46 CFR § 32.53-30
Positive pressure—T/ALL
April 15, 2021
Each inert gas system must be designed to enable the operator to maintain a gas pressure of 100 millimeters (4 inches) of water on filled cargo tanks and during loading and unloading of cargo tanks.
[USCG-2003-16630, 73 FR 65160, Oct. 31, 2008]