Frame 7FA.03 – 1st, 2nd, 3rd Stage Buckets
7FA.03 1st Stage Bucket Design Advantages:
- Trailing edge undercut to alleviate trailing edge cooling hole cracking
- Cooled platform to resolve platform burn and cracking (leading cause of scrapping 1st stage buckets)
- Improved cooling distribution to reduce peak metal temperature
- Proprietary directionally solidified alloy and thermal barrier coating (TBC) system to provide improved creep and oxidation life
7FA.03 2nd Stage Bucket Design Advantages:
- Significant creep life improvement for the tip shroud
- Cutter tooth is replaced with an abrasive rail coating
- Proprietary equiaxed alloy and TBC system to provide improved creep and oxidation life
- Improved fillet design to reduce stress
7FA.03 3rd Stage Bucket Design Advantages:
- Significant creep life improvement for the tip shroud
- Cutter tooth is replaced with an abrasive rail coating
- Proprietary equiaxed alloy and a chromide coating system provide improved creep and corrosion life
Frame 7FA.03 – Nozzles and Shrouds
7FA.03 1st Stage Nozzle Design Advantages:
- Full gas path TBC to improve oxidation life, reduce airfoil metal temperature, and reduce thermal gradients
- Improved airfoil to sidewall fillets to improve cracking resistance
7FA.03 2nd Stage Nozzle Design Advantages:
- Full gas path TBC provides reduced airfoil metal temperature and eliminates fatigue debit from external aluminum coating
- Improved airfoil to sidewall fillets to improve cracking resistance
- Proprietary alloy improves creep, oxidation life, and maintains the ability to weld repair
- Inner diaphragm material changed to 310SS for improved oxidation over Ni-Resist; more operator-friendly during repair weld schemes
7FA.03 3rd Stage Nozzle Design Advantages:
- Inner diaphragm material changed to 310SS for improved oxidation over Ni-Resist; more operator-friendly during repair weld schemes
7FA.03 1st Stage Shroud Block Advantages:
- Made of commercially available 310 stainless steel alloy
- Shroud block shoes are manufactured from a proprietary nickel alloy
- Shroud tiles are coated with a proprietary coating specially formulated to provide durability with abradability for improved tip clearance control with the 1st stage bucket
7FA.03 2nd Stage Shroud Block Advantages:
- Made of commercially available Haynes 120 (AMS 5916)
7FA.03 3rd Stage Shroud Block Advantages:
- Made of commercially available 310 stainless steel alloy
Frame 7FA.03 – Combustion Parts
7FA.03 Transition Pieces Design Advantages:
- Improved impingement cooling air and hard face coatings
- Proprietary gas path TBC for demonstrated improvement in oxidation life
7FA.03 Combustion Flow Sleeve Design Advantages:
- 304 stainless steel alloy that eliminates corrosion and pitting associated with carbon steel parts and improves oxidation lives
7FA.03 Liner Cap Assembly Pieces Design Advantages:
- TBC coated effusion plate to improve component life
7FA.03 Combustion Liner Pieces Design Advantages:
- Proprietary gas path TBC for demonstrated improvement in oxidation life
- Proprietary exterior coating system for improved oxidation life
Frame 7FA.03 – Compressor Hardware
R0 Compressor Blade
The R0 blade has been redesigned to address ongoing field issues with this component. The design is made from a higher strength alloy with superior corrosion and cavitation erosion resistance. Design enhancements include:
dovetail relief cut, compound fillet radii transitions, and airfoil tuning to provide superior blade design life.
S0 – S4 Compressor Vane Assemblies
The S0 – S4 compressor stator vanes have been redesigned to address ongoing field issues. Design enhancements include the fabrication of the shorter vane carrier in a non-corrosive alloy, relief slot in the vane carriers for ease of removal, elimination of shims, curved squealer tips to decrease leakage, and non-uniform S0 and S1 vane spacing to mitigate R0 and R1 vibratory response.
S5 – S17, Exit Guide Vanes (EGV) Stator Vanes
The design for all compressor vanes has arched (radius) bases to conform to the compressor case. This radius base configuration provides less wear on the components. We increased the widths of the vane platforms at the horizontal joint. These vane platforms will be machined during the outage to fit the case, negating the need for shims.
We can also perform compressor vane pinning.
