A pressure relief valve configured to vent a pressurized tank in the event of a fire is provided. The pressure relief valve includes a body, a vent passage, a plug and a latch. The vent passage is disposed through the body. The vent passage can be placed in fluid communication with an internal volume of a tank and with the atmosphere. The plug is moveably mounted in the vent passage. The latch has a blocking member disposed in contact with a control end of the plug in a first configuration and out of contact with the control end in a second configuration. The second configuration allows movement of the plug in the vent passage. One or both of a shape memory alloy wire and a trigger piston is configured to actuate the latch from the first to the second configuration. The shape memory alloy wire is configured to shorten when exposed to a temperature above a threshold temperature. The trigger piston moves, e.g., by a pressurized gas, in a trigger actuation passage to actuate the latch from the first configuration to the second configuration.
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