ZDR6DB2-4X/150YM

The ZDR6DB2-4X/150YM pressure reducing valve is part of the ZDR Pressure Reducing Valves series from Bosch Rexroth, intended to maintain stable downstream pressure in hydraulic automation circuits. It is built in nominal size 6 so it fits standard NG6 subplates without occupying extra space. The valve follows the ISO 4401-03-02-0-05 porting pattern, enabling direct mounting on common modular manifolds. Pressure is reduced through channel B, which specifies the internal flow path to the secondary circuit. Downstream setting is adjusted with a hex sleeve that is covered by a protective cap, allowing tamper-resistant tuning on site. Pilot oil is taken internally and returned externally, a configuration that simplifies supply lines while directing drain oil to tank. There is no integral check valve, therefore reverse flow must be handled elsewhere in the system. The sealing elements are made of NBR, permitting use with conventional mineral oils, and the unit can be installed in any position to ease layout within compact power packs.

The valve handles operating pressures up to 350 bar, ensuring it withstands typical high-pressure pump outlets while still limiting the secondary side to 150 bar for component protection. A counter pressure of 160 bar at port T is acceptable, allowing back-pressure-dependent circuits to function without instability. Flow capacity reaches 50 l/min so the device can supply medium-size actuators without excessive pressure loss. It tolerates hydraulic media with viscosities up to 800 mm²/s, which accommodates cold-start conditions or specialty fluids. Both ambient and fluid temperatures may rise to 80 °C, matching the thermal envelope found in most industrial machines. Cleanliness should meet ISO 4406 20/18/15 to avoid spool sticking and wear, emphasizing the need for adequate filtration. When these limits are observed, the ZDR6DB2-4X/150YM maintains accurate pressure reduction and supports reliable motion control in automated hydraulic equipment.