A283C plates API standard 650 ground supported liquid storage tanks

The main reason of "small breathing" loss of API standard 650 ground supported liquid storage tanks is the change of atmospheric temperature. When the temperature rises with the increase of solar radiation from dawn, the temperature of oil in the API standard 650 ground supported liquid storage tanks also changes, resulting in the acceleration of evaporation speed and the increase of evaporation pressure. When the pressure exceeds the positive pressure rating of the breathing valve, the oil-gas mixture in the API standard 650 ground supported liquid storage tanks is discharged into the atmosphere through the breathing valve, which is the "exhalation" process of the oil tank.

API standard 650 ground supported 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 ground supported 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.