Abstract: A device for thermally insulating at least one undersea pipe. The device comprises a thermally insulating covering surrounding the pipe, the covering being covered by an outer leak proof protective case, and the case being made of a flexible or semi rigid material suitable for remaining in contact with the outside surface of the insulating covering when it deforms. The device is characterized in that the insulating covering comprises a phase-change material confined in at least one container made of a flexible or semi rigid material that is deformable, and the container is disposed around the pipe.

Abstract: The present invention relates to a reinforced undersea unit pipe element (1) suitable for being laid empty at great depth. The element includes a tubular wall, having at least one external peripheral reinforcing element (6, 7) creating a plurality of localized zones on the outside surface of the wall, the radial distance (d1) between the outside surface of the pipe and the longitudinal axis (XX?) of the wall in the zones being greater than the outside radius (R) of the tubular wall portions lying between the successive zones in the longitudinal direction (XX?), two successive ones of the zones being spaced apart in the longitudinal direction (XX?) of the tubular wall by a distance (D) equal to ½ to 4 times the outside diameter (d) of the tubular wall portions, the successive zones preferably being spaced apart regularly.