Parker’s series of 2-way, pilot-operated directional control valves feature a robust design for maximum durability that can operate with hydraulic system flows as high as 100 lpm and pressures up to 420 bar. The high pressure and flow capabilities of Parker’s selection make these valves suitable for high flow switching or unloading applications within a broad range of markets, such as the aerial, construction, material handling and industrial markets.
Normally-open or normally-closed options are available depending on application needs, and can even be configured with an additional port in order to externally vent the spring chamber. Parker’s external spring chamber venting design is especially advantageous when high pilot pressures are not readily available, which will help ensure proper valve and system operation.
Markets:
• Aerial
• Construction equipment
• Material Handling Equipment
• Miscellaneous Industrial
• Miscellaneous Manufacturing
• Off-highway equipment
Features/Benefits:
• High flow and pressure capacity
• Two switching and one compensating spring available
• Very accurate flow regulation when used with separate orifice
• Sealed pilot option available
• Industry common cavity
• Hardened working parts for maximum durability
• All external parts zinc plated
Applications:
• Unloader valve
• Switching valve
Additional Technical Insight:
Parker’s 2-way, pilot-operated series of directional control valves are available both normally-open and normally-closed, with flow and pressure ranging up to 100 lpm (26 gpm) and 420 bar (6,000 psi) respectively. These valves open or close the main flow path by utilizing pilot pressure from elsewhere within the hydraulic system and acting against the internal spring which keeps the valve in its "normal" position. A selection of valves in this series use 3 ports, with pilot pressure entering port 1 (nose) of the valve, and main flow passing through ports 2 and 3 on the sides of the valve. When a pilot signal is supplied to port one, pressure acts upon the spool and compresses the spring, opening/closing the flow path from port 2 to port 3 (depending if the valve is normally-closed or normally-open). Simply, the pilot pressure will shift the valve from its normal position. Because the spring chamber is vented internally through port 3, it is advised that port 3 is located on the lower pressure side of the valve and/or the tank line. When the pilot signal is removed, the spring acts upon the spool forcing the valve back into its normal position. Pilot pressures of 5 and 10 bar are available as standard options on this valve. This valve series also includes a selection of 2-way, 2 position, 4 ported valves. Similar to the 3 ported options, these valves receive the pilot signal at port 1, shifting the valve against the spring and opening/closing flow from port 2 to port 3, however the additional 4th port is connected to the spring chamber, thus allowing the oil to vent independently of the pressure seen at port 3. This additional 4th port feature adds flexibility for the hydraulic oil to flow either from port 2 to 3 or from port 3 to 2 with less effect on the pilot pressure and spring force interaction.
On the 3 ported valves, the 3rd port should be connected to the lower pressure flow path and/or ideally the tank line.
