4.01 What type of storage tank is used in a building?

Tanks inside buildings are steel tanks of UL 142 or UL 2085 fire rated construction. They are typically horizontal tanks, although vertical tanks are sometimes used because of the available dimensions of the room.

Tanks may be cylindrical or rectangular. Rectangular tanks are advantageous in that they are somewhat more compact. But more importantly their dimensions can be readily modified to fit through doorways, between columns, and into narrow rooms.

Tanks may be single wall or double wall. Single wall tanks are used where the room itself provides the required secondary containment capacity. Otherwise double wall tanks are more typical.

Fire-rated tanks are sometimes required by local fire marshalls. Often the fuel tank room is required to be constructed for 4 hour fire resistance, and the fire rating on the tank would be unnecessary. Also the greater weight of the fire rated tank might require additional structural characteristics, or special procedures during installation.