ASTM A216 grade WCC external floating roofs API 650 petroleum storage tanks

API 650 internal floating roof oil tank executive standard: domestic design standard: GB50341-2003 "Vertical cylindrical steel welded oil tank design code"; domestic construction standard: GB50128-2005 "vertical cylindrical steel welded oil tank" Construction and Acceptance Specification; API 650 petroleum storage tanks Foreign design standard: API650-2007 "Standard for Welded Steel Petroleum Storage Tanks."

During the use of API 650 petroleum storage tanks, the tank material is prone to crack and leakage under the action of pressure, corrosion, wear and other conditions. Especially in the oil producing area, the temperature difference in four seasons is large and the natural environment is bad, which will accelerate the consumption of oil storage tank and cause many potential safety hazards. Therefore, the API 650 petroleum storage tanks must undergo strict inspections before being put into use after the production and installation are completed, so as to avoid cracks and leakage in short-term use and affect production safety.

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.

The company has a mature technical team whose reponsibility is to design the drawing, choose suitable material and evaluate the whole production processaccording to customers’ requirement. The company is led by talents and technology, and comprehensively promotes its six business segments like steel material supply, precision steel casting, environmental protection equipment, household appliance, API 650 petroleum storage tanks steel structures and oil tank projects. Seeking new developments in new technology and business areas, and fostering a large number of industry-leading, international-level projects.

The company's logistics team adheres to the development concept of “gathering advantages, providing superior services, creating value, and leading the market”, and tightly focuses on the strategic positioning of “developing large-scale steel logistics and building large-scale steel supermarkets”. Facing the whole country and integrating into the world to build an "one center, one network" international circulation system. Through the development of 5-10 years, it is expected to form a modern steel industry with annual operating income exceeding 2.5 billion yuan.