Hi-
For years I have always known that Methyl Alcohol has been used as a method of removing water from natural gas piping. For example - a pressurized natural gas pipe has a small amount of water trapped in it. Some in the liquid phase, some in the vapor phase. The water, under certain flow...
25362-
Thanks a million. I followed you 100% did the calcs out and came up with the same. However, assume same conditions except say 1% rh to start? This would give you 0.00007533882 lbs of H20 / lb of dry air at initial (atmospheric conditions and 0.003 lbs of H20 / lb of dry air at after you...
Hi-
Air at atmospheric pressure (14.7 PSIA) enters the inlet of a simple air compressor at 50 Deg F. drybulb and 50% RH. The air exits the compressor at 80 Deg F. drybulb at 90 PSIG. How do you calculate the RH of the compressed air?
Any help would be greatly appreciated!
Thank you,
TB
David-
To clarify. I am really only trying to determine the maximum possible amount of water that could have entered the pipe during the pressure test - proir to service. I believe that most, if not all, the water entered the main during the construction phase. It's possible that a poor pigging...
Quark-
Thanks for the information. I will sit down and digest it.
Before you made your post I sat down and crammed out a calculation. I think I'm on the right track. The amount of water appears low. However, the actual pipe volume is very small. Still I've read that (for example) On a 75F...
...with a slug of nitrogen before the natural gas. We are thinking that perhaps the 90 PSIG air was full of water vapor and condensed in the pipe prior to purging.
I was advised in a physics forum that...
"a the ideal gas law, it would just be the ratio of the two air pressures: 90/14.7 *...
Hi-
A recently installed natural gas main is showing evidence of water infiltration. Water is getting into the customers regulator and meter and freezing. The gas main was cleaned and "pigged" after the installation. The system is currently operating at an MAOP of 60 PSIG.
When the main was...
I thought that I had it but.....
The SW part was drawn by someone else in SW in inches. I Had my SW units set to mm. I changed it back to inches (re-saved) and made sure that the AutoCAD user preferences "drag and drop scale" was set to inches for both "Source content units" & "Target drawing...
Hi-
When I import an SW file into AutoCad via "Exchange Works" the part always imports larger into AutoCad than it's actual size in SW. For example: a part that has a length dimension in SW of 10.11 inches in SW has to be scaled down in AutoCad by 0.0393 to get the 10.11 inches. I checked my...
I have been an AutoCad user for years. A year ago my company purchased an AutoCAD add-on called Mech-Q pipe. This add on gives you a number of fittings (in 2d & 3d) welded, threaded, etc .... elbows, flanges, tees, threadolets, etc... My company is thinking of making the jump to SW. I've poked...
I am trying to calculate the flow rate of natural gas through an upstream valve on a block and bleed set up on a large boiler. The purpose of this is to determine the flow rate so that I can size the vent line off the bleed-off.
Here is what I am working with:
P_atm = 14.7 PSIA
P_base = 14.7...
Thanks David and Katmar. I tried Davids approach and calculated 4001 SCFH - real close to my other calc + what Katmar calculated - I used the general flow equation with the "fanning" friction factor (calculated by means of Colebrook-White). I use the fanning friction factor (which is 4 times...
Not sure what you mean by "assume the density at the lower pressure (i.e. at the exit) and do the whole calculation based on incompressible flow". It was always drilled into my head to find the "choked flow" condition then work backwards. I do a lot of pipe sizing for natural gas distribution -...