SEV Trunnion mounted ball valve set many years of experience in valve design and manufacturing, using the international standards developed, mainly used for the long distance pipeline of petrol, natural gas and various industries. In view of the unique features of valves for long distance pipes, the design is fully considering its ability to withstand pipeline stress, as well as safety, weather resistance. The operation modes are including manual, pneumatic, electric, gas-liquid linkage, and various special control modes.