Method Exit bag and inert gas megathread

[lion4000b]

My nitro cylinder valve sits at 150 bar (out of 350). Is that still enough gas/pressure for my 10L tank to cib using SCBA?

 

[Placo]

I ordered a helium tank which according to the manufacturer is 99.0% pure, it is 0.40m3.

I also ordered one of those gym backpacks that close elastically, maybe now I'm just missing a tube; or could I try to inflate the backpack like a balloon and immediately put it on my head?

 

[Theresnoescape]

Im not familiar with metric international connections...but if you can get a hose attached to it, then it would work.
This is for the hood application?
Also, Im not sure if 2L is enough. We use cubic feet in the US.....a 40cf tank is about 8L.
It seems to be the consensus that at least 15 min of running time at minimum of 15L per min.
I just dont know if a 2L bottle will last that long releasing at that rate needed.

SCBA system uses compressed air. It is meant for firefighters & keep them from breathing smoke filled outside air.
Usually the gas (in this case normal air) is at least 2200 psi (150 bar or15k kPa) ( I hope I have the conversions correct)
No the gas does not need to be purified. The gases used are Nitrogen, Helium etc. They usually are supplied in high pressures as well, so no problems.
Suppliers offer these in clean tanks, so no contaminants.
Im not sure what you are worried about with contaminants.....this is ultimately for CTB.

The SCBA system uses a regulator that brings the pressure in the tank down to about 85-130 psi (690 kPa).
This regulator is attached to the tank. Its part of the SCBA system.
Then the gas flows to a 'lung demand valve'...which is a fancy one way valve that activates on breathing demand.
This valve then allows the gas to enter the face mask.
The whole purpose is for fire fighters to breath only air from the tanks they carry & not smoke filled outside air.
But for CTB purposes, it is being utilized for a different purpose.

I will produce a tutorial using images explaining the SCBA system with parts someday.

Hi, I'll search for a larger tank, thanks for the help. I'm sure I'll have more questions.

 

[Kawaii_Shoujo215]

It is meant for firefighters & keep them from breathing smoke filled outside air.
Usually the gas (in this case normal air) is at least 2200 psi (150 bar or15k kPa) ( I hope I have the conversions correct)
No the gas does not need to be purified. The gases used are Nitrogen, Helium etc. They usually are supplied in high pressures as well, so no problems.
Suppliers offer these in clean tanks, so no contaminants.
Im not sure what you are worried about with contaminants.....this is ultimately for CTB.

The SCBA system uses a regulator that brings the pressure in the tank down to about 85-130 psi (690 kPa).
This regulator is attached to the tank. Its part of the SCBA system.
Then the gas flows to a 'lung demand valve'...which is a fancy one way valve that activates on breathing demand.
This valve then allows the gas to enter the face mask.
The whole purpose is for fire fighters to breath only air from the tanks they carry & not smoke filled outside air.
But for CTB purposes, it is being utilized for a different purpose.

I will produce a tutorial using images explaining the SCBA system with parts someday.

Thanks for the reply. I just wanted to clarify that I am well aware that nitrogen is used, as well as am quite well-versed in SCBA basics. My question was referring to testing the SCBA or, more specifically, the exhalation resistance, as well as generally getting used to the feel, doing practice runs, etc., and that I'd like to use compressed air for this testing (since nitrogen would make me pass out, with potentially leaks/problems/discomfort while exhaling, etc., which could make CTB fail or make it less comfortable, such as with SI/anxiety)).

The problem is that compressed air is used for many things (like welding, power tools, cutting, cleaning, etc.), and that there is a certification here in Europe (EN 12021) for compressed air specifically used for firefighting or scuba diving, which has had potential contaminants removed. My question was whether or not compressed air without this certification is safe to use for testing, or if it can lead to lung problems, dizziness, health problems, etc., since it may contain small traces of CO, CO2, water vapor, methane, etc.

 

[devils~advocate]

Hi, I'll search for a larger tank, thanks for the help. I'm sure I'll have more questions.

Glad to help. Im in this boat as well.
If you are in the EU you might can get the SCBA system from the source or at least locally there.

My nitro cylinder valve sits at 150 bar (out of 350). Is that still enough gas/pressure for my 10L tank to cib using SCBA?

