As per code B31.3 it has been specified for calculating both stress and nozzle loads based on cold Modulus of elasticity .
please let me know is caesar also do the same or it calculated based on hot modulus of elasticity

By default, unless you are using EN 13480, CAESAR II will use the "reference modulus" (we say Cold Modulus) for all stress calculations. Version 5.00 allows you to change the modulus used for each load case in the load case editor.

For cryogenic piping expansion stress, which E is customerially used in computing flexibility stress using code ASME B 31.3:2004 - reference modulus at 21 C as per clause 319.4.4or cold modulus at the minimum temperature - as the second one is conservative ?

regards,

sam

Sam,

I have an Agenda Item to prepare a revision ballot for B31.3 on this one.... take a careful look at 319.2.2 (b) note 4 and follow its guidance! As soon as my @^&%^@^%$^@ 2006 code book shows up I will prepare the ballot and then spend the years to get something enacted!

Thank You, Sir. I read 319.2.2 (b) note 4. It is code guidance - surely I will follow. But, it's okay for hot piping; for cold piping,as with temperature reduction modulus of elasticity increases, ambient temperature is not the minimum temperature; also cold modulus is considered to have conservative estimation of flexibility stress - isn't it ?

regards,

sambhu

Analyze with the cold modulus (you can set this in the load case editor) and then ratio the calculated stresses by hand as note 4 specifies.

For "Cold" piping it will increase your end reactions the modulus ratio will correct for the difference in stresses as it regards Markls original SIF research. Markls work was done at "ambient" and hence the SIFS need to have a temperature correction applied.

The problem with what the code does not is that it uses the nebulous "when significant" leaving this as a judgement call by the designer. The majority of designers have not read the code let alone this particular note!

Therefore my proposal will be to eliminate the when signicant part and just thou shall do this. In this fashion it will then direct the software people to program their software accordingly. Its sad in a way... a form of baby-sitting!

Sir, You have opined right.

Today, I was reading robots are now created to spare cardiologists in angioplasty to avoid strain in leg & x-ray exposure to the attending docs. In this A/E field too in developing world, people say piping stress training of 2 days & PDS/PDMS exposure of 2 weeks are sufficient - rest is done by software!

regards,

sam