API 650 carbon steel storage tanks welding procedure and welder qualifications
Requirements for prefabrication of bottom plate of large vertical API 650 carbon steel storage tanks:1. The diameter of tank bottom should be enlarged by 0.1% ~ 0.15% according to the design diameter.2. The minimum dimension of edge plate along the radius direction of tank bottom shall not be less than 700mm.3. The distance between any adjacent welds of the base plate shall not be less than 300 mm.
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.
One of the most widely used design codes is the API 650 Standard, from the American Petroleum Institute. The main objective of this standards API 650 carbon steel storage tanks is, through the requirements contained in its various sections, to facilitate the purchase and construction of vertical, aboveground, welded fabricated tanks assuring that required safety regulations are met.
As steel transportation belongs to the transportation of major parts, so in the process of transportation, modern logistics technology, such as centralized transportation, information technology, is a bit out of place. Based on the current situation of China's API 650 carbon steel storage tanks steel transportation industry, highway transportation is a way of transportation that many enterprises often choose. Naturally, its business volume also accounts for more than 50% of the whole API 650 carbon steel storage tanks steel transportation industry.
