R901502770 4WRDE16W8-150L-6X/MXY/24A5 German Rexroth proportional directional valve

FAQ:

1. 3-Stage Design & High Dynamics

   Unlike standard 2-stage valves, the 4WRDE series uses a 3-stage amplification​ (pilot + main spool). The pilot stage is a high-response nozzle-flapper system (4WS2EM6), which provides exceptional dynamic response and is ideal for servo-grade applications.

2. Control Signal (/A5)

   The /A5​ suffix indicates a ±10 V DC voltage input​ for the command signal. This valve also outputs a ±10 V DC actual value signal​ representing the main spool position, enabling full closed-loop control via an external controller.

3. Pilot Oil Configuration (/MXY)

   This valve requires external pilot oil supply (X port) and external pilot oil return (Y port). You must provide clean, filtered pilot oil to the X port and ensure the Y port drains directly to the tank with minimal backpressure (typically < 10 bar).

4. Spool Type (W8)

   The W8 spool​ is an overlap spool​ (positive overlap). This design minimizes internal leakage when the valve is in the center position but requires a higher deadband control signal to initiate movement. It is suitable for applications where holding position and minimal leakage are critical.

5. Critical Installation Notes

   • Drain Line:​ The external pilot drain (Y port) must be connected directly to the tank with a dedicated line. Backpressure on Y must be kept low.

   • Cleanliness:​ Maintain high oil cleanliness (recommended NAS 1638 Class 8 or ISO 4406 20/18/15) due to the sensitive nozzle-flapper pilot stage.

   • Pilot Supply:​ Provide clean, regulated pilot pressure to the X port (typically 25–315 bar).