Line Modeling with SIF

In my personal experience I try to model only relevant items in a calculation, sometimes when I am calculating a 16” pipe I don’t include the 2” lines associated to that pipe.

- What do you think about this assumption?

- Does anybody include a SIF without modeling the branch line (i.e. the metioned 2" pipe or lower diameters)?

-Is it correct for CAESAR II to run a model which has a SIF and do not include the branch?

Thanks in advance

Including these SIFs and small branches can sometimes cause inexperienced stress engrs to take the WRONG corrective action, e.g., unnecessariy reroute the pipe.

Paulin Research's (www.prg-software.com) last Webinar brought up this vey subject; webinar042 "What is 100% of the Allowable Stress for Pipes and Pressure Vessels"

Note that per B31.3, a 24"x18" WOL SIF is equal to a 24"x3" WOL SIF. The SIF is a function of the Header size only. This is the code we use and obviously this is "silly".

Mr. Paulin quoted WRC 329 Para. 4.4 Run Moments where it stated to the effect '...for this example the code requirements are obviously silly ...(SIFs for a 24"x3/4" branch SIF applying to the Run pipe)... use JUDGEMENT...'

Try to register for these webinars there are only a few more scheduled. Tony Paulin and his team are doing a great free service to us stressmen.

It has been my pleasure to know Tony for many years, he is beyond any doubt one of the premier experts in the field and is under contract to bring order to chaos for branch SIFS in B31.3.

Last webinar of PRG was very interesting but Does it have audio explaination??

Regards!