Treatment of Tube Bundle Leakage of Titanium Heat Exchanger

With the progress of welding technology, most of the connection methods of titanium heat exchanger tube bundles, tubes and tube sheets are welding or expansion. The weld leakage between tube and tube sheet is a difficult problem in the treatment of 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 the use process, so that the strong bubbles, slag, interlayer formed in the welding process and the local stress concentration caused by welding, cracks may appear near the repair welding nozzle, causing new leakage.
Therefore, for the strength of welded titanium heat exchanger tube bundles, the way to avoid solder joint failure is: first, reasonably select materials, that is, reasonably select tube sheets and heat exchange tubes according to the medium, especially to avoid electrochemical corrosion between tube sheets and tubes. Secondly, the root of the weld shall ensure the welding penetration and have a high enough strengthening height.
Moreover, the actual production shows that the strength of solder paste expansion is the key to ensure that the solder joints of titanium heat exchanger will not fail. For pure strength expansion tube bundle, the expansion port leaks, and can be supplemented after pressure relief. The number of times of supplementary expansion shall not be greater than three.