3003 aluminum pipe API standard 650 tanks
The thickness of the API standard 650 tanks annular bottom plates shall be in accordance with Table Q-4 (for steel or aluminum, as applicable). The thicknesses shown are minimums. The ring of annual plates shall have a circular outside circumference, but it 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 Q.7.1.1, Item b. The plates of the first shell course shall be attached to the annular bottom plates by a weld as required by API 620 oil tank 5.9.5 except when a full-penetration weld is used or required (see Q.7.1.1). Butt-welds in annular plates shall be not closer than 12 in. from any vertical weld.
When API 650 storage tank is designed, when the design pressure is small F2 kPa, the impact of air pressure on the API standard 650 tanks tank wall thickness is not considered in the tank wall design.
The most popular standards for API standard 650 tanks are API Std 650, JIS B8501, BS2654, GB50341, etc. The formulas used in each standard are derived from the hoop stress calculation formula of membrane theory. Combined with the stress characteristics of API standard 650 tanks, plus the allowable stress, weld coefficient and additional wall thickness, the wall thickness calculation formula is complete. The allowable stress and weld coefficient are determined according to the material performance characteristics and construction technology level of each country. According to different API standard 650 tanks standards, the calculation results of tank wall thickness are sometimes quite different.