Spherical Shells and Hemispherical Heads Under Internal Pressure

The ASME Code equation for spherical shells under internal pressure is:

The calculated minimum thickness of formed heads is not rounded up to standard plate because of the thinning that occurs in portions of the head during forming. The calculated value should be the minimum thickness at any point on the head. Using the same vessel example as above:

The calculated thickness should be increased by corrosion allowance:
t = 0.162 + 0.125 (c.a.) = 0.287 in.

Categories: Mechanical and Structural | Leave a comment