Abstract: A screw operated emergency release and safety valve includes a valve housing having a flow passage therethrough and adapted to be connected to a lower portion of a tubing string. A full opening ball valve is disposed in the valve housing for opening and closing the flow passage. A stinger assembly is adapted to be connected to an upper portion of the tubing string, and includes a stinger mandrel releasably telescopingly received within the valve housing. An actuating mandrel assembly is operably associated with the stinger mandrel and connected to the ball valve and is movable between first and second positions for opening and closing the ball valve in response to manipulation of the upper portion of the tubing string. A threaded connecting collar releasably interconnects the valve housing and the stinger assembly.

Abstract: A full opening emergency release and safety valve includes a valve housing having a flow passage therethrough and adapted to be connected to a lower portion of a tubing string. A full opening ball valve is disposed in the valve housing for opening and closing the flow passage. A stinger assembly is adapted to be connected to an upper portion of the tubing string, and includes a stinger mandrel releasably telescopingly received within the valve housing and operably associated with the ball valve for opening and closing the ball valve in response to manipulation of the upper portion of the tubing string. A threaded connecting collar releasably interconnects the valve housing and the stinger assembly.