HXD type electric actuators is on the basis of electric putter and electric actuators, according to user's actual need, our factory introduction of foreign advanced technology and developed a new type of electric actuators. Suitable for all kinds of craft process of automatic control system. Accept DC4 ~ 20ma from the regulator control signal, realize new actuator due to linear displacement. This series actuator was used as damper actuators, with all the requirements of the damper itself action transformation function and the opening signal function and manual function. Because of its small size, especially suitable for the secondary air damper control of boiler. It is widely used in electric power, metallurgy, petroleum, chemical industry, light industry, environmental protection engineering projects, etc.