Model Code Explanation (D661-4186)

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

4: High‑flow platform

18: 180 L/min nominal flow rating

6: High‑dynamic, single‑feedback, enhanced‑response base

(No suffix): Standard electronics, premium null stability

Technical Specifications

Part Number: D661-4186

Mounting: ISO 4401‑05 (NG10), 4‑hole, M5 screws (torque 8 Nm)

Control Function: 4‑way/3‑position, spring‑centered, zero‑lap, closed‑loop controlMoog Inc.

Hydraulic

Nominal Flow (Δp = 35 bar): 180 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)Moog Inc.

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. 5.8–6.0 kg

Electrical

Supply: 24 VDC (18–32 VDC), quiescent 230 mA, dynamic ~500 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%): ≤9 ms @ 210 bar

Hysteresis: <0.20% (closed‑loop)

Linearity: <±0.25%

Resolution: <0.08%

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, high‑accuracy for 180 L/min flow)Moog Inc.

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

Key Features

180 L/min Nominal Flow: Higher than 4157B/4158B/4168; slightly lower than 4178Moog Inc.

Ultra‑High‑Dynamic Response: 9 ms step response for high‑speed control

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

Premium Null Stability: Excellent null shift performance for long‑term precisionMoog Inc.

Single‑LVDT Precision: Reliable closed‑loop feedback for consistent accuracyMoog Inc.

Applications

High‑dynamic test benches (fatigue, vibration, aerospace components)Moog Inc.

Heavy‑duty industrial automation (forging presses, steel rolling mills)

Metallurgy (roll gap control, high‑tension systems)

Heavy machinery (mining excavators, die‑casting, large injection molding)

Energy (high‑flow hydraulic control, turbine governing)

Compatibility

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

Drop‑in upgrade for D661‑4168 (higher flow, faster response)Moog Inc.

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