MOOG D661-4773 Electro‑Hydraulic Servo Valve
May 29, 2026

MOOG D661-4773 Electro‑Hydraulic Servo Valve

Product Description The D661-4773 is a two‑stage, pilot‑operated ServoJet® servo valve from MOOG’s D661 high‑response series, featuring integrated 24 VDC amplifier and LVDT spool position feedback. It complies with ISO 4401‑05 (NG10) mounting standard, designed for high‑flow, high‑precision closed‑loop hydraulic control in demanding industrial and test applications

Description

Model Definition

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

  • 4773 = Spool/sleeve assembly; rated flow 200 L/min @ ΔP=35 barMoog Inc.

  • Typical full config example: P60HDAM6NSF2‑A

    • P60 = High flow & high frequency response version

    • HDAM = Standard hydraulic layout, 24 VDC, ±10 V/±10 mA command, centered nullMoog Inc.

    • 6 = 6+PE connector, IP65Moog Inc.Moog Inc.

    • NSF2 = NBR seals, wide temperature range, LVDT feedback 4–20 mAMoog Inc.

    • A = Standard ServoJet® pilot stageMoog Inc.

Technical Specifications

Hydraulic Parameters
  • Rated flow: 200 L/min (ΔP=35 bar)Moog Inc.

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

  • Step response: 8–14 ms (0→100%, 210 bar)Moog Inc.

  • Hysteresis: <0.2%Moog Inc.

  • Resolution: <0.1%Moog Inc.

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

  • Null leakage: <25 mL/minMoog Inc.

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

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.Moog Inc.

  • Current draw: ≤750 mAMoog Inc.

Physical & Environmental
  • Operating temperature: −40 ℃ to +85 ℃Moog Inc.

  • Weight: approx. 10.2 kg

Interface & Communication Configuration

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

  • 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: Superior contamination resistance, low null drift, extended service lifeMoog Inc.

  • Integrated 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 loss

  • High‑flow dynamics: Optimized for 200 L/min with fast response for high‑speed applicationsMoog Inc.

Application Scenarios

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

  • Test equipment: High‑force dynamic material testers, 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 vibrationMoog Inc.

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

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

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


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