API 650 uplifting tanks anchor straps

According to the standard of head of API 650 uplifting tanks, there should be no crack, delamination, inclusion and other defects on the groove surface, which is consistent with the steel plate standard. The API 650 uplifting tanks head polishing can adopt different technology according to different requirements, including rough polishing, medium polishing and fine polishing. Only the materials used for the third type of pressure vessels must be retested, and the materials used for the first and second class pressure vessels are not generally re inspected.

In this project, an elemental area of tank wall used is constructed of ASTM A442 Grade 55 steel plate subjected to a meridional unit force, T1, of 4000 lbf/in.2 tension and a latitudinal unit force, T2, of 5060 lbf/in.2 compression. The meridional radius of curvature, R1, is 75 in., and the length of the normal from the surface to the axis of revolution, R2, is 300 in. The joints in the wall are of double-welded butt-joint construction with a tensile efficiency of 85%. A corrosion allowance of 1/16 in. is required.
The problem in this example is to graphically find the minimum thickness of tank wall required for the given conditions (see 5.10.3.3).
Solution: As determined from Table 5-1, the maximum allowable tensile stress value, Sts, for ASTM A442 Grade 55 steel plate in simple tension is 16,500 lbf/in.2. Since the compressive stress is latitudinal, the governing value of R in this situation is R1, or 75 in.

The API Std 650 standard published by the American Petroleum Institute (API) is designed to provide the petroleum industry with welded steel tanks for use in the API 650 uplifting tanks storage of petroleum products and other liquid products commonly handled and stored by the various branches of the petroleum industry.