I. Core Parameters (D633-4728B Official Standard)

1. Basic Specifications

Model: D633-4728B (NG6 direct-acting servo valve, custom high-pressure return oil)

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

Pressure grade:

P/A/B: 350 bar

T/Y: 350 bar (high-pressure return oil, different from the ordinary B type with 50 bar)

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℃)

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) MGG China

Interface: 6+PE circular aviation connector (DIN 43650)

Hysteresis: <0.1% FS

Resolution: <0.1%

Linearity: ±0.25% FS

Electronic board: Integrated PWM drive, closed-loop control MGG China

3. Model Meaning (4728B)

4: D633 series, 24VDC, integrated electronics

72: Flow specification code (40 L/min, high-pressure return oil)

8: Custom code (high-pressure return oil, special adaptation)

B: Basic version, FPM 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

High-pressure return oil (350bar): Suitable for high-pressure circuits, no need for separate return oil pipeline

Top-level response: 320Hz + frequency response, 10ms step, preferred for high-speed control

Power-off safety: Spring centering, load stop

II. Typical Application Scenarios

High-pressure high-speed hydraulic machines, heavy material testing machines, large thrust servo actuators

Injection / die-casting / forging machine main control shaft (high-pressure return oil condition)

Electro-hydraulic position / speed / pressure closed-loop (high dynamics + high-pressure circuit)

Metallurgy, heavy machinery, ship hydraulic systems high-precision control

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