Abstract: An improved butterfly valve with self energizing seal, having a body with parallel faces and a substantially circular opening therethrough, and a shaft transverse to said opening. A closure disc is rigidly attached to said shaft and spaced from said shaft a selected distance, with its plane parallel to a plane through the axis of said shaft. A seal ring, comprising a thin cylindrical metal ring with an elastomeric ring bonded to the inside surface thereof, is inserted into the upstream face of said body. The elastomeric ring has an internal seating surface which is a truncated conical surface, tapering upstream, and which is tangent to a spherical surface centered at the intersection of the axes of said opening and said shaft. The edge of the closure disc is in the form of a ridge, having a peak which is circular in crosssection. When the valve is closed, by rotating the shaft, the disc is in the plane of the seating surface and the ridge has a small radial penetration into the elastomeric surface.

Abstract: An improved check valve having a housing or body with parallel faces and a substantially circular opening therethrough, and a shaft transverse to the opening. A flapper disc is rigidly attached to the shaft. A seat means comprising a metal ring is inserted into the upstream face of the body, and has a seating surface which is a truncated conical surface, tapering upstream. The conical surface is tangent to a sphere centered in said body. The disc, when closed, is in the plane of the seating surface. The edge of the plate is in close spacing to the seating surface, and is correspondingly tapered. The edge of the plate has a rectangular groove having a cylindrical base and walls perpendicular to the base. An O-ring is seated in the groove, and provides a self energizing seal. Means are provided to center the disc in the seat. Means are provided to apply a selected torque to the shaft.