RETURN VALVE Russian patent published in 2010 - IPC F16K15/04 

FIELD: machine building.

SUBSTANCE: invention is provided for usage in oil wells with co sucker-rod pumps or with electric-centrifugal pumps, dispensing mainly liquids with high content of mechanical impurities. Return valve includes casing, seat, gate. The later is installed in restraint with tapered openings, transferring into tapered bores. Restraint is implemented with ability of increasing of open flow area between gate and restraint at axial movement of gate.

EFFECT: increasing of durability of return valve and increasing of processability of its manufacture.

6 cl, 5 dwg