API RP 1621 (R2020) PDF
Primarily applied to underground storage of motor fuels and used oil at retail and commercial facilities. Assists the operator in controlling bulk stock losses, thereby achieving a high level of safety and pollution control while maximizing profits.
The primary application of this recommended practice is in connection with the underground storage of motor fuels and used oil at retail and commercial facilities. This recommended practice does not apply to inground (that is, where a part of the tank is aboveground) or aboveground bulk storage systems. Hereafter, the use of the term tank refers to an underground petroleum storage tank. Any merchandising operation in which a commodity is handled in bulk is susceptible to stock or inventory losses. This problem becomes even more critical at retail outlets selling motor fuels since the principal bulk commodity handled is volatile.
Thus, special care must be exercised to control product losses to (a) provide a safe environment for the operator, employees, customers, and neighbors; (b) minimize air and water pollution; and (c) maximize profits.
