Design, construction and testing of temperature relief valves of the automatic reseating type, specifically intended for use with and protection of storage water heaters of the unvented type. Does not give recommendations on application or installation of the valves.Cross References:BS 21BS 864:Part 2BS 864:Part 5BS 970:Part 4BS 1726:Part 1BS 2056BS 2779BS 2803BS 2870BS 2871:Part 1BS 2872BS 2874BS 3074BS 3075BS 3457BS 4504:Section 3.3BS 4781BS 5216BS 5412:Part 5BS 6283:Part 1BS 6283:Part 3BS 6283:Part 4BS 6920:Part 1BS 7206