4WRZE25 E325 Rexroth Proportional Valve 315Bar

Product Overview

The 4WRZE25 E325-70/6EG24N9K31/A1D3M Pilot-Operated 2-Stage Proportional Directional Valve belongs to the Bosch Rexroth 4WRZE series (covering NG16, NG25, and NG32 industrial frames). Equipped with main spool electrical position feedback and On-Board Electronics (OBE), this valve provides high-precision closed-loop control of hydraulic fluid direction and flow rate. Manufactured strictly to ISO 4401-08 (CETOP 8) mounting standards, it guarantees 100% direct drop-in mechanical and electrical interchangeability. Built with induction-hardened alloy spools, precision-lapped sleeves, and high-accuracy position sensors, every valve undergoes 100% factory bench testing under simulated 315 bar working conditions to ensure zero drift, low hysteresis, and reliable long-term performance.

Technical Specifications

• Full Model Code: 4WRZE25 E325-70/6EG24N9K31/A1D3M (Cross-compatible series: 4WRZE16, 4WRZE25, 4WRZE32)

• Nominal Size (NG): NG25 / CETOP 8 / ISO 4401-08-08-0-05

• Nominal Flow Rate: 325 L/min (at $\Delta p = 10\ \text{bar}$)

• Maximum Flow Capacity: Up to 650 L/min

• Max Operating Pressure (Ports A, B, P): 315 bar (31.5 MPa)

• Max Tank Return Pressure (Port T): 250 bar

• Control Electronics & Power Supply: Integrated On-Board Electronics (OBE), 24V DC supply (G24), $\pm 10\ \text{V}$ command signal (A1)

• Pilot Oil Configuration: D3 (Internal pilot supply, external pilot drain)

• Seal Material & Temp Range: NBR seals (M code), operating temperature -20°C to +80°C

• Net Weight: Approx. 16.8 kg

Key Technical Advantages

• 100% Drop-In OEM Interchangeability: Subplate mounting patterns, oil port coordinates, and 7-pin (6+PE) connector pinouts strictly match OEM standards for plug-and-play installation without circuit modification.

• Closed-Loop Position Control & High Dynamics: The main spool features a high-precision LVDT position transducer combined with an integrated digital amplifier to minimize hysteresis ($< 0.1\%$) and maximize dynamic response.

• Hardened Spool & Contamination Resistance: Nitrided alloy steel spool and sleeve assembly (hardness $> 60\ \text{HRC}$) with optimized metering notches resist erosion, thermal expansion, and silting-induced sticking.

• 100% Simulated Load Bench Tested: Every valve undergoes full dynamic response, step response, internal leakage, and static curve testing under 315 bar rated pressure before factory release.

Application Areas

• Metallurgy & Steel Mills: Rolling mill screw-down systems, plate levellers, and continuous caster electro-hydraulic control.

• Industrial Presses & Forging: High-tonnage hydraulic press ram synchronization, fine stamping, and pressure-position compound control.

• Plastics & Injection Molding: High-speed injection units and mold clamping proportional circuits in large injection molding machines.

• Marine & Offshore Engineering: Ship stabilizers, heavy deck winches, and high-precision hydraulic power units (HPUs).

Expert Maintenance Tips

• Manage Pilot Drain Pressure: Ensure the external pilot drain line (Y port) in D3 configuration is unpressurized ($< 2\ \text{bar}$) to prevent sluggish pilot response or main spool positioning errors.

• Maintain Strict Fluid Cleanliness: System hydraulic fluid must be filtered to ISO 4406 16/14/11 (NAS Class 5) or cleaner. Install a high-pressure inline filter ($\le 10\ \mu\text{m}$) directly upstream of Port P.

• Ensure Proper Electrical Shielding: Use a fully shielded 7-pin cable for command signals and ground the shield at the control cabinet side only to protect the OBE electronics from industrial electromagnetic interference.