US Patent 7971798 Resettable thermal pressure relief device

A resettable thermal pressure relief device (TPRD) is disclosed. The TPRD includes a piston, a housing adapted to receive the piston and allow movement between an open and a closed position. The housing includes an actuator having a temperature sensitive material disposed therein. The temperature sensitive material volumetrically expands, increasing a length of the actuator and forcing a lever from a first position to a second position. The piston is held in the closed position by the lever in the first position. When the lever moves to the second position, the piston is allowed to move to the open position, allowing a fluid to flow through the TPRD from a high pressure vessel in communication therewith.