Pilot-operated, pressure reducing/relieving valve with drain to port 4.

Externally drained, pilot-operated pressure reducing/relieving valves reduce a high primary pressure at the inlet (port 2) to a constant reduced pressure at port 1, with a full-flow relief function from port 1 to tank (port 3). Draining the pilot section at port 4 makes these valves insensitive to pressure at tank (port 3) and provides a means for remote control by pilot or 2-way valves.

• Maximum pressure at port 3 should be limited to 210 Bar.
• Pilot operated valves exhibit very low dead-band transition between reducing and relieving modes.
• Recommended maximum inlet pressure is determined by the adjustment range. The PVDA-LAN valve is tested with a 210 Bar maximum differential between inlet and reduced pressure.
• Pressure at port 4 should not exceed 350 Bar.
• Pilot operated valves exhibit exceptionally flat pressure/flow characteristics, are very stable and have low hysteresis.
• Pressure on the drain (port 4) is directly additive to the valve setting at a 1:1 ratio and should not exceed 350 bar.
• Pilot operated reducing, reducing/relieving valves by nature are not fast acting valves. For superior dynamic response, consider direct acting valves.
• Full reverse flow from reduced pressure (port 1) to inlet (port 2) may cause the main spool to close. If reverse free flow is required in the circuit, consider adding a separate check valve to the circuit.
• By controlling the pressure at the drain (port 4), the effective setting of the valve can be increased over the nominal valve setting.
• Incorporates the Sun floating style construction to minimize the possibility of internal parts binding due to excessive installation torque and/or cavity/cartridge machining variations.