Abstract: An expanding gate valve having a pressure-secured seat. The valve includes a valve body having a cavity formed therein and an inlet and outlet formed in the body, both of which intersect the cavity. A counterbore is formed about the circumference of both the inlet and the outlet at their respective intersections with the cavity. An annular seat having a rear surface and a front seat surface is received within the inlet counterbore. An annular seal is formed on the front seat surface and a second annular seal is disposed between the rear surface and the valve body. The front annular seal has a sealing diameter greater than the rear annular seal and an annular recess is formed on the front seat surface on the radially inward side of the annular seal. A second annular seat having a planar front seat surface is received within the outlet counterbore.

Abstract: A ball valve comprising a housing having inlet and outlet ports provided a fluid passageway therethrough, a rotatable closure member disposed within the housing and interposed between the inlet and outlet ports for providing alternate open and closed positions for the valve, a rotatable valve stem secured to the closure member for moving the closure member between the open and closed positions therefor, a valve seat removably secured to the housing and engagable by the closure member in the closed position thereof, and a removable sealing member provided for the valve seat to substantially preclude leakage of fluid around the closure member in the closed position of the valve.