Fuel oil storage
Fuel oil can be stored in storage tanks above ground (ASTs) or in tanks underground (USTs). Each has both advantages and disadvantages, and it is important to determine the correct type to ensure optimum design.
ASTs are typically made of steel. UL 142: Standard for Steel Aboveground Tanks for Flammable and Combustible Liquids specifies the specifications for single- and double-wall tanks from an AST benchmarking point of view, UL 2080: Standard for Fire Resistant Tanks for Flammable and Combustible Liquids specifies the requirements for fire-resistant tanks, and UL 2085: Standard for Fire Resistant and Combustible Tanks. ASTs offer ease of maintenance; typically, lower installation costs and the ability of the mechanical contractor of the project to install; ease of relocation; and the option of custom sizes to suit site conditions.
The use of an AST may not be suitable for all projects because it requires accessible real estate, poses a greater fire hazard, acceptable storage space is usually limited by applicable codes and insurance companies, and fuel heaters may be required in cold weather applications where the tank is exposed to sub-freezing ambient temperatures.
USTs are available in steel or fiberglass construction. UL 58: Standard for Steel Underground Tanks for Flammable and Combustible Liquids and UL 1746: Standard for External Corrosion Protection Systems for Steel Underground Storage Tanks define the specifications for steel tanks and related corrosion safety; and UL 1316: Glass-Fiber Reinforced Underground Plastic Storage Tanks for Petroleum Products, Alcohols.