CASING STRINGS VALVE Russian patent published in 2005 - IPC

FIELD: oil industry.

SUBSTANCE: valve has limiter with saddle and side channels, check valve, placed at lower portion, bushing, mounted in axial channel of limiter at shear elements above side channels with possible hermetic overlapping thereof. According to invention limiter is additionally equipped with stop, interacting with bushing in its lower position. Outer surface of limiter is provided with elastic ring with stop above side channels, and made with possible hermetic mounting of limiter in required range between casing string pipes during assembling thereof. Saddle is made with cylindrical piece at lower plane of limiter. Check valve is made plated, spring-loaded with possible rotation relatively to fixture to limiter. The latter consists of rigidly interconnected elastic collar, localizer and cylindrical plate. On the latter ring-shaped recess is made, mounted oppositely to inner lower plane of limiter. Outer plane of cylindrical plate is positioned oppositely to limiter saddle. Elastic collar is placed between lower plane of limiter and cylindrical plate.

EFFECT: higher reliability, simplified manufacture and maintenance.

1 dwg