| 摘要 |
A blow out preventer is described including a housing with a first annular wedge member fixed to an interior sidewall of the housing. A second annular wedge assembly is provided which includes a plurality of wedge segments disposed within an interior of the housing. The contact face of each of the wedge segments in the second annular wedge assembly is in sliding face to face contact with the contact face of the first annular wedge member. The second annular wedge assembly is movable between an open position spaced from central drill pipe receiving bore and a closed position in sealing engagement with a drill pipe disposed within the central drill pipe receiving bore. An annular piston seal is disposed within the interior at the second end of the housing. The piston has a first contact face and a second contact face. The first contact face engages the second annular wedge assembly. When the second contact face is exposed to fluid pressure symptomatic of a blow out condition, the piston moves in response to such pressure to move the inclined planes formed by the contact faces of the wedge segments of the second annular wedge assembly up the inclined plane formed by the contact surface of the first annular wedge member to the closed position.
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