Dear Sir,

I was checking one of our vendors calculations for a tank. They have used TANK ver. 2.50 software.
Although 1.5 mm corrosion allowance has been specified, the resisting weight (and therefore the resisting moment)has been calculated considering the weight of shell, roof plate, roof structure and columns, all in uncorroded condition.
in my opinion it is not in accordance with para. 3.11.2 of API std.
Does the software calculate the resisting weight for uncorroded condition or our vendor has made a mistake in entering the input data?

Regards