Abstract: An improved seal ring for a ball valve comprising, a metal ring of rectangular cross section, the inner wall of which constitutes part of the axial opening for fluid flow. The upstream face of the seal ring includes means to said seal ring to the housing. The downstream face of the seal ring includes a cylindrical channel, concentric with the axial opening in the valve housing and concentric with the inner wall of the seal ring. The downstream portion of the seal ring is cut at an angle to be substantially parallel to the spherical surface of the ball against which seal is to be made. A seat ring is provided having in cross section a rectangular portion that fits into the cylindrical groove in the seal ring and has a C-shaped portion adapted to house a length of helical spring of the same diameter as the circular interior cavity of the C portion.

Abstract: A valve having integrity assurance means including a valve body with a flow passageway through it, the flow passageway having a circumferential valve seat and the valve body having a small diameter test opening communicating the seat with the exterior of the valve, and having a valve disc with a circumferential sealing surface supported in the body, the disc being rotatable to an open position permitting fluid flow through the valve to either side of the disc and to another position to close the valve by the contact of the disc sealing surface with the valve seat, the disc sealing surface and the valve seat having cooperative configuration to provide two spaced apart circumferential contact areas between the seat and the disc, the test opening communicating between these contact areas so that when the valve is in the fully closed position the test opening can be utilized as a means to test the integrity of the valve, that is, to insure that no leakage is occurring past the valve disc.