In this fixing variant, flanges are built onto the expansion joint bellows, which are then pressed against the duct flanges using the backing flanges. This construction is able to meet high impermeability requirements. 

The temperature limit for flanged expansion joints is approx. 400 °C. At high temperature, the duct flanges need to be enlarged in order to create distance between the expansion joint and the duct. Pre-insulation ensures additional temperature dissipation.

At high temperature, the duct flanges need to be enlarged in order to create distance between the expansion joint and the duct. Pre-insulation ensures additional temperature dissipation.