What is the working principle of smoke control valve?

The fire protection valve should be installed in the air duct section close to the wall or floor, the fire protection valve on both sides of the partition wall should not be more than 200mm from the wall surface, both sides of the fire valve within 2.0 m of the pipeline and its thermal insulation material should be used non-combustible materials. The fire valve is installed in a air conditioning air duct system and operates on a temperature-controlled, fusible alloy that uses gravity and a spring mechanism to close the valve.

When a fire occurs, the flame enters the air duct, high temperature causes the fusible alloy on the valve to melt, or causes the memory alloy to produce the distortion to cause the valve to close automatically, uses in the air duct and the fire partition penetration occasion.