| 摘要 |
A recloseable auxiliary valve includes a cylindrical housing having a central flow passage disposed therethrough. A flapper valve is disposed in the housing and is movable between a closed position wherein the central flow passage is closed and an open position wherein the central flow passage is open. An operating mandrel is provided for operating the flapper valve upon telescoping movement of the mandrel relative to the housing. A releasable locking system is provided for locking the mandrel and the flapper valve in their open position. A time-delay system is provided to prevent premature telescopingly collapsing movement of the mandrel relative to the housing as the auxiliary valve is run into the well.
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