| 摘要 |
The invention relates to a safety valve for oil wells intended to be inserted in a receptacle sleeve with no stop shoulder. This valve comprises a system of anchoring in the receptacle sleeve which is characterised by the presence of a peripheral socket 401 adapted to clamp the anchoring dogs 54 in a low position and, on the contrary, to release the latter, in a high position, by means of windows which it comprises. During the lowering of the valve in the receptacle sleeve, this ring bears against the machining clearance 1d of the said sleeve and moves from its low position towards its high position releasing the dogs 54 which penetrate into the anchoring groove 1b under the effect of spring rods 402. The invention is applicable both in the case of a well functioning by natural flow due solely to the pressure of the effluents and in the case of a well functioning by artificial flow due to the injection of a fluid under pressure. <IMAGE>
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