4WRBKE27W430SJ-1X/6ZG24K31/A1D3M Rexroth Proportional Servo Valve 280bar 430L/min

Product Overview

The 4WRBKE27W430SJ-1X/6ZG24K31/A1D3M is a pilot-operated two-stage proportional directional servo valve from Bosch Rexroth 4WRBKE series 1X component family. It features inductive main spool position feedback and integrated on-board electronics (OBE), delivering high-precision closed-loop control of flow direction and magnitude.

Manufactured strictly to original Rexroth design standards and machining processes, the valve offers 100% drop-in interchangeability with original Rexroth units of the same model, with full compatibility in mounting dimensions, port pattern and electrical interface — no modification to system piping, subplates or wiring is required. Every unit undergoes 100% full working condition simulation testing covering full pressure range, full flow range and temperature cycles before delivery. With high dynamic response, low hysteresis and excellent repeatability, it is ideal for precision control in heavy-duty industrial hydraulic systems, and complies with CE and RoHS standards.

Technical Specifications

• Model: 4WRBKE27W430SJ-1X/6ZG24K31/A1D3M
• Nominal size: NG27
• Rated flow (Δp = 5 bar per control edge): 430 L/min
• Maximum operating pressure (ports P, A, B): 280 bar
• Maximum operating pressure (port T, external return): 250 bar
• Maximum pilot pressure (external pilot port X): 280 bar
• Spool type: Type W, open center, progressive flow characteristic
• Design: Pilot-operated two-stage proportional directional valve, with inductive position closed-loop feedback on main spool
• Integrated electronics: On-board electronics (OBE) with fault detection and safety protection
• Integrated function: Built-in ZDR 6 DP0 pilot pressure reducer (code D3) for stable pilot supply
• Supply voltage: 24 VDC
• Control signal: A1 interface, ±10 V analog voltage input
• Electrical connection: Connector per DIN EN 175301-804 (code K31)
• Mounting: Subplate mounting, port pattern conforming to ISO 4401
• Seal material: NBR (Nitrile Butadiene Rubber, code M)
• Recommended viscosity range: 15 to 100 mm²/s
• Ambient temperature range: -20 to +50 °C
• Protection class: IP65
• Net weight: approx. 18.8 kg

Key Technical Advantages

1. Two-stage pilot servo architecture for high dynamic precision The two-stage design uses a pilot proportional valve to drive the main spool. An inductive position sensor captures main spool displacement in real time, forming a full closed loop via the OBE. With hysteresis ≤ 3% and repeatability ≤ 0.5%, plus fast step response, it delivers high-speed, accurate flow and direction control for servo-grade applications.
2. High-flow heavy-duty capability for stable high-pressure operation Size NG27 with 430 L/min rated flow and 280 bar pressure rating at ports P, A, B enables actuation of large-bore actuators and supports high-load conditions in heavy hydraulic equipment. Precision lapped spool and sleeve assembly provides extremely low internal leakage, minimizing heat buildup and performance degradation during continuous high-pressure operation.
3. 100% drop-in interchangeability for reduced downtime and cost Mounting face, port layout and electrical interface fully match original Rexroth 4WRBKE27 series 1X valves. The unit can be installed directly without modifying subplates, piping or wiring, greatly cutting equipment downtime and retrofit costs.
4. Integrated functional design simplifies system configuration The built-in pilot pressure reducer (function D3) takes supply directly from the main circuit to deliver stable pilot pressure, eliminating the need for a separate pilot oil source and pressure reducing circuit. Integrated OBE removes the need for an external amplifier, reducing system wiring and potential failure points for improved overall reliability.
5. Full-condition factory validation for extended service life Each valve is factory-tested under full pressure, full flow, temperature cycling, shock and vibration conditions in accordance with DIN EN 60068 standards. High-strength cast iron housing, wear-resistant bearing structure and oil-resistant NBR seals ensure exceptionally long service life under rated operating conditions.

Application Areas

• Clamping, injection and ejection servo hydraulic systems of large injection molding and die casting machines
• Speed and position closed-loop control of actuators in metallurgical rolling equipment and forging machinery
• Pressure and flow compound control loops of heavy hydraulic presses and packaging machinery
• Proportional control systems for main actuators in construction and mining machinery
• High-precision hydraulic servo systems for material testing machines and simulation test platforms
• High-flow hydraulic regulation circuits in marine and wind power equipment

Expert Maintenance Tips

1. Before installation, ensure system fluid cleanliness meets ISO 4406 class 18/16/13. A pressure line filter with a filtration rating of ≥ 10 μm is recommended upstream of the valve to prevent spool seizure, mating surface wear and pilot stage clogging.
2. The subplate mounting surface must have a flatness tolerance ≤ 0.02 mm. Use M10 socket head cap screws, tighten evenly in diagonal sequence to a torque of 25 ± 5 N·m to avoid housing deformation, spool binding and increased internal leakage.
3. Use double-shielded cable for control signal wiring, with the shield grounded at one end. Do not route signal cables in the same conduit or tray as power cables to prevent electromagnetic interference from causing signal fluctuation, spool oscillation and system noise.
4. Before initial commissioning, verify supply voltage and control signal polarity. Increase the command value gradually from zero to confirm spool actuation direction matches system logic. Perform zero calibration after commissioning to ensure the spool centers at zero command.
5. For continuous operation above 45 °C ambient temperature, inspect seal condition and spool wear every 12 months. For long-term storage, drain all fluid from the valve and seal all ports. Store in a dry, well-ventilated environment to prevent moisture damage to electronic components.