Parker’s pilot operated relief valves provide a stable design with low pressure drop meant for continuous duty applications while operating with less hydraulic noise. These valves can work with pressures up to 420 bar (6000 psi) and flows up to 350 lpm (92 gpm) in a reliable and compact design that contains an integrated free reverse flow check valve. Parker’s pilot operated relief valves are ideal for relief or load holding applications within mobile equipment such as agricultural machinery, aerial equipment, refuse vehicles, industrial power unit systems, mining equipment, and other heavy duty fluid power pressure control circuits.

Markets:
• Agriculture
• Aerial
• Material Handling
• Miscellaneous Industrial
• Miscellaneous Manufacturing
• Miscellaneous Mobile

Features/Benefits:
• High flow capacity
• Leak free
• Compact design
• Hardened, precision ground parts for durability
• All external parts zinc plated
• Adjustable, fixed, or tamper resistant adjustments available

Applications:
• Load holding
• Actuator control
• Motor control

Additional Technical Insight:
This particular model of spool type pilot operated valve has a reverse check.  This allows flow to pass in the opposite direction, port 2 to 1.  This may be advantageous in an anti-cavitation application, or where reverse flow needs to be accommodated.

Pilot operated relief valves are available is -08 to -20 size cavity configurations.  This family of valves is best suited for continuous duty systems where the valve is asked to operate beyond any intermittent use.  They can be used to maintain system pressure for long periods of time.  Additionally, where systems may have large rates of change in flow, the pilot operated valves can accommodate these changes without excessive pressure rise or sometimes called pressure override.  Due to the flow opening areas through the valve, these spool type valves will operate more quietly than a conventional direct acting valve. One must also consider the leakage component as the spool is, by design, going to pass a small leakage flow, whereas a direct acting valve does not pass significant flow until the cracking pressure is reached.