API standard 650 partially anchored liquid-storage tanks gauging device

The factors that affect the "small breathing" loss of API standard 650 partially anchored liquid-storage tanks are: 1. Generally, the larger the storage tank is, the larger the total open area is, the larger the evaporation area is, and the greater the "small breathing" loss is; conversely, the smaller the storage tank is, the smaller the evaporation area is and the smaller the "small breathing" loss is. 2. It is related to the atmosphere. The lower the atmospheric pressure is, the greater the "small breathing" loss is; otherwise, the loss is reduced.

API standard 650 partially anchored liquid-storage 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.

Design calculations and drawings required API standard 650 partially anchored liquid-storage tanks for the fabrication and erection of each API 650 tank. A drawing index for each API 650 tank is required and shall be re-submitted each time drawings are revised and re-issued.