46 CFR § 154.522 - Materials for piping.

(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) The temperature of the cargo at the pressure relief valve setting is −55 °C (−67 °F) or warmer; and

(2) Liquid cannot discharge to the vent piping.

(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.

[CGD 74–289, 44 FR 26009, May 3, 1979, as amended by USCG–2014–0688, 79 FR 58285, Sept. 29, 2014]