Pilot Piston Style Pilot Operated Check Valves

Parker’s reliable pilot piston style P.O. check valves are designed for critical applications where safety and load holding is required and flows from 38 to 226 lpm (10 to 60 gpm) and pressures up to 350 bar (5,000 psi) are needed. These valves are generally used in conjunction with linear actuators across several markets within mobile or industrial hydraulics, such as aerials, material handling, and construction where durable and low leak valves are necessary to keep the machinery and operators safe.

Markets:
• Aerial
• Construction
• Material Handling
• Miscellaneous Mobile

Features/Benefits:
• Spherical poppet for low leakage
• Hardened precision ground parts for durability
• “D”-Ring design eliminates back-up rings
• Optional sealed pilot piston

Applications:
• Load holding without fine metering

Additional Technical Insight:
The CSP(H) series uses a standard pilot piston and a standard Parker check valve in an assembled body. At rest the check valve remains seated, blocking flow from exiting the actuator port and locking the circuit in place.  When pressure and flow are opened to the valve inlet, the check valve will allow free flow to the actuator.  The valve assembly also utilizes an internal pilot piston with a 3:1 or 4:1 ratio.  When sufficient pressure is applied to the pilot port, the piston will respond quickly and will shift against the return check.  This action mechanically pilots the valve open, unlocking the circuit, to allow return flow to pass through the valve from the actuator back to tank.  When system pressure is shut off to the valve, the valve will return to the holding condition restricting actuator movement and locking the system in place. These valves are ideal for load holding applications, where metering conditions are not required.