What is the difference between electric valves and pneumatic valves?

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Hi, I’m the Industrial Control Assistant. Today, we’re sharing some industrial control knowledge related to valves. As you know, there are many types of valves, such as electric valves, pneumatic valves, and manual valves, among others. Do you all know what the differences between them are? Today, on this topic, we will introduce the differences between commonly used electric valves and pneumatic valves, as well as their respective characteristics. An electric gate valve is a type of valve that moves in a linear manner; it is used in conjunction with Z-type multi-turn actuators, and is available in both on/off and intelligent versions. This valve is simple to operate and is one of the most common on-off valves; it uses the upward and downward movement of a gate to open and close the fluid medium in the pipeline. It is widely used in industries such as electricity, metallurgy, petroleum, chemicals, papermaking, and sewage treatment. The pneumatic gate valve features a dual-cylinder pneumatic actuator, as well as a buffering mechanism and manual control along with protective devices. Thanks to its dual-cylinder structure, its lifting force is twice that of a pneumatic gate valve with a single cylinder. This fundamentally solves the problem of certain single-cylinder pneumatic gate valves getting stuck inside the valve body and failing to open. Difference between electric valves and pneumatic valves: 1. The fundamental difference between electric valves and pneumatic valves lies in the use of different driving devices, that is, actuators; there is no difference in the regulating valves themselves. The choice of different actuators is primarily determined by the operational requirements; in applications such as the chemical industry where explosion protection is necessary, pneumatic valves are most commonly used. They meet high safety standards, are inexpensive, and can be connected to a bus system using intelligent positioners, making their control method simple as well. 2. Pneumatic valves require a greater actuating torque compared to electric valves. The switching speed of pneumatic valves can be adjusted; they have a simple structure and are easy to maintain. Due to the cushioning properties of gas itself, they are less likely to get damaged due to jamming during operation. However, a gas supply is necessary, and their control systems are more complex than those of electric valves. Pneumatic valves are responsive, safe, and reliable; many factories with high control requirements set up compressed air stations specifically for pneumatic instrument control components. The power source for pneumatic valve actuators is air, which comes from air compressors. A positioner is used to convert electrical control signals into pneumatic control signals, thereby driving the pneumatic actuator to adjust the valve position. 3. The power source for electric valve actuators is electricity; if there are faults with the circuit board or motor, sparks can be generated. Therefore, they are generally used in environments with low requirements and where no hazards exist. When comparing the performance of pneumatic actuators and electric actuators, pneumatic actuators have a faster response time, which makes them more suitable for use in control applications. As a result, manufacturers of control valves also produce pneumatic actuators to go together with them. 4. The adjustment response speed of electric actuators is not fast enough; therefore, pneumatic actuators are used more frequently on control valves than electric actuators. Well, that’s all for this little piece of knowledge. It will be updated regularly, so feel free to follow!