Pneumatic actuator, electric actuator, hydraulic actuator or comparison

regulating pneumatic valve actuator is used in pneumatic actuator, electric actuator, hydraulic actuator ( Electric hydraulic actuators) The three, its use performance each have advantages and disadvantages, the points mentioned below.

and actuators with most of today's industrial control occasions actuators are used in pneumatic actuator, because the use of gas source in power, by contrast, is economical and practical than electric and hydraulic, and simple structure, easy to master and maintain. By the maintenance point of view, pneumatic actuators than other types of actuators is easy to operation and calibration, also can easily achieve positive and negative at the scene around the swaps. Its biggest advantage is safety, when using the locator, is ideal for flammable and explosive environment, and telecommunications, if it is not explosion-proof or intrinsically safe has the potential danger of fire caused by the flames. So, although now electric regulating pneumatic valve application scope is more and more widely, but in the field of chemical industry, pneumatic control pneumatic valve still occupies the absolute advantage.
is the main disadvantages of pneumatic actuators: the response is slow, poor control precision, poor ability to resist deviation, this is because the compressibility of the gas, especially when using large pneumatic actuators, the air filled cylinder and emptying time. But this should not be a problem, because many working condition does not require a high degree of control accuracy and extremely fast response and ability to resist deviation.

, electric actuators, electric actuators is mainly used in power plant or nuclear power plants, because in the high pressure water system needs a smooth, stable and slow process. The main advantage of the electric actuator is a high degree of stability and the user can be used of constant thrust, maximum actuators that generates the thrust can be as high as KGF, can achieve only so big thrust hydraulic actuators, but the cost is higher than the electric hydraulic actuators. Electric actuator deviates from the resistance is very good, the output of the thrust or torque is basically constant and can be very good to overcome the medium unbalanced force, to achieve accurate control of process parameters, so the control accuracy is higher than pneumatic actuators. If with servo amplifier, can easily achieve positive and negative role reversal, also can easily set off pneumatic valve position signal status ( Keep/open/close) And failure, must remain in situ, which is less than pneumatic actuators, pneumatic actuators must use a set of integrated protection system to achieve the position.
electric actuator faults mainly include: structure is complex, are more likely to happen malfunction, and because of its complexity, the technical requirements of maintenance personnel on the spot is relatively high; Motor running to generate heat, if the regulation is too frequent, easily cause motor overheating, thermal protection, it will also increase the wear reduction gear; The other is to run slower, output a signal from the controller and pneumatic valve response and to adjust the movement to the corresponding position, need a long time, this is not as good as pneumatic, hydraulic actuator.

and hydraulic actuators when abnormal need to deviate from the resistance and high thrust and the formation of fast speed, we tend to use hydraulic or electro-hydraulic actuator. Because the incompressibility of the liquid, the use of the advantages of hydraulic actuators is a better ability to resist from, this is very important for operating conditions, because when regulating elements closer to the pneumatic valve seat throttling condition is unstable, the more the pressure difference is big, the more powerful the situation. In addition, the hydraulic actuators to run smoothly, fast response, so can realize high precision control. Electric hydraulic actuators is the motor, oil pump, electro-hydraulic servo pneumatic valve is integrated into an organic whole, as long as connected to the power and control signals can get a job, and hydraulic actuators and cylinder, only higher pressure than cylinder ability, it is needed to outside of the hydraulic system, the need in the factory is equipped with hydraulic station and pipelines, in contrast, more convenient or electro-hydraulic actuator.
the main disadvantage of hydraulic actuator is expensive, check-up hulking, particularly complex and require specialized engineering, so most of them are used in some special occasions such as power plants, petrochemical.
the masses of users should be according to the actual conditions of their own needs, select the appropriate actuators.