CFR›Title 49›Subtitle B›Chapter I›Part 179›Subpart E›49 CFR 179.300-4 Citation49 CFR 179.300-4CorpusDaily eCFRDisplayed edition2026-10-01Last updated2026-10-01 § 179.300-4 Insulation.(a) Tanks shall not be insulated.(b) [Reserved] Previous 179.300-3 § 179.300-3 Type and general requirements. Next 179.300-6 § 179.300-6 Thickness of plates.