1. Basic Identification

• Model: D633-7398

• Brand: MOOG

• Type: Direct Drive Electro-Hydraulic Servo Valve (DDV), single-stage, pilotless

• Series: D633 (ISO 4401 Size 03 / NG6)

• Rated Flow: 75 L/min (at Δp=35 bar per metering edge)

2. Mechanical & Environmental

• Structure: 4/3-way, permanent magnet linear force motor direct drive, integrated closed-loop electronicsMoog Inc.

• Mounting: ISO 4401-03-03-0-94 (NG6)Moog Inc.

• Weight: Approx. 2.5 kg

• Protection: IP67 connector, IP65 valve body

• Temperature: Ambient -20℃ ~ +60℃; Fluid -20℃ ~ +70℃

• Fluid: Mineral hydraulic oil, ISO 4406 18/15/12, viscosity 15–100 mm²/s

3. Hydraulic Specifications

• Rated Flow: 75 L/min

• Max Working Pressure: P/A/B ports 350 bar; T port (without Y) 50 bar; T port (with Y) 350 barMoog Inc.

• Null Leakage: ≤1.2 L/min

4. Electrical Specifications

• Supply: 24 VDC (18–32 VDC)Moog Inc.

• Control Signals: ±10 V, ±10 mA, 4–20 mAMoog Inc.

• Feedback: 4–20 mA (spool position)

• Max Current: ≤1.2 A

• Connector: M12, 6+PEMoog Inc.

5. Core Performance

• Step Response Time: ≤12 ms

• Hysteresis: ≤0.2%

• Linearity: ≤0.1%

• Resolution: ≤0.05%

• Features: Pressure-independent dynamics, spring-centered on power loss, low hysteresis, high contamination resistanceMoog Inc.

6. Compatible Accessories

• Grade 10.9 M5 mounting bolts

• Standard seal kit

• 5-core shielded cable

• 10 μm high-pressure filter

• M12 waterproof connector

7. Applications