Model Code Explanation (D661-4157B)

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

• 4: High‑flow platform

• 15: 150 L/min nominal flow rating

• 7: High‑pressure, single‑feedback, heavy‑duty base

• B: Standard electronics, enhanced null stability

Technical Specifications

Hydraulic

• Nominal Flow (Δp = 35 bar): 150 L/min (±8%)Moog Inc.

• 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 bar

• 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. 5.8–6.0 kg

Electrical

• Supply: 24 VDC (18–32 VDC), quiescent 230 mA, dynamic 420 mA

• Command Signal: ±10 V differential (10 kΩ impedance); optional ±10 mA

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

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

• Step Response (0→100%): ≤14 ms @ 210 barMoog Inc.

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

• Linearity: <±0.30%Moog Inc.

• Resolution: <0.10%Moog Inc.

Interface & Communication

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

• Feedback: Single integrated LVDT (full‑stroke closed‑loop, high‑accuracy for 150 L/min flow)Moog Inc.

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

Key Features

• 150 L/min Nominal Flow: High‑flow capacity for medium‑to‑large industrial hydraulic systemsMoog Inc.

• High‑Pressure Rated: 350 bar max working pressure for heavy‑duty applicationsMoog Inc.

• Enhanced Null Stability (B): Improved null shift performance for long‑term precision

• Single‑LVDT Precision: Reliable closed‑loop feedback for consistent accuracy at high flowMoog Inc.

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

Applications

• Medium‑to‑large industrial automation (heavy‑duty forging presses, large steel rolling mills)

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

• Metallurgy (roll gap control, high‑tension systems)

• Heavy machinery (large mining equipment, high‑tonnage die‑casting, high‑capacity injection molding)

• Energy (medium‑high flow hydraulic control, large 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 (4085/4086/4090/4125E)

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