API standard 650 mixed material tanks located on Site Class F type soils

Large-scale vertical API standard 650 mixed material tanks mostly use internal tank bottom heating coils to heat the medium stored in the storage tanks. The heating coils are mostly smooth tube structures arranged in an annular circle along the bottom of the API standard 650 mixed material tanks. Commonly used heating methods include hot oil circulation heating method and hot water steam circulation heating method. The hot oil circulation heating method is to continuously extract part of the liquid medium from the storage tank, and then return it to the container to mix with the medium in the tank after heating, and the heat is quickly transferred through mechanical stirring.

The thickness of the API standard 650 mixed material 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.

API 650 tank has the advantages of less load on the floating plate, simple and light structure, and can save the central drainage pipe and rotating floating ladder on the API standard 650 mixed material tanks floating plate. The materials for easy construction and maintenance and sealing parts can avoid aging due to sunlight.