Pilot operated pressure unloading valves series R5U are exceptional – both in function and design – even under high flow conditions. They are part of the Parker valve range with SAE flanges which is unique in its variety. Series R5U has a similar design to the subplate mounted R4U series.

R5U valves are used to unload a circuit at low pressure. The SAE flange allows to mount the valve directly on the outlet flanges of pumps. A typical application is the unloading of pumps in an accumulator circuit. The combination of an R5U, C5V and R5V on a double pump generates a high pressure/low pressure system without the need of a manifold block or piping between the valves. The R5U is optionally available with a vent function for unpressurized circulation.

Markets:
• Industrial

Features/Benefits:
• Maximum adjustable pressure of 350 bars and flow capacity ranging from 90 l/min to 600 l/min - high performance
• Sophisticated pilot stage design - reduces pressure overshoot and cracking flow to a minimum, thus reducing heating, power and production losses in high pressure operation
• Design combines a poppet type seat valve with the pilot control - precise adjustment and quick response to eliminate pressure variation and system shocks
• Short delivery time - no warehousing necessary
• 3-port body with SAE61 flange - enables compact design
• 4 sizes (SAE ¾", 1", 1¼", 1½")
• 3 pressure stages
• 3 adjustment modes
    - Hand knob
    - Acorn nut with lead seal
    - Cylinder lock
• With optional vent function

Applications:
• Suitable for general hydraulic applications

Pilot Operated Pressure Unloading Valve, SAE Flange - Series R5U