This product is a small hydraulic power unit equipped with an electro-hydraulic actuator, which is designed and produced independently by our company through the introduction of advanced hydraulic control technology from Europe. The pump, motor, and hydraulic control components in the unit are all high-quality products of international leading brands. The opening/closing of the single-acting power unit ATSR/DCB is driven by hydraulic pressure, and it resets by mechanical spring. The output flow of the power unit is 1.0L/min, 2.15L/min,4.3L/min, and 6.0L/min, respectively, which can be flexibly selected according to the user's switching time requirements of the actuator. The common regulating electro-hydraulic actuator adopts a frequency conversion motor, which can adjust the valve opening degree arbitrarily according to the control signal of 4~20mA, and the adjustment accuracy is about 0.6-0.8%. High precision adjusting type is driven by a high-performance servomotor, and the highest adjustment accuracy can reach about 0.1-0.2%.