shell opening 3

[mectarek]

we want to open a window or a door in the shell of a 220 ft diameter oil storage tank. what do the standards ( API650, API653) say about it and in what sections I can find it. the door si about a 6.5 by 6.5 ft[sup][/sup] and we want to open it so we can repair the tank's bottom.

 

[JStephen]

That's a "door sheet", see API-653, Section 9.2.4. Should be cut and re-welded by someone with experience doing that.
Generally, API-653 would apply to periodic inspection and bottom repairs as well.

 

[IFRs]

Your choices include (2) radius corners and cut to the tank bottom or (4) radius corners and maintain weld spacing to the corner weld. Be sure to use the correct radius - the greater of 6" or 6 times the shell thickness. Make smooth cuts using a track, be sure to call out the weld preparation (bevel), low-hydrogen electrode and NDE (RT and may also include MT/PT depending on shell thickness).

 

[mectarek]

Thank you for your great answers