3-Way Pilot-Operated Directional Control Valves

The high pressure and flow capabilities of Parker’s selection make these valves suitable for high flow switching, diverting, bypassing, or unloading applications within a broad range of markets, such as the agriculture, construction, material handling and industrial markets.

Normally-open or normally-closed options are available depending on application needs, and can even be configured with a vent to atmosphere option for the spring chamber.

Parker’s spring chamber vent to atmosphere design is especially beneficial when high pilot pressures are not readily available, which will help ensure proper valve and system functionality.

Parker’s 3-way, pilot-operated series of directional control valves are available both normally-open and normally-closed, with flow and pressure ranging up to 90 lpm (24 gpm) and 420 bar (6,000 psi) respectively.

Two versions of both the normally-open and normally-closed are available at varying flow and pressure ratings depending on the application needs.

This series of valve acts as flow diverters and redirects the hydraulic fluid’s flow path from the valve’s neutral position to its shifted position by providing external pilot pressure to port 1 (nose) of the valve. The neutral or un-shifted position of the normally-open valves allow bidirectional flow from port 3 to port 2, with the 4th port blocked. 

When pilot pressure is provided to port 1, the spool shifts and then redirects the flow to between the 3rd and 4th port, blocking port 2.

There is a selection of valves in this family that vent to atmosphere, allowing pressure equalization in the spring chamber. The remaining valves in this family vent the spring chamber internally through the 4th port, and as a result it is advised that port 4 is located on the lower pressure side of the valve and/or the tank line.

Also, any additional pressure seen at port 4 is additive to the spring setting, which may impact the pilot pressure necessary to shift the valve.

Pilot pressures of 2.8 bar (40 psi), 5.5 bar (80 psi), and 11 bar (160 psi) are available as standard options on the lower flow valves, and pilot pressures of 5 bar (73 psi) and 10 bar (145 psi) are available for the higher flow valves.

For all valves where the spring chamber is vented internally, the 4th port should be connected to the lower pressure flow path and/or ideally the tank line.