I have seen a lot of stainless steel tanks that are used for food storing or processing to fail. Like bottom and legs fail (correct MJCronin!). Also a fails in cooling jackets (50t tank) with a solution of propylene glycol inside (!). All these tanks are made with thin sheets of stainless steel. I mentioned an example from a quote of ready made tanks (with various capacities 5t, 10t, 25t). So for a 5000 liters volume with 1,5m diameter and 2,5m height, manufacturer stated that thickness is 2,5 mm (bottom) and 2mm (shell and roof). The bottom and roof are conical (angle 14 degrees).
Ik know that hydrostatic pressure is about 3.5 psi, but I am wondering if was made true design or empirical practice.
Mr MJCronin the country that will be installed is Greece. Frequently in wineries the ullage is pressurized with nitrogen gas, tank blanketing 20mbar.
I know that there is no necessity to design these tanks with a code. But wine spills are costs more than oil.
In the past wine stored in concrete tanks. Later in steel tanks epoxy painted, but there weren't any problems except corrosion (for instance a steel tank of 8000 liters, thickness 8mm).