API 650 tank for oil storage

API 650 standard governs welded tanks for oil storage. API 650 dictates tank design, fabrication, welding, inspection, and erection requirements. API 650 is typically used for carbon, stainless steel and aluminium tanks located in terminals, refineries, pipelines and other process facilities.

API 650 sets minimum requirements for the design, material, construction, and testing for aboveground, open and closed-top, cylindrical steel storage tanks in different capacities and sizes, roughly equating to the pressure of the atmosphere (not greater than the weight of the roof plates). If additional requirements are met, higher internal pressures are allowed.

API 650 only covers tanks that support the whole bottom evenly and tanks in non-refrigerated service that have a maximum design temperature of 90 degrees Celcius (200 degrees Fahrenheit).  API 650 tank requires that you have a minimum material thickness of 3/16 inch.  

API 650 tank can store contents at a lower pressure (maximum of 2.5 PSI) but at much higher temperature (-40 degrees F to 500 degrees F) than API 620 tank. API 650 tank can be any tank size. API 650 tank is used to store products such as crude oil, gasoline, chemicals and produced water.