(a) If a material of a cargo tank is not listed in Sec. Sec. 154.610, 154.615 or Sec. 154.620, the allowable stress of that material must be specially approved by the Commandant (CG-ENG).
(b) For cargo tanks of aluminum alloys with welded connections, the minimum tensile strength ([sigma]B) for the calculations under Sec. 154.440, Sec. 154.447 and Sec. 154.450 must be the minimum tensile strength of the alloy in the annealed condition.
(c) Increased yield strength and tensile strength of a material at low temperature for independent tanks type A, B, and C must be specially approved by the Commandant (CG-ENG). [CGD 74-289, 44 FR 26009, May 3, 1979, as amended by CGD 82-063b, 48 FR 4782, Feb. 3, 1983]
Construction