150 bar = 2175 psi. 10L tank is about the same as a 80 cubic foot tank.
The conversions are confusing. But from what I know SCBA systems operate btwn 85-130 psi.
Now how long a tank would last at a rate that is efficient....Im not sure, here is my attempt using SCUBA method
Water Volume = 10 L
Working Pressure = 150 bar
Ideal capacity 10 ×150 ÷1.01325 = 1480 L
Z Factor =1.0263
True capacity 1480 ÷1.0263 ≈ 1440 L
Usage: (assuming 15L/min for CTB) 1440L ÷ 15L/min = 96 minutes

This is assuming that regular Air is being used. Nitrogen compressed acts differently, but I would assume not that much.
Someone will need to check the mathematics of this.

Thanks for the reply. I just wanted to clarify that I am well aware that nitrogen is used, as well as am quite well-versed in SCBA basics. My question was referring to testing the SCBA or, more specifically, the exhalation resistance, as well as generally getting used to the feel, doing practice runs, etc., and that I'd like to use compressed air for this testing (since nitrogen would make me pass out, with potentially leaks/problems/discomfort while exhaling, etc., which could make CTB fail or make it less comfortable, such as with SI/anxiety)).

The problem is that compressed air is used for many things (like welding, power tools, cutting, cleaning, etc.), and that there is a certification here in Europe (EN 12021) for compressed air specifically used for firefighting or scuba diving, which has had potential contaminants removed. My question was whether or not compressed air without this certification is safe to use for testing, or if it can lead to lung problems, dizziness, health problems, etc., since it may contain small traces of CO, CO2, water vapor, methane, etc.

Oh sorry, I didnt know you meant for Testing purposes.

I obtained the same Air tanks that are typically used with the SCBA systems for the fire fighters.
There are plenty available for purchase. If you can get one, I would recommend it. They are used only for normal air and are clean with no contaminants.
The issue I had was that in the USA, there are laws that only allow air tanks to be filled that fit some time parameters.
One is that the tank must be within 15 years of manufacturer to the day you want to fill it. The manufacture date is printed on the tanks for this purpose.
Another is that the tanks must be tested every 5 years. The testing agency will place a stamp on the tank showing that is has been tested.
In the EU it appears there is a similar requirement (I am not sure though).

But I would recommend attempting to get one of these scba air tanks and have it filled to the normal pressure with normal air.
Usually before they fill it, they can clean out the tank.

As for other types of tanks....that the risk. Usually tanks are designated for the gas they will contain.
I would think a Helium tank or CO2 tank would be fine.
They would take the valve off of the tank, clean it out with water & soap...dry it....then replace the valve...then fill with normal air to the correct pressure.

What type of tank have you acquired?

I ordered a helium tank which according to the manufacturer is 99.0% pure, it is 0.40m3.

I also ordered one of those gym backpacks that close elastically, maybe now I'm just missing a tube; or could I try to inflate the backpack like a balloon and immediately put it on my head?

(Assuming you referring to the hood method)
I think a tube that would supply a constant flow to a sealed hood would work.
the consensus is that 15L/min should work. CTB time needed at least 15 min....so 15L/min X 15 min = at least 225 L of expanded gas is needed.

 

[ClownWorld2023]

My question was whether or not compressed air without this certification is safe to use for testing, or if it can lead to lung problems, dizziness, health problems, etc., since it may contain small traces of CO, CO2, water vapor, methane, etc.

My EEBD set had a compressed air cylinder too, apparently for breathing purposes.
I tested it out, but the air was way too contaminated.
Like you could smell gasoline fumes or whatever that's emitted by air compressors normally.


I don't think the certification is that important, but you'll want clean compressed air that's filtered properly.
So compressed air straight from a regular backyard air compressor without filters won't do for this purpose.

The problem is that compressed air is used for many things (like welding, power tools, cutting, cleaning, etc.), and that there is a certification here in Europe (EN 12021) for compressed air specifically used for firefighting or scuba diving, which has had potential contaminants removed. My question was whether or not compressed air without this certification is safe to use for testing, or if it can lead to lung problems, dizziness, health problems, etc., since it may contain small traces of CO, CO2, water vapor, methane, etc.

Diving gas cylinders with regular compressed air would be suitable for this.
We're nearing summer now so you can go to any diving shop and get it refilled as often as you want.

I had the same idea previous winter, but it would have been too suspicious at the time, because most people don't go diving during the cold.

