... series Material:Cast iron /Ductile iron /WCB "U" type butterfly valve:1) Material: body-CI/DI/WCB 2) Disc ... projects, urban water supply and drainage, sewage treatment, electric power, petroleum, petrochemical , heat supply,shipbuilding, medicine ... off media in pipelines. Suitable media include water, sewage, seawater, air, foodstuff and oil. Suitable for handles (DN50~300), gear operators,electric ...