California Code, Labor Code - LAB § 7681

(a) The division shall inspect or cause to be inspected each installed tank at least every five years, except for any tank specified in subdivision (b).

(b) Any air pressure tank which contains 25 cubic feet or less and is not subject to pressure of more than 150 pounds per square inch and any liquefied petroleum gas tank used for storage, except a tank used for dispensing purposes as part of a dispensing unit, which contains 575 gallons or less shall be inspected or caused to be inspected by the division when the tank is initially placed into service if the tank is constructed, inspected and stamped in compliance with the American Society of Mechanical Engineers (ASME) Code, or the design, material, and construction of the tank is approved by the division as equivalent to the ASME Code.

(c) “Dispensing unit,” as used in this section, means a stationary liquefied petroleum gas installation, other than a bulk plant, from which a product is dispensed, for final utilization, into mobile fuel tanks or portable cylinders.