Problems with leaks in the heat exchange tubes and welds of vertical reboilers.
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A heat exchange tube in the vertical reboiler at the bottom of the tower leaked; after the tube was blocked, a leak was found at the weld. The medium flows through the tube side; the temperature is around 60 degrees, near atmospheric pressure, and it is basically non-corrosive ； Steam flows through the shell side, at a temperature of 150 degrees and a pressure of 5–10 kilograms.
Question: Have you all encountered leaks in such vertical reboilers? How were they resolved?
This reboiler is designed with strength welding combined with expansion joints; it’s not known how it was actually manufactured.
I didn’t go to the scene; I just took some photos and came back. Visually, the weld seam of the pipe joint is not very visible.
Keep an eye on it; two units in our office have the same problem. Cathodic protection was just applied; no effects have been observed yet
It seems there’s a problem with the visual inspection of the weld; the tube ends appear to be slightly burned. For those types of casings through which steam passes, we carry out welding and also apply expansion strips
Fixed tube sheet heat exchanger? If leakage persists after patch welding, it may be because the process specifications did not specify the exact temperature conditions of the metal walls; those responsible for equipment design used the arithmetic average value, which resulted in the axial stress on the heat exchange tubes having opposite signs, thereby leading to a lack of expansion joints