Abstract: A high temperature rectangular exhaust duct expansion joint structure for securement to a high temperature gas stream and particularly, but not exclusively, a turbine engine exhaust duct. The support flange structure incorporated in the duct has a connecting flange which defines opposed side walls of the rectangular support flange structure. A T-shape radial web is connected to an outer surface of the connecting flange. The radial web has a vertical wall component and a transverse end component extending beyond opposed sides of the vertical wall component and is connectable to a flexible membrane of the joint structure. The support flange has reinforced corner sections wherein the connecting flange and the vertical wall component of the T-shape radial web are of increased thickness to reduce thermal stress in the corner sections and to effectively redistribute the stress in the support flange.

Abstract: A cylindrical flexible joint unit for interconnecting a hot gas duct of circular cross-section to a further duct structure of circular cross-section. The flexible joint unit comprises an inlet annular flexible wall structure for connection to the hot gas duct and an outlet flexible annular connector. Heat insulating material is retained between the annular wall structures and an outer flexible annular membrane. The inlet wall structure has a cylindrical inner sleeve and an annular step connecting flange secured about an outer surface of the sleeve. The inner sleeve has a duct connecting end and a free end. The step connecting flange has a short transverse connecting wall and an elongated annular spaced wall section extending from the connecting wall, and disposed substantially parallel above the outer surface of the inner sleeve toward the duct connecting end to define an air gap therebetween.