ZDR Pressure Reducing Valves

Bosch Rexroth ZDR pressure reducing valves are pilot-operated, screw-in or manifold-mounted cartridge valves designed to limit the pressure in a specific part of a hydraulic circuit. These valves function by having the pressure acting on the spring-loaded main spool opposed by the pilot pressure sensed downstream, which opens the connection to the tank once the pre-set pressure is exceeded. When the pressure in the secondary (actuator) port reaches the set value, the spool modulates to restrict flow from the primary (pump) port, maintaining a controlled, lower pressure downstream. Their primary function is to ensure that pressure-sensitive components, like lower-rated actuators or clamping cylinders, are not subjected to the full system pressure. They are essential for applications requiring multiple operating pressures from a single pump source.