I. Core Parameters (D633-447B Official Standard)

1. Basic Specifications

Model: D633-447B (NG6 Direct Acting Servo Valve)

Flow Specification: 25 L/min @ Δp=35 bar

Pressure Rating:

P/A/B: 350 bar

T/Y: 50 bar (standard low-pressure return oil)

Frequency Response: 260–300 Hz (−3dB)

Step Response: ≤8 ms (0→100%)

Leakage: <0.25 L/min (neutral position)

Valve Core Type: Standard zero coverage, linear gain

Neutral Function: O-type (fully closed)

Sealing Material: NBR (−20 to +80℃)

Weight: Approximately 3.0 kg

Installation Standard: NG6 / ISO 4401-03

2. Electrical Parameters (Standard Configuration)

Power Supply: 24VDC (18–32V)

Control Signal: ±10V Analog Voltage

Feedback: Built-in LVDT Valve Core Position Closed Loop

Interface: 6+PE Circular Aviation Plug

Hysteresis: <0.2%

Resolution: <0.1%

Electronic Board: Integrated PWM Drive, Closed Loop Control

3. Model Meaning (447B)

4: D633 Series, 24VDC, Integrated Electronics

47: Flow Specification Code (25 L/min)

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

4. Key Features

Direct Drive without Pilot: Strong anti-pollution, no pilot leakage, high reliability

Linear Force Motor: Bidirectional large thrust, dynamic and pressure independent

LVDT Closed Loop: High precision, low hysteresis, high repeatability

Low Pressure Return Oil: T port ≤ 50 bar, suitable for ordinary return oil circuits

Power-off Safety: Spring centering, load stops

II. Typical Application Scenarios

Medium-high speed precision presses, dynamic testing equipment

Electro-hydraulic position/velocity/pressure closed-loop control system

Industrial Automation, Metallurgy, Plastic Machinery

General temperature conditions (−20 to +80℃), standard hydraulic oil