German Rexroth Proportional Hydraulic Directional Valve 4WRA Series with 30 l/min Flow Rate 350 bar Maximum Pressure and 1 Year Warranty

4WRA6E1-20-1X/24NZ4/M
4WRA6EB05-1X/24NZ4/M
4WRA6E10-1X/24N9Z4/M
4WRA6E05-1X/24NK4/M
4WRA6EA20-1X/24NK4/M German Rexroth proportional hydraulic directional valve 4WRA

FAQ;

What are the most common failure modes and troubleshooting steps?

Common failures are often related to contamination or electrical issues :

• Valve does not respond / no movement:

◦ Cause: No electrical signal, coil failure, or severely stuck spool.

◦ Action: Check input signal and power supply. Verify coil resistance with a multimeter. Inspect for a spool stuck due to oil contamination .

• Erratic or unstable operation (cylinder drift, jerky movement):

◦ Cause: Contamination blocking the spool or orifices, worn spool, or issues with the feedback sensor in closed-loop models.

◦ Action: Check oil cleanliness and filters. Clean the valve internals. For electrical issues, verify signal integrity and check for excessive hysteresis .

• Increased leakage or unable to maintain pressure:

◦ Cause: Internal wear of the spool and sleeve or damaged seals.

◦ Action: Check for wear. Replace the valve or seals as necessary .

• Slow response:

◦ Cause: Air in the system, clogged damping orifices, or a failing solenoid.

◦ Action: Bleed air from the system. Clean the valve thoroughly .

8. How often does the valve need calibration?

Calibration ensures the valve's output (flow/pressure) accurately corresponds to the input signal. The frequency depends on the application's precision demands and operating conditions :

• General guideline: Annual calibration is a good baseline for valves under normal conditions .

• High-precision or harsh applications: Calibration may be needed every six months or even quarterly .

• After repair or modification: The valve should always be calibrated before being returned to service .

9. Can the 4WRA valve be repaired, and how is it calibrated?

Simple mechanical issues like a contaminated spool can often be resolved by a trained technician through disassembly and cleaning. However, repairing internal electronic components (e.g., a damaged solenoid or integrated amplifier) is complex.

Calibration is a specialized process that typically requires a dedicated test bench to adjust the mechanical zero (spool's neutral position) and the electrical zero (ensuring equal flow output for equal input signals in both directions) . This is best performed by qualified personnel using proper equipment.

10. Where can I find technical data like flow rates and pressure ratings?

This information is specific to each model code. You should consult the official Rexroth product datasheet or sample for the exact valve type (e.g., 4WRA 6 E30-2X/G24K4/V). Key specifications to look for include:

• Nominal Flow Rate: (e.g., 30 l/min at a pressure drop of 10 bar) .

• Maximum Operating Pressure (e.g., 350 bar) .

• Power Supply Voltage (e.g., 24V DC) .

• Input Signal Type (e.g., ±10V or 4-20mA for 4WRAE models) .

For specific model details and application engineering, always refer to the official Rexroth technical documentation or contact an authorized distributor .