Model Explanation (D661-104)

D661: Series Code (D660 series, ISO 4401-05, Integrated Electronics)

1: Valve Core Type / Flow Code (Corresponding to Small Flow Specifications)

04: Electrical Configuration / Version Code (Basic Type, ±10V/±10mA Commands)

Suffix (Common): G = Standard Four-way Valve Core; J = 315bar; A = ServoJet Pilot; V = FPM Seal; S = 6+PE Connector Technical Specifications

Part Number: D661-104

Valve Specification: ISO 4401-05 (CETOP 05), Diameter Ø6mm

Control Function: Four-way flow / pressure / position control, spring alignment, zero cover

Rated Flow (Δp = 10bar): 8L/min (±10%)

Maximum Working Pressure (P/A/B): 350bar (K type) / 315bar (J type)

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

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

Response Time (0→100%): 6.5–12ms Moog Inc.

Hysteresis: <0.5% (closed loop)

Linearity: <±0.5%

Electrical:

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

Command Signal: ±10V, ±10mA (standard) Moog Inc.

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

Connection: 6+PE (EN 175201-804)

Protection Grade: IP65 (locked state)

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

Temperature:

Environment: -20°C ~ +60°C Moog Inc.

Oil: -20°C ~ +80°C Moog Inc.

Weight: Approximately 5.7kg

Sealing: Standard NBR; optional FPM (V)

Interface and Communication Configuration

Electrical Interface: Analog command (±10V/±10mA) + 24VDC power supply; 4–20mA position feedback Moog Inc.

Feedback: Integrated LVDT valve core position sensor (closed loop control)

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

Oil Ports: P, A, B, T; optional external Y oil drain (T > 210bar) Moog Inc. Core function

ServoJet® Pre-Stage: Jet tube technology, low leakage, high resistance to contamination, long lifespan

Integrated closed-loop electronics: On-board PID, high control accuracy and repeatability

High dynamic response: Fast 6.5ms step response, suitable for high-speed and precise working conditions of Moog Inc.

Low zero-point leakage: <15ml/min, energy-saving and efficient

Fault-safe design: Valve core returns to center when power is lost / in case of failure, ensuring system safety Application scenario

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

Test Equipment: Material mechanics testing machine, fatigue test bench, hydraulic simulation platform

Metallurgical Industry: Roll gap control of rolling machines, tension control system

Aerospace: Ground simulation equipment, flight test devices

Compatibility Notes

Series Compatibility: Can be interchanged with D662/D663/D664/D665 series (ISO 4401-05~10)

Upgrade Replacement: Can directly replace old servo valves such as D633/D634 to improve dynamic performance

System Requirements: 24VDC power supply, analog controller, ISO 4401-05 standard valve block