So just go to any diving shop and ask for a regular diving/breathing gas cylinder.

 

[Schmopo]

It certainly sounds that you have a flowmeter since it has a ball and indications of liters per minute.

If you have decided on eebd hood you have most of the equipment required. You just have to figure out how to mount the eebd hose onto the flowmeter since 5/8 would probably be too big. I would suggest using a 5/8 to 1/4 barb adapter with a 5/8 hose between the flowmeter and adapter.

Quick update: Upon looking at the photo now, I realised I bought the wrong adapter as both ends are 5/8. Doesn't matter much because the 5/8 hose for my cylinder only just slips in and out of the 5/8 adapter end fairly easily and using the hose clamps are not doing anything to keep it secure. What am I missing?

 

[devils~advocate]

Quick update: Upon looking at the photo now, I realised I bought the wrong adapter as both ends are 5/8. Doesn't matter much because the 5/8 hose for my cylinder only just slips in and out of the 5/8 adapter end fairly easily and using the hose clamps are not doing anything to keep it secure. What am I missing?

Can you post a photo of what you are talking about?
My suggestion is take whatever adapter you have (assumed from what you are saying that is a barb connection) and take it to the hardware store to get the right diameter plastic hose to fit it. The big box home stores have all that. The sales people can help as well.

My EEBD set had a compressed air cylinder too, apparently for breathing purposes.
I tested it out, but the air was way too contaminated.
Like you could smell gasoline fumes or whatever that's emitted by air compressors normally.


I don't think the certification is that important, but you'll want clean compressed air that's filtered properly.
So compressed air straight from a regular backyard air compressor without filters won't do for this purpose.




Diving gas cylinders with regular compressed air would be suitable for this.
We're nearing summer now so you can go to any diving shop and get it refilled as often as you want.

I had the same idea previous winter, but it would have been too suspicious at the time, because most people don't go diving during the cold.

So just go to any diving shop and ask for a regular diving/breathing gas cylinder.

Certification is important if in the USA for an air tank used for breathing. No place will fill it legally without a certification stamp.
I obtained the same tanks as made for the SCBA systems.
They have to be within a 15 year manufacture date
They also have to get a hydrostatic test. This is valid for 5 years. There are places that do all this.
I had it done and have tanks filled to 3000 psi & 2200 psi. This was done a a scuba dive shop. They will only fill if there is a stamp & manufacture date.

This is doable regardless. The tanks fit the scba systems exactly (cga-346 & 347 types) & was able to test my scba system.
I wanted to make sure the few LDVs I got, worked. One of them did not work, or I can't figure out how to keep it from leaking.

BTW, I know it was mentioned that for the cga-347 scba system there didnt seem to be a way to connect to a cga-580 nitrogen connection.
But there are simple straight forward adapters to make the cga-347 system work that I found easily. Once I get it all together, I will post a photo.

 

[Placo]

I bought one of those gym backpacks but unfortunately it lets the air through, at this point I'm wondering what I can invent for the helium without having to buy too much equipment.

I could buy the balloons and then inflate them and explode them in a plastic bag and then put it in so I'm sure there is a good percentage of helium, or inflate the bag directly with helium as if it were a balloon and then put it in, the helium should being lighter than air while CO2 is heavier so by keeping the bag in the right position I shouldn't lose large quantities before placing it.

I'm sure the bag doesn't let air pass through, I've already done experiments, one thing I wonder is if breathing helium CO2 is produced by the body anyway, I know it's produced by oxygen but if one inhales air which is mainly composed of helium and nitrogen, would it be produced anyway? So I could tie the bag tightly around my neck to prevent gas from escaping and at the same time not feel the effects of the rising CO2.

I just asked Google's AI and it responded like this:

No, your body wouldn't produce CO2 if you breathed air made mostly of helium and nitrogen. Carbon dioxide (CO2) production is a byproduct of cellular respiration, a process in which cells use oxygen (O2) to break down nutrients and generate energy.

Why oxygen is essential for cellular respiration:

1. Electron acceptance: Oxygen molecules act as the final electron acceptors in the electron transport chain, a process crucial to the production of ATP, the cell's energy molecule.
2. Concentration gradient: The difference in oxygen concentration between the inside and outside of the cell promotes its movement inward through passive diffusion, fueling cellular respiration.

