Temperature relief valve with thermal trigger

A pressure relief valve for use with a receptacle containing compressed gas, the pressure relief valve comprising:

• a first valve body having an inlet, an outlet and a flow path between the inlet and the outlet, the first valve body configured to be connectable to the receptacle so that the inlet is in communication with an interior of the receptacle, the flow path of the first valve body being configured to define an orifice within the first valve body, the orifice having a longitudinal axis and a diameter;
• a second valve body having a first end, a second end opposite the first end, a longitudinal axis and a longitudinal passage extending from the first end to the second end, the longitudinal passage defining a secondary flow path, the second valve body positioned in the flow path of the first valve body such that the first end of the second valve body sealingly engages the orifice of the first valve body;
• a seal in the longitudinal passage of the second valve body, the seal blocking the secondary flow path;
• a movable member within the flow path of the first valve body adjacent the outlet, the movable member being coaxially aligned with the orifice and the longitudinal passage of the second valve body, the movable member being movable from a first position to a second position;
• bias means in operable association with the movable member for biasing the movable member toward the second position;
• and
• a thermally responsive restraining member operably coupled with the movable member, the restraining member holding the movable member in the first position when ambient temperature is below a predetermined temperature threshold, the restraining member releasing the movable member when the ambient temperature is above the predetermined temperature threshold so as to allow the movable member to move to the second position to interrupt the seal in the longitudinal passage of the second valve body and thereby expose the secondary flow path, wherein exposure of the secondary flow path interrupts the seal between the second valve body and the orifice to expose the flow path of the first valve body.

A method of releasing compressed gas from a pressurized system, the method comprising the steps of:

• providing a first valve body having a primary flow path for releasing a compressed gas from an interior of the pressurized system, the primary flow path in communication with an interior of the pressurized system;
• providing within the primary flow path a movable second valve body having secondary flow path;
• blocking the primary flow path with the second valve body;
• providing a seal in the secondary flow path in the second valve body;
• providing a movable member within the primary flow path adjacent to the seal, wherein the movable member is maintained in a spaced relationship with the seal when the temperature is below a predetermined temperature threshold;
• releasing the movable member when the temperature is above a predetermined temperature threshold, wherein the movable member interrupts the seal in the second valve body to expose the secondary flow path;
• and
• exposing the primary flow path.