API 650 flat-bottom oil storage tanks pipe and tube

Every customer who has visit us and witness the steel materials before delievry will be impressed by our quality control departemnt. Even not come to inspect the steel materials before delievry, our quality control departemnt will also send inspection report to the customer. For each order, no matter its quantity and value, our quality control departemnt will make strict inspection before delivery, the inspection contents include apperance, tolerance, dimension, mark, special requirements of customers, etc. To guarantee our steel materials sent to the customer is qualified.

Some defects may be found after the regular safety inspection for the API 650 flat-bottom oil storage tanks. The common API 650 flat-bottom oil storage tanks defects are: Tank cracks, tank welding defects. The cracks on the base metal, surface and near surface of the tank wall shall be eliminated by grinding with circular arc, and then magnetic particle inspection or re inspection shall be carried out. Cracks in heat affected zone: generally, grinding method is used to eliminate cracks, and magnetic particle or dye flaw detection is used to confirm that there is no crack, and then repair welding or grinding smooth transition.

In this project, an area of tank wall is constructed of ASTM A285, Grade C, steel plate that is 5/8-in. thick and has spot-radiographed, double-welded butt joints. The wall is subject to tension in a meridional direction and to compression in a latitudinal direction. The values of R1 and R2 at the point under consideration are 75 in. and 300 in. respectively. A corrosion allowance of 1/16 in. is required. The computed (meridional) tensile stress, stc, in the net thickness after deduction of the corrosion allowance is 6000 lbf/in.2.
The problem in this example is to find the maximum allowable (latitudinal) compressive stress value for the given conditions, in conformance with the provisions of API 620 tank standard 5.5.4.5.