The Firechek FC-4 Series valve is a heat activated pneumatic shut-off valve. When the FireChek senses excessive heat from a nearby fire, it immediately vents the pneumatic actuator and closes the actuator air supply line. FireChek triggers quickly, securing pneumatically operated process line valves. Because this valve responds to heat, not flame, it offers dramatically improved protection compared with conventional plastic tubing burn-through. It shuts off the air supply line to prevent plant air from feeding oxygen to a fire.