A516 Gr 70 plates API Std 650 insulated tanks

API Std 650 insulated 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.

Supply covers for API Std 650 insulated tanks connections specified with the service covers remaining in place following tests. For API 650 tank connections not specified to be supplied with service covers, the test covers may be removed after testing.

The water dissolved in the oil will be separated out from the oil stored in the API Std 650 insulated tanks for a long time, and the acidic water layer will appear at the bottom of the API Std 650 insulated tanks for a long time, which will accelerate the corrosion of the API Std 650 insulated tanks and cause the wall thinning and even leakage. With the increase of service life, the API Std 650 insulated tanks must be inspected and cleaned regularly to check the hidden danger.