API 650 open top welded storage tanks foundations for elevated temperature service

Prefabricating API 650 open top welded storage tanks components before construction can improve construction efficiency, save time and cost, and is currently a common method for the construction of large vertical storage tanks. The main prefabricated components of a large vertical API 650 open top welded storage tanks include the tank body, the storage tank wall, the top of the storage tank, the bottom of the storage tank, and the accessories of the storage tank. The prefabrication of the components should follow a reasonable workflow, and carry out appropriate heat treatment and testing, so as to improve manufacturing accuracy.

Design of Reinforcement for Single Openings in Tank Walls
The 20 in. x 29 in. obround manhole shown in Figure F-5 is located in solid plate in the sidewall of a cylindrical storage tank 45 ft in diameter in an area where the thickness of the wall plate, tw, is 1/2 in. No corrosion allowance is required. The total internal pressure, Pl + Pg, at the horizontal centerline of the opening is 27.5 lbf/in.2 gauge. The thickness of the wall plate, t, required by 5.10.3 for the latitudinal unit forces, T2, acting at this level is 0.485 in. The manhole neck is fabricated by welding from 3/8 in. plate. The materials in the API 620 tank wall, the manhole neck, and the reinforcing pad conform to ASTM A516 Grade 60. The joints in the welded steel storage oil tank wall and the longitudinal joint or joints in the manhole neck are double-welded butt joints, spot radiographed in accordance with 7.16 and 7.17.

The calculated thickness of the above-mentioned wall panels required by the hydrostatic pressure is also It API 650 open top welded storage tanks should be increased by the same ratio, unless special analysis is performed to determine the seismic overturning moment and the corresponding stress at the bottom of the wall of each layer of API 650 tank.