摘要 |
A subsurface control fluid pressure actuated well safety valve employs one or more spindles attached to the valve housing and spindle sleeves attached to a shiftable actuating flow tube. The spindles and spindle sleeves are positioned between the valve housing and the flow tube and a change in the pressure force acting on the spindle and on the spindle sleeve will result in relative movement of the spindle sleeve with respect to the spindle to cause the flow tube actuator to shift and open a fluid transmission conduit.
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