Abstract: A safety and service valve for a high pressure tank having a sealing portion within the tank, an external portion externally of the tank, a flow passage between inlet and outlet ports, and a chamber having an inlet end and an outlet end, the outlet end having a valve seat. A valve element is loosely received by the chamber and adapted to engage the valve seat to thereby close the flow passage when the fluid pressure at the chamber inlet end is higher than the fluid pressure at the chamber outlet end. A stop member prevents the valve element from engaging the valve seat until the external portion of the body is severed from the sealing portion.In one aspect, the valve includes a bleed passage in the sealing portion of the valve for placing the tank in fluid communication with the flow passage and allowing release of pressure in the tank in a safe manner if the external portion of the body is severed from the sealing portion.

Abstract: An apparatus and associated method for relieving the pressure within a high pressure tank having an opening plugged by a broken safety valve of a special type utilizes a mechanism acting between the annular flange of the tank normally provided for the securement of a valve protector cap and the valve to permit pressurized contents confined within the tank to escape through the valve. The special valve includes a flow passage in axial alignment with the tank opening in which the valve portion is received and defines a ball chamber in which a spherical ball is seated. The apparatus of the invention includes a stem which is movable through the valve portion flow passage for engagement with the spherical ball to thereby unseat the ball and open the valve flow passage. By unseating the ball, contents of the tank pass out of the valve flow passage and are directed either into the atmosphere or another vessel for reclaiming purposes.

Abstract: A combination safety and service valve including a body having a sealing portion for closing an opening in a high-pressure tank and an external portion which, when the sealing portion closes the tank opening, is positioned externally of the tank utilizes a ball chamber in its flow passage and a spherical ball loosely received in the chamber for preventing the escape of contents of the tank if the external portion were to separate from the sealing portion. The ball chamber is adapted to sealingly accept the ball at its outlet end, and the ball is of such size that a pressure differential across the ball chamber urges the ball into sealing engagement with the ball chamber outlet. A stem associated with the external portion of the valve body prevents the ball from engaging the chamber outlet end until the external portion is separated from the sealing portion.