ZDR6DP1-4X/25YM/12

The ZDR6DP1-4X/25YM/12 valve belongs to the ZDR Pressure Reducing Valves series and is produced by Bosch Rexroth for hydraulic automation circuits that need controlled secondary pressure. It is supplied in size 6, defining the port dimensions for compact manifolds. Direct-operated control lets the spool react to inlet pressure without pilot amplification, supporting fast response in low-flow branches. The adjustment uses a rotary knob, so technicians can set the required output pressure without tools. A secondary pressure limit of 25 bar protects downstream actuators from overload, while the inlet can accept up to 350 bar to maintain a wide safety margin between primary supply and reduced circuit pressure. Pressure reduction occurs through port P, isolating the regulated line from the main pump flow. Pilot oil is taken internally and returned externally through port Y, simplifying internal passages and keeping back-line pressure low. Sandwich plate mounting allows the valve to sit between standard subplates without extra piping.

The valve handles up to 50 l/min, making it suitable for moderate flow demands in auxiliary branches. Counterpressure at port T is permitted up to 160 bar, so back pressure in return lines does not disturb the set secondary pressure. Its porting pattern follows ISO 4401-03-02-0-05, ensuring interchangeability with other NG6 components. A G1/4 pressure gauge port enables direct connection of instrumentation for monitoring the reduced line. Because installation position is unrestricted, designers can place the unit in any orientation without affecting performance. There is no integrated check valve, which prevents unintended bypass and keeps the design simple. Four ISO 4762 M5-10.9 screws secure the stack, providing the clamping force needed for gasket sealing. Cleanliness should meet ISO 4406 20/18/15 to avoid spool sticking and wear, highlighting the importance of filtered oil in precision pressure control systems.