What is the difference between electric butterfly valve and pneumatic butterfly valve?

1. Under the condition of having a gas source, pneumatic butterfly valves are preferred, especially for media such as combustible gases and coal gas, which require quick opening and closing of valves and ventilation butterfly valves. Pneumatic butterfly valve actuators can be selected as double acting or single acting. Single acting pneumatic valves can be selected, and the valve can be normally open or normally closed. The spring mechanism inside the actuator will automatically reset when the gas source is lost, so that the valve can be automatically opened or closed. It is suitable for use in special working conditions with high safety requirements.

2. Electric butterfly valves have high power torque, can be operated manually or electrically, and have a high degree of automation. They can be remotely controlled through control boxes and PLCs, and are widely used in industrial pipeline control in industries such as chemical, metallurgical, and petroleum.

The structural characteristics of electric butterfly valves and pneumatic butterfly valves enable butterfly valves to be used for cutting off or connecting media in pipelines, as well as regulating media in pipelines, with good flow control characteristics. The valve stem is a through shaft structure with high strength and strong corrosion and abrasion resistance. When the butterfly valve is opened and closed, the valve stem only rotates horizontally in place, and the packing at the valve stem is not easily damaged, ensuring the sealing performance of the packing.
In addition, the valve stem is fixed to the butterfly cone pin, and the protruding part is designed to prevent bursting out. The structural characteristics of stainless steel butterfly valves are as follows. Compared to other types of valves, butterfly valves are more suitable for large-diameter valves. Electric regulating butterfly valves and flange type fluorine lined butterfly valves are both suitable for pipelines with corrosive flowing media. But as a type of soft sealed butterfly valve, their common disadvantage is that they are not suitable for high temperature environments.
The price will vary depending on the material, connection method, and even the pneumatic head used. Why is the double acting clamp type pneumatic butterfly valve cheaper than the single acting pneumatic head butterfly valve, and what is the difference between them? The price of clamp type pneumatic butterfly valves varies depending on the material used. If it is a single acting actuator, customers generally need to be asked whether they want a normally open or normally closed type. Pneumatic heads are generally classified into single acting and double acting, gear and rack type, fork type, diaphragm type, and piston type. Without a locator, it can only function as a switch. Only with a locator can adjustment be achieved.

The disadvantages of electric actuators are:
The structure is more complex and prone to malfunctions, and due to its complexity, the technical requirements for on-site maintenance personnel are relatively high; The operation of the motor generates heat, and if adjusted too frequently, it can easily cause the motor to overheat, resulting in thermal protection and increased wear on the reduction gear. Another type is slow operation, where the output signal from the regulator takes a long time and responds to the regulator valve moving to the corresponding position. Not as good as pneumatic and hydraulic actuators.

Advantages of pneumatic actuators:
Accept continuous gas signals and output linear displacement (can receive continuous electrical signals after powering on/gas conversion device). Some can be equipped with rocker arms to output angular displacement. It has both positive and negative functions.
The movement speed is high, but it slows down when the load increases, and the output force is related to the working pressure.
High reliability, but unable to maintain the valve after gas supply interruption (can be maintained after adding the holding valve). It is inconvenient to implement segmented control and program control. Easy to maintain and upkeep, with good adaptability to the environment. The output power is very high. It has explosion-proof function.