DEVICE FOR CHANGING GATE VALVES UNDER PRESSURE Russian patent published in 2003 - IPC

FIELD: oil and gas industries. SUBSTANCE: device designed for replacing faulty shutoff valves, ball cocks, and the like under pressure in gas and oil wells, and other pressure conduits has split and nonsplit supporting cross-arms with axial holes. Coupled with cross-arms by means of guide screws is assembly for attaching device to valves. Hollow rod is installed in central axial hole of split cross-arm. Composite drive shaft of hollow rod is disposed in the latter and in central axial hole of nonsplit cross-arm. Hollow rod has thread to receive packer. Device also has mechanism for sealing hollow rod relative to valve body. This mechanism has case with flanges, packing member, collar bush, and threaded pressure lid. Split cross-arm mounts supporting nut. In addition device is provided with packing coil that has case with flange, packing member, and annular pressure nut. Assembly for attaching device to valve is made in the form of split plate with two split clamps Split plate is mounted on pipe. Split clamps are fixed in position on pipe by means of toothed blocks. EFFECT: provision for replacing valves (ball cocks) on gas extraction branches of gas-main pipelines. 3 dwg