Product Overview
The Rexroth 4WS2EM10-51/20B11ET315K31EV (Material Number R900909227) is a high-response, two-stage directional servo valve engineered by Bosch Rexroth for precise electrohydraulic control of position, velocity, force, and pressure in demanding closed-loop industrial systems. The valve operates on a nozzle-flapper pilot stage principle that hydraulically actuates a robust main spool, delivering infinitely variable directional flow proportional to the electrical command signal. With a nominal size of NG10 and a rated flow capacity of approximately 20 L/min at a 31.5 bar (315 bar rated system pressure) pressure drop per land, this servo valve serves as the critical control element in high-dynamic servo axes where fast response, minimal hysteresis, and excellent repeatability are essential. Its integrated design allows direct interfacing with Rexroth servo amplifiers and proportional control electronics, making it a drop-in solution for OEM and retrofit applications requiring exacting motion control fidelity.
Technical Specifications
| Parameter | Specification / Feature |
|---|---|
| Component Type | Directional Servo Valve (Two-Stage, Nozzle-Flapper Pilot) |
| Model Designation | 4WS2EM10-51/20B11ET315K31EV / R900909227 |
| Nominal Size | NG10 (Size 10) |
| Rated Flow (Δp = 31.5 bar per land) | ≈ 20 L/min |
| Maximum Operating Pressure | 315 bar (rated system pressure) |
| Spool Configuration | 4-way, 3-position, closed-center, zero-lap critical spool |
| Actuation | Electrohydraulic torque motor with mechanical feedback |
| Mounting & Connection | ISO 4401-05 / CETOP 5 subplate mounting; standard Rexroth interface |
| Hydraulic Fluid | Mineral oil based hydraulic fluid per DIN 51524 (ISO VG 32–68) |
| Filtration Requirement | ISO 4406 cleanliness class 16/13/10 or better (β10 ≥ 75) |
Engineering Features & Advantages
- Precision Performance: The nozzle-flapper pilot stage with mechanical spool feedback delivers extremely high resolution, low hysteresis (<1%), and excellent repeatability, enabling accurate metering of flow and directional control in closed-loop servo axes.
- Industrial Reliability: Constructed for continuous duty with durable, corrosion-resistant materials and proven engineering for maximum system uptime.
- Direct Fit Replacement: Exact dimensional and functional compatibility with original Rexroth OEM standards, ensuring drop-in replacement without modification to existing manifolds or piping.
Typical Industrial Applications
Its integrated design allows direct interfacing with Rexroth servo amplifiers and proportional control electronics, making it a drop-in solution for OEM and retrofit applications requiring exacting motion control fidelity.
PRODUCT IMAGES
Rexroth 4WS2EM10-51/20B11ET315K31EV / R900909227 Directional Servo Valve
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- Authentic & Fully Tested: 100% bench tested for hydraulic response, pressure rating, and null-bias stability before dispatch.
- Fast Dispatch: In-stock units ready for same-day dispatch via DHL / FedEx Express directly to your plant.
- Pre-Shipment Verification: High-definition photos, video testing runs, and serial number verification provided prior to shipment.
- Peace of Mind: Covered by our 12-Month Replacement Warranty.
Shop the genuine Rexroth 4WS2EM10-51/20B11ET315K31EV / R900909227 Proportional Directional Valve. This Germany-made 315 bar hydraulic component features a 4-way, 2-position proportional design, delivering leak-free, reliable fluid control for heavy-duty industrial systems.