What is the difference between electric and pneumatic valves?

What electric and pneumatic valves, each have advantages and disadvantages, suitable for working purpose, specific have the following: a, electric valve use motor to do the power, pneumatic valve using compressed air as power. （ ） Electric valve advantages: the liquid medium and large diameter gas effect is good, is not affected by climate. Is not affected by air compressed air pressure. Disadvantages: high cost, in the damp environment is bad. （ ） Pneumatic valve advantages: the gas medium and small diameter liquid effect is good, low cost, convenient maintenance. Disadvantages: being affected by the fluctuation of the air pressure of compressed air, in the northern winter vulnerable to empty air water effect, cause transmission part to freeze, not action. Second, the general pneumatic faster than electric, electric flashlight dual-use. And pneumatic hand, gas and the price is quite high. Three, electric valve used in some large diameter place because it is difficult to do but the stability of the electric valve pneumatic pneumatic switch is better than slow long time there will be a card tooth phenomenon of pneumatic actuator valve switch speed high accuracy but need stable air supply. Fourth, slow electric valve, electric valve can achieve explosion-proof brand isn't a lot; Pneumatic valve action quickly, explosion-proof relatively price is the bottom of the electric. Involves the chain also use electric valve, why? （ ） According to the local climate, weather if damp climate cannot use pneumatic valve, because the air with water. （ ） Electric valve can also realize interlock function won't increase additional cost, pneumatic realize interlock will increase, the position control valve increased costs. The advantages and disadvantages of electric valves and pneumatic valve what circumstances need to use pneumatic, electric valve without the need below what time use pneumatic instead of electric valve, what advantages and disadvantages between them, what about the price. In the moment than electric valve, pneumatic valve action of pneumatic valve switching speed can be adjusted, simple structure, easy maintenance, action for buffer characteristics of the gas itself in the process, not easy to damage due to get stuck, but must have a gas source, and its control system is more complicated than the electric valve. Electric valve electric, in places that have requirements of explosion-proof requirements do not apply, such as the environment has a large number of flammable gas, can only rely on the air. Response time is slower than the electric pneumatic. As accurate, electric pneumatic valve is based on air power. And electric valve is DianZhuan into electromagnetic energy powered, the sensitivity of electric valve is higher than the pneumatic valve, safety and reliability than pneumatic valve to the strong, simple maintenance is not as good as pneumatic valve, power is not as good as pneumatic valve to strong. Pneumatic valve control than electric valve to complex. And the cost is very expensive, if involves the automatic control, must add the electromagnetic directional valve, and the sensitivity of the electromagnetic directional valve directly affect the pneumatic valve. I'm more in favor of the first floor. As long as there is electricity, electric valves are available, and in some factory, a lot of tools and equipment is done with compressed air, this case may use pneumatic valve, because there are ready-made. Response is sensitive, safe and reliable, many factory of high control requirements for pneumatic instrumentation control components set the compressed air station.