FAQ:

FAQ: REXROTH 4WRA6 Series Proportional Valve

1. What is the REXROTH 4WRA6 proportional valve?

The REXROTH 4WRA6 is a direct-operated, proportional directional valve without electrical position feedback or integrated electronics (OBE). It controls the direction and volume of hydraulic fluid flow and is designed for subplate mounting per ISO 4401 standards. Its maximum operating pressure is 315 bar, with flow rates up to 75 L/min (depending on model) .

2. What are the key features of the 4WRA6 valve?

• Direct-operated design for precise flow control without external feedback .

• Proportional solenoid control with detachable coils and centering thread for easy maintenance .

• Spring-centered spool that returns to neutral when de-energized .

• Compatiblity with external electronics (e.g., Eurocard amplifiers) for signal control .

• Compact sizes: NG6 and NG10 .

3. How does the 4WRA6 valve work?

When an electrical signal is sent to the proportional solenoid, it generates a force that moves the spool proportionally. This adjusts the opening of flow paths between ports P (pressure), A/B (actuator lines), and T (tank), enabling continuous control of flow direction and volume. The spool returns to center via springs when de-energized .

4. Where is the 4WRA6 typically used?

This valve suits applications requiring precise hydraulic control, such as:

• Industrial machinery (e.g., presses, plastic injection molding) .

• Mobile equipment (e.g., cranes, excavators) .

• Systems needing directional and flow control without integrated electronics .

5. How do I select the right model?

Model codes indicate specifications (e.g., 4WRA6E07-2X/G24N9K4/V):

• 4WRA6: Series and size (NG6).

• E07: Spool type and control configuration.

• G24N9K4: 24V DC supply, corrosion-resistant coating .

Consult REXROTH datasheets or suppliers for exact requirements like flow rate, spool type, and electrical inputs .

6. What are critical installation notes?

• Use the specified subplate (ISO 4401) to avoid leakage .

• Ensure the tank line is never unloaded; a pre-load valve (~2 bar) may be required .

• Verify electrical connections (e.g., 24V DC) and coil compatibility .

7. How is maintenance handled?

• Regularly check for spool sticking or contamination.

• Clean filters and monitor hydraulic fluid quality.

• Replace coils or seals if movement is sluggish .

8. What if the valve fails to respond?

• Check power supply to the solenoid .

• Inspect for debris blocking the spool .

• Verify external amplifier signals (if used) .

If issues persist, contact technical support.