Recurring Tube Leakages

[ww2i]

We have noticed frequent tube leaks in two of our heat exchangers. And now performing an analysis on what could be the causes and just in case not to miss any, what are the most overlooked causes of recurring tube leaks in shell-and-tube exchangers?

[sys1]

Recurring tube leaks in shell-and-tube heat exchangers are often attributed to the obvious causes (corrosion, erosion, vibration), but in many investigations the actual root cause is hidden in a combination of process conditions, design details, and operational practices.
You need to make sure you do not miss on all available operational. maintenance, and integrity data throughout its operations and during these leaks.

[ben]

Okay, you may then look into the tube expansion /rolling quality which can be improper.
There could be some SCC under mild service conditions. That stays invisible until failure occurs.
High velocity consideration due to flow maldistribution can lead to erosion - check those signs. Low velocity at the same time can get you fouling and then corrosion.
Two phase flow can have impact as well with induced vibrations, cavitation, fretting damage can happen.
Galvanic corrosion at tube-to-tubesheet interface can occur as well.

[octane]

My experience says that recurring leaks are frequently the result of multiple contributing causes rather than a single failure mechanism.
A structured root cause analysis that combines inspection findings, operating history, chemistry data, and mechanical design review is the most effective way to identify and eliminate the underlying problem.

[neo]

1. Have these heat exchangers facing such tube leaks for the 1st time?
2. Any recent operational changes happened which might have gone unnoticed?
3. What about the heat load and other variables as you experience these leaks?

[ww2i]

Answered.

1. Have these heat exchangers facing such tube leaks for the 1st time? Yes but this frequent, no
2. Any recent operational changes happened which might have gone unnoticed? We are looking into any such changes on the tube side
3. What about the heat load and other variables as you experience these leaks? Operations tell us that there hasn't been any changes however still under evaluation

[neo]

There can be some underlying causes contributing to recurring Tube leakages, already present but now surfacing more frequently. What sort of tube damages have you observed in terms of inspection findings? And what exactly the tube leaks locations are?

[ww2i]

Our inspection team says that there are local damages, fretting phenomena happening.
And how that is happening, and why recently with such recurring leaks, we are all looking into.
Thanks for all your inputs.