In the absence of oxygen:

* Anaerobic respiration: Cells activate alternative energy production mechanisms that do not require oxygen, such as fermentative glycolysis. However, these processes produce less ATP than cellular respiration and generate byproducts such as lactic acid, which can cause muscle fatigue.
* Cell Death: Prolonged oxygen deprivation leads to cell death, as essential cellular processes cease to function.

So, if you only breathed helium and nitrogen:

* No oxygen intake: Oxygen would not be present for cellular respiration.
* No CO2 production: Cellular respiration would not occur, therefore no carbon dioxide would be produced.
* Cell Death: Cells would eventually die due to lack of oxygen and the resulting disruption of vital metabolic processes.

In summary, CO2 production is closely linked to cellular respiration, which requires oxygen. In the absence of oxygen, the body would not produce CO2, but would suffer serious consequences, including potential cell death.

Good news I'd say.

 

[ClownWorld2023]

Certification is important if in the USA for an air tank used for breathing. No place will fill it legally without a certification stamp.
I obtained the same tanks as made for the SCBA systems.
They have to be within a 15 year manufacture date
They also have to get a hydrostatic test. This is valid for 5 years. There are places that do all this.
I had it done and have tanks filled to 3000 psi & 2200 psi. This was done a a scuba dive shop. They will only fill if there is a stamp & manufacture date.

Yes the gas cylinders are all certified (or atleast, supposed to be).

I think @Kawaii_Shoujo215 was asking whether it was possible to also use compressed air gas cylinders which are not intended for breathing/diving purposes.

It should be possible as long as the cylinder's connection matches the SCBA regulator, and the compressed air is clean (you'd have to ask for this).

There are differences between the different compressed air cylinders.
I remember the diving gas cylinders here were either rated at 230 bar or 300 bar.
The prices can also vary wildly, but the 300 bar cylinders are (much) more expensive in general.

 

[annasharon]

The Regulator:

A regulator screws on to the cylinder and does two things: 1) it reduces the pressure in the cylinder to a useable level, otherwise the 2000psi tank pressure would just blow the exit bag off your head as soon as you opened the valve, and 2) it controls the rate of gas flow into the exit bag —specifically, it should release it at 15Lpm, which is the minimum adequate to carry away exhaled CO2 and fool your lungs into believing there's enough air.

The good news is that while gas cylinder sizes are not globally standardized, the cylinder valve threads are —and both N2 and Ar cylinders have the same threads (other gasses have different threads), so a regulator that fits on one cylinder will fit equally well on another.

You don't need to worry about being sure to choose a regulator that will reduce the pressure: they all do that. The flowmeter is the critical element of the regulator for our purposes.

Some regulators come with a "click adjust" flowmeter that is very simple, allowing you to dial in 15Lpm without needing to think about it. To the best of my knowledge, these are medical grade regulators; generally very good quality, but often a bit more expensive. Others here may know more about them, and where to acquire them, than I do.

A typical welding regulator will have two gauges: the tank pressure gauge (unimportant to us) and the flowmeter gauge.

A welding regulator's flowmeter gauge will be marked in either cubic feet per hour (Cfh), Lpm, or both. Some welding systems require a fairly low flow of inert gas, much lower than our necessary 15Lpm, and this low flow is most easily measured in Cfh. If you see a gauge marked only in Cfh, it probably will not work for our purpose. Look at the highest Cfh setting on the flowmeter and do the math, to be certain. If the gauge reads in Lpm, a glance should tell you whether the regulator provides the necessary 15Lpm flow.

Harbor Freight Tools offers a cheap CO2/Ar regulator (it also works for N2) with a flowmeter that shows flow in both Cfh and Lpm and goes high enough for our purposes. This is what I have.

The Hose:

The hose needs to be long enough to reach from the gas cylinder beside you, up into the exit bag on your head. I have found it easiest to lead the hose up my back and into the bag at the very back of my neck. It seems to disrupt the fit of the bag less right there.

Some regulators come with a hose that threads directly into the regulator body. Some regulators come with a hose-barb, onto which a length of soft tubing can be pressed. Some regulators come with neither.

For the first situation, just thread the hose into the regulator, tighten it with a wrench, and it's ready.

(Regardless of what type of threaded fitting is used, you do need to wrench-tighten this fitting: a lot of gas can leak out at this connection. If it is a brass fitting, you should not need teflon tape on the threads; the soft metal deforms enough when tightened to provide an adequately gas-tight connection.)

