Abstract: An eccentric butterfly valve, suitable for high-pressure fluids, in which: even if a dimensional error among components is large, the seat ring is aligned with the disk while sealability between the seat ring and the body is ensured; for either pressure, positive pressure or counter pressure, the seal surface pressure between the disk and the seat ring is ensured to achieve sealability; and a continuous seal portion is ensured between the body and the seat ring, thereby reliably inhibiting fluid leakage, and a method of manufacturing the eccentric butterfly valve. A tapered surface 31 formed on a seat ring 20 and a step portion 30 formed on a body 2 are opposed to each other. With a corner portion 35 of the step portion 30 on a tapered surface 31 side digging into the tapered surface 31, an annular seal portion 33 is formed on an opposed plane between the body 2 and a seat ring 6.

Abstract: Provided are an eccentric butterfly valve, in particular, suitable for high-pressure fluids, in which: even if a dimensional error among components is large, the seat ring is aligned with the disk while sealability between the seat ring and the body is ensured; for either pressure, positive pressure or counter pressure, the seal surface pressure between the disk and the seat ring is ensured to achieve sealability; and a continuous seal portion is ensured between the body and the seat ring, thereby reliably inhibiting fluid leakage, and a method of manufacturing the eccentric butterfly valve. A tapered surface 31 formed on a seat ring 20 and a step portion 30 formed on a body 2 are opposed to each other. With a corner portion 35 of the step portion 30 on a tapered surface 31 side digging into the tapered surface 31, an annular seal portion 33 is formed on an opposed plane between the body 2 and a seat ring 6.