Advantages and Disadvantages of Electric Valve and Pneumatic Valve

Author:     Published time:2016-10-11 10:33     Reading times:499    

Electric valves

   Valve electric actuators are mainly used in power plants or nuclear power plants, because in the high-pressure water system needs a smooth, stable and slow process. The main advantage of the electric actuator is a high degree of stability and the user can apply a constant thrust, the maximum actuator thrust can be as high as 225000kgf, can achieve such a large thrust only hydraulic actuators, hydraulic actuators cost more than electric Much higher. The anti-deviation ability of the electric actuator is very good, the output of the thrust or torque is basically constant, can be a good medium to overcome the imbalance force, to achieve accurate control of process parameters, so the control accuracy than pneumatic actuators high. If equipped with a servo amplifier, you can easily achieve the exchange of positive and negative effects, you can easily set off signal valve position (keep / fully open / fully closed), and failure must stay in place, which is Pneumatic actuators do not, pneumatic actuators must rely on a combination of protection systems to achieve protection.

The shortcomings of electric actuators:

    The structure is more complex and more prone to failure, and because of its complexity, on-site maintenance personnel technical requirements are relatively higher; motor running to produce heat, if the adjustment is too frequent, likely to cause motor overheating, thermal protection, Will increase the wear on the reduction gear; the other is running slower, from the regulator output a signal to the valve response to the movement to the appropriate location, takes a long time, it is not as good as pneumatic, hydraulic implementation Place.

 

Pneumatic valves

   Valve pneumatic actuator actuator and adjustment mechanism is a unified whole, and its implementing agencies have two types of film and piston. Piston stroke length, apply to require a larger thrust of the occasion; and film-style trip is small, can only directly drive the stem. Because the pneumatic actuator has the advantages of simple structure, large output thrust, stable and reliable action, and safety explosion-proof, it has wide application in power plant, chemical industry, oil refining and other safety production processes.

The main advantages of pneumatic actuators:

1. Accept continuous gas signal, the output linear displacement (plus electrical / gas conversion device, you can also accept a continuous electrical signal), and some coupled with the rocker, the output angular displacement.

2. There are positive and negative function.

3. Moving speed, but the load increases when the speed will slow down.

4. Output force and operating pressure.

5. High reliability, but the gas source can not be interrupted after the valve to maintain (plus the retention valve can be maintained).

6. Inconvenience to achieve sub-control and program control.

7. Repair and maintenance is simple, good adaptability to the environment.

8. Output power is large.

9. With explosion-proof function.

 


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