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:
Code of Federal Regulations
Footnote(s): 3 See Appendix B for stress analyses definitions.
Code of Federal Regulations
Code of Federal Regulations
Code of Federal Regulations
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where:
σm=equivalent primary general membrane stress 4
σL=equivalent primary local membrane stress 4
σb=equivalent primary bending stress 4
f=the lesser of (σB/A) or (σY/B)
F=the lesser of (σB/C) or (σY/D)
A, B, C, and D=stress factors in Table 2.
Nickel steel and carbon manganese steel values | Austenitic steel values | Aluminum alloy values | |
---|---|---|---|
Stress factors: | |||
A | 4.0 | 4.0 | 4.0 |
B | 2.0 | 1.6 | 1.5 |
C | 3.0 | 3.0 | 3.0 |
D | 1.5 | 1.5 | 1.5 |
(b)
An independent tank type B designed from plane surfaces must have allowable stresses specially approved by the Commandant (CG-522).
[CGD 74-289, 44 FR 26009, May 3, 1979, as amended by CGD 82-063b, 48 FR 4782, Feb. 3, 1983]