Gas Pipe Sizing

[JaManni]

Good Morning,
Could anyone help me to find the formula to design the pipe diameter and thickness if I know the pressure, temperature, CFM, type of gas and length of pipe?

 

[MFJewell]

What do you require for fluid velocity? Once you determine that, use volumetric flow rate and velocity to get required cross sectional area (which will give diameter).

Are you moving the fluid a long distance (and worried about pressure drop)? Otherwise velocity and CFM will drive line size.

 

[LittleInch]

Start with this lot -

http://www.engineeringtoolbox.com/natural-gas-pipe-sizing-d_829.html

Note that many online calculators etc are only valid for low pressure systems where Pin and P out only change by 10% or less

Thickness is from the relevant design code or material spec.

High pressure, long pipelines, large differences in Pin to P out are more complex, but often a rough approximation can be made or you divide your pipe into segments and iterate between them.

see

https://www.lmnoeng.com/Flow/weymouth.php

for a bit of an explanation

Did you do any research into this?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[PEDARRIN2]

Generally, the local AHJ has a code requirement, whether IFGC or the NFGC for sizing natural gas piping within a building.

Start there.

 

[JaManni]

Thank you.
I don't have the velocity. Following are rest of my parameters:
Pressure = 450 PSI
Pipe Capacity = 100 CFM
Pipe Length = 300 ft
Gas = Nitrogen

Yes, I did some research, but couldn't find out an appropriate answer.

 

[PEDARRIN2]

Look at the Darcy equation for compressible flow.

That is the best bet.

 

[mk3223]

To the pipe sizing, you still need either the desired gas velocity or pressure drop allowed for the 300ft pipe.

 

[JaManni]

If I have the velocity what equation I can use?

 

[mk3223]

The Crane tech paper #410 "Flow of Fluids" is good to have for the engineering reference.

 

[LittleInch]

At that pressure your 100 cfm is about 3 cfm in the pipe. That's about 7.5 cu inches per second. So work out internal area of your pipe sizes and then velocity to see which pipe size works.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.