Butterfly Dampers

Butterfly dampers are typically used to intercept or regulate gas flows; they are similar to single-louver dampers with one blade and they can be used in round or square/rectangular ducts. Blade is typically designed with air-foil configuration which minimizes the pressure drop; shafts are made of solid section and “stub” type to be connected to the blade by keys and blocks. This basic rule of design will optimize the assembly operations reaching high accuracy; in addition, in case of need, the blade can be removed from the damper frame without removing the complete unit from ductwork. Actuation system is normally by electric actuator, pneumatic actuator or manual by irreversible gear box.Butterfly dampers can be supplied with internal or external fiber insulation or, when required, with internal concrete (refractory) insulation. A large variety of metals are used in design and fabrication, from simple carbon steel to stainless steel and low-alloy/high-alloy materials.