Surface control well safety valve

摘要: A well safety valve for controlling the fluid flow through a tubing in which is biased closed. When control pressure supplied from surface, opened, but closes when exceeds predetermined value. The tubular member actuation of includes first upper and second lower telescoping section with releasable locking means normally securing sections together. stop shoulder positioned path movement opening direction actuating release force said value, moved closing released. may be either shear pin or resettable lock.