Parker’s family of dual pilot operated check valves feature a space and cost saving design that fits in a common industry cavity and can operate with hydraulic system flows as high as 226 lpm and pressures up to 350 bar. The internal pilot piston of Parker’s selection make these valves suitable for load and position holding applications within a broad range of markets, such as the aerial, construction, material handling, industrial markets, and many more. These reliable valves have pilot ratios of 3:1 and 4:1 as available options depending on application needs.

Markets:
• Aerial
• Construction Equipment
• Forestry Equipment
• Material Handling Equipment
• Miscellaneous Industrial
• Miscellaneous Manufacturing
• Miscellaneous Mobile

Features/Benefits:
• Cost effective – replaces two cartridges
• Hardened, precision ground parts for durability
• Internal pilot piston
• Common cavity
• All external parts zinc plated

Applications:
• Load holding
• Position holding

Additional Technical Insight:
These valves use a standard pilot piston and two standard Parker check valves in an assembled body. At rest the check valves remain seated, blocking flow from entering and exiting the cylinder and locking the cylinder in place. When system pressure is applied to either valve port, the check valve will open allowing free flow from the inlet to the actuator port across the check valve. As pressure builds to shift the cylinder, the internal pilot piston, utilizing a 3:1 or 4:1 ratio, will respond quickly to the system pressure and will shift against the return check.  This action mechanically pilots the valve open to allow return flow to pass through the valve from the actuator back to tank.  With both ports now open, the valve is unlocked and the hydraulically powered cylinder is free to move.  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.