Thanks for your suggestions.

But I am in a position of deciding this. Actually my problem is, My designed participating area passes the Annex F (Required area), but failed with 5.10.6. Because of with more external loads (Gravity loads P) are acting on roof (live, vacuum, insulation, nozzles, platforms, coils etc.). The more you apply loads, the design fails with 5.10.6.2.

So let me share some more details of my tank design and you can get any other idea..

Dome roof of radius 1.2D, with sections welded to the roof, both roof and sections are supported at periphery (Roof plates at top angle (detail-d) and sections at the shell).

As per NOTE of 5.10.6 and my understanding, the above details comes under self-supported roof category which means no need to check the minimum thickness requirement but the check for roof-shell junction is needed..

Hence, my question is before increasing the participating area by increasing the Top angle thickness, please clarify my understanding is whether correct and the check for 5.10.6.2 is really required or not??


Thanks in advance for your reply..