The full name of Electric volume control damper is Duct Volume Control Damper, which is used to adjust the air volume in the exhaust gas treatment and exhaust pipeline, and is resistant to acid and alkali. The diameter below 315 is a one-time forming duct damper, and the diameter above 315 is made by manual processing. The PP duct damper is an accessory of the PP duct damper, which is indispensable in the exhaust engineering. Different, the air volume changes, each tuyere cannot guarantee the same air volume, so the PP air duct is installed with the tuyere to adjust the cross-sectional area of the tuyere and maintain a constant wind speed and air volume. The installation of PP duct damper linkage pressure controller and fan frequency converter in the exhaust system can control the air volume, reduce the frequency of the fan, and save energy and protect the environment.