pages from api 650 11_edition addendum 2.pdf
DESCRIPTION
API 650TRANSCRIPT
WELDED TANKS FOR OIL STORAGE 5-49
lation rings, and electrical conduit and fixtures. Items installed above the maximum liquid level of the tank are not permanentattachments.b. Temporary attachments are items welded to the shell that will be removed prior to the tank being commissioned into itsintended service. These include items such as alignment clips, fitting equipment, stabilizers, and lifting lugs.
5.8.1.2 When attachments are made to shell courses of material in Group IV, IVA, V, or VI, the movement of the shell (particu-larly the movement of the bottom course) under hydrostatic loading shall be considered, and the attachments shall meet the fol-lowing requirements:
a. Permanent attachments may be welded directly to the shell with fillet welds having a maximum leg dimension of 13 mm (1/2 in.).The edge of any permanent attachment welds shall be at least 75 mm (3 in.) from the horizontal joints of the shell and at least150 mm (6 in.) from the vertical joints, insert-plate joints, or reinforcing-plate fillet welds. Permanent attachment welds may crossshell horizontal or vertical butt welds providing the welds are continuous within these limits and the angle of incidence between thetwo welds is greater than or equal to 45 degrees. Additionally, any splice weld in the permanent attachment shall be located a mini-mum of 150 mm (6 in.) from any shell weld unless the splice weld is kept from intersecting the shell weld by acceptablemodifications to the attachment.b. The welding and inspection of permanent attachments to these shell courses shall conform to 7.2.3.5.c. Temporary attachments to shell courses shall preferably be made prior to welding of the shell joints. Weld spacing for tempo-rary attachments made after welding of the shell joints shall be the same as that required for permanent attachments. Temporaryattachments to shell courses shall be removed, and any resulting damage shall be repaired and ground to a smooth profile.
Figure 5-15—Rotation of Shell Connection
Position of shell afterelastic movement
Initial shell radius = R
Shell radius = R + R
Height of bendingin shell varies with
tank radius and thickness
Transition plate
BottomReinforcing plate
Inside diameter of shell
75 mm (3") min
(See Details a and b)
Initial centerlineof connection
Angle ofrotation
Centerline ofconnection after
elastic movementof shell
Inside of shell atcenterline of opening
75 mm(3") min
75 mm(3") min
Inside of shell atcenterline of opening
Notch to suit bottom reinforcing plate
W + 300 mm (12") min,except as limited by
curvature of foundation(see Detail b)
Detail a Detail b
DETAILS OF NOTCH IN RINGWALL