A spherical gas-storage tank with an inside diameter of 8.0 m is being constructed to store gas under an internal pressure of 1.62 MPa. The tank will be constructed from steel that has a yield strength of 295 MPa. If a factor of safety of 3.0 with respect to the yield strength is required, determine the minimum wall thickness tmin required for the spherical tank.

The minimum wall thickness Tmin required for the spherical tank is 65.90mm

Explanation:

Solution

Recall that,

Tmin = The minimum wall thickness = PD/2 бp

where D = diameter of 8.0 m

Internal pressure = 1.62 MPa

Then

The yield strength = 295MPa/3.0 = 98.33

thus,

PD/2 бp = 1.62 * 8000 / 2 * 98.33

= 12960/196.66 = 65.90

Therefore the wall thickness Tmin required for the spherical tank is 65.90mm