Help Nitrogen regulator

[how2toGetout]

Oxygen regulators or flow meters are easier to find and cheaper than nitrogen ones, for whatever reason. Oxygen and Nitrogen are also similar enough in atomic weight that the devices calibrated for oxygen are fairly close in displayed flow rates when used with nitrogen.

So, in other words, just because Oxygen Regulators can "accurately" measure Nitrogen flow rates, Oxygen regulators are okay to use for Nitrogen method?

 

[Lookingforabus]

That's the theory, yeah. Personally, I found it easier to get a CO2/argon flowmeter and do the math over getting an adapter for the oxygen flowmeter, but whichever you prefer should work just fine.

 

[how2toGetout]

That's the theory, yeah. Personally, I found it easier to get a CO2/argon flowmeter and do the math over getting an adapter for the oxygen flowmeter, but whichever you prefer should work just fine.

What do you mean by "do the math" part? Is there calculation involved when using a CO2/argon regulator?

 

[Lookingforabus]

What do you mean by "do the math" part? Is there calculation involved when using a CO2/argon regulator?

Yeah, the flow rate of a gas at standard pressure and temperature is a function of its molecular weight. Flowmeters are calibrated for a particular gas, so if you're using a different gas, the displayed flow rate will not be accurate. You can find conversion tables and factors online to tell you how much the displayed flow rate is off by when using a different gas.

 

[how2toGetout]

Yeah, the flow rate of a gas at standard pressure and temperature is a function of its molecular weight. Flowmeters are calibrated for a particular gas, so if you're using a different gas, the displayed flow rate will not be accurate. You can find conversion tables and factors online to tell you how much the displayed flow rate is off by when using a different gas.

By a conversion table and factor, do you mean something like the following: https://www.mksinst.com/n/gas-correction-factors-for-thermal-based-mass-flow-controllers
The above link has a table that has factors with respect to Nitrogen.
Am i supposed to find a table that has factors with respect to Argon/CO2?

Can you help me on how to "do the math" (or find the conversion tables/factors) if using a CO2/argon regulator for a Nitrogen method?
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That's the theory, yeah. Personally, I found it easier to get a CO2/argon flowmeter and do the math over getting an adapter for the oxygen flowmeter, but whichever you prefer should work just fine.

Just another question came up:
Wouldn't an oxygen flowmeter/regulator also need a conversion table/factors to "do the math calculation"?
EDIT/ANSWER TO MY OWN QUESTION: Oh, wait i forgot.. you already had said that oxygen is close enough to nitrogen in terms of molecular weight such that oxygen regulator's difference to nitrogen regulator is almost negligible with regards to measuring a flow rate of nitrogen accurately.

 

[Lookingforabus]

Yup, that's the conversion factor and the "math" I was talking about. I got my numbers by knowing the gas volume, emptying my tank, timing it, and calculating the actual flow rate. Comparing it to the display flow rate on my argon flow meter got a result close to the 1.4 conversion factor I saw online.

If it helps, it seems that a 20 cu ft tank filled with compressed nitrogen from an industrial gas supplier is sufficient. That's what I suspected based on the old advice of using 2 helium tanks (9.8 cu ft each), but I feel better having done the math and tested it out. If I get super paranoid, I might upgrade to a 40 cu ft tank... and figure out how to properly conceal that for transport to my bus stop.

 

[how2toGetout]

Yup, that's the conversion factor and the "math" I was talking about. I got my numbers by knowing the gas volume, emptying my tank, timing it, and calculating the actual flow rate. Comparing it to the display flow rate on my argon flow meter got a result close to the 1.4 conversion factor I saw online.

If it helps, it seems that a 20 cu ft tank filled with compressed nitrogen from an industrial gas supplier is sufficient. That's what I suspected based on the old advice of using 2 helium tanks (9.8 cu ft each), but I feel better having done the math and tested it out. If I get super paranoid, I might upgrade to a 40 cu ft tank... and figure out how to properly conceal that for transport to my bus stop.

Does the conversion factor of 1.4 mean that a Nitrogen flow rate (using a CO2/argon flowmeter) is 1.4 time faster OR slower than if an Argon were to flow instead of Nitrogen?

Maybe i'm understanding things wrong.. i'm a bit confused..

 

[Lookingforabus]

Using an argon flow meter and running nitrogen gas through it means dividing the displayed flow rate by 1.4 (the argon gas flow conversion factor). It's about the same as multiplying by .7, if that's easier for you.

