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Woodward 8915-1009

Product Description:​ This Woodward assembly combines a 3103-series stainless steel gas metering valve with an EM-35 electric actuator to form a complete fuel-control actuator/valve package. It is purpose-built for industrial gas turbine fuel control. The EM-35 actuator receives command signals from an electronic controller and drives the 3103 valve’s rotary metering sleeve with a fully electric drive system, achieving high-accuracy fuel flow metering. The unit is fully electric, low-maintenance, and factory-matched and base-calibrated for direct installation into turbine fuel systems.

Detailed content

Technical Specifications:
  • Part Number: 8915-1009
  • Manufacturer: Woodward
  • Equipment Type: Actuator and valve combination unit
  • Valve Type: 3103 series stainless steel gas valve
  • Actuator Type: EM-35 electric actuator
  • Drive Mode: Fully electric servo drive (brushless DC motor + planetary gear reduction)
  • Position Feedback: Built-in high-precision resolver directly coupled to the valve metering sleeve
  • Control Compatibility: Compatible with Woodward analog and digital EM35 motor drivers
  • Actuator Output Shaft Rotation: 60° (limited by valve stroke)
  • Continuous Output Torque: ±25 N·m (±220 lb-in) maximum
  • Peak Output Torque: ±45 N·m (±400 lb-in) minimum
  • Clutch Release Torque: ±68 N·m (±600 lb-in)
  • Actuator Power: 28 Vdc nominal, 18–32 Vdc operating range
  • Current: 15 A continuous, 25 A peak (100 ms)
  • Steady-state Current: ~3 A
  • Valve Flow Range: 23–18144 kg/h (50–40000 lb/h)
  • Fuel Supply Pressure: Up to 6205 kPa (900 psia)
  • Differential Pressure Range: 172–6205 kPa (25–900 psi)
  • Gas Temperature Range: -40°C to +149°C (-40°F to +300°F)
  • Ambient Temperature Range: -40°C to +93°C (-40°F to +200°F)
  • Position Accuracy: ±0.50° (analog drive), ±0.10° (digital drive)
  • Bandwidth: >5 Hz
  • Stroke Time: 150 ms open, 80 ms close (28 Vdc, room temperature)
  • Explosion-proof Certification: CSA listed Class I, Division 1, Groups C & D; LCIE Zone 1 Group IIB
Key Features:
  • Actuator and valve are pre-matched with factory calibration, minimizing on-site commissioning effort.
  • EM-35 actuator uses brushless DC motor, fully electric drive with no hydraulic oil supply, reducing maintenance requirements.
  • Motor uses samarium-cobalt permanent magnets; rotor position detected via magnetic field orientation unit for precise control.
  • Planetary gear reduction provides high torque output with high transmission efficiency.
  • Clutch between motor and gearbox protects the motor and drive train when the valve is obstructed.
  • Output shaft directly drives the valve through a stainless steel torsion coupling, providing zero-backlash transmission.
  • Resolver is directly mounted on the valve metering sleeve; position feedback is precise and unaffected by intermediate transmission error.
  • 3103 gas valve adopts rotary sleeve and shoe-type throttling structure, featuring self-cleaning and contamination resistance.
  • Valve design includes an inlet guide tube that directs fuel impurities toward the metering port, reducing debris accumulation in the valve body.
  • Metering sleeve support bearings are fully sealed from fuel to protect internal mechanisms.
  • On loss of power, valve spring loads to minimum fuel position, providing fail-safe protection.
Application Scenarios:
  • Fuel control for industrial gas turbine generator sets
  • Fuel management for gas compressor drivers
  • Gas supply regulation in combined heat and power (CHP) systems
  • Gas flow control in distributed energy stations
  • Fuel metering for dry low-emission (DLE) gas turbines
  • Marine and offshore platform gas power units
Material Composition:
  • Actuator Housing: Cast aluminum explosion-proof enclosure, surface treated
  • Motor Rotor: Samarium-cobalt permanent magnet, bonded and sleeve-fixed
  • Motor Stator: Fully encapsulated windings
  • Gearbox: Planetary gear reduction, high-strength alloy steel
  • Coupling: Stainless steel torsion coupling
  • Valve Body: Precision cast stainless steel
  • Metering Sleeve and Shoe: Fully hardened stainless steel, precision lapped
  • Seals: Fluororubber (FKM) or other fuel-resistant elastomer
Structural Characteristics:
  • Actuator and valve directly connected via adapter with no intermediate transmission link.
  • Rotary sleeve and shoe metering structure with excellent flow resistance characteristics.
  • Explosion-proof cast aluminum housing effectively dissipates motor heat to surrounding environment.
  • Output shaft supported by double roller bearings, providing strong load capacity.
  • Resolver directly coupled to valve metering sleeve, eliminating transmission chain error.
  • Compact overall structure, facilitating installation layout within turbine compartments.
Working Principle:​ The electronic controller sends a position command signal to the EM-35 driver. The driver energizes the brushless DC motor to produce precise rotation. The motor, after planetary gear reduction, directly drives the 3103 gas valve’s metering sleeve via a stainless steel torsion coupling to change the opening. The resolver detects the actual position of the metering sleeve in real time and feeds it back to the driver, forming a high-precision closed-loop position control. When the control system loses power or receives a shutdown command, the driver cuts off motor power and the valve’s built-in spring pushes the metering sleeve to the minimum fuel position, achieving fail-safe protection.
Installation Requirements:
  • Handle the unit carefully during handling and installation to avoid damage to seals, mounting surfaces, and factory adjustments.
  • Protect fuel connection ports with plastic plugs or caps when not connected to formal piping.
  • Ensure precise alignment of actuator and valve adapter via locating pins; ensure no jamming during installation.
  • Tighten actuator fixing bolts to specified torque.
  • Tighten coupling fixing screws to specified torque.
  • Configure a 25-micron absolute accuracy filter at the fuel inlet.
  • Route electrical connections through conduit interfaces; seal unused interfaces with explosion-proof plugs.
  • Use shielded cable for actuator and resolver wiring and ground properly.
Usage Notes:
  • Fuel cleanliness is critical to valve life; filters must be inspected and replaced regularly.
  • Fuel impurity levels must be strictly controlled: solids smaller than 10 microns not exceeding 30 ppm concentration, and larger than 10 microns not exceeding 0.3 ppm.
  • Regularly check the sealing of electrical connectors and the stability of position feedback signals.
  • Avoid operation under conditions of overpressure, overtemperature, or outside the voltage range.
  • Regularly check actuator housing temperature to ensure good heat dissipation.
  • Follow Woodward OEM recommendations for actuator maintenance intervals; return to factory for overhaul upon expiration to restore to “like-new” condition.
  • When replacing the actuator, no re-calibration of the valve is required because the resolver is directly installed on the valve metering sleeve.

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