D634-542A
May 25, 2026

D634-542A

The D634-542A is a pilotless, single‑stage, direct‑drive servo valve (DDV) in the MOOG D634 series (ISO 4401‑05 / NG10). It uses a permanent magnet linear force motor, integrated LVDT spool position feedback, and 24 VDC PWM drive. Designed for high‑pressure, ultra‑high‑flow, high‑response hydraulic closed‑loop control, it is built for the most demanding industrial applications.

Description

  • Brand: MOOG

  • Model: D634-542A

  • Series: D634 (ISO 4401‑05 / NG10)Moog Inc.

  • Structure: Pilotless, single‑stage, direct‑drive valveMoog Inc.

  • Drive: Permanent magnet linear force motorMoog Inc.

  • Feedback: Integrated LVDT spool position closed‑loop

  • Power Supply: 24 VDC (18–32 VDC), max. 2.2 AMoog Inc.

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

  • Protection Class: IP65

  • Weight: Approx. 6.8 kg

  • Mounting: ISO 4401‑05 (NG10)Moog Inc.

Function & Positioning

Core Functions

  • Precise Flow/Direction Control: Four‑way servo with spool closed‑loop for accurate position, speed, pressure, force regulation。

  • Pilotless Operation: No pilot oil required; simplifies circuits, reduces leakage, improves reliabilityMoog Inc.

  • Spring Centering: Returns spool to neutral on power loss for safe, fail‑safe shutdownMoog Inc.

  • Pressure‑Independent Dynamics: Direct‑drive design maintains stable response regardless of system pressure fluctuationsMoog Inc.

Product Positioning

  • Ultra‑high‑flow, high‑pressure hydraulic system core control component.

  • Top‑tier performance alternative to traditional pilot‑operated servo valves, offering lowest maintenance, highest stability, ultimate precision.

  • Optimized for 300 L/min nominal flow and 350 bar high‑pressure industrial closed‑loop applications。

Core Performance Parameters

  • Max. Working Pressure (P/A/B): 350 bar (5,000 psi)

  • Max. T‑Port Pressure: ≤ 50 bar (without Y port); 350 bar (with Y port)Moog Inc.

  • Rated Flow (Δp = 35 bar): 300 L/min

  • Peak Flow: 380 L/min

  • Null Leakage: 1.5–5.5 L/min

  • Full‑Stroke Step Response: ≤ 24 ms

  • ‑3 dB Bandwidth: 28–45 Hz

  • Hysteresis: < 0.25% of full scale

  • Resolution: < 0.10% of full scale

  • Working Fluid: ISO 11158 mineral hydraulic oil

  • Fluid Temperature: ‑20 °C to 80 °C

Universal Matching Accessories

  • ISO 4401‑05 standard mounting manifoldMoog Inc.

  • M18 6+PE‑pin electrical connector (IP65)Moog Inc.

  • High‑precision hydraulic filter (10 μm)

  • Special sealing kit (for ‑20 °C to 80 °C)

  • Pressure sensor (0–350 bar)

Applicable Equipment Fields

  • Super‑large‑tonnage hydraulic presses and heavy forging lines

  • Ultra‑high‑speed injection molding and large die‑casting machines

  • Multi‑axis high‑load vibration test benches and fatigue rigs

  • Heavy‑duty industrial hydraulic systems (steel, mining, marine, aerospace)

  • High‑precision automatic closed‑loop control equipment requiring maximum flow


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