For the second situation, take the hose-barb to a hardware / home improvement store and purchase tubing that fits onto the barb. Once home from the hardware store, thread the barb into the regulator body, tighten with a wrench, and press the tube onto the barb. It should be a snug fit; if you're worried it's too loose, use a small hose clamp / jubilee clip to secure it in place. If it's a little too tight to get the hose into place, soak the end of the tube in very hot water to soften it and press it onto the barb. I used clear vinyl tubing. Aquarium tubing should work. Surgical tubing may not; I don't know for sure.

For the third situation, you'll need a hose-barb fitting (typically brass) that threads into the regulator body. Take the entire regulator to the hardware store and ask someone to help you fit it with a hose barb. Then proceed as for the second situation.

Cover story: as with purchasing the gas cylinder, you're using N2 for brewing, or Ar for filling partial paint cans. Why Ar? because it's heavier than air and settles down onto the paint surface inside the can. For extra confidence that they won't ask inconvenient questions, you're doing it for your father, or your brother, and you don't know why they want it for their paint locker, they just said to get a hose barb and six feet of tubing…

The Exit Bag:

There are several videos on YouTube detailing construction of exit bags. I strongly recommend watching them. That's how I learned.

The short version of what you want is a turkey roasting bag —available in the supermarket, in with the zip-locks and cling wrap— with an elastic drawcord worked into a turned hem, and a cord-lock to adjust the drawcord's tension.

I used 3/8" elastic cord. I purchased both it and the cord lock at a sewing and crafts store (JoAnn's).

To construct the turned hem you'll need micropore (surgical) tape, available at a pharmacy in the first aid section. It's the right tape to use because it will reliably stick to the material of the bag itself. Sometimes it isn't labeled as "micropore." Ask a clerk if you can't find it.

Cover story: you were asked to re-stock the family first aid kit with micropore tape and you don't recognize any of the brands available.

Using an elastic drawcord is important: it needs to fit snugly around your neck, but not seal tightly. It must still be flexible enough for the flow of inert gas, lightly pressurizing the exit bag, to push past the elastic and flush away the CO2 you're exhaling. Don't use a non-elastic drawcord or do something like duct tape the bag to your neck; you don't want to create a seal, just a restriction.

Hi, they are asking me at the shop "which hose do I need". What should I say?

Hi, they are asking me at the shop "which hose do I need". What should I say?

What length should the hose be and which kind of hose? They are asking at the shop

 

[devils~advocate]

Hi, they are asking me at the shop "which hose do I need". What should I say?

What length should the hose be and which kind of hose? They are asking at the shop

I guess what regulator are you using? The type it is makes a difference. Some have a barb that plastic (polyethylene vinyl) tubing fits over.
My first thoughts are that the clear vinyl type of tubing would work fine.
Length...I'd say at least 4-5 ft (120-150cm)

 

[devils~advocate]

Normal human breaths are about 0.5L at 12 times per minute.
Thats about 6L per minute. It doesnt seem like much.

Divers using scuba gear typically consume about 15 - 25L per minute.

So the consensus of a supply at 15L per min sounds reasonable. Maybe a tad higher.

 

[Placo]

I found a way to make this method work partially without the need for a lot of equipment, in this post I explain how to do it, it doesn't guarantee the same purity of gas as a more elaborate method but I'm satisfied, for me it's a good compromise.

 

[Placo]

I found a way to make this method work partially without the need for a lot of equipment, in this post I explain how to do it, it doesn't guarantee the same purity of gas as a more elaborate method but I'm satisfied, for me it's a good compromise.

Unfortunately I have to give some bad news, even the helium cylinders sold in Europe is not true that they are 100% pure, I noticed this from the fact that I still had hypercapnia, so having hypercapnia is because oxygen is present which in turn with metabolism produces CO2, I would dare to say that they are at 50/50, they study them all to make our lives difficult but I still have a plan B even if it's off topic to talk about it here.

I think nitrogen cylinders are definitely more reliable, but if I buy one, is a pressure reducer necessary? Can't I just let the air go into a plastic bag and then put it over my head like I planned with the helium tank? Would the pressure be so strong that it would break the bag? It seems there is a valve, maybe the pressure can be adjusted from there.

