API standard 650 cylindrical tanks bottom connections

When welding API standard 650 cylindrical tanks, in order to avoid weld deformation, it is necessary to use corresponding welding process according to the type of steel used in the tank, such as welding requirements of steel plate, welding position, etc. Reasonable arrangement of the assembly sequence, the use of subsection back welding and jump welding method, strict control of welding process parameters, rigid fixation measures, take corrective measures for deformation compensation are necessary.

Allowable Design Stresses
The maximum allowable design stresses for the API standard 650 cylindrical tanks materials outlined in Q.2.1 shall be in accordance with Table Q-3.The values for the allowable design tensile stress given in Table Q-3 for materials other than bolting steel are the lesser of (a) 331/3% of the specified minimum ultimate tensile strength for the material or (b) 662/3% of the specified minimum yield strength, but they are 75% of the specified minimum yield strength for the stainless steel, nickel alloy, and aluminum materials. Allowable test stresses are based on the limitation of API 620 oil tank storage standard Q.8.1.3.

The floating roof is the top cover floating on the liquid level, so the sealing performance of API standard 650 cylindrical tanks API 650 oil storage tank is very important. The floating plate mainly adopts elastic packing, and at the same time, it is compressed with the wall of API 650 oil storage tank with pressure strip around, and fixed with the floating plate with bolts. After the API standard 650 cylindrical tanks floating plate is lowered to a certain position of about 1.8m, a prop will support the floating plate to keep it in position.