Patent ID: 7367398

Claim:
Apparatus for heating and lagging at least one undersea main bottom-to-surface connection pipe for carrying a flow of hot effluent, the apparatus comprising: a covering of at least one thermally insulating material surrounding said at least one main pipe; said insulating covering being covered by a leaktight outer protective casing; an internal chamber with a solid wall of cylindrical shape and coaxially disposed inside said outer casing, such that: said insulating covering surrounds said internal chamber and is disposed within an annular space between said outer casing and said internal chamber; said at least one main pipe is contained inside said internal chamber; and said heat-transfer fluid surrounds said at least one main pipe and circulates longitudinally between both longitudinal extremities of said internal chamber; and means suitable for maintaining the temperature of a heat-transfer fluid and for causing it to circulate inside said internal chamber.