... ,S.S304,S.S316Disc : Ductil iron,S.S304,S.S316 Casting Iron Water Butterfly Valve:1,30years focus on QA2,decades ... : Ductil iron,S.S304,S.S316,Ni-painted Ductil iron,Nylon coated Ductile iron,Aluminum,Brozenand Monel.Shaft : S.S416,S ... .S316,S.S304Seat : EPDM,PTFE,NBR,VITON Casting Iron Water Butterfly Valve