4WRBAE6W18J-2X Rexroth Proportional Valve 18 L/min 315 Bar

Product Overview

The 4WRBAE6W18J-2X/G24N9K31/A1M (Material No. 0811404153) and 4WRBAE6E18J-2X/G24N9K31/A1M (Material No. 0811404151) series direct-operated proportional directional valves are manufactured to original Bosch Rexroth technical standards. Belonging to the 4WRBAE series with size 6 (NG6 / CETOP 3 / ISO 4401-03), these valves are high-performance electro-hydraulic proportional directional control valves. Featuring a direct-operated subplate mounting design conforming to ISO 4401-03-02-0-94 mounting standards, they are equipped with integrated on-board electronics (OBE) without electrical position feedback. The proportional solenoid directly drives the spool for continuous, precise proportional control of both direction and flow magnitude.

The series features positive overlap design with a nominal flow rate of 18 L/min (at Δp = 5 bar per metering notch) and maximum operating pressure of 315 bar (ports P/A/B) and 250 bar on port T. The integrated electronics (OBE) convert the command signal into solenoid drive current. Valves are preset at the factory. Supply voltage is 24 VDC (G24), command signal supports 0-10 V voltage input (interface A1) or 4-20 mA current input (interface F1), electrical connector is K31 type (per DIN 43563-AM6), and seal material is NBR (M type). The W18J spool provides 4-way 3-position function, while the E18J spool provides 4-way 2-position function (EA type, single-sided actuation, normally closed NC), both featuring positive overlap design for different hydraulic circuit control requirements.

These products are dimensionally and functionally identical to the original Rexroth 4WRBAE6 series valves, offering true drop-in interchangeability for direct replacement of same-specification OEM valves. Every unit undergoes 100% bench testing under simulated working conditions, including rated pressure holding, flow linearity, internal leakage measurement, and solenoid response characterization. These products are interchangeable with Rexroth original part numbers 0811404153 (W18J type) and 0811404151 (E18J type).

Technical Specifications 

General Specifications

• Model: 4WRBAE6W18J-2X/G24N9K31/A1M (Material No. 0811404153) / 4WRBAE6E18J-2X/G24N9K31/A1M (Material No. 0811404151)

• Product Series: 4WRBAE (Size 6 / NG6 / CETOP 3 / ISO 4401-03)

• Component Series: 2X

• Spool Symbol: W18J (4-way, 3-position) / E18J (4-way, 2-position, EA type, normally closed NC)

• Design: Direct-operated, subplate mounting proportional directional valve with integrated on-board electronics (OBE), without electrical position feedback

• Mounting Pattern: ISO 4401-03-02-0-94 (NG6)

• Installation Position: Any

Hydraulic Parameters

• Nominal Flow: 18 L/min (at Δp = 5 bar per metering notch)

• Maximum Flow Capacity: 42 L/min (NG6)

• Maximum Operating Pressure (Ports P/A/B): 315 bar (4570 psi)

• Maximum Tank Port Pressure (Port T): 250 bar (3625 psi)

• Hydraulic Fluid: Mineral-based hydraulic oil (HL, HLP) per DIN 51524

• Fluid Temperature Range: -20°C to +80°C

• Filtration: ISO 4406 18/16/13

• Seal Material: NBR (M type)

Electrical Parameters

• Supply Voltage: 24 VDC (G24)

• Command Signal: 0-10 V voltage input (interface A1) / 4-20 mA current input (interface F1)

• Electrical Connector: K31 type (per DIN 43563-AM6)

• Maximum Solenoid Current: 2.5 A

• Integrated Electronics: OBE (On-Board Electronics), preset at factory

• Manual Override: Concealed (N9)

• Duty Cycle: Continuous (ED = 100%)

• Protection Class: IP65

Materials & Construction

• Valve Body: High-strength cast iron, cavity-type housing

• Control Spool: Carburized steel, precision ground

• Seals: NBR (standard)

• Surface Treatment: Phosphating / anti-corrosion coating

Weight

• Weight: approx. 3.9 kg

Key Technical Advantages

1. Integrated OBE Electronics for Simplified System Architecture
The 4WRBAE6W18J-2X/G24N9K31/A1M integrates the proportional amplifier directly into the valve body (On-Board Electronics), eliminating the need for an external amplifier. Users can directly drive the spool via a 0-10 V voltage signal or 4-20 mA current signal. The integrated design reduces external wiring and cabinet space requirements while minimizing electromagnetic interference on signal transmission. Valves are preset at the factory with the ramp set to minimum ramp time, and flow magnitude is adjustable via the command value.

