Dear all expert,

Please help me how to determine the number of stiffener ring in tower.
if DP is 4. kg/cm2
DT is 160 C
Full Vacuum
2400mm ID
30,000 TL
SA516-70

Compress automatically calculating thickness of shell considering the external pressure.
Compress not recommending how many stiffener ring required to reduce thickness.

Please help me to determined how many stiffener ring required.

Thanks in advance
Axeus