NFPA 31 is a standard for the safe, efficient design and installation of heating appliances that use a liquid fuel, typically No. 2 heating oil, but also lighter fuels, such as kerosene and diesel fuel, and heavier fuels, such as No. 4 fuel oil. NFPA 31 applies to the installation of these systems in residential, commercial, and industrial occupancies.
The provisions of NFPA 31 apply to stationary oil-burning equipment and appliances, including steam, hot water, and warm air heating system; domestic-type range burners and space heaters; and portable oil-burning equipment. Related fuel oil storage and supply, accessory equipment, and control systems are also covered.