Home › CFR › Title 30 › Part 56 › §56.1901130 CFR §56.19011 — Drum flanges.Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗Copy linkFlanges on drums shall extend radially a minimum of 4 inches or three rope diameters beyond the last wrap, whichever is the lesser.