Equipment for securing and sealing heat transfer tubes in heat exchanger tube plate

The attachment and sealing is claimed of heat transfer tubes in the heat exchanger tube plate such that tube fittings are inserted in the ends of the tubes mounted in a first tube plate which are attached to the second tube plate. The fittings are fastened to the tubes preferably by explosive welding or rolling-in. The space between the two tube plates may be used for leak testing. Coolant leaking into the space may be diverted. If required, the space may be filled with a sealing material. (Ha)