CFR > Title 46 - Shipping > CHAPTER I—COAST GUARD, DEPARTMENT OF HOMELAND SECURITY > SUBCHAPTER F—MARINE ENGINEERING (parts 50 to 64) > PART 54—PRESSURE VESSELS > SUBPART 54.25—Construction With Carbon, Alloy, and Heat Treated Steels (§54.25-1 to §54.25-25) > 54.25-7—Requirement for postweld heat treatment (modifies UCS-56).

54.25-7—Requirement for postweld heat treatment (modifies UCS-56).

(a) Postweld heat treatment is required for all carbon and low alloy steel Class I, I-L, and II-L vessels regardless of thickness. (Refer to Table 54.01-5(b) for applicable requirements.)
(b) Cargo tanks which are fabricated of carbon or low alloy steel as Class II pressure vessels, designed for pressures exceeding 100 pounds per square inch gage and used in the storage or transportation of liquefied compressed gases shall be postweld heat treated regardless of thickness.
[CGFR 69-127, 35 FR 9977, June 17, 1970]