GEAR TO REPLACE GATES IN VALVES ACROSS WELL-HEAD Russian patent published in 2001 - IPC

FIELD: mining industry, repair of well-head equipment. SUBSTANCE: gear comprises body with joining flange and axial conduit. Casing with key anchored in it is installed in axial conduit. Casing housing driving shaft and shaped bushing linked by threaded connection are put into casing. Shaped bushing is mounted for axial movement relative to driving shaft. Key is placed in axial groove of shaped bushing. Hollow rod is put on end of driving shaft. Sealing member in the form of expanding collar and supporting blocks which present split sector members are placed outside of hollow rod. Internal surface of expanding collar interacts with external surface of supporting blocks. Conical nozzle communicates with shaped bushing. Spring split ring is put on the outside of supporting blocks. Assembled gear is joined for replacement of faulty gate to its flange. Slide of gate is open and hollow rod and expanding collar are moved by rotation of casing relative to body to point of sealing. Then driving shaft starts rotating relative to casing. Conical nozzle interacts with supporting blocks moving them apart together with expanding collar in radial direction. Internal conduit of well-head gear is reliably sealed. Split ring prevents forcing of material of collar under action of excessive internal pressure. Then nut is unscrewed and body is removed from flange of faulty gate together with casing. Faulty gate is dismantled from equipment and is replaced with serviceable gate. Body with casing is again connected to flange of replaced gate, then collar is unpacked and hollow rod in moved to starting position in sequence. When repair is over gear is taken down from flange of replaced gate. EFFECT: enhanced operational reliability of gear, expanded technological capabilities of gear thanks to growth of difference between outer diameter of sealing member in transportation and operational positions. 2 cl, 2 dwg