What are the disadvantages of electric actuators are used on

Valve electric actuator 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 electric actuators 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 225000 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 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. 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; Another is running slowly, from the regulator output a signal, the response and the regulator movement to the corresponding position, need a long time, this is not as good as pneumatic, hydraulic actuator.