Selection between electric high-pressure control valves and pneumatic control valves

Pneumatic type has stable performance, while electric type offers rapid adjustment but at a higher cost

Electric adjustment is not actually fast; when choosing an electric version, the site’s explosion-proof requirements should be taken into account. If it is convenient to have a stable gas supply on site, pneumatic valves are generally chosen; nowadays, such valves are also easy to calibrate.

The electric adjustment is also very stable, and it’s not too expensive. For pneumatic systems, a positioner is needed as well, which makes maintenance rather troublesome. Industries such as printing and dyeing, woodworking, and rubber now mostly use electric tools, and the results are quite good

Pneumatic valves operate quickly and are suitable for harsh working conditions such as explosion-proof environments

The fundamental difference between electric control valves and pneumatic control valves lies in the use of different driving devices, that is, actuators; the control valves themselves are not different. 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 control 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. The power source for electric actuators is electricity; if there are faults with the circuit board or motor, sparks can occur, so they are generally used in environments with low requirements and where no hazards are present. The power source for the pneumatic actuator is air, which comes from an air compressor. A positioner is used to convert electrical control signals into pneumatic control signals, thereby driving the pneumatic actuator to adjust the valve position. When comparing the control performance of pneumatic actuators and electric actuators, pneumatic actuators have a faster response time, which makes them more suitable for use in control applications; therefore, manufacturers of control valves also produce pneumatic actuators to go with them. The adjustment response speed of electric actuators is not fast enough; for example, a ROTORK-type actuator can make only 1200 adjustments per hour. Therefore, pneumatic actuators are more commonly used on control valves than electric actuators. Electric actuators are expensive and have poor explosion-proof properties, but from an energy-saving perspective, they offer clear advantages, as pneumatic actuators need to maintain a certain air pressure at all times to function, resulting in high air consumption over the course of a year! Generally, electric ones are more commonly used in power plants, while pneumatic ones are more used in the petrochemical industry

The signal of an electric control valve can be transmitted from a great distance; in other words, its transmission range is quite large. However, since it comes from a power source, sparks are likely to be generated, so explosion-proof measures must be taken. On the other hand, the signal of a pneumatic system cannot travel over long distances, as its transmission is limited to a certain extent, which makes it unsuitable for long-distance transmission. But its transmission speed is very fast

Pneumatic valves can also be operated remotely; you might be confusing them with pneumatic gauges. The choice between pneumatic and electric systems is mainly based on the actual conditions at the site. Chemical plants typically have air compressors, which raise explosion-proofing concerns; therefore, pneumatic valves are generally used. Power plants and those enterprises that do not have air compressors, as well as those with less stringent requirements regarding explosion-proofing, can use electric valves. Personally, I think pneumatic valves are better than electric valves. Because the electric valve has a large dead zone, it is not very sensitive.

Learn* these phrases. It’s possible; I’ll go down and take a closer look. Thank you for the correction

Pneumatic valves are used in anti-corrosion and explosion-proof applications, while electric valves are generally used in thermal power plants

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Electric control valves for explosive environments are relatively expensive