API 650 flat-bottom tanks special considerations

API 650 internal floating roof oil tank is a volatile liquid storage tank with a combination of a dome tank and an internal floating roof structure, which is a floating roof assembled under the dome of the API 650 flat-bottom tanks storage tank. The combination of the vault roof outside the API 650 storage tank and the floating roof inside the tank has been widely used in gasoline, aviation kerosene and more volatile chemical liquids.

In the petrochemical industry and other industries, large vertical API 650 flat-bottom tanks are often used to store various production raw materials. Usually, the medium with high melting point and easy to crystallize at room temperature can be exported and used after heating, which involves the heating of large vertical storage tanks. The heating system is an auxiliary facility for heating of large vertical storage tank. It is often necessary to design external heating coil or internal heating coil system.

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.

BEBON is a large steel group with finance department, production department, sales team, technical department, quality control department, logistics department and after-sales service team. We are committed to creating a various culture system with its own characteristics, and work hard to create a first-class steel plate company in China. Based on the business philosophy of quality-oriented and strengthened management, the company continues to develop in this industry.

The company adheres to the needs of customers, adheres to win-win integrity, and relies on scientific and technological innovation to continue to improve the level of logistics equipment technology and information technology, and enhance the logistics technology research and development and innovation capabilities. Based on market demand and innovation as the driving force for development, the company actively expands the field of logistics services, accelerates the extension of the logistics industry chain, and scientifically advances the diversification of the logistics industry.