The pressure regulator RP500 serves controlling larger volumetric flows up to 250 m3/h at 6 bar. The large secondary deaering cross section ensures quick deaering or adjustment of secondary pressure even in case of larger volumes. A sensor situated in the output area monitors the actual value which is continuously compared with the control signal. In case of deviations the control pressure in the piston chamber is adjusted via two solenoid valves. The piston operates the large main valve seat. Fast and precise settling of secondary pressure is achieved.