Valve with pressure differential seating
A valve for use in oil and gas production or similar applications includes a plug or other flow barrier disposed in a cavity of a hollow valve body with a metal-to-metal sealing surface that is not reliant on any rubberized or elastomeric material to effect a seal.
1. A valve comprising:
a valve body comprising a cavity, an interior bore with a central longitudinal axis, and a radially projecting shoulder;
a flow barrier disposed within said cavity and operable to move between an open position in which the interior bore of the valve body is unobstructed and a closed position in which the flow barrier obstructs the interior bore;
a removable bore-end connection connected to the valve body;
a seat comprising a first axial surface adjacent to said interior bore, a first radial surface adjacent to said flow barrier and a second radial surface, the second radial surface being larger than the first radial surface, said seat disposed between the flow barrier and the removable bore-end connection, such that it does not contact the radially projecting shoulder of the valve body.
2. The valve of claim 1 further comprising a support member attached to the seat and a biasing member disposed between the support member and the valve body.
3. The valve of claim 1 , further comprising one or more elastomeric sealing elements disposed within a groove formed in an upper surface of the seat.
4. The valve of claim 3 , further comprising one or more elastomeric sealing elements disposed within a groove formed in an upper surface of the removable bore-end connection.
5. The valve of claim 1 in which the flow barrier comprises a plug.
6. The valve of claim 1 in which the flow barrier comprises a gate.
7. The valve of claim 1 in which the seat is comprised of metal, such that contact between the first radial surface and the flow barrier creates a metal-to-metal seal.
8. The valve of claim 1 , further comprising a biasing member disposed between the removable bore-end connection and the seat and configured to exert an axial force on the seat in the direction of the flow barrier.
9. The valve of claim 1 , wherein the connection between the removable bore-end connection and the valve body is threaded.