What are the differences between the electric valve and the pneumatic valve?
Functions of the electric valves and pneumatic valves:
The
pneumatic valve is driven by a compressed air valve body switch valve. The electric valve refers to the use of an electric actuated control valve, so as to achieve the opening and closing of valves. The force of action is larger than ordinary
valves. The switching speed can be adjusted. It has a simple structure and it is easy to maintain. Then, what are the differences between the electric valves and the pneumatic valves? I believe that this problem is also how to choose the electric valve and pneumatic valve the first time. The price of the two valves is not very different. How can we choose them mainly according to the working conditions, the valve body component of the electric valve and the pneumatic valve is the same. The main difference is that the actuator drive mode is different. Pneumatic valves are powered by compressed air.
The differences between electric valves and pneumatic valves
1. The actuator action form of electric valves is divided into positive action, reaction, control form, regulation type and switch type. Input signal (4-20mA, 4-12mA, 12-20mA, 0-10mA). When the input signal is interrupted, the working position of the regulator can be freely selected to stop in situ, fully open, and fully closed. The output signal is 4-20mA. The power supply is (DC24V, 110V, 220V, 380V) 50/60Hz. The explosion-proof level is also divided into EXDIIBT4, EXDIICT4, EXDIICT5, and EXDIICT6 explosion-proof levels.
2. The actuator action form of pneumatic valves is divided into a single action, double action, control form, regulation type, and switch type input signal (4-20mA, 4-12mA, 12-20mA). The gas supply pressure is 140-400kpa. The fully open, fully closed, spring return function and adjustable configurable positioner can be selected for working position. The explosion-proof level is also divided into SIL1, SIL2, SIL3, SIL4 and intrinsically safe explosion-proof levels.
Advantages and disadvantages of the electric valve and the pneumatic valve
Electric valves
1. The advantages of the electric valve are more suitable for the valve matching on the large-caliber pipeline. The power supply is used as the power, and the torque value is sufficient. You can choose to attach a handwheel mechanism, as well as explosion-proof, and protection levels. The electric valves are not affected by climate, and they will not be affected by air pressure.
2. The disadvantage of the electric valve is that it is not good in a humid environment. The opening and closing process is slow to switch. The entire valve-switching action takes 15 seconds to complete. The cost will be relatively high for some requirements of the switch opening and closing time.
Pneumatic valves
1. The advantages of pneumatic valves are more suitable for small and medium-sized diameter pipelines. The use of compressed air transmission in the case of stable air pressure to switch quickly on and off the time of about 2.5 seconds. It can be opened and closed freely. It has low cost and it is easy to maintain.
2. The disadvantage of the pneumatic valve is that it is easily affected by air pressure fluctuations. It will cause the transmission part to freeze, and the cylinder to lose control. There is no reaction.
