Model Code Decoding

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

• Z: High‑flow 4‑way configuration (enhanced flow paths)

• 10: Rated flow 100 L/min (Δp=35 bar/land)

• 44: Special revision 44 (wood‑processing heavy‑duty build, enhanced vibration/shock resistance, extended sealing)Moog Inc.

Technical Specifications

• Part Number: D634Z1044

• Valve Size: ISO 4401‑05 (Size 05 / NG10)

• Control Function: 4‑way flow control, spring‑centeredMoog Inc.

• Rated Flow (Δp=35 bar/land): 100 L/min (±10% tolerance)

• Max Flow: 180 L/min

• Operating Pressure:

  • P/A/B ports: 350 bar (5,000 psi)

  • T port (without Y): 50 bar; (with Y): 210 barMoog Inc.

• Response Time (0→100% step): ≤20 ms

• Hysteresis: <0.2%Moog Inc.

• Null Shift (ΔT=55 K): <1.5%Moog Inc.

• Vibration/Shock: 30 g (3‑axis, 10 Hz–2 kHz) / 50 g (6‑direction, 3 ms) (heavy‑duty rating)Moog Inc.

• Electrical:

  • Supply: 24 VDC (18–32 VDC), 3.0 A maxMoog Inc.

  • Signal: ±10 V, ±10 mA, or 4–20 mAMoog Inc.

  • Connector: 6+PE (EN 175201), IP65 (mated)Moog Inc.

• Fluid: Mineral oil (DIN 51524), viscosity 15–100 mm²/s

• Temperature:

  • Ambient: −20°C to +60°C (extended for dusty/high‑vibration environments)Moog Inc.

  • Fluid: −20°C to +80°C

• Mass: ~7.9 kgMoog Inc.

• Seals: FPM (high‑temperature, dust‑resistant)

Interface & Communication Configuration

• Electrical Interface: Analog command (±10 V / ±10 mA / 4–20 mA) + 24 VDC powerMoog Inc.

• Feedback: Integrated spool position sensor (closed‑loop control); optional 2–10 V / 4–20 mA actual‑value outputMoog Inc.

• Mounting: 4‑bolt ISO 4401‑05 pattern (M6 screws, 11–13 Nm torque)

• Porting: P, A, B, T; optional drain Y (for T > 50 bar)Moog Inc.

Core Functions

1. High‑Flow 4‑way Design: Optimized for 100 L/min rated flow, suitable for large‑bore actuators

2. Direct‑Drive Linear Motor: No pilot flow, high force, pressure‑independent dynamicsMoog Inc.

3. Integrated Closed‑Loop Control: Onboard electronics for spool position feedback, high accuracyMoog Inc.

4. Heavy‑Duty Mechanical Build: Revision 44 upgraded for wood processing / sawmill shock/vibration conditionsMoog Inc.

5. High Dynamic Response: ≤20 ms step response, ideal for fast high‑flow positioning/force control

6. Low Hysteresis & High Resolution: <0.2% hysteresis, precise repeatabilityMoog Inc.

7. Fail‑Safe Spring Center: Spool returns to mid‑position on power lossMoog Inc.

Application Scenarios

• Wood Processing: Sawmills, planers, heavy‑duty log handling machinery (primary target for Rev 44)Moog Inc.

• Industrial Machinery: Large injection molding, die‑casting, heavy‑duty metal forming presses

• Test & Simulation: Large‑scale flight simulators, high‑force vibration test benchesMoog Inc.

• Harsh Environment Systems: High‑dust, high‑vibration industrial hydraulic systemsMoog Inc.

Compatibility Note

• Series Compatibility: Interchangeable with D634Z 60/80/100 L/min models and standard D634 4‑way valves

• Key Difference (44 vs 20/21/22/38 Version):

  • 20: Standard null

  • 21: Improved thermal stability

  • 22: Enhanced EMC

  • 38: Extended temperature + diagnostics

  • 44: Heavy‑duty shock/vibration, FPM seals, dust resistance (wood processing)Moog Inc.

• Replacement: Drop‑in upgrade for lower‑flow D634K series or pilot‑operated high‑flow servo valves