Pressure equalizing valve

摘要

A gate valve includes a body with a flow passage intersected by a gate cavity and a gate with an axis, the gate being axially movable in the gate cavity between a gate closed position and a gate open position. A lifting device is in engagement with a stem of the gate to move the gate to the gate open position. A port extends from a first external surface of the gate to a second external surface of the gate. A seal member is mechanically connected to the lifting device, the seal member being moveable in response to axial movement of the lifting device between a seal open position where fluids can flow through the port and a seal closed position where the seal member blocks fluids from flowing through the port.

主权项

1. A gate valve, comprising:
a body with a flow passage intersected by a gate cavity; a gate with an axis, the gate being axially movable in the gate cavity between a gate closed position and a gate open position; a lifting device in engagement with a stem of the gate to move the gate to the gate open position; a port extending from a first external surface of the gate to a second external surface of the gate; and a fluid pressure energized seal member mechanically connected to the lifting device, the seal member oriented to be retained in the seal closed position by a fluid pressure of a fluid in the flow passage that is upstream of a downstream side of the gate and being moveable in response to axial movement of the lifting device from a seal closed position where the seal member forms a non-elastomeric seal and blocks fluids from flowing through the port, to a seal open position where fluids can flow through the port, in response to initial movement of the lifting device overcoming the fluid pressure acting on the seal member, before the lifting device begins to move the gate.