Electric actuators are a common type of actuator and are a very modern device that can accurately control the position of valves. Its ability to stop further spread of danger while reducing plant losses to a minimum has made it popular. Its ability to resist deviation is very good, and the output thrust or torque is basically constant, which can well overcome the unbalanced force of the medium and achieve accurate control of the process parameters, so the control accuracy is higher than that of the pneumatic actuator. If equipped with servo amplifier, it can easily realize the interchange of positive and negative action, and also can easily set the state of broken signal valve position (hold/fully open/fully closed), and when it fails, it must stay in the original position, which is not possible with pneumatic actuator, and the pneumatic actuator must be protected by a set of combined protection system to realize the position preservation.
The actuator is an essential part of the automatic control system. Its role is to accept the control signal sent by the controller, change the size of the controlled medium, so as to maintain the controlled variable at the required value or within a certain range. Actuators can be divided into three categories according to their energy forms: pneumatic, hydraulic and electric. More and more factories adopt automatic control, manual operation is replaced by mechanical or automatic equipment, people require the actuator to play the role of interface between the control system and the mechanical movement of the valve, moreover, the actuator is required to enhance the work safety performance and environmental protection performance. In some dangerous occasions, the automated electric actuator can reduce the injury of personnel.
Its housing is light in weight because of the use of aluminum alloy. Moreover, the surface and exterior are anodized and the exterior is coated with polyester powder, which is highly corrosion resistant. The motor output torque is large, and the built-in thermal protection switch for temperature control can avoid damage to the motor. The clutch can be operated manually by pulling the clutch handle when power is not applied. When power is applied, the clutch is actively reset. Position indicator – The indicator is installed on the center shaft, which can investigate the valve position. And there is an indicator available for selection. Dryer – Used to control the temperature, to avoid moisture coalescence inside the actuator, and to keep the internal electrical components dry.
The equipment must be stored in a clean, cool and dry area, the top cover must be equipped and the terminals must be sealed, the storage area must be elevated off the ground, and the actuator must be carefully and accurately operated after delivery to the site, away from risky things. Under normal circumstances, the actuator should be repaired once every 6 months, but if the operating environment of the actuator is more severe than usual, it is recommended to increase the repair frequency. Make sure that the valve and actuator are well adjusted, the wires are insulated, the terminals are accurately connected and secure, the screws are locked, the internal electrical structure is cleaned, the terminals are accurately connected and kept dry, the internal condensing equipment, and the power supply of the dryer. Check whether the “O” ring is sealed and the “O” type is not damaged in the edge of the electric actuator. Check whether the organization of the brake clutch and the operation of the actuator switch are normal.