The metal hard sealing butterfly valve is an eccentric metal sealing structure. The sealing forms can be divided into: metal to metal sealing, replaceable metal sealing ring to metal sealing, and stainless steel plate and graphite composite plate sealing ring to metal sealing. In addition to electric, the driving forms of hard seal butterfly valve also include manual, worm gear rod drive, pneumatic, etc. W & T brand metal hard ball valves comply with ASME standards and can provide a wider range of products.