Gas Pressure loss in Pipelines

[cougarfan]

I want to make sure I am doing something correctly . It has been awhile... I am trying to determine the pressure drop of a gas thorugh a pipe line with elbows and entrances oout of vessels and into vessels and staight out of pipes etc.. Questions.....
1. In order to determine pressure loss of the fittings and extrances and exits would I use the formula
Delta P = Density*Kt*Velocity^2/(2*32.2)
2. Pressure line loss for pipe would find the Mach number at entrance and then at actual and subtract to find the exit mach number etc to determine the pressure drop etc....

I think I am on thr right track... is thera table somewher which correlates pipe fittings to pipe lengthsa - one less calculation to do......

 

[TD2K]

A lot of hydraulic books have tables that give you fitting losses in terms of equivalent feet, Crane is one example, there are lots others.

For the pressure drop, if you calculate it using the first equation, why go back and calculate the Mach numbers and then recalculate the pressure drop from that? Seems to be redundant to me. If this is a typical cross country pipeline, I would not expect the Mach numbers to be very large, thus I'm not sure why you are using this approach (it's not the way I would do it). If the difference in Mach numbers is fairly large, you'll need to take the compressibility of the gas into account rather than using a constant density equation as yours appears to be.

Crane has several equation for calculation pressure drop, if you post your email address here, I can forward the scanned copy I made of the key pages out of their booklet. If you are going to do many of these calculations, I would buy a copy, it's very good.

 

[cougarfan]

Thanks - my email address is:
jsweeney@ruetgers-organics-corp.com...

Look forward to seeing them......