CSA G40.21 Gr 350WT plates API standard 650 ground supported tanks

Requirements for prefabrication of bottom plate of large vertical API standard 650 ground supported tanks:
1. The diameter of tank bottom should be enlarged by 0.1% ~ 0.15% according to the design diameter.
2. The minimum dimension of edge plate along the radius direction of tank bottom shall not be less than 700mm.
3. The distance between any adjacent welds of the base plate shall not be less than 300 mm.

Any joints between the adjacent sections of API 620 oil storage tank stiffening rings, as shown in Figure Q-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 joint ends. All weld passes shall be started at the rat hole and other weld joint ends and shall be completed by moving away from these ends. Passes shall be overlapped away from edges to provide a smooth continuous weld.

There is a gap of 100 mm to 500 mm between the shell of API 650 crude oil storage API standard 650 ground supported tanks tank and the floating plate of external floating roof to ensure that there is no chuck during operation. Use API standard 650 ground supported tanks edge sealing system to reduce edge evaporation. The support legs of API 650 crude oil tank floating roof are usually movable and retractable and suspended in liquid.