Anti-surge protection device for pneumatic actuator, has position controller pneumatically controlling actuating drive, where two control signals are respectively produced by pressures of actuating drive and controller

摘要

The device (1) has a main valve (V) comprising a pneumatically adjustable actuating element, and a pneumatic actuating drive (SA) for positioning the actuating element. An electro-pneumatic position controller (SR) pneumatically controls the actuating drive, which is connected with an auxiliary valve (HV). The auxiliary valve is controllably formed by a differential element (U) e.g. inverse amplifier, which outputs a control signal (A2) for controlling the auxiliary valve. Two control signals (Z, A1) are respectively produced by pressures of the actuating drive and the position controller. An independent claim is also included for a method for position control of a pneumatic actuator.