Treatment method for tube bundle leakage of titanium heat exchanger

With the advancement of welding technology, most of the connection methods of titanium heat exchanger tube bundles, tubes and tube sheets are welded or expanded. The weld leakage between the tube and the tube sheet is the difficulty of the tube bundle leakage. Repair welding is not a good method, because there must be impurities in the hole gap between the tube and the tube sheet during use, which makes the strong slag, interlayer and local stress concentration caused by welding during the welding process. Cracks may develop near the welding nozzle, causing new leaks.
Therefore, for the strength of the welded titanium heat exchanger tube bundle, the way to avoid the failure of the solder joints is: first, to choose the material reasonably, that is, to choose the tube sheet and heat exchange reasonably according to the medium to avoid electrochemical corrosion between the tube sheet and the tube. Secondly, the root of the weld should ensure the welding penetration and have a high enough strengthening height.
Furthermore, the actual production shows that the strength of the solder paste expansion is the key to ensure that the solder joints of the titanium heat exchanger do not fail. For pure-strength expansion tube bundles, if the expansion port leaks, it will be filled after pressure relief, and the number of supplementary expansions shall not exceed three times.