ZDR6DP3-4X/75YM/12

The ZDR6DP3-4X/75YM/12 pressure reducing valve is part of the ZDR Pressure Reducing Valves series from Bosch Rexroth and is used to hold a defined downstream pressure in automated hydraulic systems. Its 3-way pressure reducing function diverts excess flow to tank so branch circuits stay within set limits. Direct-operated actuation shortens response time by having the control spool react without a pilot stage. Secondary pressure is limited to 75 bar, protecting sensitive actuators that cannot tolerate full system pressure. A lockable rotary knob with scale is provided for setting this limit, allowing operators to record and secure the chosen value. Pressure reduction is carried out on port P so the primary supply is conditioned before it reaches the controlled line. Internal pilot supply feeds control oil from the inlet, simplifying external piping, while the pilot return is routed through external port T(Y) to prevent back-pressure from influencing the setting. The valve withstands a maximum operating pressure of 350 bar in the primary circuit.

The unit mounts as a sandwich plate, fitting into compact stacks without additional manifolds. Its interface follows ISO 4401-03-02-0-05, ensuring compatibility with standard size 03 subplates. Four ports are provided so flow, tank, pilot, and service connections are arranged according to common practice. A maximum flow rate of 50 l/min permits use in medium-capacity circuits, while a permitted counter-pressure of 160 bar at port T(Y) allows the tank line to share return headers without upsetting regulation. Approved hydraulic fluids include HL, HLP, HLPD, and HFC, giving flexibility to match mineral or water-glycol media specified in the plant. Tight sealing is maintained by NBR seals, which are suited to the listed fluid group. The complete assembly weighs 1.301 kg, allowing manual installation during maintenance without lifting equipment. These characteristics integrate the valve into pressure control modules where space, serviceability, and fluid compatibility are critical.