Thermal relief valve with improved bayonet

Abstract

A thermally activated relief valve is used with a compressed gas storage cylinder. A valve body has a passage for communication with the interior of the cylinder. A metal disc sealing the passage has a first side exposed to the interior of the cylinder and a second side opposite the first side. A cutting end of a movable hollow bayonet is positioned in the passage of the valve body adjacent to the second side of the metal disc. A spring biases the bayonet toward the metal disc. A thermal trigger is operably coupled to the bayonet for holding the bayonet in spaced relation to the metal disc until the thermal trigger reaches a predetermined temperature threshold. Upon reaching the predetermined temperature threshold, the thermal trigger releases the bayonet thereby allowing the cutting end of the hollow bayonet to move toward the metal disc under force exerted by the spring to pierce the metal disc and thereby expose a flow path through the hollow bayonet. A portion of a wall of the bayonet, adjacent to the cutting end, is removed to prevent any potential remaining flap of the metal disc from wedging inside the hollow bayonet and blocking the flow path through the hollow bayonet.