CHECK VALVE FOR OIL-WELL ELECTRICAL CENTRIFUGAL PUMP Russian patent published in 2002 - IPC

FIELD: operation of oil wells by means of electrical centrifugal pumps. SUBSTANCE: check valve has module-head mounting seat connected with tubing and shut-off member, which is made in form of plastic plug with longitudinal splined slots. Outer diameter of splined slots of upper butt of plug exceeds inner diameter of tubing screwed in module-head. Inner diameter of slots is lesser than inner diameter of tubing. Inner of splined slots of lower butt of plug exceeds diameter of hole of module-head seat. Lower butt of plug is made in form of cone, truncated cone, ball or ellipsoid; height of plug is lesser than distance between hole of mounting seat and tubing. EFFECT: enhanced tightness of closed valve; simplified construction of valve; enhanced reliability and durability of valve. 4 dwg