Dear All,

For large diameter piping, to consider radial expansion on the support location, I have modelled Rest (+y) support and base spring after considering a rigid element equal to radius of the pipe.

My Questions :
1. Is it accurate to do so???...If yes...then above what size should I use this methodology..???
2. For a long header that starts from the Quench tower with pipe size 90"....then going to 36" after intermediate reduction using reducers...there is problem of intermediate support lift off (lift-off is less than 1 mm)...after reducers if I use this methodology of modelling rigid element and then support....
There is non-uniform load distribution and how is the result justified...??? (Temp = 525 / 425 deg.C)

Thanks In advance...!!!

There is a technical article on COADE site about modelling branches on large pipes. Check that paper.

In real life 1 mm is nothing on 90/36"pipes.

You do need to keep an eye where the centre line of a duct or pipe goes on high temperature large diameter. I do not think there is an answer when you need to model supports on "the outside". Each case is different and you need to consider overal design. Some theoretical designer might even consider ovalization of the duct.....