46 CFR § 153.238 - Required materials.
When one of the following paragraphs of this section is referenced in Table 1, only those materials listed in that paragraph may be used in components that contact the cargo liquid or vapor:
(a) Aluminum, stainless steel, or steel covered with a protective lining or coating.
(b) With cargo concentrations of 98 percent or greater, aluminum or stainless steel.
(c) With cargo concentrations of less than 98 percent, 304L or 316 stainless steel.
(d) Solid austenitic stainless steel.
(e) Stainless steel or steel covered with a suitable protective lining or coating. (See § 153.266.)