StacksVerified U.S. regulatory reference

46 CFR §154.703

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
Unless a cargo tank carrying methane (LNG) can withstand the pressure build up due to boil-off for 21 days, the pressure in the cargo tank must be maintained below the set pressure of the safety relief valve for at least 21 days by:
  1. (a)A refrigeration system that meets § 154.702;
  2. (b)A waste heat or catalytic furnace that burns boil-off gas, and:
    1. (1)Maintains the stack exhaust temperature below 535 °C (995 °F);
    2. (2)Exhibits no visible flame; and
    3. (3)Is specially approved by the Commandant (CG-OES);
  3. (c)Boilers, inert gas generators, and combustion engines in the main propelling machinery space that use boil-off gas as fuel; or
  4. (d)Equipment for services, other than those under paragraph (c) of this section, that use boil-off gas as fuel and that are located:
    1. (1)In the main propelling machinery space; or
    2. (2)a space specially approved by the Commandant (CG-OES).