API standard 650 low-alloy steel tanks platforms, walkways, and stairways
Prefabrication requirements of API standard 650 low-alloy steel tanks, large vertical storage tank wall panels:1. The prefabrication of wall panel shall be processed in strict accordance with the requirements of the drawings, and inspection records shall be made.2. After the wall panel is rolled, it should be placed on the platform for inspection with a template. In the vertical direction, use a straight-line template to check, the gap should not be greater than 2 mm, and in the horizontal direction, use an arc-shaped template to check, and the interval should not be greater than 4 mm.3. When wall panels are rounded, attention should be paid to prevent irreversible plastic deformation caused by external forces. After rolling, it should be placed on the platform for inspection, and then placed on the prepared mold.
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.
Prevent the storage liquid from impacting the inner wall of the API 650 petroleum storage tank or increase the internal pressure, reduce the corrosion of the tank top and the tank wall, and extend the service life of the API standard 650 low-alloy steel tanks storage tank.
The company's logistics adopts the method of cooperation with logistics companies. As a third-party logistics company is engaged in the operation of multiple logistics projects, it can integrate various logistics resources, making the logistics operation cost relatively low and the logistics operations more efficient. Thus we can provide more professional logistics services, while also focusing on our core business of steel materials.