Pressure Reducing Valve, Series PRDM
The units of the series PRDM are direct-controlled pressure reducing valves. They regulate the pre-selected pressure in a hydraulic section below the general system pressure. There is also a pressure limiting function for the secondary circuit integrated in the unit (3-way type). A manometer or gage port is built onto the unit and enables the control of the secondary pressure. These valves are „closer“ units which allow the free flow of fluids through the controlled channel. If the pressure rises in this channel to the pre-set pressure, the spool moves in the closing direction and thus adjusts the pressure again. If the pressure should continue to rise due to external forces, the spool moves further against the spring forces and drains off fluid to the tank until the pressure no longer rises. The drained oil is drained off through the spool area into the tank.