Question

A seamless pipe with 80 cm diameter carries a fluid under a pressure of 2 n/mm2. if the permissible tensile stress is 100 n/mm2, the minimum required thickness of the pipe is

Answer 1

Given:

A cylindrical pipe with diameter 80 cm carries a fluid under a pressure

=2$\frac{N}{mm^{2} }$. The permissible tensile stress is 100 $\frac{N}{mm^{2} }$ .

To Find:

Minimum thickness of pipe required

Solution:

Thin pressure vessels

Two types of stresses are generated in a pressure vessel carrying fluid

Hoop stress and longitudinal stress

Hoop stress- stress in circumferential or radial direction

Longitudinal stress- stress along the length of pressure vessel

hoop stress = $\frac{Pd}{2t}$

longitudinal stress= $\frac{Pd}{4t}$

hoop stress> longitudinal stress

Hence failure must be protected from hoop stress.

permissible tensile stress = Hoop stress

$100 = \frac{(2)(800)}{(2)(t)} \\t = 8 mm$

Thickness of the pipe is 8mm.