So what about API tank welding, this are ruled by API 650, (American Petroleum Institute); Welded Steel Tanks for Oil Storage (API 650)
. Tanks have 3 main parts, bottom, shell and roof; also it´s very important the piping connected to it. And this code starts by ruling materials, plates and sheets used for it´s construction in part 2.1, and in part 2.2.1.3 it states:
"All plates shall be manufactured by the openhearth, electric-furnace, or basic oxygen process. Steels produced by the thermo-mechanical control process (TMCP) may be used, provided that the combination of chemical composition and integrated controls of the steel manufacturing i mutually acceptable to the purchaser and the manufacturer, and provided that the specified mechanical properties in the required plate thicknesses are achieved. Copper-bearing steel shall be used if specified by the purchaser. Also in part 2.2.1.4 we read:
"Shell plates are limited to a maximum thickness of 45 mm (1.75 in.) unless a lesser thickness is stated in this
standard or in the plate specification. Plates used as inserts or flanges may be thicker than 45 mm (1.75 in.). Plates thicker than 40 mm (1.5 in.) shall be normalized or quench tempered, killed, made to fine-grain practice, and impact tested."
This is very important from the beggining of the design of an API tank, we notice here that the thickness of the shell is limited, something that is not stated in other materials.-
And as for welding, the electrodes to be used are ruled here:
"2.8 WELDING ELECTRODES
2.8.1 For the welding of materials with a minimum tensile strength less than 550 MPa (80 ksi), the manual arc-welding electrodes shall conform to the E60 and E70 classification series (suitable for the electric current characteristics, the position of welding, and other conditions of intended use) in AWS A5.1 and shall conform to 5.2.1.10 as applicable. 2.8.2 For the welding of materials with a minimum tensile strength of 550 through 585 MPa (80 through 85 ksi), the manual arc-welding electrodes shall conform to the E80XXCX
classification series in AWS A5.5."
And as you should have seen in the abobe video, it´s very important and hard to comply with is the shell´s dimensional tolerance, one welder was checking the roundness with a piece of wood, tis part is stated in part 5.5, Dimensional tolerances.
. Tanks have 3 main parts, bottom, shell and roof; also it´s very important the piping connected to it. And this code starts by ruling materials, plates and sheets used for it´s construction in part 2.1, and in part 2.2.1.3 it states:"All plates shall be manufactured by the openhearth, electric-furnace, or basic oxygen process. Steels produced by the thermo-mechanical control process (TMCP) may be used, provided that the combination of chemical composition and integrated controls of the steel manufacturing i mutually acceptable to the purchaser and the manufacturer, and provided that the specified mechanical properties in the required plate thicknesses are achieved. Copper-bearing steel shall be used if specified by the purchaser. Also in part 2.2.1.4 we read:
"Shell plates are limited to a maximum thickness of 45 mm (1.75 in.) unless a lesser thickness is stated in this
standard or in the plate specification. Plates used as inserts or flanges may be thicker than 45 mm (1.75 in.). Plates thicker than 40 mm (1.5 in.) shall be normalized or quench tempered, killed, made to fine-grain practice, and impact tested."
This is very important from the beggining of the design of an API tank, we notice here that the thickness of the shell is limited, something that is not stated in other materials.-
And as for welding, the electrodes to be used are ruled here:
"2.8 WELDING ELECTRODES
2.8.1 For the welding of materials with a minimum tensile strength less than 550 MPa (80 ksi), the manual arc-welding electrodes shall conform to the E60 and E70 classification series (suitable for the electric current characteristics, the position of welding, and other conditions of intended use) in AWS A5.1 and shall conform to 5.2.1.10 as applicable. 2.8.2 For the welding of materials with a minimum tensile strength of 550 through 585 MPa (80 through 85 ksi), the manual arc-welding electrodes shall conform to the E80XXCX
classification series in AWS A5.5."
And as you should have seen in the abobe video, it´s very important and hard to comply with is the shell´s dimensional tolerance, one welder was checking the roundness with a piece of wood, tis part is stated in part 5.5, Dimensional tolerances.
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