The attached pdf gives a more detailed description of the math, but basically, since nitrogen gas has a a conversion factor of one, it makes the math easier.

 

[pane]

Lookingforabus explains it correctly, How2Getout. If my recall is right, Chris Docker - the author of the book Five Last Acts - states in the chapter on inert gas that nitrogen is only 3% heavier than oxygen. In practical terms for the purpose of suicide, nitrogen and oxygen are essentially identical in nature. Consequently a click-style 02 regulator (with adapter) that can be set to 15 LPM is a simple, easy and accurate enough way of measuring gas flow.

 

[how2toGetout]

Lookingforabus explains it correctly, How2Getout. If my recall is right, Chris Docker - the author of the book Five Last Acts - states in the chapter on inert gas that nitrogen is only 3% heavier than oxygen. In practical terms for the purpose of suicide, nitrogen and oxygen are essentially identical in nature. Consequently a click-style 02 regulator (with adapter) that can be set to 15 LPM is a simple, easy and accurate enough way of measuring gas flow.

@pane, Thank you for helpful responses.

Some say Argon Regulator is okay to use with Nitrogen gas.. Is this true?

What you said above is that Oxygen Regulator can be used for Nitrogen gas. Can Oxygen Regulator be used for Argon gas? Will Argon be too heavy (in terms of molecular weight) for Oxygen Regulator to measure the pressure? What about for flow rate? I'm confused about this pressure measurement and flow measurement..

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Yeah, the flow rate of a gas at standard pressure and temperature is a function of its molecular weight. Flowmeters are calibrated for a particular gas, so if you're using a different gas, the displayed flow rate will not be accurate. You can find conversion tables and factors online to tell you how much the displayed flow rate is off by when using a different gas.

Wouldn't the flow rate of a gas depend upon the pressure of the gas? (and not on the molecular weight of the gas?)

I thought i understood your explanation, but now that i read again, i have my doubts.. i feel that flow rate could depend upon the pressure of the gas.. and molecular weight being negligible..

 

[pane]

@pane, Thank you for helpful responses.

Some say Argon Regulator is okay to use with Nitrogen gas.. Is this true?

What you said above is that Oxygen Regulator can be used for Nitrogen gas. Can Oxygen Regulator be used for Argon gas? Will Argon be too heavy (in terms of molecular weight) for Oxygen Regulator to measure the pressure? What about for flow rate? I'm confused about this pressure measurement and flow measurement..

1) I *believe* an argon regulator can be used on a nitrogen tank but then you have to perform mathematical calculations to adjust the flow rate because argon is somewhat heavier than nitrogen. There's a member here named Eweforia who I think is using an argon regulator with nitrogen. Search through her posts to find more info about this subject.

2) I don't have enough technical understanding to know if a click-style 15 LPM oxygen regulator can be used with a tank of argon. Can't help you there.

 

[how2toGetout]

you have to perform mathematical calculations to adjust the flow rate because argon is somewhat heavier than nitrogen.

What do you mean by the mathematical calculations to adjust the flow rate? Can you be just a bit more specific? Maybe give an example please?

What do you mean by the mathematical calculations to adjust the flow rate? Can you be just a bit more specific? Maybe give an example please?

If Nitrogen gas is flowing through an Argon Regulator/Flowmeter, and the flowmeter reads 15 Lpm, then does it mean 15 Liters of Nitrogen are flowing out per minute?

 

[pane]

What do you mean by the mathematical calculations to adjust the flow rate? Can you be just a bit more specific? Maybe give an example please?

I myself don't know how to perform these calculations. These calculations primarily determine how long the gas flow will last at 15 LPM. As I said if using argon you have to make adjustments because argon is heavier than nitrogen so you need a higher LPM figure of argon flowing to equal the 15 LPM you'd get using nitrogen. See Eweforia's posts about that. Also use the search function and look for posts by TiredHorse. He discusses this subject in great detail.

 

[how2toGetout]

I myself don't know how to perform these calculations. These calculations primarily determine how long the gas flow will last at 15 LPM. As I said if using argon you have to make adjustments because argon is heavier than nitrogen so you need a higher LPM figure of argon flowing to equal the 15 LPM you'd get using nitrogen. See Eweforia's posts about that. Also use the search function and look for posts by TiredHorse. He discusses this subject in great detail.

