Parker Pilot Operated Relief Valves RAH121S30

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 400 lpm (106 gpm) in a reliable and compact design. Parker’s pilot operated relief valves are ideal for limiting system pressure or in standard relief valve applications within mobile and industrial equipment such as agricultural, aerial, refuse, industrial power unit systems, mining equipment, and other heavy duty fluid power pressure control circuits.

Markets:
• Miscellaneous Industrial
• Miscellaneous Manufacturing
• Miscellaneous Mobile

Features/Benefits:
• High pressure and flow capacity
• Low leak ball and poppet designs
• Compact design
• Internal screens
• Hardened, precision ground parts for durability
• All external parts zinc plated

Applications:
• System pressure limiter
• Port/cross-port relief
• Swing relief
• Motor braking

Additional Technical Insight:
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.  Spool type relief valves should not be used in load holding application.