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Woodward 9908-402
Product Name: LQ25 Liquid Fuel Metering Valve (LQ25 Series)
Product Overview: 9908-402 is a member of the Woodward LQ25 family of fully-electric liquid fuel metering valves. While Woodward’s public documentation does not publish a dedicated single-page datasheet for 9908-402, the LQ25 Valve Actuator Assembly manual (Woodward 26161) defines the universal specifications for all LQ25 valves, to which 9908-402 conforms.
Detailed content
Key Technical Specifications (LQ25-series baseline per Woodward manual 26161):
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Maximum Fuel Inlet Pressure: 1,200 psig (8,274 kPa)
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Maximum Fuel Bypass Pressure: 100 psig (690 kPa)
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Nominal Metering ΔP: 50 psid (345 kPa)
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Minimum Metered Flow: 80 lb/h (36 kg/h) at SG 0.77
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Turndown Ratio: >100:1
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Command / Feedback: 4–20 mA
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Drive Voltage: 18–32 VDC
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Metering Accuracy: ±5% of nominal flow or ±0.5% of max flow
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Full-Stroke Time: <100 ms
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Ingress Protection: IP66 (typical for LQ25)
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Operating Temperature: –28 °C to +85 °C
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Storage Temperature: –40 °C to +103 °C
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All wetted materials: corrosion-resistant or corrosion-protected
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Options: Pressurizing Valve (PIV); integral separate-command Shutoff Valve (SOV, closes in <0.100 s)
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Resolver: single- or three-speed frameless resolver
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Marine versions: stainless steel housing & wetted parts
Functional Features: Patented single-stage droop-compensated ΔP regulator for excellent metering accuracy across all inlet/outlet pressures. Self-cleaning shear-action metering. All-electric, no hydraulic power unit. PIV option for low-flow accuracy; SOV option for <0.100 s emergency shutoff.
Working Principle: Identical to the LQ25 architecture: 4–20 mA command → driver → brushless DC motor rotates metering plate → constant ΔP regulator makes flow a deterministic function of port area.
Installation Requirements: Install per Woodward manual 26161. Positive-displacement pump upstream, filter ≤20 µm. Shielded cable, single-point ground. Driver within 100 m of valve.
Application Scenarios: 1,000–42,000 kW industrial and aeroderivative gas turbines; power generation, mechanical drive, marine propulsion.
Usage Precautions: Refer to the LQ25 Valve Actuator Assembly manual (26161_R) for model-specific options and torque values. Confirm whether 9908-402 is fitted with PIV / SOV options before specifying spare parts.
