Abstract: A union connection between uncooled pipe and cooled double-wall pipe in a heat exchanger comprising a double-wall pipe comprising in turn an internal pipe traveled by a fluid to be cooled and an external pipe defining with the internal pipe an air space traveled by a cooling fluid with one end of the double-wall pipe being connected to an inlet duct of the fluid to be cooled through a connection part also forming a bottom wall of the air space virtually transversal to the double-wall pipe extension and characterized in that the connection part has an annular form with U cross section to define two annular shanks extending longitudinally to the pipe with each shank being welded to one end of one of the two pipes of the double-wall pipe and in that the end of the inlet duct is welded to the connection part at said bottom wall of the air space.

Abstract: A connection between an uncooled pipe and a cooled double-wall pipe with between the walls a hollow space run through by cooling fluid let into the hollow space and taken from the hollow space through side passages connected to cooling fluid inlet and outlet ducts and including a connection zone with longitudinal cross section generally in fork form to have single tubular end connected to the uncooled pipe and an opposite double-wall tubular end to which are connected the corresponding walls of the cooled double-wall pipe so that the fork bottom constitutes a terminal closing of the hollow space and a side passage is made opposite the connection and a portion thereof nearest the uncooled pipe is almost at the height of the fork bottom. A double-pipe heat exchanger includes such a connection.

Abstract: A union connection between uncooled pipe and cooled double-wall pipe in a heat exchanger comprising a double-wall pipe comprising in turn an internal pipe traveled by a fluid to be cooled and an external pipe defining with the internal pipe an air space traveled by a cooling fluid with one end of the double-wall pipe being connected to an inlet duct of the fluid to be cooled through a connection part also forming a bottom wall of the air space virtually transversal to the double-wall pipe extension and characterized in that the connection part has an annular form with U cross section to define two annular shanks extending longitudinally to the pipe with each shank being welded to one end of one of the two pipes of the double-wall pipe and in that the end of the inlet duct is welded to the connection part at said bottom wall of the air space.

Abstract: A connection (10) between an uncooled pipe (11, 111) and a cooled double-wall pipe (12) with between the walls a hollow space (13) run through by cooling fluid let into the hollow space and taken from the hollow space through side passages (14, 114) connected to cooling fluid inlet and outlet ducts and comprising a connection zone with longitudinal cross section generally in fork form to have a single tubular end (16, 116) connected to the uncooled pipe and an opposite double-wall tubular end (117, 118) to which are connected the corresponding walls (19, 20) of the cooled double-wall pipe so that the fork bottom (21, 121) constitutes a terminal closing of the hollow space (13) and characterized in that a side passage (14, 114) is made opposite the connection and a portion thereof nearest the uncooled pipe (11, 111) is almost at the height of the fork bottom (21, 121). A double-pipe heat exchanger includes such a connection.