MULTIFUNCTIONAL NON-RETURN VALVE Russian patent published in 2004 - IPC

FIELD: oil and gas production, well drilling. SUBSTANCE: multifunctional non-return valve has body, shut-off element including closure in the form of ball with pins positioned in grooves of body on single axis displaced with respect to symmetry axis of closure. Closure is mounted for rotation around axle of pins. Lower seat is spring-loaded. Shut-off seat is mounted on cheeks of body for contact with closure. Side seat is made in body between upper spring-loaded seat and shut-off seat. Upper seat has side holes, ball is located in one of holes and is above side seat when axle of pins is positioned below symmetry axis of closure and ball is conjugate to side seat when axle of pins is positioned above symmetry axis of closure. EFFECT: increased operational reliability of drilling equipment and improved protection of it against fouling and impurities. 2 dwg