| 摘要 |
An improved control line blow out preventer valve is provided, having a fluid pressure chamber interposed in a control line extending from a surface control panel to a downhole safety valve in a subterranean well. Axially spaced inlet and outlet openings are provided in the pressure chamber and a piston is reciprocally mounted intermediate the inlet and outlet openings. A sealing plug carried by the piston cooperates with a seal surrounding the inlet opening. A bypass passage through the piston mounts a check valve which permits free fluid flow in the direction from the control panel to the subsurface safety valve but only a restricted fluid flow in the opposite direction. A check valve is mounted in the outlet passage to prevent fluid flow from the subsurface safety valve to the control panel. A fusible link normally maintains this check valve off its seat so that it does not close until the occurrence of an elevated temperature caused by fire. At the inlet port a bleed valve which is thermally activated is incorporated in order to bleed off the safety valve, or other apparatus, pressure in the event of a fire.
|
