Model Definition

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

• 4776 = Spool/sleeve assembly; rated flow 250 L/min @ ΔP=35 bar (max flow for NG10)

• Typical full config example: P30HDAM6NSF2‑A

  • P30 = Ultra‑high flow & high frequency response version

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

  • 6 = 6+PE connector, IP65

  • NSF2 = NBR seals, wide temperature range, LVDT feedback 4–20 mA

  • A = Standard ServoJet® pilot stage

Technical Specifications

Hydraulic Parameters

• Rated flow: 250 L/min (ΔP=35 bar, max for NG10)

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

• Step response: 10–18 ms (0→100%, 210 bar)Moog Inc.

• Hysteresis: <0.2%

• Resolution: <0.1%

• Null drift: <1.5% (ΔT=55 K)

• Null leakage: <30 mL/min

• 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.

• Current draw: ≤800 mA

Physical & Environmental

• Operating temperature: −40 ℃ to +85 ℃

• Weight: approx. 11.0 kg

Interface & Communication Configuration

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

• Electrical interface:

  • Power: 24 VDC, GND, PE

  • Command: ±10 V / ±10 mA

  • Feedback: 4–20 mA (spool position)

  • Status: Fault alarm outputMoog Inc.

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 lossMoog Inc.

• Ultra‑high‑flow dynamics: Optimized for 250 L/min with stable response for high‑flow heavy‑duty applications

Application Scenarios

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

• Test equipment: Super‑high‑force dynamic material testers, large‑scale high‑frequency vibration tables

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

• Energy & heavy industry: Large 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 6Moog Inc.

• 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