API 650 SUG III tanks impulsive water parameters

When talking about our team, it is hard not to mention our QC department (Quality Control). We have built strict qualitycontrol system to guarantee the steel quality. During the steel materials production, we have strict monitoring measures and indicators, and ensure no chemical composition, mechnical properties and so on technical problems for the steel materials API 650 SUG III tanks. After production, our QC department will conduct another inspection regarding to the steel quantity, dimension, mark and so on points before delivery.

The process parameters should be strictly controlled in sand blasting of API 650 SUG III tanks. The working pressure of abrasive chamber is between 0.5 and 0.6a, and the outlet pressure of air compressor shall not be lower than 0.6 WPa. According to the test results, the distance between nozzle and workpiece shall be controlled at 80 - 200 mm and spraying angle of 30 ~ 75°is appropriate.

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.