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Woodward 8915-898
Product Name
3103 Series Electric Fuel Valve with EM35MR All-Electric Actuator
Product Introduction
The Woodward 8915-898 is a fully electric fuel metering valve assembly of the 3103 valve family, integrated with an EM35MR all-electric actuator. It delivers precise fuel metering for industrial gas turbines with a completely electric drive solution, eliminating the need for hydraulic oil supply and associated maintenance.
Detailed content
- 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 EM35MR actuator directly coupled to 3103 valve body
- Resolver coupled to metering sleeve via stainless steel bellows
- Inlet flow guide tube with redundant sealing design
Working Principle
The electronic controller sends a position command signal to the EM35MR driver, which energizes 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 in real time and feeds back to the driver, forming a high-precision closed-loop position control. On power loss or trip command, the driver cuts motor power and the internal spring pushes the sleeve to minimum fuel position for fail-safe protection.
Functional Features
- Fully electric drive, no hydraulic oil source
- Brushless DC motor with samarium-cobalt magnets, stator windings fully encapsulated
- High-precision brushless resolver, non-contact position feedback
- Dual resolver redundant configuration
- Built-in slip clutch protects transmission
- Fault detection and automatic protection
- Spring return to minimum fuel on power loss
- Analog 4–20 mA or digital serial communication control
- Flameproof design with CSA and ATEX certification
- Self-cleaning metering structure suitable for sour gas service
Application Scenarios
- Industrial gas turbine fuel control
- Installations with no hydraulic oil source
- Explosion-proof zone applications
- DLE high-precision control
- Integration with Woodward NetCon and MicroNet systems
- Power generation, chemical industry, oil & gas transmission
Installation Requirements
- Handle with care to avoid damage to seals and factory calibration
- Protect fuel connection ports with plastic plugs before final piping
- Actuator and valve adapter aligned with locating pins, ensured no binding
- Actuator mounting bolts torqued to specification
- 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 is 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
- Regularly check actuator housing temperature for adequate heat dissipation
- Overhaul at Woodward OEM recommended intervals
- Valve recalibration not required when replacing actuator (resolver directly mounted on metering sleeve)
