46 CFR § 132.110
Piping
April 15, 2021
(a) Except as provided for liftboats by §134.180 of this subchapter, each fitting, flange, valve, and run of piping must meet the applicable requirements of part 128 of this subchapter. Piping must be—
(1) Hot-dip galvanized;
(2) At least extra-heavy schedule; or
(3) Of a suitable corrosion-resistant material.
(b) Each distribution cut-off valve must be marked in compliance with §131.820 of this subchapter.