1. Product Overview

2. Basic Information

• Brand: MOOG

• Model: D634-520A

• Type: Pilotless electro-hydraulic direct-drive servo valve (DDV)

• Mounting: ISO 4401-05 (NG10)

• Drive: Permanent magnet linear force motor (no pilot oil required)Moog Inc.

• Power Supply: 24 VDC (18–32 VDC), max 2.2 A

• Feedback: Integrated LVDT spool position closed-loop

• Reset: Spring-centered; fail-safe neutral return on power lossMoog Inc.

• Protection: IP65

• Weight: ~6.3 kg

• Connector: M18 6-pin + PE

3. Function & Positioning

• Core Function: Precise flow/direction control via analog signals; closed-loop regulation of position/velocity/pressure/force with low hysteresis, high repeatability, and pressure-stable responseMoog Inc..

• Positioning: High-flow model in the D634 series, optimized for heavy-duty, high-dynamic industrial hydraulics (e.g., presses, injection molding, test benches)Moog Inc..

4. Core Performance Parameters

Hydraulic Parameters

• Max working pressure (P/A/B): 350 bar

• Max T-port pressure: ≤50 bar (no Y-port); ≤350 bar (with Y-port)Moog Inc.

• Rated flow (Δp=35 bar): 100 L/min

• Peak flow: ~185 L/min

• Null leakage: 0.25–1.8 L/min

• Fluid: ISO 11158 mineral oil

• Fluid temp: -20°C ~ 80°C

• Cleanliness: ISO 4406 17/14/11

Dynamic Parameters

• Full-stroke step response: ≤12 msMoog Inc.

• -3dB bandwidth: 70–90 Hz

• Hysteresis: ＜0.15% full scale

• Resolution: ＜0.06% full scale

• Temp drift: ＜1.0% full scale

Electrical Parameters

• Standard control signal: ±10 VDCMoog Inc.

• Optional signals: ±10 mA, 4–20 mAMoog Inc.

• Spool feedback signal: 0–10 VDC

• Ambient temp: -20°C ~ 60°C

• Certification: CE compliant

5. Matching Accessories

• Shielded twisted signal cable, M18 waterproof connector

• ISO 4401-05 standard mounting manifold

• High-precision hydraulic filter

• 24 VDC low-ripple power supply

• Servo controller, displacement/pressure sensors

6. Application Fields

• Large-tonnage hydraulic presses & forging equipment

• High-speed injection molding & die-casting machines

• High-frequency vibration & material fatigue test benches

• High-power wind turbine pitch control

• Aerospace/automotive motion simulation systems