The advantages of pneumatic butterfly valves are as follows:

1. It is convenient, quick, labor-saving, and has low fluid resistance. It can be operated frequently.

2. Simple structure, small size and light weight.

3, can transport mud, the least amount of liquid accumulated in the pipe mouth.

4, under low pressure, can achieve a good seal. 5, the adjustment performance is good.

The disadvantages of pneumatic butterfly valves are as follows:

1. The use pressure and working temperature range are small.

2. Poor sealing.

The butterfly valve can be divided into a bias plate type, a vertical plate type, a slant plate type and a lever type according to the structure. According to the sealing form, it can be divided into two types: a relatively sealed type and a hard sealed type. The soft seal type is generally sealed with a rubber ring, and the hard seal type is usually sealed with a metal ring. According to the connection type, it can be divided into flange connection and clip type connection; according to the transmission mode, it can be divided into manual, gear transmission, pneumatic, hydraulic and electric.

First, reliability

Before we used to think that pneumatic valves have high reliability and the reliability of electric valves is poor. However, the new generation of electric valve actuators for pneumatic butterfly valves adopts new circuit integration technology. After abandoning the previous Achilles heel, the actuator can be used for an average of 5-10 years to meet or exceed the service life of the pneumatic valve. Therefore, in terms of reliability, both types of valves have their own advantages.

Second, the power source

In the occasions where the explosion-proof requirements are extremely high, pneumatic valve actuators are mostly used. One of the advantages of pneumatic valves is intrinsically safe explosion-proof, and the disadvantages are obvious. It is necessary to establish a relatively complete pneumatic mechanism and increase the configuration cost. The electric valve actuator can be taken locally, and the electric valve is preferred when the explosion-proof requirements are not high and the air source is inconvenient.

Third, the price

The electric valve actuator is basically the same as the pneumatic valve actuator + valve positioner. Pneumatic butterfly valves know that the prices of the two products, whether domestic or imported, are comparable. Pneumatic valves need to be equipped with air source facilities such as air compressor stations, so the choice of electric valves has an advantage in price.

Fourth, the output is obvious

The choice of actuator is based on the type of valve and the allowable differential pressure. Therefore, the specific selection should be determined according to the actual situation, which needs to be flexible.

Five, fire and explosion protection

At the level of fire and explosion protection, the pneumatic actuator + valve positioner is far superior to the electric actuator:

1. Only a few electric actuators can be produced into an explosion-proof series.

2, high flammable, explosive and other special occasions are usually not allowed to use electric actuators.