Abstract: A plug or gate valve including two seats shaped as cylindrical segments and having a first continuous seal surrounding the flow passage and at least one satellite seal outside the first seal to reduce the area upon which pressure acts to force the segment toward the plug or gate.

Abstract: The present invention is directed to a check valve assembly comprising an upstream body member and a downstream body member which are joined in sealing engagement to thereby form a closed body; a generally ring-shaped seating member formed from a unitary piece of material and comprising a flat base surface positioned in said closed body with said flat base surface facing upstream, a flat top surface parallel to said flat base surface, a flow passage extending from said base surface to said top surface and a bore extending into said top surface toward said base surface, said bore defining an annular lip surrounding said flow passage and a recessed upward-angled planar top sealing surface; said seating member further comprising a cut-out segment formed in said lip which defines two extensions projecting axially from the top sealing surface and a transverse hole in each extension through which a hinge pin is received to connect a movable flapper lid to said seating member; said flapper lid comprising a flapper s

Abstract: A valve comprising a body having an interior cavity, an inlet port and an outlet port; an upstream seat and a downstream seat positioned within the cavity, each seat including a bore in alignment with the inlet and outlet ports to define a flow passage through the valve body; a closure member movably positioned between the seats to either open or close the flow passage; a seat-to-closure member seal defined between each seat and the closure member, the seat-to-closure member seal defining a first area between the seat-to-closure member seal and the bore of the upstream seat; wherein the upstream seat includes a sealing member between the seat and the valve body which is positioned asymmetrically around the bore; and wherein the sealing member defines a second area between the sealing member and the bore which is larger than the first area.

Abstract: A pipe connector device for interconnecting first and second pipe elements using a retention member removably secured to the first pipe element by load elements. The retention member is secured to the second pipe element by pipe threads or a second retention member can be secured to the second pipe element by load elements and the first and second retention members threaded together. A seal is extended along a portion of the length of the first and second pipe elements adjacent to an end portion of each of the pipe elements to prevent leakage. This provides a fluid-tight seal which is relatively independent of any pressure exerted between the first and second pipe elements by the retention member.