Model Interpretation

D661: Series code (Integrated Electronics, 24VDC, NG10)

4647: Valve core / valve body combination, ServoJet® pilot, rated flow 60 L/min

B: Fail-Safe version, valve core returns to center position or safety position when power is lost Technical Specifications

Hydraulic parameters

Rated flow rate: 60 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: <12 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)

Connection: 6+PE, protection IP65 Moog Inc.

Physical and environmental

Working temperature: -40℃ ~ +85℃

Weight: Approximately 5.3 kg

Interface and communication configuration

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

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

ServoJet® Jet Pipe Pre-Controller: Strong anti-pollution 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

Safety-Reliable (Type B): Automatically returns to the middle position when power is lost/fault occurs, ensuring equipment safety

Application Scenarios

Metallurgy: Rolling mill AGC down pressure, tension control (requires safe reset)

Test Equipment: Vibration table, material testing machine (high safety requirements)

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

Energy and Heavy Industry: Wind turbine pitch control, shield tunneling machine, ship rudder

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 point 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