the formulas of thikness of shells
You need to reference the ASME code or similar codes to determine the formulas since it varies depending several factors. Corrosin allowances, the degree of non destructive testing and the allowable stress all enter into the calculation. It is not just the classic formula for wall thickness of a cylinder.
The maximum resulting (hoop) stress in the wall of a cylindrical vessel is described by : S = RD/4t S is psi, D is inside diameter , R is the pressure difference psig and t is the wall thickness. All dimensions are in inches. This applied stress would tend to fail by splitting along the side. This is supposing that there are no weaknesses in joints and this does not address the stresses on the heads which can be of various shapes. This basic formula is for thin walls. There are correction curves for unusual thick walled cylinders. ( If the thickness is 20% of the inside radius, the stress is 10% higher.) The codes and standards among other things describe how much pressure or stress to allow for the various service conditions, designs and materials. You then must select a material that can withstand that allowable stress or else adjust the wall thickness, pressure or diameter.
