Corrosion of heat exchanger tube sheets

No severe corrosion of the tube sheet was observed; only leaks caused by quality issues with the pipes at the pipe ends were seen, along with severe blockages in the pipes.

Almost one-third of the area is blocked, and it still isn’t being remade. Corrosion, right? The exhaust fumes cause corrosion that 316L can’t withstand. It may be caused by feed impact.

Introduce your own operation experience!

It would be best to explain in detail the exhaust gas components, operating conditions, and heat exchanger structure

After looking at the pictures of the tube sheet of your heat exchanger, there is one phenomenon I hope you will consider: the leakage points on the tube sheet are all located near the areas where you had performed prior welding repairs; they do not appear in the middle or at other locations, or if they do appear, it is very rarely. In my own practical experience, I encountered the same problem, and as a result I had to replace the entire heat exchanger. The approach I used to deal with similar problems was to block those areas using pins, without performing ring welding. When choosing the material for these pins, whether it be ordinary carbon steel or aluminum, it depends on whether the medium in contact with them is corrosive. In this way, the material in the areas not affected by welding heat does not undergo any changes, nor is stress accumulated there. I suggest you give it a try if possible.

Judging from your situation, there must be some issues with the material selection – 30% of the pipes are blocked. Secondly, the inlet side is severely corroded; erosion should be taken into account. Your medium is exhaust gas – does it contain any liquid phase?