API Std 650 welded steel oil storage tanks roundness

Oil tank accessories are an important component of metal oil tanks. Common accessories of API Std 650 welded steel oil storage tanks include manholes, light holes, oil measuring holes, breathing valves, safety valves, and fire extinguishers. The functions of these accessories are different. Some are to ensure the storage quality of various oil products, some are to ensure the normal operation of oil products receiving and dispatching, and some are to ensure the safety management of API Std 650 welded steel oil storage tanks, etc.

The ring of API Std 650 welded steel oil storage 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 650 petroleum storage tank stipulates that if the thickness of the lower siding obtained by calculating the anti-overturning moment is greater than the thickness of the API Std 650 welded steel oil storage tanks hydrostatic pressure test (both do not include the corrosion margin), the calculated thickness of the above siding required by the hydrostatic pressure is It should also be increased by the same proportion, unless special analysis is performed to determine the seismic overturning moment and corresponding stress at the bottom of each layer of API 650 petroleum storage tank wall.