Methods of repairing Storage Tanks shell with out of roundness and plumbness exceeds the dimensional tolerances given in API-653 & API-650.???
Acceptance criteria for sagging & Bulging of roof plates and methods of repair if exceeds the criteria??
You have three reasonable choices;
1 -- Bring in a representative of a reputable tank erection and repair company to give you an estimate and suggest a repair plan. Or bring two different companies to estimate and bid on your work.
2 -- Bring in an experienced API-653 Inspector or a experienced Tank Engineer [*totally* different knowlege base than a vessel engineer]
3 -- Buy a copy of API-653, read it cover-to-cover twice, and then aquire at least 15-years of experience repairing tanks. [I've been doing tanks off & on for about 15 years and I *might* know enough to fix those problems you described]
You can't buy experience, but you can lease it by the day or month.