Above ground storage tanks are used to store harmful materials and wastes, including petroleum products primarily controlled under 40 CFR 112. In the federal requirements, they don’t call it above ground storage tank, but refer to it as a “bulk storage container.”
As soon as they undergo storage tank fabrication, they are used to store oil before using, before commerce distribution or while being used.
The Storage Tank Application
Above ground storage tanks are made up of two types: the low-pressure storage tank and the atmospheric storage tank. The maximum pressure for gas or vapor space of a low-pressure storage tank is 15 psi, and for an atmospheric storage tank is 2.5 psi.
Low-pressure storage tanks are utilized for keeping liquid nitrogen, volatile chemicals, pentane, light naphtha, gasoline blending stock, light crude oil and so forth. Meanwhile, atmospheric tanks store non-volatile chemicals, gasoline, naphtha, gas oils, heavy oils, crude oil, furnace oils and others. The physical shape of these two might be the same, but the inspection requirements, as well as, construction design and code are varied.
The Inspection Requirements
API STD 620 is the construction code for low-pressure storage tanks, while API STD 650 is for atmospheric storage tanks. These already incorporate the minimum requirements for testing, inspection, fabrication, design and materials.
The storage tank test plan and inspection summarize the complete inspection requirements in tabular format and in several pages. It is divided into a couple of sets, one for construction activities in the field. Meanwhile, the other section is for beveling, rolling, cutting and supply of storage tank plates.
Now that you are aware of the inspection requirements and applications, you can proceed to use them properly and avoid any mishaps. Don’t forget the routine maintenance to keep it in tiptop shape.