A flanged tube assembly includes a rigid tube (10) and a sleeve (12) disposed about an axial end portion of the tube. The axial end portion (18) of the tube (10) includes a flange portion (24) that is formed by the tube wall (36) being radially outwardly deformed over an axial end surface of the sleeve. The sleeve (12) has a radially inner surface (28), and a portion of the tube wall (36) inside of the sleeve (12) is deformed to engage and conform to the radially inner surface of the sleeve, thereby forming a non-welded connection between the sleeve and the tube. The radially inner surface of the sleeve proximal the flange defines a relief cavity (56) that receives the deformed portion of tube wall when the tube wall is deformed during the formation of the flange (24).

A technique provides for combining a subsea housing, e.g. a subsea low-pressure wellhead housing, and a casing. The casing may be in the form of a large diameter conductor positioned in a seabed to facilitate deployment of desired types of tubulars and other components in a subsea well. The casing is inserted into the subsea housing along an interior surface of the subsea housing. The casing is joined to the subsea housing by radial expansion of the casing until the casing is forced into a suitable engagement with the subsea housing.