Dear experts,

Need an advice regarding uneven surface, perforated nozzle flanges & their mating faces.
I got 8 nozzles on vessel which have corroded flange & faces.
Our recommendation is to be replaced all flanges, but our client refused due to their commercial budget.
They proposed to refaced all corroded flange face. Subjected to re-machined, flange thickness & dimension automatically reduced.
What is minimum allowable flange thickness for repair/machine, and flange integrity according their new flange thickness VS pressure rating.
In which code & standard state about this. By now, i am referring API 574 & ASME B16.5.

Kindly advice.

Thanks.
qcweld