46 CFR § 154.707
Cargo boil-off as fuel: Ventilation
April 15, 2021
(a) A ventilation hood or casing must be installed in areas occupied by flanges, valves, and piping at the fuel burner to cause air to sweep across them and be exhausted at the top of the hood or casing.
(b) The hood or casing must be mechanically exhaust-ventilated and meet §154.1205.
(c) The ventilated hood or casing must have an airflow rate specially approved by the Commandant.