API Std 650 self anchored flatbottom tanks internal structures

Changes in Tank ShapeIf in any of the foregoing tests there is an excessive rise of the bottom of the tank around the boundary of contact with grade, or off its foundations, or if any of the specified conditions of test loading cause other appreciable changes in the shape of the tank, the design shall be reviewed and means shall be provided in the tank for holding the shape within permissible limits under all conditions of loading,API Std 650 self anchored flatbottom tanks. Additional TestsThe tests prescribed in API 620 tank 7.18 are believed to be sufficient for most tanks constructed according to these rules; if, in the opinion of the designer, additional tests are needed to investigate the safety of a tank under certain other conditions of loading, as determined from the design computations, these tests shall be made on the tank involved in addition to the tests specified in this standard.

If additional requirements are met, higher internal pressures are allowed. API 650 only covers tanks that support the whole bottom evenly and API Std 650 self anchored flatbottom tanks tanks in non-refrigerated service that have a maximum design temperature of 200 degrees F. It requires that you have a minimum material thickness of 3/16 inch.

The manufacturing requirements of bottom plate of vertical metal tank, API Std 650 self anchored flatbottom tanks are as follows: 1. In order to compensate welding shrinkage, the layout diameter of tank bottom is 5-2mm than the design diameter; 2. The butt joint of edge plate of tank bottom shall be machined automatically or semi-automatically; 3. The distance between any two adjacent welding joints on the tank bottom plate and the distance between the butt joint of edge plate and the longitudinal weld of bottom ring wall plate shall not be greater than 200 mm.