API Std 650 mechanically-anchored flat-bottom tanks greater than 60 m in diameter

Large-scale vertical API Std 650 mechanically-anchored flat-bottom 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 Std 650 mechanically-anchored flat-bottom 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.

Test plates shall be welded using the same qualified welding procedure and electrodes that are required for the tank shell plate joints. The API 620 steel storage tank test plates need not be welded as an extension of the tank shell joint but shall be welded in the required qualifying positions. One test weld shall be made on a set of plates from each specification and grade of API Std 650 mechanically-anchored flat-bottom tanks plate material, using a thickness that would qualify for all thicknesses in the shell. Each test welded of thickness t shall qualify for plate thicknesses from 2t down to t/2, but not less than 5/8 in. For plate thicknesses less than 5/8 in., a test weld shall be made for the thinnest shell plate to be welded; this test weld will qualify plate thicknesses from t up to 2t.

API 650 "welded storage tanks" API Std 650 mechanically-anchored flat-bottom tanks is a standard developed and issued by the American Petroleum Institute (API), which specifies the minimum requirements for the design, manufacture, installation and inspection of welded storage tanks.