DOUBLE ECCENTRIC BUTTERFLY VALVE AND MANUFACTURING METHOD THEREFOR

摘要

In particular, provided is an eccentric butterfly valve, which is suitable for high pressure fluids, can align a seat ring with a disc while ensuring sealing between the seat ring and a body even when there is a considerable component dimensional error, can ensure a sealing surface pressure between the disc and the seat ring, whether under positive pressure or negative pressure, so as to effect sealing therebetween, and can provide a continuously sealed area between the body and the seat ring to make sure that fluid leakage is prevented. Also provided is a manufacturing method therefor.　A tapered surface 31 formed on a seat ring 20 and a stepped section 30 formed on a body 2 face each other. A corner 35 of the stepped section 30 on the tapered surface 31 side bites into the tapered surface 31 so as to form an annular sealing part 33 on the mating surfaces of the body 2 and the seat ring 6.