The difference and selection of electric valve and pneumatic valve

Nov 12, 2019

With the progress of the times and continuous reforms, China's valve products have also been innovated with the change of the times. At present, in the valve market where environmental protection and safety are getting louder and louder, the use of automatic control devices such as electric valves and pneumatic valves is gradually becoming more and more Or missing. The use of self-controlled valves is more energy efficient and safer and more reliable. Compared with the traditional manual valve, the speed of movement is faster than that of the ordinary valve, which not only reduces the manpower but also greatly improves the work efficiency.

Compared with pneumatic valves, the electric valve is simple in structure and reliable in operation, and its power source (power source or gas source) is easy to solve for long-distance operation points. The disadvantage is that the price is higher and the explosion-proof requirements are higher. When selecting, the factors such as the availability, price and control requirements of the power source should be considered comprehensively. The selection of the valve generally first confirms the valve material, valve diameter, media type, pipeline pressure, connection mode, control mode, medium temperature and other parameters.

Electric valve selection:

When the electric valve is selected (the control mode of the electric actuator is generally divided into the switch type and the adjustment type), in addition to the basic valve body diameter, pressure, material and other requirements, the following parameters should also be provided:

1. Power parameters (including voltage, phase and frequency);

2. Run time and the form of the electric actuator;

3. Whether explosion protection or explosion-proof grade is required;

4. Atmospheric protection level;

5. Overload protection requirements, such as over-travel protection, over-torque protection, etc.;

6. Local operation requirements, such as whether to operate the handwheel on the spot;

7. Operation instructions.

Pneumatic valve selection:

When pneumatic valves are selected (the operating principle of pneumatic actuators can be divided into single-acting and double-acting), in addition to determining the specific parameters such as valve body diameter, pressure, material, etc., the following parameters should also be provided:

1. Gas source parameters (including gas source pressure range, whether with self-contained gas storage tank, etc.)

2. Run time and form of pneumatic actuator

3. Whether explosion protection or explosion-proof grade is required;

4. Atmospheric protection level;

5. Overload protection requirements, such as over-travel protection, over-torque protection, etc.;

6. Local operation requirements, such as whether to operate the handwheel on the spot;

7. Operation instructions.

With the demand for industrial automation increasing significantly, the demand for electric (pneumatic) valves is increasing, and the control requirements for electric (pneumatic) valves are becoming more detailed and complex. The correct selection of electric (pneumatic) valves not only involves the correct use of the product, but also may affect the safety of the entire pipeline system. Users should understand and understand the relevant selection knowledge.