Peaking, Butt Cheeking of Longitudinal Seams

[TheYoungOne]

We recently had some long seams welded and once they were complete, the seams were peaking in toward the ID of the Tank. We try and limit this as best as we can by 50/50 welding from both sides and utilizing key plates to limit distortion. Welder had trouble on these particular seams when welding on the outside, resulting in some additional passes, therefore leading me to believe this was the cause of the excessive peaking.

My question is this, does the code address a limit for this particular issue anywhere? UG-80 addresses permissible out-of-roundness of cylinders, I assume this is the proper part to be referring to in order to make sure were still in compliance. From what we interpret as long as the cross sections are checked according to one of the figures in UG-80 we are ok and the peaking is ok. I am going to run this by our A.I. to get concurrence but was curious as to what others thoughts are.


Thanks in advance for any info,
Mike

 

[SnTMan]

Young 'Un, new term for me "butt cheeking"

I am pretty certain UG-80 is all you need to worry about. Good practice to check with the AI, until of course he doesn't see it your way.

Regards,

Mike

 

[racookpe1978]

What is pressure, service fluid, OD of the vessel and wall thickness?

.25 inch on a 15 foot dia tank at 150 psig has a different effect from 1/8 inch on a 4 inch diameter 4500 psig gas tank.

 

[TGS4]

And, further to racookepe1978's question, is the vessel in cyclic service?

 

[TheYoungOne]

Pressure is 25 PSIG @ 300°F, FV Rating. Vessel will be packed with activated carbon and have petroleum vapors passing through it. OD is 132", Wall thickness is 5/8" Nominal. Peaks in about 1/4". No the vessel is not in cyclic service.