OSHA, IFC, and NFPA have “separation distance” requirements for flammable liquid storage tanks. These requirements have been around longer than I have been dealing with hazardous materials and process safety, and yet we always come across some wildly out of “compliance” arrangements of these flammable liquid tanks. using OSHA’s Flammable Liquid Standard 1910.106 we can get a visual of this requirement: (emphasis by me)
1910.106(b)(2)(ii)(a) The distance between any two flammable liquid storage tanks shall not be less than 3 feet.
1910.106(b)(2)(ii)(b) Except as provided in paragraph (b)(2)(ii)(c) of this section, the distance between any two adjacent tanks shall not be less than one-sixth the sum of their diameters. When the diameter of one tank is less than one-half the diameter of the adjacent tank, the distance between the two tanks shall not be less than one-half the diameter of the smaller tank.
Let’s discuss WHY the codes/standards require this spacing.