Description
The Moog D633K2063-R04KO1F0HWX2 is a size 03, single-stage direct drive proportional directional servo valve with integrated digital/analog electronics. Designed for high-performance electrohydraulic position, velocity, pressure, or force control loops, it utilizes a permanent magnet linear force motor to actively stroke the spool in both directions from its spring-centered position. The “K” designation denotes specialized ruggedized or hazardous location design variants, and the extended suffix code defines its specific flow capacity, spool type, fail-safe behavior, seals, and electrical command interface.
Procurement and Availability
- Availability: Stock dependent; available in new surplus, factory-sealed, or certified factory-refurbished conditions. Due to specific configuration variations, verify exact part code nameplates prior to ordering.
- Lead Time: 2 to 4 weeks for standard factory configurations if out of stock; expedited options available for select inventory.
- Warranty: 12-month standard replacement warranty on new surplus units; 1-year warranty on fully tested refurbished hardware.
- Pricing Note: Listed price is indicative, not final. Price subject to market conditions; contact us for a firm quote.
Technical Specifications
| Parameter | Value |
| Manufacturer | Moog |
| Product Series | D633 Series Direct Drive Valve (DDV) |
| Complete Model String | D633K2063-R04KO1F0HWX2 |
| Valve Size / Mounting Pattern | ISO 4401-03-03-0-0-94 (NFPA D03 / CETOP 03) |
| Rated Flow (\Delta p_N = 5 bar / 75 psi per land) | Configured per dash number code (Typically 4 to 40 l/min nominal range for D633 series variants) |
| Maximum Operating Pressure (Ports P, A, B) | 350 bar (5,000 psi) |
| Maximum Operating Pressure (Port T) | Up to 350 bar (5,000 psi) when external drain port Y is used (50 bar / 725 psi max without port Y) |
| Spool Drive Mechanism | Permanent magnet linear force motor (closed-loop position controlled via LVDT transducer) |
| Supply Voltage | +24 V DC (19 to 32 V DC, permissible ripple max 5\%) |
| Current Consumption | 1.2 A max |
| Command Signal Interface | Standard analog configuration suffix (verify exact pinout for \pm 10 V or 4 to 20 mA command options per variant spec) |
| Spool Position Feedback Output | 4 to 20 mA standard monitoring output |
| Operating Temperature (Fluid) | -20 to +80 °C (-4 to +176 °F) |
| Operating Temperature (Ambient) | -20 to +60 °C (-4 to +140 °F) |
| Filtration Requirements | Recommended cleanliness ISO 4406: 15/12/9 or better (NAS 1638 Class 6) |
| Enclosure Rating | IP65 with mating connector correctly attached |
| Weight | 2.5 kg (5.5 lbs) |
System Integration and Compatibility
The D633 series relies on integrated pulse-width modulation (PWM) drive electronics, removing the requirement for external controller card racks while providing fast step-response dynamics independent of pilot oil pressure lines.
- Fail-Safe Operation: Upon loss of supply voltage, cable break, or an emergency stop command, the internal centering springs automatically drive the spool to its designated mid-position safely without passing through uncontrolled active load movements.
- Hydraulic Flushing: Prior to initial installation of the valve onto a subplate, execute a complete system flush using a flushing plate (Moog part B46634-002 or equivalent) to purge particulate contamination from supply lines.
- Electrical Connection: Mates via a standard 6+PE pole industrial electrical connector (such as Moog part B97007-061). Ensure protective earth shielding is connected correctly to minimize electromagnetic interference (EMI).
Frequently Asked Questions
Q: Can this valve operate without an external pilot pressure supply? A: Yes. Because it is a Direct Drive Valve (DDV) utilizing a linear force motor coupled directly to the spool, it requires no pilot oil supply lines or internal pilot choking. Dynamic performance remains completely independent of system pressure drops.
Q: What happens to the valve spool if the 24 V DC power supply fails? A: The internal spring assembly immediately forces the spool to its center (failsafe) position. Verify the exact suffix configuration to confirm whether the center position blocks all ports or opens specific paths according to your system safety requirements.
Q: What level of oil cleanliness is mandatory for this valve? A: Due to the tight tolerances of the precision-hardened spool and bushing assembly, maintain fluid cleanliness at or better than ISO 4406: 15/12/9 using a high-pressure inline filter with a dirt alarm.
