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Woodward 8915-904
Product Name
3103 Series Electric Fuel Valve with EM35MR All-Electric Actuator
Product Introduction
The Woodward 8915-904 is a fully electric fuel metering valve assembly of the 3103 valve family, driven by an EM35MR all-electric actuator. It provides precise fuel metering for industrial gas turbines with a fully electric, hydraulic-free design, suitable for the most demanding explosion-proof and high-precision fuel control applications.
Detailed content
Technical Specifications
- Pressure Rating: CE limited to 4964 kPa (720 psia); Enhanced up to 6205 kPa gauge (900 psig)
- Differential Pressure Range: 172 to 6205 kPa (25 to 900 psi)
- Fuel Temperature: –40 to +149 °C
- Ambient Temperature: –40 to +93 °C
- Metered Fuel Types: Natural gas, propane, methane
- Fuel Specific Gravity: 0.5 to 1.05
- Fuel Filtration: 25 µm absolute (β = 75)
- Flow Accuracy: ±5% of point or ±0.25% of maximum flow; ±2% of point for DLE applications
- Minimum Differential Pressure: 172 kPa (non-DLE), 345 kPa (DLE)
- Output Shaft Rotation: 60°
- Continuous Output Torque: ±24.9 N·m (±220 lb-in)
- Peak Output Torque: ±62.4 N·m (±552 lb-in)
- Clutch Disengagement Torque: ±68 N·m (±600 lb-in)
- Torque Constant: 1.8 N·m/A
- Motor Type: Brushless DC motor, samarium-cobalt permanent magnet
- Power Input: 28 Vdc nominal, 18 to 32 Vdc operating range
- Current: Max 37 A (50 ms), max continuous 15 A
- Slew Rate: 50° stroke — 150 ms opening, 80 ms closing
- Bandwidth: > 5 Hz
- Position Accuracy: ±0.50° analog, ±0.10° digital
- Resolver Accuracy: ±0.05°
- Assembly Weight: Approx. 44 kg (96 lb)
- Fuel Connection: 2-inch 600# ANSI B16.5 flange
Material Composition
- Valve Body: Stainless steel
- Internal Components: Fully hardened stainless steel
- Actuator Housing: Cast aluminum flameproof enclosure
- Motor: Samarium-cobalt permanent magnet brushless DC motor
- Resolver: Non-contact electromagnetic induction structure
- Coupling: Stainless steel torsion coupling
Structural Features
- Planetary gear reduction actuator directly coupled to valve body
- Resolver directly coupled to valve metering sleeve for position detection, eliminating transmission chain error
- Inlet flow guide tube with redundant sealing design
- Compact overall structure for easy installation in turbine compartment
Working Principle
The electronic controller sends a position command to the EM35MR driver, which excites the brushless DC motor for precise rotation. After planetary gear reduction, the motor drives the 3103 fuel valve metering sleeve via a stainless steel torsion coupling. The resolver detects the actual sleeve position and feeds back to the driver, forming a high-precision closed-loop control. On power loss, the driver cuts motor power and the internal spring pushes the metering sleeve to the minimum fuel position for fail-safe protection.
Functional Features
- Fully electric drive, no hydraulic oil source, eliminating hydraulic contamination and maintenance
- Brushless DC motor with samarium-cobalt magnets, stator windings fully encapsulated
- High-precision brushless resolver directly coupled to metering sleeve
- Dual resolver configuration for redundant position detection
- Built-in slip clutch protects transmission, disengages at 1.5× maximum output force
- Fault detection circuit monitors 4–20 mA interface, position controller, driver, and feedback
- Automatic motor power cut-off on fault or trip; spring return to minimum fuel
- Analog driver accepts 4–20 mA; digital driver communicates 16-bit position data via serial link with NetCon/MicroNet
- Flameproof cast aluminum enclosure, ATEX Category 2 compliant
- CSA certified: Class I, Division 1, Groups C, D; Class I, Division 2, Groups B, C, D (NRTL/C); LCIE Zone 1 Group IIB
- Driver CSA certified: Class I, Division 2, Groups A, B, C, D (NRTL/C)
- Self-cleaning metering structure suitable for sour gas service
Application Scenarios
- Industrial gas turbine fuel metering and regulation
- Installations with no hydraulic oil source
- Explosion-proof zone (Zone 1 / Division 1) fuel control
- DLE high-precision control
- Integration with Woodward NetCon and MicroNet systems
- Power generation, chemical processing, oil & gas transmission, distributed energy
Installation Requirements
- Handle with care to avoid damage to seals, mounting faces, and factory adjustments
- Protect fuel connection ports with plastic plugs before final piping
- Actuator and valve adapter aligned with locating pins
- Actuator mounting bolts and coupling set screws torqued to specification
- 25 µm absolute filter at fuel inlet
- Shielded cable for electrical connections with proper grounding
- Unused conduit openings sealed with flameproof blanks
Usage Notes
- Fuel cleanliness critical: solid particles < 10 µm ≤ 30 ppm, > 10 µm ≤ 0.3 ppm
- Regularly inspect electrical connector sealing and position feedback signal stability
- Avoid operation beyond pressure, temperature, or voltage ratings
- Monitor actuator housing temperature for adequate heat dissipation
- Overhaul at Woodward OEM recommended intervals
