StacksVerified U.S. regulatory reference

46 CFR §154.522

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
  1. (a)The materials for piping systems must meet § 154.625 for the minimum design temperature of the piping, except the material for open ended vent piping may be specially approved by the Commandant (CG-ENG) if:
    1. (1)The temperature of the cargo at the pressure relief valve setting is −55 °C (−67 °F) or warmer; and
    2. (2)Liquid cannot discharge to the vent piping.
  2. (b)Materials for piping outside the cargo tanks must have a melting point of at least 925 °C (1697 °F), except for short lengths of pipes with fire resisting insulation that are attached to the cargo tanks.