1. Pneumatic actuator: The actuators used in most industrial control occasions are pneumatic actuators, because the air source is used as power, from the maintenance point of view, pneumatic actuators are easier to operate and calibration than other types of actuators, and can easily realize positive and negative exchanges on site. Its biggest advantage is safety. When using a positioner, it is ideal for flammable and explosive environments, and if the telecommunications signal is not explosion-proof or intrinsically safe, there is a potential risk of fire caused by ignition. Therefore, the application range of electric control valve is getting wider and wider. However, in the chemical industry, pneumatic control valve still occupies an absolute market advantage.
2. Electric actuator: Electric actuator is mainly used in power plants or nuclear power plants, because a smooth, stable and slow process is required in the high-pressure water system. The main advantages of electric actuators are high stability and constant thrust that users can apply. The thrust generated by the maximum actuator can be as high as 225000kgf. The anti-deviation ability of electric actuators is very good, 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 it is equipped with a servo amplifier, it is easy to realize the exchange of positive and negative effects, and it can also easily set the status of the cut-off signal valve (hold/fully open/fully closed), and when it fails, it must stay in place, this is not done by pneumatic actuators. Pneumatic actuators must rely on a combined protection system to achieve positioning.