BACK VALVE Russian patent published in 2009 - IPC F16K15/06 

FIELD: machine building.

SUBSTANCE: invention refers to oil and gas producing industry and is designed for implementation in pumps transferring viscous fluids, particularly in well sucker-rod pumps used for mechanised extraction of oil from wells. The back valve consists of a case with a chamber. A cage, saddle and shut off element interacting with the saddle are arranged in the chamber; the shut off element has packed surface and a cylinder shank end. A split protecting bushing is installed in the case. Grooves with collars are made in the direction of case axis. The saddle is installed on one side in the case with a gap between internal diametre of the groove and the saddle. Through threaded elements the saddle with a branch is fixed in the case. The cage with channels for fluid flow and with the central opening is installed in the case on the other side. The cage is fixed with a threaded ring. The shut off element with the shank end, threaded point and circular gap for fluid flow between the shut off element and the chamber is installed above the saddle through the central opening of the cage. A lifting screw with adjustment of its weight is arranged at the end of the shut off element. The saddle, a partition, the shut off element and the split protecting bushing are made out of corrosion resistant polymer material.

EFFECT: upgraded reliability and service ability, reduced number of repair of wells equipped with sucker-rod pumps with said valves.

5 dwg