Again, I'd like to thank everyone for their insight. I feel a lot better about myself after wracking my brain for hours trying to figure out what equation to use, and then trying to derive one, and finally just following lines on charts trying to find anything that made sense (this is when I did...
One other parameter of note. The tank has a vent line approximately 600 yards long and 6" pipe, so quite significant. If, as you say, the fluid in the tank expanding is doing work on the fluid in this vent line, might that also drive it closer to an isentropic process?
The phenomenon is definitely real - I had my hands on the discharge line and it frosted over quite quickly and became so cold I couldn't keep my hands on it. The depressurization takes place in approximately 1.5 minutes.
Emmanueltop, thank you for running the models. I had actually looked at...
Emmanueltop, that is exactly correct. It seemed odd to me also that the tank cooled this much upon venting. I was expecting minimal cooling dropping from only 65 psia. Last night I vented a gas sample through a small valve, so that the pressure in the tank was minimally impacted by the...
I'm embarrassed to say that I need help explaining this real world observation. It's been too long since I've had my thermo class, and as an operations jack-of-all trades it's easy to forget the finer points.
We have a 13,000 gallon well-insulated tank. It is filled with nitrogen at...
Hello. I am doing some safety engineering work for an aerospace customer. They have a large high pressure gaseous hydrogen storage area that feeds other facilities. There is a large relief valve on the pipeline, as required by code. The RV dumps into a ~20 foot tall vent stack.
NASA...
I have been hired to do some safety engineering work. In my exploration of the work site I have found numerous high pressure (up to 6000 psig) flex hoses without restraints. These are high quality stainless convoluted or stainless/PTFE hose, but many are decades old. They receive a visual...
I should also say that what I've suggested is essentialy a homemade Thread o Let/"Boss o Let". They aren't very easy to find in tube sizes (1" OD is a standard tube size... 1" pipes aren't 1" OD.) so thats why I suggested making them instead of buying them. Additionally, the 1/4" inside hole...
Too late now, but another (good) way to do it would be to take a piece of round stock, maybe 5/8" thick or a little larger. Turn it off to about 1" long in a lathe, then bore a 1/4" ID hole in it. Then tap a female pipe thread (or an SAE straight thread port - easier to clean) in the hole. On...
I have a vacuum system which contains a flammable gas. I am trying to determine the explosion risks if this system were to be vented to atmosphere. I have calculated that once the pressure equilibrates (assuming no diffusion), the atmosphere is roughly:
10% O2
37% N2
48% He
5% H2
I guess I...
