A573 Gr 58 plates API Std 650 unanchored flat-bottom tank

Weld inspection of API Std 650 unanchored flat-bottom tank, vertical oil tank wall plate: In the welding inspection process of oil tank wall plate, attention should be paid to the defects of thick wall plate, such as incomplete penetration, incomplete root fusion and cracks. If there is a root incomplete penetration defect, it is necessary to open the weld joint with carbon arc air gouging and grinding machine grinding, or even weld through, and then weld again after the defect is removed.

Welding certification is regulated by Section 10 of the American Society of Mechanical Engineers (ASME). For both API Std 650 unanchored flat-bottom tank storage tank API 650, non-destructive inspection is required, but third-party inspection is not required.

Our company doesn't need the cheapest quotation to choose international logistics company, but the price performance ratio will be high, the service will be good, and the transportation must be safe and punctual, which will not affect the time when the API Std 650 unanchored flat-bottom tank goods arrive at the destination, and the logistics situation will be well communicated with customers in advance. Therefore, when we choose international logistics companies, we will have a look at their timeliness and service attitude in advance. It is only important to transport goods according to the requirements of customers for logistics.

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.