Answer to Question #172830 in Mechanical Engineering for George

Question

3.4 A storage tank is 5 m in diameter, 4 m high and the density of the fluid it

contains is 795 kg/m3. Determine the required wall thickness if the yield

stress of the material is 325 MPa, the factor of safety is 10 and the efficiency of

the longitudinal joint is 80 %.

Answer 1

t_m = F_s P_md_i / 2δ_m

tm = Minimum wall thickness (m)

F_s = Safety factor

P_m = Internal pressure (N/m²)

d_i = Inside diameter (m)

δ_m = Metal yield stress (N/m²)

P_m = $\rho$ g h = (795 kg/m³)(9.8 m/s²)(4 m) = 31 164 N/m²

t_m = 10 (31 164 N/m²)(5 m)/ 2(325 000 000 Pa)0.8 = 0.0030 m = 3.0 mm