AXIAL PRESSURE EQUALIZING VALVE FOR A WELL SAFETY VALVE

摘要

A subsurface valve (10) with a pressure equalizing mechanism is provided to permit pressure above and below a valve closure member (24) to equalize prior to the opening of the valve closure member. An actuating key (46) is releasably engageable with a recess (52) in a flow tube (18) that is moveably disposed within a longitudinal bore of the safety valve. An equalizing plug (48) is disposed for reciprocal movement within a plug bore, and is moveable in response to movement of the actuating key (46). To open the valve closure member, the flow tube (18) moves downwardly into engagement with the actuating key (46), thereby carrying the actuating key into engagement with the equalizing plug (8) to shift the equalizing plug to an open or equalizing position. Pressure above and below the valve closure member is equalized through the equalizing plug prior to the opening of the valve closure member by further downward movement of the flow tube (18).