Abstract: An oil-well safety valve comprising a movable shutter flap, an inner tubular slide, a return spring for the slide, hydraulic means displacing the slide downward by pressuring a control fluid and a system for anchoring the valve in a receiving sleeve, the flap hinging on a shutter body (108) screwed on the lower end of the valve by means of a shaft (121) provided with a heel (123), the heel being locked by the low end of the valve when the shutter body is screwed on this valve, so that the shaft (121) is locked with respect to rotation and translation without resort to any other auxiliary component, and it is released when the shutter body (108) is unscrewed.

Abstract: 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.