Question

A spherical vessel with an inside diameter of 2 m is made of material having an allowable stress in tension of 500 kg/cm². The thickness of a shell to withstand a pressure of 25 kg/cm² should be:

1. 5 cm
2. 10 cm
3. 2.5 cm
4. 1.25 cm

Answer 1

Correct Answer - Option 3 : 2.5 cm

Concept:

For thin spherical vessel:

For a thin spherical pressure vessel, both longitudinal and hoop stress is the same and given as

\({σ _h} = \frac{{pd}}{{4t}} = {σ _L}\)

Calculation:

Given:

d = 2 m, σ_L = 500 kg/cm², P = 25 kg/cm², t = ?

\(500 = \frac{{25 \times 2 \times 100}}{{4 \times t}} \)

t = 2.5 cm