 

[devils~advocate]

I think nitrogen cylinders are definitely more reliable, but if I buy one, is a pressure reducer necessary? Can't I just let the air go into a plastic bag and then put it over my head like I planned with the helium tank? Would the pressure be so strong that it would break the bag? It seems there is a valve, maybe the pressure can be adjusted from there.

Yes a regulator (reducer) would be needed to reduce the pressure down to something manageable.
It also provides a way of being a sort of adapter as well btwn the tank and hose.
The tanks require a specific connection & typically only regulators fit these anyway.
This thread goes into specifics about this.

 

[Placo]

Yes a regulator (reducer) would be needed to reduce the pressure down to something manageable.
It also provides a way of being a sort of adapter as well btwn the tank and hose.
The tanks require a specific connection & typically only regulators fit these anyway.
This thread goes into specifics about this.

View attachment 142141

So there's no question of using it without a depressurizer? Too risky?

Unfortunately I have to give some bad news, even the helium cylinders sold in Europe is not true that they are 100% pure, I noticed this from the fact that I still had hypercapnia, so having hypercapnia is because oxygen is present which in turn with metabolism produces CO2, I would dare to say that they are at 50/50, they study them all to make our lives difficult but I still have a plan B even if it's off topic to talk about it here.

I think nitrogen cylinders are definitely more reliable, but if I buy one, is a pressure reducer necessary? Can't I just let the air go into a plastic bag and then put it over my head like I planned with the helium tank? Would the pressure be so strong that it would break the bag? It seems there is a valve, maybe the pressure can be adjusted from there.

However, thinking about it, perhaps the purity of 50% is a bit low estimate, if it was mixed with 50% helium and 50% oxygen the balloons wouldn't even take flight while in the reviews people complain that they deflate easily and that there is little gas in the tank but not much about balloons which don't take flight, 100% helium obviously not even, at this point I would say something like 80% helium and 20% air, in short more or less these percentages but still with helium in the majority, I don't know whether to implement it in my method anyway or not, I would swear to having seen my hand cyanotic yesterday for a moment so even if we are not 100% the percentage is higher than 50%.

 

[devils~advocate]

So there's no question of using it without a depressurizer? Too risky?

However, thinking about it, perhaps the purity of 50% is a bit low estimate, if it was mixed with 50% helium and 50% oxygen the balloons wouldn't even take flight while in the reviews people complain that they deflate easily and that there is little gas in the tank but not much about balloons which don't take flight, 100% helium obviously not even, at this point I would say something like 80% helium and 20% air, in short more or less these percentages but still with helium in the majority, I don't know whether to implement it in my method anyway or not, I would swear to having seen my hand cyanotic yesterday for a moment so even if we are not 100% the percentage is higher than 50%.

Yes, inert gas tanks are all under pressure.....at least 2000 psi (140 bar). The gases are compressed in the tanks and at normal atmospheric pressure, they would fill a much larger area (i.e. 80 cubic feet or 3 cubic meters, etc etc)
The regulator brings that pressure down to a workable level in the trades that they are used in.
Helium in tanks would be pressurized as well. It was my initial method 20 years ago when I started thinking about all this.
I got a large tank of helium at the time....still have it.
The process is still the same as any other inert gas used....to displace oxygen.

Some have mentioned using an oxygen meter to test if a setup would work well or not. These are available to purchase.
Letting some of the gas flow to the setup one has and then measuring the oxygen levels.
I dont remember the recommended results to look for, but this thread might have it.

You seem to be discussing the 'Hood' method. Actually helium was the gas suggested by the author that wrote a book about the topic.
I dont see why it wouldnt work fine. His suggestion was to use helium for balloons...the small tanks are sold at party supply stores and other places.
For effectiveness, keeping the gas from escaping the hood is most important. So the manufacture of the hood is the most crucial part.

 

[heavenplzhelp77]

Yes, inert gas tanks are all under pressure.....at least 2000 psi (140 bar). The gases are compressed in the tanks and at normal atmospheric pressure, they would fill a much larger area (i.e. 80 cubic feet or 3 cubic meters, etc etc)
The regulator brings that pressure down to a workable level in the trades that they are used in.
Helium in tanks would be pressurized as well. It was my initial method 20 years ago when I started thinking about all this.
I got a large tank of helium at the time....still have it.
The process is still the same as any other inert gas used....to displace oxygen.

