Deficiencies for Skirt Opening

[StressPE]

Dear All,

How can I resolve below deficiency ? my standard drawing from Customer says to consider 12" sleeve on skirt for a 4" flanged pipe outlet . But if I go higher than 6", I receive below deficiency! How can it be resolved? my tower(skirt) diameter is just 18".
Any prompt help is highly appreciated.
Amir


Deficiencies for Skirt Opening #2 (SO #2)
Operating Hot & New Weight Compressive (governing): 4.5.17: Opening diameter (7.981 in) is greater than 25% of the Support Skirt #1 diameter (0.25*25.8113 = 6.4528 in).

 

[pdiculous963]

You would either need to change the design or perform a more advanced analysis. Compress uses the design by rule methods of ASME Sec. VIII-2 to evaluate skirt openings. Those rules are limited to openings less than 25% of the shell diameter. VIII-2 requires that the opening be designed using design by analysis procedures if this 25% criterion is exceeded. Given the size of the opening compared to the skirt, local buckling would likely be a concern.

 

[StressPE]

Thanks for your reply. Generally speaking when we use skirt support instead of Legs. in my case the vessel dia is 24" and the height is 24'