Model Definition

• D661 = Series (integrated electronics, 24 VDC, NG10)Moog Inc.

• 4697 = Spool/sleeve assembly; rated flow 300 L/min @ ΔP=35 bar

• C = Pressure class; max working pressure 350 bar (P/A/B ports)Moog Inc.

• Full config (typical: G75JOAA6VSX2HA):

  • G = ServoJet® pilot stage, standard spoolMoog Inc.

  • 75 = Frequency response class (≥160 Hz bandwidth)

  • J = 24 VDC power, ±10 V / ±10 mA analog commandMoog Inc.

  • O = Null position: centered (fail‑safe, power‑off centering)

  • AA = Standard hydraulic/electrical base config

  • 6 = 6+PE connector, IP65Moog Inc.

  • VS = Wide‑temperature sealing

  • X2HA = LVDT feedback, 4–20 mA outputMoog Inc.

Technical Specifications

Hydraulic Parameters

• Rated flow: 300 L/min (ΔP=35 bar)

• Max working pressure: 350 bar (P/A/B); 210 bar (internal drain T) / 350 bar (external drain T)Moog Inc.

• Step response: 7–9 ms (0→100%, 210 bar)

• Hysteresis: <0.2%

• Resolution: <0.1%

• Null drift: <1.5% (ΔT=55 K)

• Null leakage: <22 mL/min

• Fluid cleanliness: NAS 1638 Class 6 / ISO 4406 18/15

Electrical Parameters

• Power supply: 24 VDC (18–32 VDC)Moog Inc.

• Control signal: ±10 V (differential) or ±10 mAMoog Inc.

• Feedback signal: 4–20 mA (LVDT spool position)Moog Inc.

• Connector: 6+PE, IP65Moog Inc.

• Current draw: ≤600 mA

Physical & Environmental

• Operating temperature: −40 ℃ to +85 ℃

• Weight: approx. 10.5 kg

Interface & Communication Configuration

• Hydraulic interface: P/A/B/T, ISO 4401‑05 (NG10)

• Electrical interface:

  • Power: 24 VDC, GND, PEMoog Inc.

  • Command: ±10 V / ±10 mAMoog Inc.

  • Feedback: 4–20 mA (spool position)Moog Inc.

  • Status: Fault alarm output

Core Functions

• ServoJet® pilot stage: Excellent contamination resistance, low null drift, long service lifeMoog Inc.

• Integrated ultra‑high‑response amplifier: Built‑in PID, dead‑zone compensation, overload protectionMoog Inc.

• LVDT closed‑loop feedback: High linearity and precision across full strokeMoog Inc.

• Fail‑Safe centering: Spool returns to neutral on power lossMoog Inc.

• G75 extreme dynamics: ≥160 Hz bandwidth for ultra‑high‑speed industrial applications

Application Scenarios

• Metallurgy: Ultra‑high‑flow AGC roll gap control, tension control for heavy plate mills

• Test equipment: High‑force dynamic material testers, ultra‑high‑frequency vibration tables

• Industrial automation: Large CNC machine tools, high‑speed hydraulic presses, heavy‑duty injection molding machines

• Energy & heavy industry: Wind turbine pitch control, shield machine main control, marine hydraulic systems

Usage & Maintenance

• Installation: Horizontal/vertical mounting; avoid severe vibration

• Fluid: ISO VG46 mineral oil; maintain cleanliness per NAS 1638 Class 6

• Commissioning: Apply 24 VDC power; connect ±10 V/±10 mA command; calibrate zero and gain via 4–20 mA feedback

• Maintenance: Inspect fluid contamination regularly; calibrate zero/gain every 6 months; avoid long idle periods at high pressure