CHECK VALVE FOR CASING STRIP Russian patent published in 2024 - IPC E21B34/06 E21B34/14 F16K15/02 

FIELD: oil and gas industry.

SUBSTANCE: invention relates in particular to check valves used in cementing casing strings. A check valve for a casing string contains a body, a seat with a seating surface rigidly installed in the body, a rod, a plate rigidly connected to the rod, a spring, and a collet. The check valve is equipped with a pedestal rigidly connected to the body, a pressure sleeve and a bushing rigidly mounted on the stem. The collet in the lower part is rigidly connected to the pedestal. The collet in the upper part in the opening zone is equipped with a thickening that has a flat surface at the bottom, perpendicular to the valve axis and a conical surface at the top. The collet is surrounded by a burst safety clamp. The pre-compressed spring rests against the pedestal at one end and against the thrust bushing at the other. The inner diameter of the collet in the open state at the thickening point and the inner diameter of the pressure sleeve provide free passage in the axial direction of the thrust sleeve.

EFFECT: simplification and increased reliability of the design.

1 cl, 4 dwg