摘要 |
An oil-well safety valve comprising a movable shutter (11), an inner tubular slide (9), a return-spring (10) for the slide, hydraulic means for moving the slide downward by pressurization of a control fluid, a system (14) for anchoring the valve in a receiving sleeve (1) and packings (15, 16) at the contact of the receiving sleeve (1), the packings (15, 16) being located on either side of the control fluid intake; the anchoring system (14) being located above the packings and the return spring (10) being located below in a part of the sealed volume receiving the control fluid. The spring being mounted around the slide between a bushing (20) and a ring nut (19) for eliminating any danger of relaxation of the spring during disassembly.
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