ABSTRACT
In pneumatic actuating systems, the electropneumatic control valve is the key element. This device controls the air flow to the actuator according to the drive current or voltage from the control system. Thus, an electropneumatic servo valve is the power element (together with actuator), in which a small-amplitude, low-power electrical signal is used to provide a high response modulation in pneumatic power. The dynamic response, null shift, threshold, and hysteresis are the most critical valve parameters that strongly influence the dynamic and static characteristics of the pneumatic actuator.
