Heat Exchanger Fin damage-Level of acceptance as per Code

[athilatt]

The Fins of Tube bundle of a Heat exchanger got badly damaged. Bundle is U1 stamped and API 661 requirements to conform.(New construction)

what would be the acceptance limit/criteria in damage of Fins ?

 

[SnTMan]

athilatt, if not addressed in API 661, then it will be per the customer, or, failing that, the limit would be where the exchanger no longer performs.

Regards,

Mike

 

[gr2vessels]

As SnTMan said, the limit is the performance of the exchanger;- the damage I assume is flattening / bending of the fins, which in turn will affect the air flow. Also, local overheating could be a case to look at. However, there is so much margin included in the design of these exchangers, that it takes a large percentage of the fins flattening, to notice significant degradation of performance.
I'd be concerned also with the impact on the tubes, being deflected perhaps excessively and the ends (expanded or welded) in the tubesheets being also overstressed.
Cheers,
gr2vessels