Z2DB6VD2-4X/200V

The Z2DB6VD2-4X/200V pressure relief valve is produced by Bosch Rexroth for the ZDB Pressure Relief Valves series and is intended to limit line pressure in compact hydraulic automation blocks. It uses a sandwich plate connection so it can be inserted between standardized subplates in a stack. The porting pattern follows ISO 4401-03-02-0-05, allowing direct fitment without additional adapters. Size 6 passages provide the flow area expected in small power units while keeping the envelope minimal. A relief function that works from A to B and from B to A protects both service ports, preventing over-pressure regardless of flow direction. The assembly tolerates operating pressures up to 315 bar, and its set pressure can be adjusted up to 200 bar to match individual circuit requirements. Pressure tuning is carried out through a sleeve with a hex drive and a protective cap, giving field technicians access while guarding the setting against accidental change. Fastening is completed with M5 screws that secure the valve in the manifold.

Maximum flow capability is 60 l/min so the valve can handle medium-sized actuator circuits without excessive pressure drop. Counter pressure at the tank line may reach 40 bar, which defines the back pressure the spring chamber can withstand without influencing the setting. Pilot oil is drained externally via port T to isolate the control stage from manifold fluctuations and improve stability. FKM seals are installed to resist common mineral oils and many synthetic fluids used in modern installations. The required fluid cleanliness is ISO 4406 20/18/15, guiding filter selection to prevent spool wear. The unit can be mounted in any position, simplifying layout inside tight power packs. No locating hole is provided, so alignment relies on the sandwich bolts alone and eases machining of the subplate. A minimum fluid viscosity of 10 mm²/s is specified to ensure reliable damping in the pilot stage and consistent relieving behavior.