Device and method for restoring the tube-to-tube sheet weld joints in a shell-and-tube equipment

A method for repairing damaged tube-to-tube sheet weld joints in a shell-and-tube equipment using at least one device including a tubular connection element oriented along a central axial direction,

• the device comprising:
• at least one inner surface, designed to enclose an inner conduit for the passage, along said central axial direction, of at least one fluid processed by said shell-and-tube equipment;
• and
• at least one outer surface, surrounding said at least one inner surface,
• wherein said tubular connection element is provided, at one end thereof, with at least one first connecting portion for connection, through a butt-welded joint, to one corresponding tube of said shell-and-tube equipment and, on one side thereof, with at least one second connecting portion for connection, through at least one weld bead, of said tubular connection element to at least one portion of the tube sheet of said shell-and-tube equipment,
• the method comprising the steps of:
• cutting an annular portion of the tube sheet, wherein said annular portion of the tube sheet surrounds at least a hub of one old tube to be replaced, so as to obtain a through hole in said tube sheet for the insertion of said tubular connection element;
• removing the old tube from the shell-and-tube equipment;
• inserting a new tube into the shell-and-tube equipment;
• butt-welding said new tube, at one end thereof, to said tubular connection element;
• fitting up said tubular connection element into said through hole;
• and
• forming a weld bead in a cavity obtained between said tubular connection element and said through hole, so as to obtain a root welding between said tubular connection element and said tube sheet.