| 摘要 |
A subsurface safety valve assembly for connection in a well pipe, including a valve member disposed in a valve body having a bore or passageway therethrough, a pair of spaced apart and oppositely facing valve seats in surrounding relation to an intermediate portion of the passageway, the valve positioned thereat and operable to open and close said passageway, a space within the valve body outwardly of the passageway therethrough, a control frame guidably movable within the space and having a piston associated therewith adapted to define first and second variable capacity pressure chambers within the space, means for moving the control frame in opposite longitudinal directions to open and close the valve, the means for moving the control frame including first and second ports, the first port providing fluid communication between the first variable capacity pressure chamber and an external source of pressure fluid, the second port providing fluid communication between the second variable capacity pressure chamber and the passageway through the valve body.
|
