Gas Volume Calculations

Just a quick one for my own edification,

Can anyone recite the formula for calculating gas volume, or figuring gas flow using differential pressure.

I ask because I've searched a few times and seem to be a little off target with all of my results.

A website with some literature would help also.

Would this help?

This is a search result, just my first one! Imagine what Goggle would reveal!

See if this helps:
http://www.lmnoeng.com/flowrate.htm

I have started adding some of this but its a work in progress:
http://www.patchn.com/fluid_law's.htm

http://www.patchn.com/mechanics.htm

Thanks guys, the sites helped tremendously, I used MSN search and I got alot of people trying to sell "gas calculation/ differential pressure solutions" no educational value.

I do appreciate the help,

I have goggle, two of them but they only help when diving.

Orifice Meter Calculation:

Qv = C'* sq root [Hw*Pf]


Qv = Volume, cubic feet per hour at base condition
Hw = Differential pressure, inches of water at 60 degs
Pf = Absolute static pressure, psia
sq root [Hw*Pf]= Pressure extension
C' = Fb*Fr*Y*Fpb*Ftb*Ftf*Fgr*Fpv

C' = Orifice Flow Constent
Fb = Basic orifice factor
Fr = Reynolds number factor
Y = Expansion factor
Fpb = Pressure base factor
Ftb = Temperature base factor
Ftf = Flowing temperature factor
Fgr = Real gas relative density factor
Fpv = Supercompressibility factor

The trick is computing all these factors. See AGA Report No. 3.
You can get that from The American Gas Association ( for a fee of-course)

This may help if you're looking for the physics behind how the gas behaves. http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/idegas.html

Otherwise, I think the earlier posters have the info you're looking for.

Thanks Jimbo and Mickey,

I appreciate the help, like I said at the beginning of the post, this was mainly for my own edification and I wanted to study up on gas formulas and calculations to get an understanding of them for later use.

Everybody Have a Merry Christmas.