Model Code Decoding

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

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

• 35: Rated flow 180 L/min (Δp=35 bar/land)

• 9: Spool/bushing type (4‑way, linear, special overlap, enhanced null stability)

• C: Revision C (industrial standard, FPM seals, enhanced EMC)

• Y: External drain port Y (T‑line pressure up to 210 bar)

Technical Specifications

• Part Number: D634Z359CY

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

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

• Rated Flow (Δp=35 bar/land): 180 L/min (±10% tolerance)

• Max Flow: 200 L/min

• Operating Pressure:

  • P/A/B ports: 350 bar (5,000 psi)Moog Inc.

  • T port (with Y): 210 bar (vs 50 bar without Y)Moog Inc.

  • Y port: Depressurized to tankMoog Inc.

• Response Time (0→100% step): ≤20 msMoog Inc.

• Hysteresis: <0.2%Moog Inc.

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

  • Fluid: −20°C to +85°C

• Mass: ~8.2 kgMoog Inc.

• Seals: FPM (Viton, high‑temp 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); optional 2–10 V actual‑value output

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

• Porting: P, A, B, T + Y (external drain)Moog Inc.

Core Functions

1. 180 L/min High‑Flow: For large‑bore actuators, heavy machinery

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

3. Integrated Closed‑Loop: Onboard spool feedback for high accuracy

4. Special 9‑Spool: Optimized overlap, minimal null leakage, stable at low flows

5. Y‑Port (Key Feature): T‑line backpressure up to 210 bar, enables high‑return‑line systemsMoog Inc.

6. Revision C: FPM seals, enhanced EMC, industrial temp range

7. Fail‑Safe Spring Center: Spool centers on power lossMoog Inc.

Application Scenarios

• Heavy Industrial: Large injection molding, die‑casting, metal forming presses

• High‑Backpressure Systems: Hydraulic circuits with high T‑line pressure (e.g., long return lines, multiple valves)

• Test & Simulation: High‑force vibration test benches, large flight simulators

• Precision High‑Flow Control: Large‑bore cylinder control requiring stability + high flow

Compatibility & Key Differences

• Series Compatibility: Interchangeable with D634Z 160/180 L/min models (same ISO 05 mounting)

• 359CY vs 351C:

  • 351C: 180 L/min, zero overlap, no Y‑port (T=50 bar max)

  • 359CY: 180 L/min, special 9‑spool, Y‑port (T=210 bar max), better null stability

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