Description
Woodward 8516-045
Technical Specifications
- Speed Setting Range: 2400 to 4000 RPM (adjustable).
- Drive Rotation: Counterclockwise.
- Output Torque: 23.7 N·m (17.5 ft-lb) rotary output.
- Safety Device: Integrated Overspeed Test Device (OTSD) for ATEX environments.
- Droop Characteristic: Fixed mechanical droop for stable parallel or droop operation.
Functional Features
- Self-Contained Hydraulics: Generates its own hydraulic pressure via an integrated shaft-driven oil pump.
- Mechanical Speed Sensing: Uses a centrifugal ball head assembly to directly measure turbine speed.
- Steam Flow Modulation: Translates mechanical speed errors into precise rotary valve movements.
- Fail-Safe Design: Purely mechanical operation ensures continued control even during total plant power loss.
Application Scenarios
Ideal for driving industrial compressors, boiler feed pumps, and backup generators in petrochemical, refining, and power generation facilities.
Performance Parameters
- Control Accuracy: Maintains stable speed within mechanical droop limits under varying load conditions.
- Reliability: Exceptional mean time between failures (MTBF) due to the absence of electronic components.
- Hazardous Area Rating: Safe for use in explosive atmospheres when equipped with OTSD.
Material Composition
Features a rugged die-cast aluminum TG-17 enclosure protecting precision-machined steel hydraulic spools, springs, and centrifugal weights.
Structural Characteristics
- Housing: Die-cast aluminum for thermal stability and vibration resistance.
- Connections: Mechanical input drive and rotary output terminal shaft.
- Adjustments: External screw for speed set point adjustment and droop calibration.
Working Principle
Turbine rotation drives the internal ball head, which translates rotational speed into linear mechanical displacement. This displacement acts on a hydraulic servo valve that meters oil to a rotary actuator. The actuator turns the output shaft to open or close the steam valve, balancing the mechanical forces to maintain the desired droop speed.
Installation Requirements
- Align the input drive shaft carefully to avoid excessive vibration or premature bearing wear.
- Connect the output terminal shaft to the steam valve using the specified torque coupling.
- Verify the ATEX compliance labeling matches the installation zone requirements.
Usage Precautions
- Do not exceed the maximum rated speed for the specific model configuration.
- Lubricate mechanical linkages according to the maintenance schedule.
- Monitor for hydraulic oil leaks at the shaft seals and replace seals immediately if detected.
