wet alarm valve ductile cast iron Dia: 3", 4", 5", 6", 8" ductile ... .P.: 1.6MPa , PN 16, Wet alarm valvenamed as alarm check valve,ductile cast iron1) Applicable areas: workshops, warehouses, hotels, shops, recreational ... Diameter(mm)Symmetric Hole Diameter ΦB (mm)Screw Hole NO. and Dia. φA (mm)ZSFY1001.2DN1002201808*φ18ZSFY150DN1502852408*φ22ZSFY200DN20034029512*φ22 fire alarm check valve