Stress Analysis vs. Code Formula

When sizing relief devices, I frequently come across old tanks and vessels that do not state a design pressure/MAWP. One of our plants has this issue now.
They contracted with a local Engineering firm (Italy) to guide us on what the design pressure/MAWP is.

Their report says, “Analysis was conducted by stress analysis and not by formula. Doing it in this way the design pressure is obtained considering the weakest point.
The design pressure applicable is equal to pressure yield stress with a safety coefficient equal to 1.5."

So, the yield stress of 1.5 barg came from the flat, I- or C- beam reinforced top, which is the weakest point. Therefore design pressure/MAWP is 1 barg.

Does this meet Code? Why or why not?