Think i found @Eweforia's post (regarding using Argon Regulator for Nitrogen gas): https://sanctioned-suicide.net/threads/exit-bag-and-inert-gas-megathread.8393/post-396412

Ewforia says something about "nudge the flow up from the suggested 15 L/min to somewhere between 19-22 L/min "

Think i found @Eweforia's post (regarding using Argon Regulator for Nitrogen gas): https://sanctioned-suicide.net/threads/exit-bag-and-inert-gas-megathread.8393/post-396412

Ewforia says something about "nudge the flow up from the suggested 15 L/min to somewhere between 19-22 L/min "

But shouldn't the situation be "nudging down the flow" from the 15 L/min?
Because I feel the Argon Regulator reading 15Lpm means that more than 15 Liters (of Nitrogen) is flowing through the Regulator per minute (since Nitrogen gas is lighter than Argon gas)..



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EDIT: I was reading here (http://ch301.cm.utexas.edu/gases/ideal-gas-law/idealgaslaw-all.php) and it mentions a concept called 'Number Density'. So i googled "do all gases have same number density" and one of the first search results leads me to the similar questions list where it asks "do all gases have same pressure?"

So i click "do all gases have same pressure?" and it gives me a link to Avogadro's law (https://en.m.wikipedia.org/wiki/Avogadro's_law). According to Wikipedia, Avogadro's law says that:
"Equal volumes of all gases, at the same temperature and pressure, have the same number of molecules."
"For a given mass of an ideal gas, the volume and amount (moles) of the gas are directly proportional if the temperature and pressure are constant."

So, would Avogadro's law imply the following?:
The # of Nitrogen molecules flowing at 15 Lpm would be the same as the # of Argon molecules flowing at 15 Lpm, at a given point in a Regulator.

So, if the above is implication is true, then what would that mean (in terms of the flow rate inside a Regulator)?

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2nd EDIT:
So, measurement-wise, the Regulator/Flowmeter will measure the flow rate by the amount of momentum the flowmeter gets hit during a given moment. So.. since Argon is heavier than Nitrogen, Argon will have more amount of momentum measured on the flowmeter during a given moment (let's say in a second).

So, Nitrogen would need to flow faster in order to meet this amount of momentum measured on the flowmeter during a given moment (i.e. in a second).

So, this would mean that Nitrogen flow rate needs to be higher than 15 Lpm for the Argon Regulator/Flowmeter to display the measurement of 15 Lpm (the "15Lpm of Argon" standard).

So, this means that if the reading is 15 Lpm on Argon Flowmeter, then the reading means Nitrogen is flowing at higher rate than 15 Lpm.

So we should nudge down the flow to less than 15 Lpm to appear on Argon Flowmeter, in order for Nitrogen to be flowing at 15 Lpm (because Nitrogen was flowing at higher rate than 15 Lpm when the reading actually says 15 Lpm on Argon Flowmeter).

Is this argument valid?

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3rd EDIT:
I guess it depends on what the actual mechanism the Flowmeter operates with in order to measure the flow rate.....
Does a Flowmeter measure a gas's flowrate (Lpm) with a measure of how many molecules are passing through during a given moment?

Would the above question be the same thing as asking the following question?:
Does a Flowmeter measure a gas's flowrate (Lpm) with a measure of an amount of momentum during a given moment?


In ANY CASE, it seems the important question is: How does a Flowmeter measure the flow rate? Is it with oil in the flowmeter cylinder? What's the underlying mechanism that allows the flowmeter to measure a flow rate?

Final EDIT: I found this video here (https://www.omega.com/en-us/resources/flow-meters) about flowmeter. After watching the video, i keep getting a feeling that a Gas Flowmeter's mechanism possibly operates in either "Paddlewheel Flow Meter" principle or "Variable Area Flow Meter" principle.

 

[Eweforia]

The information I read on nudging an AR regulator up from 15 L/min to somewhere between 19-22 L/min to measure N2 flow came directly from post #592 by TiredHorse in the Exit bag and Inert Gas Megathread at https://sanctioned-suicide.net/threads/exit-bag-and-inert-gas-megathread.8393/page-20#post-377302. One has to choose who they trust to provide good information on these forums, and TiredHorse was at the top of my trusted list. BTW, has anyone heard from TiredHorse lately? I think his last post was August 6.

 

[frees]

To make the confusion complete: The sources i see in this thread are for thermal flowmeters. These work by a different principle than "floating ball" meters, thus are not applicable.

 

[Deleted member 1768]

Why is it that if you flush your lung completely out of air, your CO2 level will stay below discomfort threshold?

I'm a bit confused about the CO2 part. Could you elaborate a little bit more please?

Please do your own research. Try the megathread.