API 650 cylindrical liquid-storage tank piping and forgings

Shell Stiffening Rings for Tanks That Contain Liquid
Internal or external shell stiffening rings may be required to maintain roundness when the tank is subjected to wind, vacuum, or other specified loads. When API 650 cylindrical liquid-storage tank stiffening rings are required, the stiffener-to-shell weld details shall be in accordance with Figure Q-1 and Q.3.5.2 through Q.3.5.5.
Three-plate laps or butt-weld junctions in tank bottoms shall be not closer than 12 in. from each other or from the butt-welds of the annular plates.
Bottom plates, other than annular bottom plates for a 9% or 5% nickel steel or stainless steel tank that contains liquid, may have a minimum thickness of 3/16 in. exclusive of any specified corrosion allowance.Welding certification is regulated by Section 10 of the American Society of Mechanical Engineers (ASME). For both API 650 cylindrical liquid-storage tank storage tank API 650, non-destructive inspection is required, but third-party inspection is not required.The Seamless Pipe Q345D to Thailand. In November of 2015, Thailand OTTO group contacted with us from Internet. They are finding the trustable supplier of S355/2H seamless pipe for the cable car supporter. Due to the special using of the pipes, they are very careful and serious when choosing the supplier. After one months contact and discussion by email, they come to our company. We drive to the pipe mill for visit of 2 days. Through this visit, they are very confident with our production ability and products quality. Finally, they accept the grade we suggest Q345D. After back to office, they put the order of 1800 tons pipe to us directly.The main reason of "small breathing" loss of API 650 cylindrical liquid-storage tank is the change of atmospheric temperature. When the temperature rises with the increase of solar radiation from dawn, the temperature of oil in the API 650 cylindrical liquid-storage tank also changes, resulting in the acceleration of evaporation speed and the increase of evaporation pressure. When the pressure exceeds the positive pressure rating of the breathing valve, the oil-gas mixture in the API 650 cylindrical liquid-storage tank is discharged into the atmosphere through the breathing valve, which is the "exhalation" process of the oil tank.Both parties shall confirm the API 650 cylindrical liquid-storage tank material object and the quality of the products, confirm the reasons for the defects and the quality of the products, and sign the quality inspection agreement. Major quality objections shall be reported to relevant leaders in a timely manner, and shall be discussed and solved with the API 650 cylindrical liquid-storage tank steel plant.