API Std 650 unanchored flat-bottom tank dynamic liquid hoop forces

The tank wall design of API 650 oil storage tank. Since there is no ventilation pipe directly connected with the outside on the top of the API Std 650 unanchored flat-bottom tank tank, the ventilation between the inside and outside of API 650 oil storage tank is realized by the respiration valve. The constant pressure of the respiration valve is 0.3kPa, so the pressure on the top of the tank is 0.3kPa.

The specifications used in the design of large oil tanks, API Std 650 unanchored flat-bottom tank mainly include American Petroleum Institute Standard API 650, Japanese Industrial Standard JIS B8501, British Industrial Standard BS2654 and Chinese National Standard GB50341 from a global perspective. The formulas used in each specification are based on the hoop stress in the membrane theory. Each specification is based on the performance characteristics of materials and the construction technology level of their respective countries to determine the allowable stresses and weld coefficients. Therefore, the calculation results of tank wall thickness of API Std 650 unanchored flat-bottom tank with the same volume are sometimes quite different according to different specifications.

Any joints between the adjacent sections of API 620 oil storage tank stiffening rings, as shown in Figure Q-1, shall be made so that the required moment of inertia of the combined ring-shell section is provided. Weld joints between adjacent sections shall be made with full-thickness and full-penetration butt-welds. Stiffening-ring butt-welds may employ metal backing strips. Backing strips and the associated welding shall be made in a manner that provides a smooth contour in the rat hole and all other weld joint ends. All weld passes shall be started at the rat hole and other weld joint ends and shall be completed by moving away from these ends. Passes shall be overlapped away from edges to provide a smooth continuous weld.

Our quality control department will do inspection for details of the steel materials API Std 650 unanchored flat-bottom tank before delivery. We would invite the customer side to attend the inspection together. If they can not come, we will also take rich pictures for them to check. Meanwhile, we will publish inspection report and send them the PDF version. Besides, we accept any third party inspection such as SGS, BV, etc. And our quality control department will support the third party to inspect the steel materials smoothly and try our best to deliver the qualified steel materials to customers earlier.

In particular, the EU imports a large amount of iron ore from central and South America and Oceania, which are mainly transported by sea. The perfect port infrastructure makes the port operation cost of EU iron ore raw materials import relatively low. However, the API Std 650 unanchored flat-bottom tank steel transportation between EU Member States is mainly railway transportation, and the EU member states have established a very developed railway network and railway information infrastructure.