API Std 650 unanchored flat-bottom tank constructed according to API Standard 650

We can process the steel materials according to your drawing. Or if you can not make drawing, please send us API Std 650 unanchored flat-bottom tank specific data and requirements, our technical department can make design and drawing for you, and then confirm with your technician or engineer. If all is OK, our processing center will process the steel materials according to the drawing. So no matter what size and shapes you need, we can meet demands at the most time.

API Std 650 unanchored flat-bottom tank Manhole: The manhole is used for the operator to enter and exit the oil tank for inspection, cleaning and repair. For the convenience of personnel access, the installation position of the manhole is generally on the center line of the oil tank bottom, and the vertical oil tank is installed at the lowest layer of the tank wall. API Std 650 unanchored flat-bottom tank Light-transmitting hole: Light-transmitting hole is also called day-lighting hole. It is used for lighting and ventilation when inspecting, repairing and scrubbing the oil tank. It is generally installed on the top of the oil tank above the inlet and outlet pipes.

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.