The actuator and adjustment mechanism of the pneumatic actuator are a unified whole. There are two types of actuators: diaphragm type and piston type. The piston type has a long stroke and is suitable for occasions requiring larger thrust; while the diaphragm type has a smaller stroke and can only directly drive the valve stem. Because pneumatic actuators have the advantages of simple structure, large output thrust, smooth and reliable movement, and safety and explosion-proof, they are widely used in power plants, chemical industries, oil refining and other production processes with high safety requirements.
The simplest feature of the electric actuator is that it uses electricity instead of manpower to control the valve. Convenient and convenient. As for the characteristics of the product, there are many to talk about, because there are different configurations according to different needs. Electric actuators are mainly used in power plants or nuclear power plants, because high-pressure water systems require a smooth, stable and slow process. . The main advantages of electric actuators are high stability and constant thrust that users can apply. The thrust generated by the largest actuator can be as high as 225,000kgf. Only hydraulic actuators can achieve such a large thrust, but the cost of hydraulic actuators is higher than that of electric actuators. Much higher. The anti-deviation ability of electric actuators is very good, and the output thrust or torque is basically constant. It can well overcome the unbalanced force of the medium and achieve accurate control of process parameters, so the control accuracy is higher than that of pneumatic actuators. high. If equipped with a servo amplifier, the forward and reverse effects can be easily interchanged, and the off signal valve position state (maintained/fully open/fully closed) can be easily set. When a fault occurs, it must stay in the original position. This is What pneumatic actuators cannot do, pneumatic actuators must rely on a set of combined protection systems to maintain position. Our company, Tianjin Bell, produces electric actuators, and we know this aspect well.
The characteristics of pneumatic actuators are: receiving continuous pneumatic signals and outputting linear displacement (after adding a power/pneumatic conversion device, it can also accept continuous electrical signals). Some can be equipped with a rocker arm to Output angular displacement. It has positive and negative functions. Movement speed is high, but becomes slower as load increases. The output force is related to the operating pressure. The reliability is high, but the valve cannot be maintained after the air source is interrupted (it can be maintained after adding a retaining valve). It is inconvenient to realize segmentation control and program control. It has simple inspection and maintenance and good adaptability to the environment. The output power is larger. It has explosion-proof function
Your question is too big. I can only briefly introduce the differences to you. You can learn the details one by one. For electric ones, you can contact me