Wind smoke dampers mainly used for ventilation and air-conditioning systems on the damper tube action, usually in the "normally open" state damper distribution, when the air temperature reaches 70 ℃, fuse action through the internal valve automatically closes. Exhaust port, exhaust valves provided on the main pipe exhaust system, or installed in the exhaust fan fire dampers suction port, usually in a closed state, in case of fire, through the linkage duct dampers automatically open row smoke. 1. The main choice points selection damper control parameter specifications. 2. damper suitable for ventilation and air conditioning systems, in addition to public buildings damper kitchen hood systems, operating temperature of 150 ℃, in general ventilation and air conditioning systems with fire dampers operating temperature of 70 ℃. 3. The damper is suitable for the pipe ventilation, air conditioning or exhaust system, the scope and application of the basic functions are shown in Table 1. Duct damper, Yanda air conditioning (certified), Ningxia damper by Wu County Yanda air-conditioning plant. Wu County Yanda air-conditioning plant (www.wcydkt.com) (www.wcydkt.com) Shandong Dezhou, heat, refrigeration and air conditioning equipment leader, over the years, the company is implementing the scientific management, innovation and development, honesty and trustworthiness policy, and satisfy customer needs. In Yanda air conditioning leadership with the staff warmly welcome all inquiries negotiations to create Yanda air conditioning better future.