Innovative Repair of a V64.3A Combustor Casing

Case Studies

A V64.3A client of Eta Technologies LLC (Eta Tech) experienced severe fretting damage in various sealing/contact areas of their combustor casing due to excitation from combustion dynamics. Fretting wear found during maintenance outages was so extensive that seal retention features (grooves) were completely compromised (no longer grooves!). Areas of damage are indicated by arrows on the schematic diagram on this page.

Working with our client, Eta Tech not only developed repair methods for the existing damage, but also engineered a solution to eliminate fretting wear in the future. First, for severely damaged areas, patch rings were designed and fabricated to recover seal retention features and contact faces. For less severely damaged surfaces, wear strips were devised and manufactured from wear resistant material to preclude further fretting damage. Wear strip joining methods were engineered and conducted on site under Eta Tech supervision. Finally, hardface coatings were applied to various seal surfaces to further combat fretting wear.

Wear protection modifications engineered and implemented by Eta Tech have been so successful that this client has opted to apply them to new casings ordered from the OEM!