Pre-caution alarm valve,Valve,Pre-caution alarm valve,Pre-action alarm valve Item No.ZSFU100-4'',ZSFU150-5'',ZSFU200-8'' ... Pre-caution alarm valve,Valve,Pre-caution alarm valve,Pre-action alarm valveFeatures: 1) Item no.: ZSFU100, ZSFU150, ZSFU2002) Nominal diameter ... ) Pre-caution alarm valve,Valve,Pre-caution alarm valve,Pre-action alarm valve