API standard 650 aluminum tanks of adequate safety

API standard 650 aluminum tanks, floating roof tank is composed of vertical cylindrical tank wall and floating roof, which is floating on the surface of liquid storage. The volume of floating roof storage tank is generally large, and its bottom plate is arched edge plate. The difference between floating roof tank and other types of storage tank is that there is a floating top cover floating on the surface of liquid storage, and the top cover floats up and down with the rise and fall of liquid storage.

Soil Structure Interaction: Soil structure interaction per API 650, Section E.6.1.6 may be used for OLE design providing the damping ratio does not exceed 10 %.
Allowable Stresses
Design allowable stresses shall be per API 620 large welded steel storage tank, Section Q.3.3, including the 33 % increase permitted for earthquake loads.
Self-anchored Inner Tank
The anchorage ratio for a self-anchored inner tank, J, shall not exceed 1.0 for the OLE design combination to limit uplift and stresses in the annular plate and corner weld.
Foundation Stability
The overturning ratio defined in API 650, Section E.6.2.3, Equation (E.6.2.3-1) shall be equal to or greater than 3.0 for the defined OLE event.

The API 650 is the American standard for welded flat-bottomed vertical API standard 650 aluminum tanks storage tanks. This standard dictates tank design, manufacture, welding, inspection and installation requirements.