4WRAE6W15-2X/G24N9K31/A1V Rexroth Proportional Valve NG6 315 bar

Product Overview

The 4WRAE6W15-2X/G24N9K31/A1V (Material No. R900908938) is a direct-operated proportional directional valve from Bosch Rexroth’s 4WRAE series. This NG6 (CETOP D03 / ISO 4401-03) valve is available in 4/2 or 4/3-way configurations with W-type spool symbol.

The valve is actuated directly by proportional solenoids with central thread, with spool displacement proportional to the electrical input signal, enabling precise control of flow direction and magnitude. The integrated On-Board Electronics (OBE) accepts 0–10 V analog control signals directly without requiring external amplifiers. As a 4WRAE series valve, it operates without electrical position feedback yet delivers excellent control performance through precision manufacturing and integrated electronics.

As a direct OEM-replacement solution, this valve maintains 100% mechanical and functional interchangeability with the original Rexroth unit. Every valve undergoes rigorous simulation testing—including pressure cycling, thermal variation, and full-stroke endurance validation—to guarantee factory-grade performance. Ideal for small-to-medium flow hydraulic systems requiring proportional control without the need for position feedback.

Technical Specifications 

4WRAE6W15-2X/G24N9K31/A1V (R900908938):

• Model: 4WRAE6W15-2X/G24N9K31/A1V

• Material Number: R900908938

• Brand: Bosch Rexroth

• Valve Type: Direct operated proportional directional valve, without electrical position feedback, with integrated OBE

• Nominal Size: NG6 (CETOP D03)

• Mounting Interface: ISO 4401-03-02-0-05

• Mounting Type: Subplate mounting

• Valve Configuration: 4/2 or 4/3-way

• Spool Symbol: W

• Rated Flow: 15 L/min

• Max. Flow: 42 L/min (NS6)

• Max. Operating Pressure: 315 bar (ports P, A, B)

• Tank Port Rating: 210 bar

• Component Series: 2X (30–39 series, installation and connection dimensions unchanged)

• Control Type: Proportional solenoid direct actuation with integrated OBE

• Control Signal: 0–10 V (A1 type)

• Supply Voltage: 24 V DC

• Electrical Connection: Connector pole PE per EN standards

• Manual Override: Concealed manual override

• Seal Material: FKM (Fluorocarbon)

• Compatible Fluids: HL, HLP, HLPD, HVLP, HVLPD, HETG, HEES, HEPG, HFDU, HFDR

• Operating Temperature Range: -20°C to +80°C (reference)

• Weight: Approx. 2 kg

Key Technical Advantages

1. Integrated OBE Electronics – Simplified System Integration

The 4WRAE6W15-2X/G24N9K31/A1V integrates On-Board Electronics (OBE) that accept 0–10 V standard control signals directly, eliminating the need for external amplifiers. This integrated design significantly simplifies electrical wiring, reduces system costs, and minimizes potential failure points while reducing control cabinet space requirements.

2. Direct-Operated Design – Fast Response with Low Hysteresis

The direct-operated structure, featuring proportional solenoids directly actuating the spool, eliminates pilot stage delays for fast response and minimal hysteresis. Compared to pilot-operated proportional valves, the direct-operated design offers superior dynamic response in small-to-medium flow applications, making it ideal for NG6 applications requiring rapid and precise flow modulation.

3. Premium Materials and Sealing Standards for Long-Term Reliability

Manufactured with high-strength materials and FKM (Fluorocarbon) seals, the valve is compatible with a wide range of hydraulic fluids including mineral oils (HL, HLP, HVLP) and environmentally friendly fluids (HETG, HEES). FKM seals provide excellent heat resistance, aging resistance, and chemical corrosion resistance, ensuring reliable long-term operation at 315 bar operating pressure.

4. Flexible Installation and Configuration Options

The valve features ISO 4401 standard subplate mounting interface, proportional solenoids with central thread and detachable coils for easy maintenance and replacement. The concealed manual override provides added convenience for commissioning and emergency operations. The W-type spool symbol with 4/2 or 4/3-way configurations accommodates diverse hydraulic circuit requirements.

5. Drop-In Interchangeability – Minimized Downtime and Retrofit Costs

The valve strictly adheres to Bosch Rexroth’s original mounting dimensions and functional specifications, with ISO 4401-03-02-0-05 interface compliance. Whether for new system design or legacy system upgrades, this valve offers 100% mechanical and electrical interchangeability with the original Rexroth unit—eliminating the need for manifold modifications or piping changes, significantly reducing downtime and retrofit expenses.

Application Areas

• Injection Molding Machinery – Proportional control of injection speed

• Machine Tool Hydraulic Systems – Proportional control of table feed speed and direction

• Packaging Machinery – Smooth acceleration and deceleration control of actuators

• Material Handling Equipment – Direction and speed control for forklifts and lifting platforms

• Industrial Automation Lines – Proportional flow and direction regulation for hydraulic actuators

• Test Rigs and Testing Equipment – Precise hydraulic control for laboratory and production testing

Expert Maintenance Tips

1. Fluid Cleanliness Management

4WRAE series proportional valves are highly sensitive to fluid contamination. Maintain system fluid cleanliness to ISO 4406 17/15/12 or better. The spool-to-sleeve clearance is extremely tight—even minor contaminants can cause spool sticking or performance degradation. Install filters with a minimum rating of 10μm upstream of the valve.

2. Electrical Connections and Signal Matching

The valve operates on 24 V DC supply voltage with 0–10 V control signal (A1 type). Verify that supply voltage and control signal type match the system specifications prior to installation. Use shielded cables for control signal transmission with reliable single-point grounding to effectively suppress electromagnetic interference.

3. Return Line Backpressure Control

The valve has a tank port rating of 210 bar. To ensure proper operation, the return line must remain full of oil. If installation conditions prevent the return line from staying full, install a preload valve in the return line to maintain appropriate backpressure.

4. Installation and Sealing

Carefully review the Bosch Rexroth product documentation (RE29128) prior to installation. Ensure the mounting surface is flat and smooth, and tighten mounting bolts evenly to specified torque. Take care not to damage or omit FKM seals during assembly. Purge air from the system before initial power-up to prevent response degradation.

5. Periodic Inspection and Maintenance

Regularly verify the valve’s flow-current characteristic curve. If abnormal response or increased hysteresis is detected, inspect the solenoid condition and OBE electronics unit functionality. For systems that have been idle for extended periods, perform thorough system circulation filtration before restart to ensure fluid cleanliness meets requirements.