阀门标准 BS 7461-1991 Specification for electrically operated automatic gas shut-off valves fitted with throughput adjusters, proof of closure switches.pdf [db:摘要]
阀门标准 BS 1212-3-1990 Float operated valves. part 3 Specification for diaphragm type float operated valves (plastics bodied) for coldwater services only.pdf [db:摘要]
