Is skirt (straight flange) mandatory for 2:1 elliptical forged head

[jtseng123]

Dear all,

I have a vertical vessel with a 24" nozzle must be as close to bottom TL as possible. The recommendation is to trim off the straight flange and make weld line at the TL. The thickness of straight flange is exactly the same as shell. Is it ok to do so or does it violate UW-13(2) ?

There is an old string but I did not see the question got answered.

http://www.eng-tips.com/viewthread.cfm?qid=201412

 

[Duwe6]

Yes, it would be. The purpose of the flange is to move the weld joint out of the knuckle area and make it a Straight Shell-to-Straight [sort-of shell provided by the head] weld. Putting the weld into the knuckle takes you away from the "cookbook" design formulas in Div-1. You would need to go to Div-2, or switch from a dished head to a cone.

 

[doct9960]

jtseng123,

I believe SnTMan provided the correct answer in the old string. The answer is in UG-32(l). I also believe that you still meet the requirements of UW-13(b)(2). What did your AI say?

 

[jtseng123]

doct9960,

Thanks and I believe UG-32(l) is governing over UW-13(b)(2) that a straight flange is not mandatory in my case.