StacksVerified U.S. regulatory reference

46 CFR §151.03-49

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
This is an unperforated tube fitted to an ullage hole, secured so as to be vapor tight to the underside of the tank top open at the bottom, and extending to within 18 inches or less of the bottom of the tank.