OSHA CFR 29 - Faucets, Vents, Siphon Adapter Codes
Flammable or combustible liquids shall be drawn from or transferred into vessels, containers, or portable tanks within a building only through a closed piping system, from safety cans, by means of a device drawing through the top, or from a container or portable tanks by gravity through an approved self-closing valve. Transferring by means of air pressure on the container or portable tanks shall be prohibited.
Please consult your local authority having jurisdiction with your questions and for guidance in conforming to laws as they apply to your application. This is only meant for a reference and does not imply a warranty.