Questions tagged [gas]

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Understanding Permeation Units

I have encountered a type of unit that I cannot understand. The unit describes the rate of permeation through a substance:(cm^3 . mm)/m^2 . d . atm Could someone please explain how to interpret ...
-1
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1answer
394 views

Highest pressure helium(lifting gas)can be stored at? [closed]

What is the highest pressure possible today? I have a sketchy idea of using a weather balloon with the lightest possible pressure vessel that can pack as much helium as possible and would like some ...
4
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2answers
156 views

Is steel air (argon) tight?

I need to build an air tight system that can hold gas (Argon Gas). I see that most pipes use steel. Is steel tight enough to hold that gas? Argon is very dense, so I think it should have no problem.
2
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2answers
8k views

What material is used to make gas pipes?

What is the most common material gas pipes made of? I read in a unreliable website it's steel, is it true? Also how good is steel at stopping or slowing down the leaking of gas? The gas I am ...
5
votes
1answer
715 views

How do gas flow regulators avoid choking?

According to compressible flow theory, a downstream pressure of 0.528 times upstream pressure is sufficient to choke a flow device. So, how do industrial grade pressure regulators throttle a wide ...
0
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0answers
66 views

Operation of radial blower without compensators in gas pipeline - What problems to expect and how to mitigate?

The situation is this: At a current project, there's a pair of (parallel, redundant) radial blowers to raise the gas pressure for the downstream consumers (CHP, gas burner). All vibrating machinery ...
2
votes
3answers
10k views

How to calculate the velocity of gas in a pipe?

I was wondering how I can calculate the velocity of gas through a pipe. The gas, assuming ideal behavior, in a pipe (cylinder) of volume of 222.4 L has a pressure of 1.95 atmospheres and a density of ...
4
votes
1answer
644 views

Velocity of flue gases through a pipe

I was wondering if there is any equation that helps to calculate flue gas velocity through a pipe? Can I use the Poiseuille Equation to solve this problem by assuming the flue gas is acting as a ...
3
votes
1answer
4k views

Working out pressure drop from leak rate

I am trying to work out the acceptable pressure drop/increase on a leak test rig for a given leak rate. A simplified version of the test rig looks like this: The gas (air) supply is at 1 bar above ...
2
votes
1answer
284 views

Is an Explosion Proof Circuit Breaker Panel Required at a Gas Station?

Check the attached photo of a gasoline station. The two panel boxes at the center of the photo (in the corner of the station) are standard panels (IP-67), which enclose standard circuit breakers for ...
0
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1answer
314 views

Refrigerator temperature - compartment gas volume exchange, time to equilibrate?

I open the door for 30s of a 140L capacity 80W (240VAC, 0.8A) barfridge with a 20L freezer compartment (partition open to main compartment at one end) at a temperature of -5℃ with an internal main ...
3
votes
1answer
167 views

Service Life of a Flashback Arrestor

First of all, I would like to know about the service life of a flashback arrestor. In my laboratory, I got three flashback arrestors {WITTgas RF53N(1/4”NPT-F), Brass} from the ex-students who used ...
1
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1answer
69 views

Calculate pneumatic cylinder dimensions from work done

I have a project for which I need a pneumatic cylinder to impart an impact force in such a way that work-done/energy is 4.5 Joules, and the input pressure is 10 bar. How can I solve this so that I ...
2
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2answers
619 views

Pressure drop across column in gas phase: what changes?

If you force high-pressure gas through a packed-bed, the gas pressure drops. However, the ideal gas law states: $$P = \frac{RT}{v}$$ so for an ideal gas, the pressure drop must be associated with a ...
1
vote
1answer
210 views

How to calculate propulsive force of gas ejection

How can I calculate the propulsive force produced by ejection of a gas? I suppose it depends on the gas, the velocity with which it ejects, the amount of gas, and some other parameters, like the ...
5
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2answers
921 views

Pressure drop due to mass loss

How can I "tie" pressure change due to a mass leakage from the flow? In a "closed" system I'd use $pV=nRT$ but this is an "open" system... My open system is an horizontal (no gravity issue) pipe (...
1
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1answer
1k views

How can I turn home gas (LPG) from liquid to gas?

"LPG" is the term used here for a mixture of Propane & Butane sold for public use. The exact ratio varies depending on where you buy it and I think also with the season and is not known to me. I ...
2
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2answers
2k views

Typical power consumption of large compressor

This one should be easy to answer by looking at the thermodynamics, but I find it not to be. Say we have a natural gas stream, ~700 N∙m3/h, that we want to compress from 16 bar to 250 bar. What will ...
9
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2answers
429 views

How is gas flow through (extremely long) pipelines monitored and controlled?

(This is closely linked with measuring the Mach number inside a nozzle but it is not regarding the supersonic flow) Friction and heat transfer have effects on the Mach number of the compressible flow ...
5
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4answers
178 views

Determining pressures of a compressible gas

A friend and I wrote a paper for a fluids class discussing the details (as they relate to fluid dynamics) of constructing a cannon that could shoot a steak fast enough to cook it. We quickly ...
21
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3answers
1k views

How to know whether the flow is supersonic in a nozzle?

For a project I had built a convergent divergent nozzle designed for Mach number = 3. In that project, I could know the flow has gone supersonic by seeing the manometer fixed between the throat and ...
7
votes
1answer
187 views

Can using different types of alcohol in a cloud chamber produce different particle tracks?

The design for a cloud chamber is rather simple, and many factors can be changed without producing different results. There is one curious point that I've stumbled upon, though: The type of alcohol ...
6
votes
1answer
104 views

Multi-gas barometric height formula in isotope separation devices?

I think, actually the first row is needed is a barometric height formula for the mix of gases. The main problem I can see, the curves describing the minimal energy (kinetic + gravitational/...