§ 47-11. Enclosing tanks.

Steel tanks in units of not over 275 gallons' capacity each, having an aggregate capacity not in excess of 550 gallons, may be installed without enclosures. Except as permitted above, tanks shall be completely enclosed with eight inches of reinforced concrete on 12 inches of other masonry, with at least a six-inch space on the sides between the tank and the concrete filled with sand or well-tampered earth, and with 12 inches of said on top of the tank, either between the tank and the concrete slab or above the concrete slab. When more than one storage tank is installed, such tanks shall be connected with the main feed pipe line leading to the burner through a manually-operated three-way valve so that not more than one tank can in any way discharge its contents at one time.