Stilling pipe inside of a vessel

[orlandini]

I need to install a stilling pipe (stand pipe) inside of the vessel. It will be welded in the botton and in the top inside of the shell.
For a safe design, what kind of calculation I need to do?
An Expansion bellow will be required in the stilling pipe?
The internal pressure will be 25bar.

 

[pennpiper]

Do NOT use an Expansion Joint on the stilling well.

Just use a simple (three point) guide at the bottom of the stilling well pipe so it can expand down but not impede the flow

 

[orlandini]

Dear pennpiper,

I usually use a three point guide for stilling well pipe, but, for this case, my client specified a nozzle in the top and other in the botton of the vessel. The stilling pipe will be between these nozzles and it will be welded. I can´t use a guide for this case.

 

[pennpiper]

I do not understand what this will look like. Can you share a sketch of this double nozzle stilling well?

 

[orlandini]

Attached.

 

[austsa]

Is the pipe a stand pipe or a stilling well? A stilling well is a pipe with many holes, to protect instrument inside the pipe against liquid movement, but allow liquid level inside the pipe to be same as the vessel liquid level. A stand pipe does not have holes.

 

[orlandini]

Dear austsa,

It is like a stand pipe but my client calls it stilling well.
This stilling well does not have holes.

 

[austsa]

orlandini,
See definition of stilling well at

http://www.diracdelta.co.uk/science/source/s/t/stilling well/source.html

By definition, stilling well does not contain pressure, and thus to answer your question, there is no requirement for calculations for a (true) stilling well.
Regarding your client requirement however, it seems like its piping that is inside a vessel. On top of my head, I can only think of one reason for this ... heat transfer ... but it seems a very odd way to do it. If the internal flange was to leak in the future, how would you find out?
If there is reasonable temperature and/or material difference between vessel and piping, then you'll need to cater for thermal expansion.
austsa