Explosion-proof fire dampers are suitable for use in ventilation and air conditioning systems in Zone 1 and Zone 2 locations where explosive gas mixtures are formed by explosive gases or vapors mixed with air (such as tunnels, chemical plants, coal mines, petroleum facilities, pharmaceuticals, nuclear power plants, military industries, subways, textiles, paint factories, arsenals, etc.). These dampers are installed on supply and return air ducts and are normally open. In the event of a fire, when the temperature inside the duct reaches 70°C (for smoke exhaust fire dampers, it is 280°C), the fusible link melts, and the damper automatically closes under the force of the torsion spring. Within a certain period of time, it can meet the requirements for fire resistance stability and integrity, serving as a smoke and fire barrier. When the damper closes, it outputs a closure signal.