GE 6FA, 7F/FA, 9F/FA GAS TURBINE EXHAUST SYSTEM REQUIREMENTS*

*Specification from GE Schenectady’s multi-disciplinary 6FA, 7F/A, 9F/FA Task Force, April 1996

Satisfactory Service Life in both Utility and Non-Utility Generating Service
eg. Peaking Duty, 4 starts/day or 1460 starts/year, 32 Years Economic Life with 46,720 + Thermal Cycles

• Must Seal Exhaust Gas Pressures – No Gas Leakage Out or Ambient Air Let In
• Aerodynamic Performance
• Steel Structural Support Frame Service Life Not Less Than 32 Years* with Minimum Maintenance
• Fabric Component Repair/Replacement – No Less than at Major Inspection Interval [Combustion, 8000 hours; Hot Gas Path, 24000 hours; Major, 48000 hours or 6 years]
• High Reliability – No Forced Outages
• Minimum Force or Moment on Gas Turbine
• Convenient Low Cost Installation eg Minimize Time and Handling
• Convenient Interface with Gas Turbine
• Convenient Interface with GT Exhaust Duct, Diffuser, Silencer, Diverter Damper, HRSG or OTSG, By-Pass Duct, Stack
• Ability to Drain Liquid Fuel from Ignition Failure
• Ability to Drain Water and Water Detergent Solution from Off-Line Compressor Wash
• Design integrity with life calculation based on application of proven parts and features or those that can be analyzed to assure success
• Can Be Retrofitted to Existing Field Units
• Economic Cost* Based On the Above

*32 YEARS ECONOMIC COST BASED ON:

• Objective Thermal Stress and Fatigue Analysis of Application Cycle Life Expectancy Prior to Construction
• Steel Structural Support Frame Design to Survive a Minimum of 47,000 Thermal Cycles
• Fabric Flexible Bellows Component Life Extends In Relation to its Lowest Possible Exterior Surface Temperature i.e. Lower than 450ºF / 250ºC
• Reduce Incidences of Repair or Replacement of Flexible Fabric Components To Suit Scheduled Inspection Intervals to Minimize Cost