1. General Description

2. Model Definition

• D634: Series code, ISO 4401-05 (NG10) size

• 529A: High-flow rating; A = analog interface

3. Mechanical & Electrical Data

• Brand: MOOG

• Model: D634-529A

• Type: Electro‑hydraulic direct‑drive servo valve (DDV)

• Mounting: ISO 4401‑05 (NG10)

• Actuation: Permanent magnet linear force motor (no pilot oil required)

• Power Supply: 24 VDC (18–32 VDC range), max 2.2 AMoog Inc.

• Feedback: Integrated LVDT spool position closed‑loop

• Centering: Spring‑centered; fail‑safe neutral on power loss

• Protection Class: IP65

• Weight: ≈ 6.8 kg

• Connector: M18 6‑pin + PE

4. Hydraulic Specifications

• Max Working Pressure (P, A, B): 350 bar (5,000 psi)Moog Inc.

• Max T‑Port Pressure (internal drain): ≤ 50 bar; with Y‑port option up to 350 barMoog Inc.

• Rated Flow (Δp = 35 bar): ≈ 100 L/min

• Peak Flow: ≈ 160 L/min

• Null Leakage: 0.7–4.0 L/min

• Fluid: ISO 11158 mineral oil

• Fluid Temperature: –20 °C to +80 °C

• Fluid Cleanliness: ISO 4406 17/14/11

5. Dynamic Performance

• Full‑Stroke Step Response: ≤ 20 ms

• –3 dB Bandwidth: 40–60 Hz

• Hysteresis: < 0.25% FS

• Resolution: < 0.10% FS

• Temperature Drift (ΔT = 55 K): < 1.5% FS

6. Electrical Interface

• Standard Control Signal: ±10 VDCMoog Inc.

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

• Spool Feedback Signal: 0–10 VDC

• Ambient Temperature: –20 °C to +60 °C

• Certification: CE compliant (EMC per EU directives)

7. Key Features

• Pilotless design: No pilot oil, lower leakage, higher stability

• Integrated LVDT feedback: High positioning accuracy and repeatability

• Pressure‑independent dynamics: Stable response under varying load conditions

• Low power consumption: Optimized 24 VDC PWM drive

• Fail‑safe: Spring return to neutral on power loss

8. Applications

• Heavy‑duty hydraulic presses and forging machines

• Large injection molding and die‑casting equipment

• High‑displacement vibration test benches

• Industrial closed‑loop control for position, speed, pressure, force

•