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. Weld leakage between tube and tube sheet is a difficult point 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 use, which will cause strong bubbles, slag, interlayers and local stress concentration caused by welding during the welding process. , Cracks may appear near the repair welding nozzle, causing new leaks.
Therefore, for the strength of welded titanium heat exchanger tube bundles, the way to avoid the failure of solder joints is: one is to choose the material reasonably, that is, to choose the tube sheet and heat exchange tube reasonably according to the medium, especially to avoid the electric shock between the tube sheet and the tube. chemical corrosion. Secondly, the welding penetration should be ensured at the root of the weld, and there should be a sufficiently high strengthening height (≥ 2.5mm). Furthermore, production practice shows that the strength of solder paste expansion is the key to ensure that the solder joints of titanium heat exchangers do not fail.
For pure strength expansion tube bundles, the expansion port leaks and can be replenished after pressure relief, and the number of supplementary expansions must not exceed three times.