Model Explanation (D661-4009)

D661: Series Code (ISO 4401-05, Integrated 24VDC Electronics)

4: Flow Grade Code (High Flow)

00: Valve Core / Pressure / Configuration Combination Base Code

9: Electrical / Feedback Variant (Command ±10 V; Feedback ±10 V) Technical Specifications

Part Number: D661-4009

Valve Specification: ISO 4401-05 (CETOP 05), bore Ø6 mm

Control Function: Four-way three-position, spring centered, zero cover, closed-loop position/flow/pressure control

Rated Flow (Δp = 35 bar): 80 L/min (±10%) MUG China

Maximum Working Pressure (P/A/B): 350 bar Moog Inc.

Pilot Pressure: 21–210 bar (internal P or external X for oil supply)

T Port Pressure: 210 bar (internal Y return oil); 350 bar (external Y return oil) Moog Inc.

Response Time (0→100%): ≤14 ms MUG China

Hysteresis: <0.3% (closed-loop)

Linearity: <±0.25%

Electrical:

Power Supply: 24 VDC (18–32 VDC), static 200 mA, dynamic 350 mA Moog Inc.

Command Signal: ±10 V (differential, 10 kΩ impedance) Moog Inc.

Feedback Signal: ±10 V (LVDT valve core position) Moog Inc.

Connector: 6+PE (EN 175201-804) Moog Inc.

Protection Grade: IP65 (connected state)

Hydraulic Oil: Mineral oil (DIN 51524), viscosity 15–45 mm²/s

Temperature:

Environment: -20°C ~ +60°C

Oil: -20°C ~ +80°C

Weight: Approximately 5.7 kg

Sealing: Standard NBR; optional FPM (fluororubber)

Interface and Communication

Electrical Interface: 6+PE connector; analog command ±10 V, 24 VDC power supply, position feedback ±10 V

Feedback: Integrated LVDT valve core position sensor (full travel closed-loop)

Installation: 4-hole ISO 4401-05 installation (M5 screws, torque 8 Nm)

Oil Ports: P, A, B, T; optional external Y return oil (T > 210 bar)

Key Features

ServoJet Pilot: Anti-contamination, low leakage (<15 ml/min), long life

Integrated Closed-loop Electronics: On-board PID, high accuracy and repeatability

High Dynamic Response: ≤14 ms step response, suitable for high-speed and high-precision applications MUG China

Low Zero-Position Leakage: Energy-saving, suitable for long-term pressurized / standby systems

Safety-Relay Design: Valve core centered when power is lost / fault; customizable safety position MUG China Application scenario

Industrial Automation: High-precision machine tools, CNC machining centers, robot hydraulic systems

Testing Equipment: Material testing machines, fatigue test benches, hydraulic simulation platforms

Metallurgy: Roll gap control, tension control system

Aerospace: Ground simulation equipment, flight test benches

Compatibility

Series Compatibility: Can be interchanged with D661 (G/C/A type), D662/D663 (ISO 4401-05)

Upgrade Replacement: Directly replace the old D633/D634 servo valves to enhance dynamic performance

System Requirements: 24 VDC power supply, analog quantity controller (±10 V input / ±10 V output), ISO 4401-05 standard valve block