Hi everyone.

I want to talke about Flange Leakage Analysis with Caesar II,
when i do the Flange analysis with Caesarii,
Step by step, Peq, NC Method, and then Caesar Analysis Module for flange check.
but, I dont know how to input Bolt Initial Tightening Stress,
from help in caesar , there are following message.
" Bolt Initial Tightening Stress

Optionally enter the stress induced in the bolt during tightening "after" the flange has been seated. This should be the stress in the bolt when the system is about to be pressurized and thermally loaded.

If omitted a rule of thumb bolt tightenin rule will be used to compute the tightening stress in the bolt ( in English units: ?i) =45000 / ?d)

this entry is only used in the flexibility model of the flange to estimate the initial compression of the gasket

"

i dont know what is mean "Flexiblity model"

Caesar how to check this method.

if somebody know well about this catergory, please help me^_^