Model Code Explanation (D661-4375B)

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

4: High‑flow platform

37: 370 L/min nominal flow (Δp=35 bar)

5: Medium dynamic response (standard in 4xxx series)

B: Standard electronics, medium‑null‑stability trim

Technical Specifications

Part Number: D661-4375B

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

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

Hydraulic

Nominal Flow (Δp=35 bar): 370 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)Moog Inc.

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

Fluid: Mineral oil (DIN 51524), viscosity 15–45 mm²/sMoog Inc.

Temperature: Ambient −20°C to +60°C; Fluid −20°C to +80°CMoog Inc.

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)Moog Inc.

Feedback Signal: 4–20 mA (single LVDT, ±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)

Linearity: <±0.30%

Resolution: <0.10%

Interface & Communication

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

Feedback: Single integrated LVDT (full‑stroke closed‑loop)Moog Inc.

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

Key Features

370 L/min High Flow: Top‑tier flow in D661‑4xxx series

12 ms Balanced Response: “5” code delivers stable medium dynamics

350 bar Heavy‑Duty Pressure: Suitable for harsh industrial environmentsMoog Inc.

Medium Null Stability (“B”): Cost‑effective precision for standard applications

Voltage Command: ±10 V input, wide controller compatibilityMoog Inc.

Applications

High‑flow industrial test benches (non‑aerospace)

Standard forging presses and steel processing lines

General‑purpose metallurgical roll gap control

Large injection molding machines (medium dynamics)

Heavy‑duty material handling hydraulic systems

Compatibility

Interchangeable with D661‑4352C/4341C/4334C (ISO 4401‑05)Moog Inc.

Drop‑in upgrade for lower‑flow D661‑4209/4196Moog Inc.

Requires 24 VDC supply, ±10 V controller, ISO 4401‑05 manifoldMoog Inc.