A REDUCED TANK DIAMETER AT TOP

[Alirashid]

ONE TANK 85 METER DIA. IS UNDER CONSTRUCTION ACCORDING TO API650 CONSISTING OF 11 SHELL COURSES WHERE ITS DIAMETER HAS BEEN REDUCED BY 35MM AT 10TH SHELL COURSE AS WELL AS 85MM AT LAST 11TH SHELL COURSE.

WHAT IS THE SOLUTION OF THIS SITUATION?

CAN IT BE ACCEPTED UNDER THE RADIUS TOLERANCE AS PER 7.5.3 IF IT IS RECOVERED UP TO 32MM IN DIA. VARIATION?

PLEASE ADVISE CONSIDERING THE INTEGRITY OF THE TANK.

 

[JStephen]

The API-650 tolerance on it would consist of measuring roundness near the bottom of the shell, then measuring plumbness going up the shell. I think you also have a plumbness-per-shell-course requirement, and that may be the most critical measurement in this case.