API standard 650 larger diameter tanks appurtenances

The ring of API standard 650 larger diameter tanks annular plates shall have a circular outside circumference, but may have a regular polygonal shape inside the tank shell with the number of sides equal to the number of annular plates. These pieces shall be butt-welded in accordance with API Standard 620 R.7.1.1, Item b. The plates of the first shell course shall be attached to the annular bottom plates by welds as required by API Standard 620 5.9.5 except when a full penetration weld is used or required.

API Standard 650, Welded Tanks for Oil Storage, Thirteenth Edition, has been published to ensure the safety, sustainability, and environmental performance of API standard 650 larger diameter tanks oil storage tanks. The updated standard will help continue operational excellence and trust between operators and manufacturers.

API standard 650 larger diameter tanks, floating roof tank is composed of vertical cylindrical tank wall and floating roof, which is floating on the surface of liquid storage. The volume of floating roof storage tank is generally large, and its bottom plate is arched edge plate. The difference between floating roof tank and other types of storage tank is that there is a floating top cover floating on the surface of liquid storage, and the top cover floats up and down with the rise and fall of liquid storage.