Heat exchanger of the type comprising a finned tube bundle and a header comprising a header plate and a header casing

A heat exchanger comprising a bundle of tubes, each with an end portion;

• fins carried by the said tubes;
• and a header comprising a header casing having an open side and a header plate closing the said open side to define an enclosed header space between them, the header plate being formed with holes, the said end portions of the tubes being sealingly fitted in the said holes;
• and further including at least one immobilising element extending through the header plate and beyond the latter on the opposite side thereof from the header casing, in a direction parallel to the longitudinal direction of the tubes, the header plate having at least one through aperture with each said immobilising element passing through a said aperture, and the heat exchanger further including means sealing the said at least one aperture from the header space, each immobilising element including an extension, the fins including a group of several fins adjacent to the header plate with said group defining opposed longitudinal sides of the group of fins, and with the said extensions of the immobilising elements bearing on the said longitudinal sides, whereby to constitute immobilising means for opposing any relative displacement of the tube bundle with respect to the header plate.