Some have mentioned using an oxygen meter to test if a setup would work well or not. These are available to purchase.
Letting some of the gas flow to the setup one has and then measuring the oxygen levels.
I dont remember the recommended results to look for, but this thread might have it.

You seem to be discussing the 'Hood' method. Actually helium was the gas suggested by the author that wrote a book about the topic.
I dont see why it wouldnt work fine. His suggestion was to use helium for balloons...the small tanks are sold at party supply stores and other places.
For effectiveness, keeping the gas from escaping the hood is most important. So the manufacture of the hood is the most crucial part.

Speaking of helium tanks the ones made for filling balloons are under a lower pressure than needed for ctb like the helium balloon filling system is 28 bar and has 7 liters So that's much lower than what's needed right?! So do I definitely need a bigger tank to use? What's the real necessary number is it 600 liters overall

 

[devils~advocate]

Speaking of helium tanks the ones made for filling balloons are under a lower pressure than needed for ctb like the helium balloon filling system is 28 bar and has 7 liters So that's much lower than what's needed right?! So do I definitely need a bigger tank to use? What's the real necessary number is it 600 liters overall

Yep thats what I remember as well that they are lower pressures. Actually in the book, it just shows one of those balloon tank (or maybe it was two in series) with hose to a hood setup.
The recommended flow that has been discussed in this forums (and in the book) is 15 L/m....and time needed, which is about 15-20 minutes at least.
Thats about 300 L minimum....but my thoughts is to have more than needed just in case of leaks, etc.

(Btw, I know helium is used for slaughtering pigs in the meat industry, especially I think in the EU.
There are videos on YT that show this in Germany. The pigs don't even know what is happening.
Im not sure if the links can be posted.)

 

[Placo]

Nothing to do, helium is apparently expensive and it is convenient for the producers to sell you as little of it as possible by mixing it with normal air I imagine, if you are thinking of buying a cylinder of helium for balloons for this method, know that it will almost certainly not be pure.

 

[devils~advocate]

Nothing to do, helium is apparently expensive and it is convenient for the producers to sell you as little of it as possible by mixing it with normal air I imagine, if you are thinking of buying a cylinder of helium for balloons for this method, know that it will almost certainly not be pure.

Yes helium for balloons will probably be mixed with air etc. It can be tested to verify though.
But the helium used for certain trades, it is pure. It has to be due to requirements for certain industrial applications.

 

[devils~advocate]

Nothing to do, helium is apparently expensive and it is convenient for the producers to sell you as little of it as possible by mixing it with normal air I imagine, if you are thinking of buying a cylinder of helium for balloons for this method, know that it will almost certainly not be pure.

Helium for trades is in pressurized tanks like other inert gases.
Trades such as welding use this and other inert gases.
These trades get these gases everyday from retail shops that sell them. It is a common daily activity.
Any of it (gases, regulators, etc) can be obtained fairly easily by anyone. You do not have to be a trades person to obtain it.
The cost might be higher than one might expect.
This is because the tank itself is more expensive item. The gas itself is inexpensive.
Total cost might cost around €250 for a 80 cf or 2.2 cubic meter tank and a regulator.

 

[k1w1]

What's in Peru? Euthanasia ? Or N?

N

I bought one of those gym backpacks but unfortunately it lets the air through, at this point I'm wondering what I can invent for the helium without having to buy too much equipment.

I could buy the balloons and then inflate them and explode them in a plastic bag and then put it in so I'm sure there is a good percentage of helium, or inflate the bag directly with helium as if it were a balloon and then put it in, the helium should being lighter than air while CO2 is heavier so by keeping the bag in the right position I shouldn't lose large quantities before placing it.

I'm sure the bag doesn't let air pass through, I've already done experiments, one thing I wonder is if breathing helium CO2 is produced by the body anyway, I know it's produced by oxygen but if one inhales air which is mainly composed of helium and nitrogen, would it be produced anyway? So I could tie the bag tightly around my neck to prevent gas from escaping and at the same time not feel the effects of the rising CO2.

I just asked Google's AI and it responded like this:


Good news I'd say.

why not just make an exit bag or buy a hood from China, there is a well trodden path for this method in this thread that has meandered lately. Check the user set up pics. Its very simple and not at all expensive.

