Discover the maximum thickness required:
A thin cylindrical vessel of 2 m diameter and 4 m length having a particular gas at a pressure of 1.65 N/mm2. If the allowable tensile stress of the material of the shell is referring to150 N/mm2, Discover the maximum thickness required.
Solution
In a thin cylindrical shell, stress shall be higher, since it is double that of longitudinal stress. Therefore, maximum stress is reached in the circumferential direction.
Diameter of the shell, d = 2 m = 2000 mm.
Internal pressure, p = 1.65 N/mm2.
Permissible tensile stress = 150 N/mm2.
If thickness required is t, then
pd / t = 150
1.65 × 2000/ (2 × t) = 150
t = 11 mm
Therefore, minimum thickness needed is 11 mm.