Currently I am working on gas piping of 2M & larger dia. I am bit confused & not sure to what extent this analysis result is accurate Since none of the caesar technical references don't set a limitation of max. dia to be analysed by the software.

Can anybody in this forum provide me any lead/some references about this?

I don't know the code you are using, but assuming it is B31.3, The SIF and Flexibility factors are restricted by max. D/T =100.

The other issues are for such large diameter pipes to check for local stress issues at support points which can be done using simple and well known KELLOG FORMULA ( this is based on uniform loading around a circumferential ring) or FEA.

The other issue of the ovalization of the cross section at support locations,is again local and will not affect the global results is any significant way. I have checked this against some FE work I did using shell based models.Even the high local stresses at Shell/shoe ( for such large pipes, they will not be rested directly on steel) in many cases are singularity stresses and hence are not significant.

So, you can use CAESAR II , provided you keep the above things in mind.This is my personal opinion .

Regards

Hi Anindya,

Thanks for your advice.

Additionally, could u pls tell me where I can get this Kellog formula to check this local stress?

Soumitra

You can find it in the M.W. Kellog book; design of piping systems.

Regards

Just in continuation with earlier query..

Large dia piping (3300NB)while anchored at BL imposes too high loads as high as 200Ton-M leaving any stuctural arragement inconceivable

At this point, A bellow could be used to reduce loads at anchor as line pressure is very low..0.18bar(g)..design tempt-90degc

But is it a viable option to go for bellow for such large line...Is anybody having such exp. to handle such large bellow even though some supplier provide bellow for round large duct...what are special design aspect for such large size bellow if used.?

Thanks,
Soumitra

Hi Soumitra, before going for bellows.please check these options too.
Please model the pipe beyond the anchor, if you have information of piping beyond battery limit. also try to give expansion loops before battery limit.
I think giving bellow should be the last option as such a large bellow will be costly

Alternatively, can the equipment be displaced rather than adding in loops to already massive piping?