Selas Automatic Fire Check Valves are safety devices designed to prevent flashback and backfire from propagating through fuel-air mixture lines in industrial combustion systems. The valve combines a check valve, fire screen and thermal release mechanism to provide reliable protection for burners, mixers and associated combustion equipment. During normal operation, the fuel-air mixture passes through the valve. In the event of a flashback, the resulting pressure increase causes the check valve to close and interrupt the flow. The integrated flame-arresting screen helps stop the backward-travelling flame, while the thermal release mechanism activates the shut-off valve to stop the fuel-air mixture supply. The Selas Automatic Fire Check Valve is suitable for installation in premixed gas-air supply lines close to burners or other potential flashback sources, helping protect personnel, equipment and combustion processes from flashback-related hazards.