California Code of Regulations › Title 8 - Industrial Relations › Division 1 - Department of Industrial Relations › Chapter 4 - Division of Industrial Safety › Subchapter 7 - General Industry Safety Orders › Group 20 - Flammable Liquids, Gases and Vapors › Article 145 - Tank Storage › Section 5590 - Spacing (Shell-to-Shell) Between Aboveground Tanks

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
(a) The distance between any two flammable or
						combustible liquid storage tanks shall not be less than three feet.
(b) Except as provided in (c), the distance
						between any two adjacent tanks any one of which stores Category 1, 2, 3 or 4
						flammable liquids shall not be less than one-sixth the sum of their diameters,
						except 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. Tanks used only for storing liquids
						with a flashpoint greater than 199.4 °F (93 °C) (formerly designated
						Class IIIB Combustible liquids) may be spaced as provided in (a) unless within
						a diked area or drainage path for a tank storing a Category 1, 2 or 3 flammable
						liquid.
(c) Crude petroleum tanks
						at production facilities in isolated locations having capacities not exceeding
						126,000 gallons (3,000 barrels), need not be separated by more than three
						feet.
(d) For unstable flammable or
						combustible liquids, the distance between such tanks shall not be less than
						one-half the sum of their diameters.
(e) When tanks are in a diked area containing
						Category 1, 2 or 3 flammable liquids, or in the drainage path of Category 1, 2
						or 3 flammable liquids, and are compacted in three or more rows or in an
						irregular pattern, greater spacing or other means shall be provided to make
						inside tanks accessible for fire fighting purposes.
(f) The minimum separation between a
						liquefied petroleum gas container and a flammable or combustible liquid storage
						tank shall be 20 feet, except in the case of flammable or combustible liquid
						tanks operating at pressures exceeding 2.5 psig or equipped with emergency
						venting which will permit pressures to exceed 2.5 psig in which case the
						provisions of (a) and (b) shall apply. Suitable means shall be taken to prevent
						the accumulation of flammable or combustible liquids under adjacent liquefied
						petroleum gas containers such as by diversion curbs or grading. When flammable
						or combustible liquid storage tanks are within a diked area, the liquefied
						petroleum gas containers shall be outside the diked area and at least 10 feet
						away from the center line of the wall of the diked area. The foregoing
						provisions shall not apply when liquefied petroleum gas containers of 125
						gallons or less capacity are installed adjacent to fuel oil supply tanks of 550
						gallons or less capacity.
1.
						  Amendment of subsections (b) and (e)-(f) and new NOTE filed 5-5-2014; operative
						  5-6-2014 pursuant to Government Code section
						  11343.4(b)(3)
						  (Register 2014, No. 19).
Note: Authority cited: Section
							 142.3, Labor
							 Code. Reference: Section
							 142.3, Labor
							 Code.