---
kind: "range"
citation: "46 C.F.R. §§ 154.445–154.449"
title: "46"
from: "154.445"
to: "154.449"
count: 5
url: "https://uscodex.org/cfr/46/154.445..154.449"
---

# §154.445. Design vapor pressure.


If the surfaces of an independent tank type B are mostly flat surfaces, the Po must not exceed 69 kPa gauge (10 psig).


# §154.446. Tank design.


An independent tank type B must meet the calculations under [§ 154.448](/cfr/46/154.448.md).


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

# §154.448. Calculations.


The following calculations for an independent tank type B must be specially approved by the Commandant (CG-ENG):

- (a) Plastic deformation, fatigue life, buckling, and crack propagation resulting from static and dynamic loads on the tank and its support.
- (b) **A three-dimensional analysis of the stress exerted by the hull on the tank, its support, and its keys.**
- (c) The response of the tank and its support to the vessel's motion and acceleration in irregular waves or calculations from a similar vessel.
- (d) **A tank buckling analysis considering the maximum construction tolerance.**
- (e) A finite element analysis using the loads determined under [§ 154.406](/cfr/46/154.406.md).
- (f) A fracture mechanics analysis using the loads determined under [§ 154.406](/cfr/46/154.406.md).
- (g) **The cumulative effects of the fatigue load from the following formula—**

# §154.449. Model test.


The following analyzed data of a model test of structural elements for independent tank type B must be submitted to the Commandant (CG-ENG) for special approval:

- (a) **Stress concentration factors.**
- (b) **Fatigue life.**