| 摘要 |
An oil-well safety valve and installing and retrieving tools for the valve, the valve including a movable shutter (11), an internal tubular slide (9), a return spring (10) biasing the slide toward the high position, hydraulic means driving the slide down by pressurizing a control fluid, a system (14) for anchoring the valve in a receiving sleeve (1) and packings (15, 16) in contact with the receiving sleeve (1); the valve including an anchoring system comprising a hydraulically actuated mechanical system including a tubular shuttle piston (58) subjected to the pressure of the control fluid to be moved upward by this fluid, and by a locking bushing (55) located above the shuttle piston for forcing it upwardly, so that when the bushing moves, it actuates and locks anchoring dogs (54) floating in the lock body.
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