Model Code Explanation (D661-4209)

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

4: High‑flow platform

20: 200 L/min nominal flow rating (max in D661‑4xxx)

9: Standard‑dynamic, single‑feedback, high‑flow base

(No suffix): Standard electronics, premium null stability

Technical Specifications

Part Number: D661-4209

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

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

Hydraulic

Nominal Flow (Δp = 35 bar): 200 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 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 ~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%): ≤14 ms @ 210 bar (standard dynamics for 200 L/min)

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, high‑accuracy for 200 L/min flow)Moog Inc.

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

Key Features

200 L/min Nominal Flow: Maximum in D661‑4xxx series; higher than 4196/4195/4187

Standard‑Dynamic Response: 14 ms step response (stable, high‑flow operation)

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 accuracy at max flowMoog Inc.

Applications

Max‑flow industrial test benches (aerospace/defense, large‑component fatigue)

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

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

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

Energy (high‑flow hydraulic control, turbine governing systems)

Compatibility

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

Drop‑in upgrade for D661‑4196/4195/4187 (higher flow)

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