ASTM A537 plates API Std 650 mixed material tanks

API 620 Tank Design
The designer of these large tanks API Std 650 mixed material tanks shall supply the data on superimposed loadings to be assumed for the foundation design or, if there are no foundations, for direct loading on the subgrade. A slab or mat may be provided to support the superstructure and shall be considered to distribute the load more evenly over a lower natural subgrade compared with merely stripping, leveling, and rolling the existing grade.
For simple spheroids or tanks of similar design, in which the distribution of the imposed weights shifts because the liquid level in combination with the vapor pressure may change the shape of the tank, the designer shall consider the possibility of such a change.

API 650 "welded storage tanks" API Std 650 mixed material 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.

API Std 650 mixed material tanks Nondestructive testing is a technical means to detect the weld defects of large vertical tank and judge whether the weld is qualified by using the characteristics of sound, light, magnetism and electricity without damaging the tested object. Common nondestructive testing methods: ultrasonic testing (UT), magnetic particle testing (MT), liquid penetrant testing (PT) and X-ray testing (RT).