CHECK VALVE FOR WELL Russian patent published in 2011 - IPC E21B34/06 

FIELD: oil and gas industry.

SUBSTANCE: check valve includes housing with annular pocket on its inner surface, bushing with mounting seat and fixed in housing with shear member; shell connected to bushing and having radial hole covered from the outside with elastic cover, and axial hole made at the bottom, covered with shutoff element. There is also pin to restrict axial movement of shutoff element. It is arranged between shutoff element and mounting seat and radially protrudes inside the shell. Bushing and shell have the possibility of joint movement at destruction of shear member to their extreme lower position with arrangement against annular pocket of pin. Pin has possibility of being moved into annular pocket under influence of shutoff member when the device is brought into working position.

EFFECT: reliable operation and enlarged process capabilities.

7 cl, 1 dwg