Code of Federal Regulations Title 46. Shipping § 46.154.447 Allowable stress

(a) An independent tank type B designed from bodies of revolution must have allowable stresses   3 determined by the following formulae:

σ_m≤f

σ_L≤1.5 f

σ_b≤1.5 F

σ_L+σ_b≤1.5 F

σ_m+σ_b≤1.5 F

where:

σ_m=equivalent primary general membrane stress   4

σ_L=equivalent primary local membrane stress   4

σ_b=equivalent primary bending stress   4

f=the lesser of (sigma_B/A) or (σ_Y/B)

F=the lesser of (sigma_B/C) or (σ_Y/D) A, B, C, and D=stress factors in Table 2.

(b) An independent tank type B designed from plane surfaces must have allowable stresses specially approved by the Commandant (CG–ENG).