A334 grade 1 pipe API 650 carbon and low-alloy steel tanks

The company has a group of mature steel plate production and processing line construction and production management experience. In addition, the company has professional and technical personnel. BBN steel is a modern enterprise integrating scientific research and development, production processing, sales and service. The company now has finance department, production department, sales team, technical department, quality control department, logistics department and after-sales service team. At the same time, it also adheres to international standards and adheres to the international line.

There is no dome roof in the top of the vertical external floating roof oil storage tank, only the disc floating roof which can float up and down. The wall plates are connected by butt welding, and the construction is usually carried out by the forward installation method, and the storage capacity is usually more than 10000 cubic meters. Vertical internal floating roof API 650 carbon and low-alloy steel tanks has both dome roof and internal floating roof. The internal floating roof floats on the liquid surface inside the dome roof oil tank and can float up and down. The storage capacity is usually between 1000 and 10000 cubic meters.

In this project, an elemental area of API 620 oil storage tank wall is constructed of ASTM A516 Grade 55 steel plate subjected to a meridional unit force, T1, of 2620 lbf/in. tension and a latitudinal unit force, T2, of 2880 lbf/in. compression. The meridional radius of curvature, R1, is 132 in., and the length of the normal from the surface to the axis of revolution, R2, is 409 in. The joints in the wall are spot-radiographed, double-welded butt joints, and no corrosion allowance is required.
The problem in this example is to graphically find the minimum thickness of tank wall required for the given conditions (see API 620 tank standard 5.10.3.3).
Solution: As determined from Table 5-1, the maximum, allowable tensile stress value, Sts, for ASTM A516 Grade 55 steel plate in simple tension is 16,500 lbf/in.2. Since the compressive stress is latitudinal, the governing value of R for this situation is R1, or 132 in.