Regulating damper is used to regulate the flow of medium in the boiler smoke and air system. By rotating the baffles with a stroke of 900, different media flows can be achieved. In the boiler smoke and air system, it is often used to adjust the proportion of primary and secondary air and the temperature of the hot air entering the mill. It is usually installed in the cold and hot primary air duct before the coal mill entrance, and it is also used to regulate the flow of flue gas with trace ash particles in the flue and in the recirculating flue gas pipeline. This series of regulating baffle dampers cannot completely cut off the flow of the pipeline medium, so they need to be used together with closing baffle dampers and isolating doors.