Model Explanation (Basic Section)

D661: Series Code (Integrated Electronics, 24VDC Power Supply, NG10 Installation)

4640: Valve Core/Body Assembly and Pilot Specifications (ServoJet®, Standard Flow / Pressure Rating) Technical Specifications

Hydraulic parameters

Rated flow rate: 75 L/min (ΔP = 35 bar)

Maximum working pressure: P/A/B ports 350 bar; internal leakage T port 210 bar, external leakage T port 350 bar (Moog Inc.)

Step response: 6.5–12 ms (0→100%, 210 bar)

Hysteresis: <0.2%; Resolution: <0.1%; Zero drift (ΔT = 55K): <1.5%

Zero position leakage: <15 mL/min

Electrical parameters

Power supply: 24 VDC (18–32 VDC) Moog Inc.

Control signal: ±10 V or ±10 mA Moog Inc.

Feedback signal: 4–20 mA (valve core position) Moog Inc.

Connection: 6+PE, protection IP65 Moog Inc.

Physical and environmental

Working temperature: -40℃ ~ +85℃

Weight: Approximately 5.5 kg

Interface and communication configuration

Hydraulic interface: P/A/B/T four ports, ISO 4401-05 standard

Electrical interface: power supply (24VDC/GND/PE), instruction (±10V/±10mA), feedback (4–20mA), status alarm Core function

ServoJet® Jet Pipe Preamplifier: Strong anti-contamination performance, low drift, long lifespan

Integrated closed-loop amplifier: Built-in PID, hysteresis compensation, overload protection

Valve core position electrical feedback: High precision and high linearity throughout the full stroke

High dynamic response: Millisecond-level response, suitable for high-speed closed-loop control Applicable scenarios

Metallurgy: Rolling mill AGC pressing and tension control

Test equipment: Vibration table, material testing machine, fatigue test bench

Industrial automation: Precision machine tools, injection molding machines, hydraulic forming machines

Energy and heavy industry: Wind turbine pitch control, shield tunneling machine, ship rudder control

Use and maintenance

Installation: Horizontal / vertical installation, avoid strong vibration; oil cleanliness NAS 1638-6 grade or above

Commissioning: 24VDC power supply, connect ±10V/±10mA instructions; adjust zero and gain through 4–20mA feedback

Maintenance: Regularly detect oil contamination degree; calibrate zero point and gain every 6 months; avoid long-term high-pressure standby without instructions