Line Sizing Standard for n-Butane Vapor Flow. 2

[Pavan Kumar]

Hi All,

I need to size a line for n-Butane vapor flow to our reactor. Is there any code or standard that provides guideline for pressure drop in psi allowed per 100 feet for this service. Your suggestions would be very helpful to me.

Thanks and Regards,
Pavan Kumar

 

[pierreick]

Hi,
To me , you should consult peers within your organization .
You can develop a spreadsheet for compressible flows with different models ( isothermal and adiabatic) and select based on your judgment. In addition a document making the comparison between Isothermal vs adiabatic for different gas, different pressure conditions , etc.
Better to avoid simplistic model and rules of thumb.

My view
Pierre

 

[Latexman]

One should not add multiple safety factors, or one will find oneself unrealistically conservative. Make an engineering judgement. If the pipe is longish (km's), uninsulated, and/or there is plenty of time for heat transfer - isothermal; if the pipe is shortish (m's), insulated, and/or not much time for heat transfer - adiabatic.

Good Luck,
Latexman

 

[georgeverghese]

For compressible flow, the isothermal calc procedure is almost always used for high velocity / high pressure drop lines since it gives slightly higher pressure drop that adiabatic flow calcs. The adiabatic flow calcs are some what more complicated even with a computer spreadsheet, since it involves a few iterations for each line.
Use isothermal flow calcs for PSV inlet lines if you expect high dp, otherwise, even simpler incompressible flow calcs with compressibility factor included will do just as well.

 

[Pavan Kumar]

Thank you everybody for your guidance provided on this topic.

Thanks and Regards,
Pavan Kumar

 

[pierreick]

Hi ,
2 spreadsheets to support your work .
Hope this is helping you.
Pierre

 

[pierreick]

Hi ,
a second one about compressible flows ( isothermal and adiabatic) with algorithms and methods to solve them .
Hope this is helping you an others .
Good luck
Pierre

 

[Pavan Kumar]

Hi pierreick,

The spreadsheets I developed(shared in my earlier posts above) based on the Isothermal and Adiabatic Frictional flow Equations are similar to the ones you shared above. I will go through your spreadsheets and improve on my mine.

Thanks for sharing your spreadsheets.

Thanks and Regards,
Pavan Kumar