Hello IshaqHashmi

I again caution you that a tank should never under any circumstances be allowed to lift from the foundation. It is a violation of the most fundamental engineering and safety principles.

Stresses from external pipe work are an entirely different consideration. CAESAR can give you a good estimate of the loads at any given nozzle. However, it is often the case that tanks must be designed long before the piping system analysis is available. Because tanks generally have a large diameter thin thing wall, there is a fairly low degree of stiffness, and tanks usually survive if the rules of the design code are followed.