Question

You have been assigned to design an open cylindrical storage tank 4 meters tall with a diameter of 8 meters to be made out of A-36 steel. The tank will hold a fluid with density of rho = 1.2 g/cm^3 (or 1200 kg/m^3 ). Using a safety factor of 4, what wall thickness is required?

Answer 1

The required wall thickness is
`1.506 * 10^(-3)` m

Step-by-step explanation:

Given:

Fluid density
`\rho = 1200`
`(kg)/(m^(3) )`

Diameter of tank
`d = 8` m

Length of tank
`l = 4` m

F.S = 4

For A-36 steel yield stress
`\sigma = 250` MPa,

Allowable stress
`\sigma _(allow) = (\sigma)/(F.S)`

`\sigma _(allow) = (250)/(4) = 62.5` MPa

Pressure force is given by,

`P = \rho gh`

`P = 1200 * 9.8 * 4`

`P = 47088` Pa

Now for a vertical pipe,

`\sigma _(allow) = (Pd)/(4t)`

Where
`t =` required thickness

`t = (Pd)/(4 \sigma _(allow) )`

`t = (47088 * 8 )/(4 * 62.5 * 10^(6) )`

`t = 1.506 * 10^(-3)` m

Therefore, the required wall thickness is
`1.506 * 10^(-3)` m