1. General Description

2. Model Code (D634‑368C)

• D634: Series = Direct drive servo valve, ISO 4401 Size 05 (NG10)

• 368: Configuration = high‑flow, high‑dynamic spool, 24 VDC, industrial‑tuned

• C: Revision C (current production baseline)

3. Hydraulic Specifications

• Mounting: ISO 4401 Size 05 (NG10)

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

• T‑port Pressure (no Y port): 50 bar (725 psi)Moog Inc.

• T‑port Pressure (with Y port): 350 bar (5,000 psi)Moog Inc.

• Rated Flow (Δp = 35 bar/orifice): 150 L/min (39.6 gpm)

• Max Flow: ≈220 L/min

• Internal Leakage: ≤3.0 L/min

• Fluid: Mineral oil (ISO 11158 / DIN 51524)

• Fluid Temp: −20 °C to +80 °C

• Fluid Cleanliness: ISO 4406 17/14/11

• Weight: ≈7.1 kg

4. Dynamic Performance

• Full‑stroke Step Response: ≤20 ms

• −3 dB Bandwidth: 55–65 Hz

• Hysteresis: <0.25% full scale

• Resolution: <0.12% full scale

• Null Drift (ΔT = 55 K): <1.5% full scale

5. Electrical Specifications

• Supply Voltage: 24 VDC (18–32 VDC)Moog Inc.

• Max Operating Current: 2.8 A

• Standard Command Signal: ±10 VMoog Inc.

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

• Spool Position Feedback: 0–10 VDC (or 4–20 mA)

• Connector: M18, 6 pins + PE, IP65Moog Inc.

• Ambient Temp: −20 °C to +60 °C

• EMC: CE compliant

6. Key Features

• Pilotless direct drive: No external pilot supply, simpler installationMoog Inc.

• High flow + good bandwidth: Balanced for most industrial closed‑loop systems

• Pressure‑independent dynamics: Stable under varying loadsMoog Inc.

• Low leakage & high resolution: Precision control for general‑purpose test stands

• Fail‑safe spring return: Protects machinery on power lossMoog Inc.

• Integrated PWM electronics: Compact, IP65 protection

7. Typical Applications

• Industrial hydraulic presses & injection molding machines

• General‑purpose structural fatigue test rigs

• Dynamic vibration simulation tables (medium‑speed)

• Closed‑loop position/velocity control for standard machinery

8. Pin Assignment (6+PE)

1. +24 VDC

2. Power Ground

3. Command +

4. Command –

5. Position Feedback Out

6. Feedback Ground

   PE: Protective Earth

   Use shielded twisted pair for all signal wires.

9. D634 Family Quick Compare (346C/358C/361C/362C/368C)