The Po (kPa) of an independent tank type C must be calculated by the following formula: Po = 196 + AC([rho]) \3/2\ where: A = 1.813 ([sigma]m/[Delta][sigma]A)
\2\;[sigma]m = design primary membrane stress;[Delta][sigma]A = (allowable dynamic membrane
stress for double amplitude at probability level Q =
10-8) 53.9 MPa (7821 psi) for ferritic and
martensitic steels and 24.5 MPa (3555 psi) for 5083-0
aluminum;C = a characteristic tank dimension that is the greatest of h, 0.75b, or
0.45 l; where: h = the height of the tank or the dimension in the vessel's vertical
direction, in meters;b = the width of the tank or the dimension in the vessel's transverse
direction; in meters; andl = the length of the tank or the dimension in the vessel's longitudinal
direction, in meters; and[rho] = the specific gravity of the cargo.