Design Code for Thin Wall Stainless Steel Tanks

Stainless steel tanks are considered thin-walled if their design is constrained by their vulnerability to buckling. This vulnerability is most likely to be exposed during construction, transportation or installation; once a tank is actually filled, the contents contribute to its stability

Shape

The shape of a thin-walled stainless steel tank depends on efficient use of material and any physical restrictions to diameter or height. The volume of the tank must take into account head space for thermal expansion, foaming or filling control.

Stress

Many thin-walled stainless steel tanks are cylindrical because cylinders are structurally strong and easy to fabricate. They are subjected to stresses due to internal pressure within the tank and superimposed loads, such as wind, snow and ice.

Thickness

Equations for the minimum wall thickness of a stainless steel tank under internal pressure use membrane theory. The longitudinal stress, P, on the tank can be calculated from the formula P = p x d^2/4, where p is the internal pressure, in pounds per square inch gauge (psig) and d is the internal diameter, in inches.

References

• Engineer OnLine: Stainless Tanks
• "Process Equipment Design: Vessel Design"; Lloyd Earl Brownell, Edwin Harold Young; 1959