1. Basic Identification

• Model: D633-7213

• Brand: MOOG

• Category: Direct‑Drive Electro‑Hydraulic Servo Valve (DDV)

• Series: D633 (ISO 4401 Size 03 / NG6, direct drive, no pilot)

• Code meaning: 7213 = specific flow/electrical configuration; rated flow 20 L/min

2. Basic Information

• Structure: Permanent magnet linear force motor, direct drive, integrated electronic closed‑loop

• Mounting: ISO 4401‑03‑03‑0‑94 (NG6)Moog Inc.

• Weight: ~2.5 kg

• Protection: IP67 (connector), IP65 (body)

• Temperature: Ambient −20 ℃～+60 ℃; Fluid −20 ℃～+70 ℃

• Fluid: Mineral hydraulic oil, ISO 4406 18/15/12 cleanliness grade

3. Function & Positioning

• Function: 4/3‑way directional, speed, pressure, force closed‑loop control; throttling flow controlMoog Inc.

• Positioning: High‑dynamic, high‑precision, medium‑flow industrial servo valve

• Key features:

  • Pressure‑independent dynamics, fast responseMoog Inc.

  • Spring‑centered on power failure (safe state)Moog Inc.

  • Low null current, low hysteresis (≤0.2%)

  • Excellent contamination resistance (no pilot stage)

4. Core Parameters

Hydraulic

• Rated Flow: 20 L/min (Δp = 35 bar per edge)

• Max Working Pressure: 350 bar (P/A/B); 50 bar (T)Moog Inc.

• Viscosity: 15–100 mm²/s (operational)

Electrical

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

• Control Signal: ±10 V, ±10 mA, 4–20 mAMoog Inc.

• Feedback: 4–20 mA (spool position)

• Max Current: ≤1.2 A

• Connector: M12 (6+PE pins)Moog Inc.

Performance

• Step Response (0–100%): ≤12 ms

• Hysteresis: ≤0.2%

• Linearity: ≤0.1%

• Resolution: ≤0.05%

5. Compatible Accessories

• Grade 10.9 M5 mounting bolts

• NBR/FPM seal kit

• 5‑core shielded cable (M12)

• 10 μm high‑pressure filter

• M12 waterproof connector

6. Applications

• Precision injection molding (medium machines)

• High‑precision metal forming & pressing

• Metallurgical rolling equipment

• Aerospace test benches & simulators

• Industrial robot hydraulic units

• Vibration & fatigue testing (medium‑flow, high‑dynamic)