 

[heavenplzhelp77]

Yep thats what I remember as well that they are lower pressures. Actually in the book, it just shows one of those balloon tank (or maybe it was two in series) with hose to a hood setup.
The recommended flow that has been discussed in this forums (and in the book) is 15 L/m....and time needed, which is about 15-20 minutes at least.
Thats about 300 L minimum....but my thoughts is to have more than needed just in case of leaks, etc.

(Btw, I know helium is used for slaughtering pigs in the meat industry, especially I think in the EU.
There are videos on YT that show this in Germany. The pigs don't even know what is happening.
Im not sure if the links can be posted.)

How hard is it to connect the regulator with a eebd mask? I mean why does everybody keep talking about leakage how hard can it be to pull that together and ensure it's done right! by the way straps and stuff are just an unnecessary addition right

 

[devils~advocate]

How hard is it to connect the regulator with a eebd mask? I mean why does everybody keep talking about leakage how hard can it be to pull that together and ensure it's done right! by the way straps and stuff are just an unnecessary addition right

Not hard at all. Some regulators come with an outlet that is a barb connection. A hose or tubing is pushed over the barb.
One can also use a hose clamp at the intersection to ensure a tight fit.

Then the tubing goes to a hood or whatever the system.

There will be leakage of some sort, since the hood method is a constant flow system.
The breathe exhaust and excess gas have to go somewhere since new gas is entering the hood.
For a hood, I think the idea is for the exhaust/excess to flow out to a remote part of the hood.
New gas should be introduced close to breathe intake.

The idea of the hood is to try to keep new gas close to breathe intake & keep away regular air (thus O2) away as much as possible,

 

[suffering_mo_7]

There's a ton of people who left timer messages saying Theyr exiting and never posted again. The gurus who have contributed a lot to this thread like vizzy, gasmonkey , etc likely gone .
If you scroll up, there seems to be an example of permanent injury from a failure…but note this failure did not follow the appropriate accepted protocol, not even close

So we have examples of people succeeding with pretty high tech setups, mostly with SCBA, SCUBA, and Vizzy with the hood but what about with exit bags? Any CTBs with Hoods besides Vizzy?

 

[Kapsyl]

So we have examples of people succeeding with pretty high tech setups, mostly with SCBA, SCUBA, and Vizzy with the hood but what about with exit bags? Any CTBs with Hoods besides Vizzy?

Exit bag is Nitschke bread and butter, he pioneered the method and swears by it. It's the most researched of the inert methods and I've read about successful ctbs with them. But ever since the easily obtained high purity helium disappeared the popularity has dropped, people now choose more advanced setups with nitrogen instead.

The thing with exit bag was that it was easily obtained, before the helium shortage. You could buy everything in one day and successfully ctb the same evening. Now with mostly nitrogen available exit bag isn't the best choice since I believe helium works better in that kinda setup.

Read this tread, there's at least two exit bags users who I believe ctb. Not everyone chooses to acknowledge their departure.

Inert gas setups gallery. Show your setup

Just ratchet straps/tie-down straps that you can get in most hardware stores: . And you tighten it after you adjust the mask or is it preset?

sanctioned-suicide.net

 

[suffering_mo_7]

Exit bag is Nitschke bread and butter, he pioneered the method and swears by it. It's the most researched of the inert methods and I've read about successful ctbs with them. But ever since the easily obtained high purity helium disappeared the popularity has dropped, people now choose more advanced setups with nitrogen instead.

The thing with exit bag was that it was easily obtained, before the helium shortage. You could buy everything in one day and successfully ctb the same evening. Now with mostly nitrogen available exit bag isn't the best choice since I believe helium works better in that kinda setup.

Read this tread, there's at least two exit bags users who I believe ctb. Not everyone chooses to acknowledge their departure.

Inert gas setups gallery. Show your setup

Just ratchet straps/tie-down straps that you can get in most hardware stores: . And you tighten it after you adjust the mask or is it preset?

sanctioned-suicide.net

Ahhh, I see. So with nitrogen, it's more critical that there are no leaks at all versus with helium, it was less of an issue?

 

[Kapsyl]

Ahhh, I see. So with nitrogen, it's more critical that there are no leaks at all versus with helium, it was less of an issue?

The helium has the advantage that it's lighter than air, so sitting vertically with a bag full of helium, it isn't keen on escaping downwards. Nitrogen which is almost the same as air easily blends with the oxygen and isn't as forgiving as helium.

I don't really have any scientific proof of this but it makes sense in my mind.