This is kind of like the chicken or the egg question.
If a vessel is designed for over 15 PSIG and operated at less than 15 PSIG is an ASME stamp required?
Is there a rule in regards to stress relieving welds in caustic storage tanks at certain temperatures and concentrations?
I have a vessel with 50% sodium hydroxide and a temperature of 110 F. Would we need to consider stress relief at those?
Does Compress factor static head and specific gravity when a vessel is designed for zero pressure? Or do I need calculate those factors and use them for my design pressure?