Why do important valves mostly use pneumatic valves instead of electric valves?
1. Safety considerations
Pneumatic valves are inherently safe. In a complex working environment, there are a large number of electrical equipment and potential electrical interference sources. Electric valves are driven by electricity. Once they encounter electrical faults such as short circuits, leakage, overload or electromagnetic interference, their control systems are likely to malfunction. For example, near areas with strong electromagnetic radiation, electric valves may receive wrong signals and accidentally open or close, which will bring serious safety hazards to the operation of the entire system.
Pneumatic valves use compressed air as their working power and do not rely on electrical signals, so they are minimally affected by electromagnetic interference and can operate stably and reliably in complex electrical environments to ensure system safety. In addition, in areas where flammable and explosive gases may exist, such as near gas transmission pipelines, the use of electric valves may cause explosion hazards due to factors such as electric sparks, while pneumatic valves do not generate electric sparks during operation, making them safer to use in such dangerous areas.
2. Reliability comparison
The structure of pneumatic valves is relatively simple, mainly consisting of cylinders, pistons, valve bodies and other components. This simple mechanical structure makes the probability of failure relatively low. In contrast, electric valves contain complex components such as motors, reducers, and control circuits. For example, long-term operation of the motor may cause overheating and damage, and the electronic components in the control circuit may also fail due to aging, moisture, and other factors.
Pneumatic valves can work stably as long as the compressed air supply is stable and the main components such as cylinders and pistons are normal. In terms of maintenance, the maintenance of pneumatic valves is relatively simple, and it is easier for technicians to understand and deal with problems that arise. Generally, the normal function of the valve can be restored by simple operations such as checking the air source pressure and replacing seals. Fault diagnosis and repair of electric valves require professional electrical knowledge and complex tools.
3. Comparison of response speed
Pneumatic valves can open and close quickly. When the factory encounters an emergency, such as pipeline leakage or overpressure, the valve needs to respond quickly to cut off the fluid. The action speed of pneumatic valves can be quickly adjusted by adjusting the air source pressure, etc., and the action can usually be completed in a few seconds or even less. The action speed of electric valves is limited by factors such as motor speed and reducer transmission ratio, and the action is relatively slow. For example, in the case of emergency cut-off of steam pipelines, pneumatic valves can stop steam leaks faster and reduce accident losses.
4. Cost factors
From a cost perspective, pneumatic valves have advantages in both initial investment and operating costs. The price of pneumatic valves is usually lower than that of electric valves of the same specifications because they have a simple structure and do not have complex motors and control circuit components. In terms of operating costs, although compressed air needs to be provided, the compressed air system can serve multiple pneumatic devices. After the cost is shared, the operating cost of each pneumatic valve is relatively low. Moreover, pneumatic valves have certain advantages in energy utilization efficiency compared with electric valves in some cases, and their energy consumption is mainly the consumption of compressed air.
5. Environmental adaptability
In terms of environmental adaptability, pneumatic valves perform well. The working environment of the factory may be very harsh, including high temperature, humidity, dust and other conditions. The main working parts of pneumatic valves are metals and seals, which have good tolerance to temperature and humidity changes. The electronic components in the electric door are easily affected by high temperature and humid environments and fail. For example, in a high temperature environment, the performance of electronic components may decline, resulting in valve control failure.
Due to the many advantages of high safety, strong reliability, fast response, low cost and good environmental adaptability, pneumatic valves are more commonly used rather than electric valves for important valves in factories.
