How to choose pneumatic and electric actuators?.

Do you know electric actuators and pneumatic actuators? This article will compare electric actuators and pneumatic actuators to help you better choose the appropriate actuator.

 

 

Basic knowledge of pneumatic actuators and electric actuators

1. Pneumatic actuator

Nowadays, most of the actuators used in industrial control applications are pneumatic actuators, because air source is used as power, which is more economical than electric and hydraulic, and the structure is simple, easy to master and maintain.

 

Its biggest advantage is safety. When using a locator, it is ideal for flammable and explosive environments, and if the electrical signal is not explosion-proof or intrinsically safe, there is a potential risk of fire caused by ignition. Therefore, although the application range of electric control valves or electric actuator valves are becoming wider and wider, in the chemical industry, pneumatic control valves still occupy an absolute advantage.

 

The main disadvantages of pneumatic actuators are: slow response, poor control accuracy, and poor anti-deviation ability. This is because of the compressibility of the gas, especially when a large pneumatic actuator is used, air is required to fill the cylinder and empty time.

 

 

2. Electric actuator

Electric actuators are mainly used in power plants or nuclear power plants, because the high-pressure water system requires a smooth, stable and slow process.

 

The main advantages of electric linear actuator are high stability and constant thrust that users can apply. The anti-deviation ability of the electric actuator 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 more than that of the pneumatic actuator high.

 

The main disadvantages of electric actuators are: the structure is more complicated and more prone to failure; the motor runs to generate heat, if the adjustment is too frequent, it is easy to cause the motor to overheat, generate thermal protection, and increase the wear of the reduction gear.

 

 

Comparison of selection between electric actuator and pneumatic actuator

1. Anti-overload capability and service life

Electric actuators can only be used for intermittent operation, so they are not suitable for continuous closed-loop operation. The pneumatic actuator has the ability to resist overload and is maintenance-free throughout its service life. No oil change or other lubrication is required. Its standard service life is up to one million switching cycles, so the pneumatic actuator is superior to other valve actuators.

 

2. Security

Pneumatic actuators can be used in potentially explosive situations, especially in the following situations: explosion-proof valves are required; valves need to be installed outside the explosive area, pneumatic actuators used in explosive areas must be driven by air pipes; electric actuators are not easy to It is used in potentially explosive situations and has high cost.

 

3. Assembly

Pneumatic technology is very simple. The installation of the pneumatic actuator on the valve drive head and the connection and drive of the air source processing device can be easily achieved. In addition, the maintenance-free design of the pneumatic actuator ensures that it is convenient and easy to install and run.

 

4. Components

Pneumatic valve components have high vibration resistance, are strong and durable, and generally will not be damaged. Even high temperatures will not damage corrosion-resistant components. Electric actuators are composed of a large number of components, which are relatively easy to damage.