The replacement and upgrade of the existing metallic expansion joint with another metal expansion joint would have required a full NDT, splicing in new section of bellow and extremely delicate welding. Alternatively, a fabric expansion joint retrofit boasted multiple advantages, including:

• Individual adjustment and modular build-up of every bellow layer.
• Outstanding vibration dampening features.
• Low shipping and mounting expenditure and low net weight.
• No power transmission to duct connecting elements due to negligible low adjusting forces.
• Outstanding insulation possibilities through targeted thermodynamic design under consideration of heat transfer mechanisms.

This project was installed within 12 days and involved the following steps:

1. Removal of cladding, lagging, weather shield and existing metallic bellow.
2. Modification of adjacent duct insulation support pins and welding of new frames externally on the diffuser.
3. Installation of pinned internal insulation bolsters and gas-tight closing of fabric expansion joint. Finally, torque fixings and installation of adjacent external insulation.