I. Core Parameters (D633-471B Official Standard)

1. Basic Specifications

Model: D633-471B (NG6 Direct Acting Servo Valve)

Flow Specification: 40 L/min @ Δp=35 bar

Pressure Rating:

P/A/B: 350 bar

T/Y: 50 bar (Low Pressure Return Oil)

Frequency Response: 320–380 Hz (−3dB)

Step Response: ≤10 ms (0→100%)

Leakage: <0.3 L/min (Neutral Position)

Valve Core Type: Standard Zero Cover, Linear Gain

Neutral Function: O-Type (Fully Closed)

Sealing Material: FPM Fluororubber (−20 to +80°C)

Weight: Approximately 3.0 kg

Installation Standard: NG6 / ISO 4401-03

2. Electrical Parameters (Standard Configuration)

Power Supply: 24VDC (18–32V)

Control Signal: ±10V / ±10mA / 4–20mA (Optional)

Feedback: Built-in LVDT Valve Core Position Closed Loop (EFB Electronic Feedback)

Interface: 6+PE Circular Aviation Plug (DIN 43650)

Hysteresis: <0.1% FS

Resolution: <0.1%

Linearity: ±0.25% FS

Electronic Board: Integrated PWM Drive, Closed Loop Control

3. Model Meaning (471B)

4: D633 Series, 24VDC, Integrated Electronics

71: Flow Specification Code (40 L/min, High Pressure Grade)

B: Standard Version, Low Pressure Return Oil, FPM Sealing

4. Key Features

Direct Drive without Pilot: Strong Anti-Pollution, No Pilot Leakage, High Reliability

Linear Force Motor: Bidirectional Large Force, Dynamic Independent of Pressure

LVDT Closed Loop: High Precision, Low Hysteresis, High Repeatability

Top Response: 320Hz + Frequency Response, 10ms Step, Preferred for High-Speed Control

Low Pressure Return Oil: T Port ≤ 50bar, Suitable for Ordinary Return Oil Circuits

Power Off Safety: Spring Centering, Load Stopped

II. Typical Application Scenarios

High-speed Hydraulic Machines, Large Material Testing Machines, Servo Actuators

Main Control Axes of Injection Molding Machines, Die-Casting Machines, Forging Machines

High Dynamic Requirements for Electro-Hydraulic Position / Speed / Pressure Closed Loop Control Systems

Industrial Automation, Metallurgy, Heavy Machinery High Precision Control

Normal Temperature Conditions (−20 to +80°C), Standard Mineral Hydraulic Oil