ZFV provide variety of seat seals butterfly valves for different requirement from different customers. Generally seat seal type include elastic seat, entire metal to metal seat, laminated stainless steel plate with graphite seat, etc .
Most commer ealstic seat material is Teflon or PTFE, which has excelent performance for high corrosive service such as for sulphuric acid, nitric acid, muriatic acid, etc. The performance of PTFE seat do not change for long time using in these high corrosive service.
Entire metal to metal seat butterfly valve have high performance in using temperature up to 600degree C, and also can be used in special service such as particle service, it achieve this by special design:
The disc seal ring is entire metal ring, instead of laminated parts. the internal part such as disc seal ring furface and body seat furface be harden by special alloy, include STL, TC etc. Since this high technic requirement, the cost of valve is expensive, and valve be used in special envirenment .
Laminated stainless steel plate with graphite seat butterfly valve is widely used in world wide market. Because this type valve can be zero leakage same as elastic seat butterfly valve , also can be used for higher temperature up to 350degree C, this is the performance that normal elastic seat valve do not have. And the cost is lower than entire metal to metal seated butterfly vlave, so are used more often.
The laminated plate include normal SS304, SS316, also other stainless steel that required by customer.
Zhejiang Zhengfeng valve