The fire-fighting smoke and fire damper is a normally closed valve. The smoke prevention and exhaust valve is opened by the control center via a 24V DC stabilized power supply or manually, and closes automatically at 280℃; manual reset is required. Its function is: when the smoke temperature reaches 280℃, people have basically completed evacuation, and exhaust ventilation is no longer practically meaningful. At this time, the smoke already contains flames, so the valve closes automatically to prevent the fire from spreading.  The exhaust air outlets of the system can also use normally closed fire-fighting positive pressure air supply outlets, eliminating the need for fire-fighting smoke and fire dampers on the risers. In case of an accident, this air outlet is opened by the control center via a 24V DC stabilized power supply or manually, and closes automatically when the air volume of the 3C smoke exhaust valve reaches 280℃; manual reset is also required. A fire-fighting smoke and fire damper should also be installed at the inlet of the fire smoke exhaust fan room to prevent the fire from spreading to the floor where the fan room is located.