creased shell plate

[yosamitysamm]

Hi All,

I have a 77' diameter tank I am building and we have a crease in the shell plate. The only reference I can find in API 650 is in 7.5.4.a which allows a deviation of 1/2" for peaking at vertical weld joints. Does anyone have any advice on evaluating this type of deviation?

Thanks.

 

[Stl63]

If you put the vertical straight edge at the crease, do you exceed the horizontal weld seam deviation? Idea on how the crease occured? If your certifying as API 650, and you deem it within the allowable deviations, then it is ok. If you feel it deviates outside the allowable tolerance, then it has to be repaired. Other factors are, you have a purchaser that may raise questions about this noticable defect, and you'll have to submit official documentation that it is within tolerances. Secondly, an engineer has to evaluate the area structurally, severity of the crease, affects on the plate, etc. API 650 is just another standard, it's not a replacement for good practice.

"Saving the World One Beam at a Time"

 

[IFRs]

I see quite an offset at the horizontal joint below and parallel to your sweep board. Check API 650 for allowable plate offset at these joints. At the very least you might want to align plates at the joint.