Model Code Explanation (D661-4125E)

• D661: Series (ISO 4401‑05, integrated 24 VDC electronics)

• 4: High‑flow platform

• 12: 120 L/min nominal flow rating

• 5: Standard pressure, single‑feedback, general‑purpose variant

• E: Enhanced electronics (improved EMC, diagnostic features)

Technical Specifications

Hydraulic

• Nominal Flow (Δp = 35 bar): 120 L/min (±8%)

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

• Pilot Pressure (X): 21–280 bar (internal P or external X)

• T Port Pressure (Y internal): 210 bar; (Y external): 350 barMoog Inc.

• Fluid: Mineral oil (DIN 51524), viscosity 15–45 mm²/s

• Temperature: Ambient −20°C to +60°C; Fluid −20°C to +80°C

• Weight: Approx. 5.8 kg

Electrical

• Supply: 24 VDC (18–32 VDC), quiescent 220 mA, dynamic 400 mAMoog Inc.

• Command Signal: ±10 V differential (10 kΩ impedance); optional ±10 mAMoog Inc.

• Feedback Signal: 4–20 mA (single LVDT spool position, ±0.02% FS accuracy)Moog Inc.

• Connector: 6+PE (EN 175201‑804), IP65 (connected)Moog Inc.

• Step Response (0→100%): ≤12 ms @ 210 bar

• Hysteresis: <0.25% (closed‑loop)Moog Inc.

• Linearity: <±0.30%

• Resolution: <0.10%Moog Inc.

Interface & Communication

• Electrical: 6+PE connector; ±10 V command, 24 VDC power, 4–20 mA single‑LVDT feedbackMoog Inc.

• Feedback: Single integrated LVDT (full‑stroke closed‑loop, cost‑effective for medium/high flow)Moog Inc.

• Ports: P, A, B, T; optional external X (pilot) and Y (return)

Key Features

• 120 L/min Nominal Flow: Balanced high‑flow capacity for medium‑to‑large industrial systems

• Enhanced Electronics (E): Improved EMC performance, built‑in diagnostics, better noise immunityMoog Inc.

• Standard Temperature Range: −20°C to +60°C ambient, suitable for most factory environments

• Single‑LVDT Precision: Reliable closed‑loop feedback for consistent high‑flow accuracy

• Good Contamination Resistance: 1.5× higher than basic D661 models

Applications

• Medium‑to‑large industrial automation (standard forging presses, medium steel rolling mills)

• General high‑flow test benches (component testing, medium‑load simulation)

• Metallurgy (standard roll gap control, medium‑tension systems)

• Heavy machinery (medium mining equipment, standard die‑casting, high‑capacity injection molding)

• Energy (medium‑flow hydraulic control, turbine auxiliary systems)

Compatibility

• Interchangeable with D661 (G/C/A), D662/D663 (ISO 4401‑05)Moog Inc.

• Drop‑in upgrade for lower‑flow D661 models (4051/4055/4059/4060/4061/4069/4070/4072/4077/4081)

• Requires 24 VDC supply, analog controller (±10 V in / 4–20 mA out), ISO 4401‑05 manifoldMoog Inc.