These requirements cover the design and construction of welded steel tanks of the atmospheric type intended for the auxiliary storage and supply of fuel oil for oil burners. They are for use in the supply piping between a burner and its main fuel supply tank.These tanks are intended for installation and use in accordance with the Standard of the National Fire Protection Association for the Installation of Oil-Burning Equipment, NFPA No. 31. An auxiliary tank equipped with a mechanism for control of a pump or otherwise controlling liquid level or for preventing the spillage of fuel oil from a tank not required to be vented to the outside of a building is to be judged under the Standard for Pumps for Oil-Burning Appliances, UL 343. A product that contains features, characteristics, components, materials, or systems new or different from those covered by the requirements in this standard, and that involves a risk of fire, electric shock, or injury to persons shall be evaluated using the appropriate additional component and end-product requirements as determined necessary to maintain the acceptable level of safety as originally anticipated by the intent of this standard. A product whose features, characteristics, components, materials, or systems conflict with specific requirements or provisions of this standard cannot be judged to comply with this standard. Where considered appropriate, revision of requirements shall be proposed and adopted in conformance with the methods employed for development, revision, and implementation of this standard.