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Woodward 9908-023
Product Name: LQ25 Series Liquid Fuel Metering Valve (Oil Metering Valve, 9908 family)
Product Introduction: The 9908-023 is a member of the Woodward LQ25 liquid fuel metering valve family. Like the 9908-011, it utilizes an integrated brushless DC electric actuator and rotary plate valve body design, delivering precise fuel metering for gas turbines in the 1000 kW to 42 000 kW range. It is configured as a standard LQ25 variant within the 9908 part-number series.
Detailed content
Technical Specifications:
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Applicable turbine output power range: 1000 kW to 42 000 kW
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Maximum fuel inlet pressure: 1200 psig (8274 kPa)
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Maximum fuel bypass pressure: 100 psig (690 kPa)
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Rated metering differential pressure: 50 psid (345 kPa)
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Fuel filtration requirement: 20 microns or finer
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Fuel water content limit: 0.1% by volume
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Solid sediment limit: 1.0 mg/L
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Minimum metering flow: 36 kg/h (80 lb/h)
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Flow turndown ratio: >100:1
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Drive power supply: 18 to 32 VDC
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Command signal: 4 to 20 mA
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Valve position feedback: 4 to 20 mA
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Operating temperature range: -28 °C to +85 °C
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Storage temperature range: -40 °C to +103 °C
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Valve body weight: approx. 35 kg (77 lb)
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Nominal bore: 29.2 mm (1.15 in)
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Protection rating: IP66
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Metering accuracy: ±5% of actual flow or ±0.5% of maximum flow
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Full-stroke actuation time: <100 ms
Functional Features:
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Self-cleaning shear-type metering action
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Single moving part design (metering sleeve integral with actuator rotor)
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Non-contacting position sensor (no gear backlash, no stepper resolution/oscillation issues)
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Rare-earth permanent magnet high-efficiency electromagnetic circuit
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Remote shut-down input and valve/driver fault output
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Fully electric — no hydraulic or pneumatic assist required
Application Scenarios: Gas turbine power generation; mechanical drive; marine propulsion liquid fuel control compatible with diesel, JP-series aviation fuel, kerosene, gasoline, and other compliant distillates.
Material Composition: Corrosion-resistant materials for valve body and internal components; fluorocarbon rubber seals compatible with diverse liquid fuels and temperature extremes.
Structural Characteristics: Brushless DC integral actuator directly coupled to the rotary metering plate and resolver feedback. Elimination of gear trains, linkages, and flex couplings maximizes reliability and contamination resistance.
Working Principle: The driver converts the 4–20 mA command into a driven current for the brushless DC torque motor. The motor rotates the rotary plate to precisely schedule the metering port area. A bypassing regulator maintains constant differential pressure across the port. The resulting shear-type metering action combined with precision EDM-machined port geometry delivers a flow turndown exceeding 100:1.
Installation Requirements: Install per Woodward LQ25 valve manuals (26161 / 26475 / 26854 / 35029 depending on enclosure material and connector type). Maintain fuel filtration ≤20 microns. Driver may be remotely mounted up to 100 m from the valve. Verify proper grounding and shielding of 4–20 mA signal wiring.
Usage Notes: Explosion hazard — power must be off before opening covers or making electrical connections in hazardous areas. ESD awareness is mandatory when handling electronics. Turbine must have an independent overspeed protection device. Fuel MSDS must be reviewed and appropriate PPE worn. Do not operate outside specified mechanical, electrical, or pressure limits.
