Submersible pump check valve

A valve element for reciprocation within a port has a body member which cooperates with a valve seat defined on a wall around the port. A plurality of resilient legs extend from the body member through the port and terminate in feet which extend radially beyond the periphery of the port. A central bore in the body member, parallel to the legs receives a locking stem which reciprocates between a locked position and an unlocked position. In the locked position, a locking disc on the stem engages projections extending radially inward from the legs to prevent the legs from moving inward, thereby locking the valve element within the port. In the unlocked position, the locking disc is out of alignment with the projections, and bevelled surfaces on the feet cooperate with the wall to cam the legs inwardly, so that the valve element can be removed from the port when it is subjected to sufficient axial force. An annular ridge on the stem cooperates with a resilient flange spaced from the body member to releasably retain the stem in its locked and unlocked positions. A pair of prongs extend from a portion of the stem outside the bore beyond the periphery of the bore and engage the valve body to prevent the separation of the stem from the valve body. A sealing ring is seated in a groove defined on a portion of the stem within the bore to prevent the flow of fluid between the stem and the body member. The body member can be used without the stem as a flow responsive flow restricting element which permits full flow in one direction and restricted flow in the opposite direction.