2. Direct-Operated Design with Positive Overlap
The valve features a direct-operated design where the proportional solenoid directly drives the spool without pilot-stage delay, achieving fast response. The spool features positive overlap design, with overlap between ports in the center position to effectively reduce internal leakage. The spool is centered by return springs, automatically returning to the center position upon de-energization, ensuring a safe system state. The control spool is precision-ground from carburized steel with micron-level clearance control, ensuring low internal leakage and smooth shifting performance.

3. W18J/E18J Spool Functions with Precision Flow Control
The W18J spool provides 4-way 3-position function, while the E18J spool provides 4-way 2-position function (EA type, single-sided actuation, normally closed NC), both featuring positive overlap design. The nominal flow is 18 L/min (at Δp = 5 bar per metering notch), with maximum flow capacity of 42 L/min. Flow rate maintains a linear relationship with the command signal for easy system calibration and precise control. The valve fills the gap between conventional solenoid valves and servo valves, providing a cost-effective proportional control solution for cost-sensitive applications not requiring electrical position feedback.

4. Compact Design with Flexible Installation
The 4WRBAE6 series features a compact design weighing only approximately 3.9 kg. Combined with Rexroth sandwich valves and multi-port subplates, compact and cost-effective system designs are achieved. A concealed manual override (N9 type) is available for commissioning and maintenance. Maximum solenoid current is 2.5 A, providing sufficient switching force while controlling energy consumption. The coil can be changed without having to open the pressure-tight chamber, significantly reducing maintenance costs and downtime.

5. 100% Simulated Working Condition Testing and Drop-in Interchangeability
Every 4WRBAE6 series valve undergoes 100% bench testing prior to shipment, covering 315 bar rated pressure holding, flow-signal linearity verification, internal leakage measurement, and solenoid response characterization. Mounting dimensions, port positions, electrical interfaces, and performance curves are strictly matched to the original Rexroth valve, with a mounting surface conforming to ISO 4401-03-02-0-94, enabling direct drop-in replacement without modifying piping or control programs.

Application Areas

• Injection Molding Machines: Proportional control of injection speed and holding pressure, precise control of mold closing and injection actions

• Hydraulic Presses: Proportional speed and direction regulation for small-to-medium flow closed-loop control systems

• Die Casting Machines: Shot speed and intensification pressure precise regulation

• Material Testing Machines: Force-displacement closed-loop control for loading systems

• Precision Machine Tools: Hydraulic clamping systems, feed control

• Metallurgical Equipment: Precision control for continuous casting machines and rolling mill auxiliary hydraulic systems

• Industrial Automation: Precision motion control for electro-hydraulic control systems

• Wind Power Generation: Pitch control system hydraulic directional control

Expert Maintenance Tips

Installation Guidelines

1. The 4WRBAE6W18J-2X/G24N9K31/A1M series can be mounted in any position. Mounting surface flatness must be ≤ 0.05 mm. Tighten mounting bolts diagonally in stages to the specified torque value. The mounting surface conforms to ISO 4401-03-02-0-94 for installation on NG6 mounting surfaces. Subplates must be ordered separately (RE 45053).

2. Thoroughly flush all piping circuits before installation. Ensure no welding slag, metal chips, or particulate contaminants remain. Prior to first operation, circulate the system through a 10 μm filter element for a minimum of 30 minutes. Recommended fluid cleanliness is ISO 4406 18/16/13 or better.

3. Electrical connections must use a K31 connector conforming to DIN 43563-AM6 to maintain IP65 protection. Control signal cables should be shielded, with the shield grounded at one end to prevent electromagnetic interference causing spool oscillation. The coil can be changed without opening the pressure-tight chamber.

Routine Maintenance Procedures

1. Fluid Cleanliness Management: Maintain system fluid cleanliness at ISO 4406 18/16/13 or better. Check fluid particulate contamination every 500 operating hours and replace filter elements and hydraulic fluid when contamination exceeds limits.

2. Electrical Zero Point Verification: Periodically check the electrical zero point for drift with the power supply disconnected. If zero point deviation exceeds ± 2%, re-calibrate using dedicated tools via the OBE electronics.

3. Coil Resistance Verification: Measure solenoid coil resistance every 1,000 operating hours. Deviation from factory value should not exceed ± 10%. Maximum solenoid current is 2.5 A; monitor for abnormal temperature rise.

4. Internal Leakage Monitoring: Due to the design principle, proportional valves have inherent internal leakage. An annual internal leakage test is recommended. If leakage exceeds 150% of the factory standard, seal replacement should be scheduled.

5. Manual Override Maintenance: Periodically check that the concealed manual override (N9 type) is in the non-activated state to prevent accidental spool shifting.

6. P-Port Orifice Note: This model features a 1.0 mm orifice in the P-port, eliminating the need for additional throttle inserts during installation.