Product Overview
The MOOG G631-3005B / H60FOMA4VBR is a high-performance, two-stage electrohydraulic servo valve engineered by Moog, the global benchmark in precision motion control. This valve operates on a torque-motor, flapper-nozzle pilot stage that hydraulically actuates a precision-ground, four-way sliding spool in the main stage. The result is an exceptionally fast, infinitely variable control of both flow direction and magnitude in direct proportion to an electrical input current. Designed for closed-loop position, velocity, force, or pressure control architectures, the G631 series is a cornerstone component in demanding industrial and aerospace-grade hydraulic systems where dynamic response, hysteresis-free operation, and long-term drift stability are non-negotiable.
Technical Specifications
| Parameter | Specification / Feature |
|---|---|
| Component Type | Hydraulic Servo Valve (Two-Stage, Four-Way, Flapper-Nozzle Pilot) |
| Model Designation | G631-3005B / H60FOMA4VBR |
| Manufacturer | Moog Inc. |
| Operating Pressure | Standard Industrial Grade (Up to 315 bar rated supply pressure) |
| Rated Flow | Nominal 5–40 L/min at 70 bar valve pressure drop (model-dependent) |
| Pilot Stage | Torque motor with dual nozzle-flapper assembly |
| Main Stage | Four-way, closed-center, critical spool-land geometry |
| Input Signal | Analog current (typically ±10 mA to ±40 mA differential) |
| Mounting & Connection | Standard ISO 4401 / Moog subplate interface with O-ring porting |
| Hysteresis | < 3% of rated current (typical) |
| Threshold | < 1% of rated current (typical) |
| Frequency Response | Up to 100–200 Hz at 90° phase lag (application-dependent) |
Engineering Features & Advantages
- Precision Performance: The hydraulic servo valve (two-stage, four-way, flapper-nozzle pilot) delivers precise, repeatable performance with low hysteresis and stable control across the full working range.
- Industrial Reliability: Designed for dependable long-term operation in demanding industrial environments, with quality bearings and sealing systems ensuring extended maintenance intervals.
- Direct Fit Replacement: Exact dimensional and functional compatibility with original MOOG OEM standards, ensuring drop-in replacement without modification to existing manifolds or piping.
Typical Industrial Applications
Designed for closed-loop position, velocity, force, or pressure control architectures, the G631 series is a cornerstone component in demanding industrial and aerospace-grade hydraulic systems where dynamic response, hysteresis-free operation, and long-term drift stability are non-negotiable.
PRODUCT IMAGES


MOOG G631-3005B / H60FOMA4VBR Servo Valve
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- Authentic & Fully Tested: 100% bench tested for hydraulic response, pressure rating, and null-bias stability before dispatch.
- Fast Dispatch: In-stock units ready for same-day dispatch via DHL / FedEx Express directly to your plant.
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- Peace of Mind: Covered by our 12-Month Replacement Warranty.
Shop the genuine MOOG G631-3005B / H60FOMA4VBR Servo Valve. This USA-made high-performance hydraulic component features a two-stage design with mechanical feedback, delivering leak-free, reliable fluid control for heavy-duty industrial systems.