Technical Specifications

• Part Number: D634K2020 (D634K2020C)

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

• Control Function: 4‑way flow control, spring‑centered

• Rated Flow (Δp = 5 bar/land): 420 L/min (±10% tolerance)

• Max Flow: 490 L/min

• Operating Pressure:

  • P/A/B ports: 350 bar (5,000 psi)

  • T port (without Y): 50 bar; (with Y): 350 bar

• Response Time (0→100% step): ≤20 ms

• Hysteresis: <0.2%

• Electrical:

  • Supply: 24 VDC (18–32 VDC)

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

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

  • Protection: IP65 (mated); Explosion‑proof “de” (ATEX II 2G EEx de IIB+H2 T4)

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

• Temperature:

  • Ambient: −20°C to +60°C

  • Fluid: −20°C to +80°C

• Mass: ~9.7 kg

• Seals: NBR (standard); FPM optional

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 actual‑value outputMoog Inc.

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

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

Core Functions

1. Direct‑Drive Linear Motor: No pilot flow, high force, pressure‑independent dynamics

2. Integrated Closed‑Loop Control: Onboard electronics for spool position feedback, high accuracy

3. High Dynamic Response: ≤20 ms step response, ideal for fast positioning/force control

4. Low Hysteresis & High Resolution: <0.2% hysteresis, precise repeatability

5. Fail‑Safe Spring Center: Spool returns to mid‑position on power loss

6. Low Power Consumption: 9.6 W at null, efficient for multi‑valve systems

7. Explosion‑Proof Construction: Suitable for ATEX hazardous areas (flameproof + increased safety)

Application Scenarios

• Industrial Machinery: Injection molding, die‑casting, metal forming presses

• Test & Simulation: Flight simulators, vibration test benches, material testing

• Robotics & Motion Control: High‑precision hydraulic actuators, synchronized motion

• Hazardous Areas: Oil & gas, chemical, pharmaceutical, and offshore systems

Compatibility Note

• Series Compatibility: Interchangeable with other D634K models (2005C–2019C)

• Key Difference (2020 vs 2019C):

  • 2019C: Rated flow 390 L/min (Δp=5 bar)

  • 2020: Rated flow 420 L/min (Δp=5 bar)

• Replacement: Drop‑in upgrade for older pilot‑operated servo valves (e.g., MOOG D660 series)