API 650 ground supported liquid storage tanks supporting legs

API 650 ground supported liquid storage tanks, Oil tank is a large-scale storage equipment used to store oil materials. Usually, the service life of API 650 ground supported liquid storage tanks is related to the actual working conditions. The design service life of most oil tanks is 20 years, and some of them are 10-15 years. Generally, none of them is less than 10 years. However, the design service life of API 650 ground supported liquid storage tanks is on the one hand, which is an ideal state, but there are many objective factors in the actual process, it is impossible to achieve the designed service life. How to effectively increase the service life of API 650 ground supported liquid storage tanks?

In this project, an elemental area of API 620 oil storage tank wall is constructed of ASTM A516 Grade 55 steel plate subjected to a meridional unit force, T1, of 2620 lbf/in. tension and a latitudinal unit force, T2, of 2880 lbf/in. compression. The meridional radius of curvature, R1, is 132 in., and the length of the normal from the surface to the axis of revolution, R2, is 409 in. The joints in the wall are spot-radiographed, double-welded butt joints, and no corrosion allowance is required.
The problem in this example is to graphically find the minimum thickness of tank wall required for the given conditions (see API 620 tank standard 5.10.3.3).
Solution: As determined from Table 5-1, the maximum, allowable tensile stress value, Sts, for ASTM A516 Grade 55 steel plate in simple tension is 16,500 lbf/in.2. Since the compressive stress is latitudinal, the governing value of R for this situation is R1, or 132 in.

The welded API 650 tank in various sizes and capacities for internal pressures approximating atmospheric pressure (internal pressures not exceeding the weight of the roof plates), but a higher internal pressure API 650 ground supported liquid storage tanks is permitted when additional requirements are met.