Hello!!

This is about very interesting subject of flange leakage check.Now , the caesar utility can carry check for leakage due to mechanical loads but it doesn't consider thermal effects such as opening up or rotation of flange or loosening of gaskets due to temperature or bolts being slightly loosened up during thermal reversals.

Can anyone suggest how to take care of these effects so that a real-world flange leakge can be carried out?

Even ASME Sect VIII -division II doesn't consider such effects??

The external loads you apply to the flange, if obtained from a piping analysis would include the effects of thermal growth.

As to the loosening of bolts, you're correct, this is not addressed.

Hi Richard!!

Thanks for your prompt reply!!

But I need some further help.

I'm looking to develop some kind of method/procedure which will give some what close to real-world problem of flange leakage.The equivalent pressure method applied widely has some of its inherent flaws. Also ASME Sec VIII-division I (Nonmandatory Appendix S) is silent on some important parameters.


Can you guide me on some specific codes/guidelines which involves consideration of all paramount parameters such as gasket stiffness, flange rotation , bolt tightening stress , loosening of bolts in thermal reversals & also consideration of thermal/mechanical loads (though this is taken care by CAESAR flange utility to great extent).?
Thanks!!

The new ASME rules for flanged joints are termed as "BFJ" rules. You can probably find a draft of it, but it is going through a long approval process and may not be approved for some years.

The EN std. that deals with external loads, thermal effects, rotation etc. is EN1591. This is an alternative method for designing flanges given in the European pressure vessel code.

Thanks Richard!!