ADU overhead Condenser Tubes Failed in Four months of operation 2

[MIANCH]

Dears
we replaced ADU overhead condenser with new one and tubes failed in four month of operation, shell side is overhead vapors and cooling media is seawater. for detail please see attached pH / Chloride analysis since January 2023. Tube material is SB-111-UNS C70600. There is not only tubes corroded but tube sheet also develop leak. tube sheet material is SB-111-UNS- C46400. Can someone can explain the rapid exchanger failure and its mitigations.
Thanks

 

[TugboatEng]

Anaerobic bacterias as they're the ones that produce H2S.

 

[EdStainless]

If you are picking up sand no Cu alloy stands a chance.
A high alloy SS (superduplex or superaustenitic) may be the only route for you.
The other option is an actual separator to remove the sand, but that takes space and pump power to run.

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P.E. Metallurgy, consulting work welcomed

 

[georgeverghese]

So maybe extend this seawater intake much further out into the sea to get clean seawater with no sand. Agreed, any CuNi grade is too soft to deal with sand. There were many reports of similar failures with CuNi in contaminated (bacterial H2S laden)seawater some years ago in KSA.

 

[Tmoose]

Hi Mianchi, are you in Africa?

 

[MIANCH]

Yes, I'm in Africa