API Std 650 tanks weld hardness

The foundation design of the API Std 650 tanks should meet the requirements of foundation stability and deformation, that is, the API Std 650 tanks foundation should not be crushed and the uneven settlement value of the foundation should be within the allowable range. The uneven settlement of the storage tank foundation should be specified in the design process of the safe allowable range, because excessive uneven settlement will reduce the safety of the API Std 650 tanks and cause distortion and deformation of the tank wall and bottom plate.

API Std 650 tanks any joints between the adjacent sections of stiffening rings, as shown in Figure R-1, shall be made so that the required moment of inertia of the combined ring-shell section is provided. Weld joints between adjacent sections shall be made with full-thickness and full-penetration butt-welds. Stiffening-ring butt-welds may employ metal backing strips. Backing strips and the associated welding shall be made in a manner that provides a smooth contour in the rat hole and all other weld joints ends. All weld passes shall be started at the rat hole.

API 650 petroleum storage tank stipulates that if the thickness of the lower siding obtained by calculating the anti-overturning moment is greater than the thickness of the API Std 650 tanks hydrostatic pressure test (both do not include the corrosion margin), the calculated thickness of the above siding required by the hydrostatic pressure is It should also be increased by the same proportion, unless special analysis is performed to determine the seismic overturning moment and corresponding stress at the bottom of each layer of API 650 petroleum storage tank wall.