The smoke damper door is primarily composed of several parts, including the frame, blades, sealing strips, main shaft, bearings, shaft seal, crank and connecting rod mechanism, actuator, and sealing air system (auxiliary system). The frame is made by stamping steel plates or welding shaped steel, while the blades are formed by stamping and welding steel plates.
Special elastic sealing structures are installed between the blades and between the blades and the frame. The blades are designed in a hollow cavity shape. When the blades are in the closed position, a mechanical sealing barrier is first formed on the cross-section of the flue, followed by the introduction of sealed air at a pressure higher than that of the working medium by a certain amount, creating a high-pressure sealed air curtain, completely separating the front and back of the blades, ensuring the partition effect.

The shaft neck features a sealed structure and bearing, which boasts excellent sealing performance, no leakage, high-temperature resistance, and corrosion resistance. The bearing is equipped with automatic alignment and compensation functions, capable of automatically compensating for the coaxiality deviation of the front and rear shafts, ensuring minimal resistance, no jamming, and flexible rotation for the single shaft double-gate door. The crank and connecting rod mechanism is fitted with bearings to ensure minimal transmission resistance. For the heavy-duty single shaft double-gate doors, a double-armed heavy-duty crank and connecting rod mechanism is used to guarantee the flawless opening and closing action. The electric or pneumatic actuator can be directly connected to the driving main shaft or used with the crank and connecting rod mechanism for remote transmission. Depending on the system process and different usage locations, special materials or processes are employed for locations requiring corrosion resistance, ensuring high corrosion resistance.