Patent ID: 7309058

Claim:
A gate valve, comprising: a body having a cavity therein; a stem having an axis and extending through a stem passage in the body into the cavity for moving a gate between open and closed positions; a conical backseat seal surface at a junction of the stem passage with the cavity; a retaining shoulder on the stem facing away from the stem passage; a metal backseat seal; the backseat seal having a bore through which the stem passes and a base that contacts the retaining shoulder; a retainer secured to the stem and pressed against the backseat seal to maintain the backseat seal in contact with the retaining shoulder; and the backseat seal having conical inner and outer surfaces that define a conical leg extending away from the stem passage, the outer surface of the leg being spaced from the backseat seal surface during normal operation of the valve, the leg being flexible and deflecting into sealing engagement with the backseat seal surface when the stem is moved axially to a backseat sealing position.