The fire damper is an important safety device in the air-conditioning system, and its fusing shut-off temperature is 70°C. When the fire damper is manufactured, the thickness of the shell steel plate should not be less than 2 mm to prevent the deformation of the shell from affecting the closure of the valve plate in a fire state. The movable parts such as valve bearings must be made of corrosion-resistant materials such as brass, bronze, stainless steel and galvanized steel, so as to avoid failure due to corrosion affecting the action of valve parts in the event of a fire. The fusible sheet of the fire damper is a key component and must be made of regular products instead of nylon rope or film. The inspection of the fusible sheet should be carried out in a water bath, and the allowable deviation between its melting point temperature and the design requirement is -2. The fusible strip is to be installed on the windward side of the valve plate. After the production is completed, an air leakage inspection should be done to ensure that the valve plate is tightly closed and can effectively isolate the air flow.