operated valves.
Part 3 ball-cock / float valves look like part 2 valves and operate in the same way – the main difference is that they are made from plastic instead of brass.
Part 3 ball-cock valves are typically used as fill valves in older handle flush toilet cisterns.
313