ZDB Pressure Relief Valves

The Bosch Rexroth ZDB Pressure Relief Valves are pilot-operated pressure relief valves available as sandwich plate valves for use in hydraulic stack systems. They work by using an internal main stage and a pilot stage: when the pressure at the inlet port exceeds the set pressure, the pilot stage opens to relieve a small amount of fluid, causing the main spool to shift and dump the main flow to the tank. The key function of the ZDB valve is to limit the maximum pressure within a hydraulic circuit, thereby protecting the system from damage. The valves feature four pressure ratings and various adjustment types, such as a rotary knob or protective cap. The ZDB type controls one port, while the Z2DB type uses two pressure valve cartridges to control two ports.