728 MW Combined Cycle Power Plant gets a GE 7FA Flex Seal Expansion Joint Upgrade
From the initial inspection, the existing leaf seal system showed signs of extreme degradation and multiple signs of improper previous repairs. The leaf seals were either missing or not attached to the manifold flange as originally designed. It’s common for leaf seals to deteriorate during cycling.
They can harden and lose flexibility causing a premature loss in sealing capability.
As shown here, the existing leaf seals show signs of extreme degradation, detached and missing parts
After all previous repairs were removed, the PSIG team designed, manufactured, and installed a complete upgrade of the leaf seal with a Flex Seal exhaust expansion joint. In addition to the new leaf seals, the upgrade included a fabric expansion joint cover, stronger insulation bolsters, enhanced fastener system and larger diameter bolts. Expected operating life is 10 – 15 years.
Scope of work:
- Removal of existing leaf seal system
- Repair / preparation of external carbon steel casing material
- Installation of hot flange assembly
- Installation of cold flange assembly, composite pre-bolster system
- Installation of internal “Superwool” insulation tube
- Installation of super heavy duty composite outer expansion system
- Splicing of Inconel gas barriers
- Installation of backing bar system & retaining hardware
- Torque and retorque of all retaining hardware
