Help Exit Bag Failure

[dyingispeaceful]

I decided to CTB today using the Inert Gas Method. I believed I had set up everything perfectly(Cylinder, Regulator, Flow meter, Hose, Exit Bag) and still do. I've done the soapy water test on all connections in my equipment at least thrice(one after my attempt). I've observed no bubbles therefore I conclude none of my equipment has any leaks. Exit Bag also shows to have no signs of leak as I observe no tears. I'm using a GLAD Large Oven Bag(35*48)cm.

So, I sit on the floor. I put the bag above my head(just above my ears and eyebrows), crumple the bag to remove all the air, turn on the gas valve and set the flow meter to 15L/min. I hear a hissing sound due to the gas flowing. I'm using my laptop webcam as a mirror. I start hyperventilating and do that for 2 mins. I see the bag is no way near to being completely filled. It's still very crumpled. It takes a whooping 10 mins for the bag to fill up like a balloon as show in the PPeH.

I'm quite confused and can't explain what happened. I would imagine the volume of the bag to be not more than 30 Litres so it shouldn't take more than 2 minutes for the bag to fill up. What do you all think could have gone wrong. Luckily, I didn't went much further into my attempt(could have ended up brain damaged).

Any help would be very appreciated. I need to fix this problem and do not have much time. Thank you.

 

[Honigwaffel]

Yes you are right. It should take 2 minutes max to fill the bag completely, there has to be something wrong with either the pressure of the gas tank or your flowrate. Do you mind sharing the exact equipment you are using? Did you buy everything new or used? Have you attached the hose at the top of the bag? Maybe your hose is too small so that it only allowes a smaller flow than 15L / min

 

[dyingispeaceful]

Yes you are right. It should take 2 minutes max to fill the bag completely, there has to be something wrong with either the pressure of the gas tank or your flowrate. Do you mind sharing the exact equipment you are using? Did you buy everything new or used? Have you attached the hose at the top of the bag? Maybe your hose is too small so that it only allowes a smaller flow than 15L / min

Following is the equipment I'm using:
Argon C Size Cylinder: https://www.totaltools.com.au/media...36de70892d86c6d221abfe/A/r/Argon-Pure-C_6.jpg
Argon Flowmeter Regulator: https://unimig.com.au/product/argon-flowmeter-regulator-2/
Oxygen Tube: https://store.independenceaustralia.com/convatec-no-crush-oxygen-tube.html
Glad Oven Bag: http://www.glad.com.au/glad-products/food-management/glad-oven-bags/index.html (large one)

All my equipment is new. Yes, the hose is attached at the top of the bag only a few cm's from the top of the bag.

How would I know if my hose is too small? The flowmeter constantly showed a reading of 15 L/m. If my hose was to small to let 15 L/min of gas in the bag, where do you reckon the rest of the gas would have been going?

 

[Purgatory]

Never thought I could tolerate the bag over my head. Not actively suicidal, but I always fantasize about using inert gas in a sealed room, tent, or even a zorb ball inflated/flooded by my dangerously lovely work companion with 3 fresh bottles. Only a fantasy, but it sometimes has a calming effect on me.

 

[Honigwaffel]

Hmm, the equipment looks fine to me. Although the gas tank has no indication on how pure the argon is, what's the pressure rating. I'm not familiar with the term c size and what that means exactly in term of pressure and volume. Do you have any of these information on the reciept? Also the flowmeter does not indicate for how much pressure it is rated. In germany we have different regulators for 200 bar / 300 bar for example. Not every regulator works for every gas tank.

But it should work fine either way when the flowmeter indicates 15 L/min. The hose is fine aswell. A user told me recently that a very small hose can create resistent pressure which some regulator can't handle (I don't know how accurate that is).

 

[dyingispeaceful]

Hmm, the equipment looks fine to me. Although the gas tank has no indication on how pure the argon is, what's the pressure rating. I'm not familiar with the term c size and what that means exactly in term of pressure and volume. Do you have any of these information on the reciept? Also the flowmeter does not indicate for how much pressure it is rated. In germany we have different regulators for 200 bar / 300 bar for example. Not every regulator works for every gas tank.

But it should work fine either way when the flowmeter indicates 15 L/min. The hose is fine aswell. A user told me recently that a very small hose can create resistent pressure which some regulator can't handle (I don't know how accurate that is).

It's pure Argon. C size is the smallest bottle size in Oz(in this case 600 L) The pressure rating is 16500 kPa. However, the pressure was 18000 kPa when I checked the gauge when the tank is new(I guess, that's a good thing as it might mean more gas). It's 300 bar. The salesman said that this regulator works for this tank and it fits perfectly because of similar threading.

It should work fine but it's not. Please let me know if you have any idea why.

 

[Honigwaffel]

It's pure Argon. C size is the smallest bottle size in Oz(in this case 600 L) The pressure rating is 16500 kPa. However, the pressure was 18000 kPa when I checked the gauge when the tank is new(I guess, that's a good thing as it might mean more gas). It's 300 bar. The salesman said that this regulator works for this tank and it fits perfectly because of similar threading.

I'm pretty sure that Kilopascal translates directly to bar, so 16500 kPa is 165 bar. If the tank is rated for 300bar / 30000 kPa you have almost half the pressure you should have. That could be a possible reason. Also I can't find any other information on the regulator regarding pressure rating. Other than that I really don't have any other idea why this shouldn't work.

Here in germany we have a tüv certification for each component to guarantee that the work together.

 

[Soul]

As an interested bystander who knows nothing of kpa's, bars, flow meters etc, I'm going to go ahead and suspect the bag. I understand that you see no tears, but what happens when you puff air into it as if blowing up a balloon?

And: How snugly does it fit around your head while you're waiting for it to fill? Could the argon be escaping out gaps in the opening? What happens if you tape or hold the bag tightly shut (without your head in it) - does the bag fill any faster?

Sorry my thoughts on this are so primitive but if everything else checks out ... blame Glad bags

 

[TiredHorse]

I'm afraid I have nothing to add to the conversation: I'm completely baffled.

Flow rate is flow rate; tubing size shouldn't matter if the gauge reads 15 LPM. Besides, it's O2 tubing, and O2 is commonly delivered at 15 LPM.

You're using an argon regulator (new, presumably fully functional) with argon gas, so that's certainly not the problem. The componants all match.

You flowmeter is reading 15 LPM. Which means everything should be fine from the cylinder to the tubing; the problem is downstream from the flowmeter.

As a wild guess, I would have to tentatively agree with @Soul that maybe the bag is at fault? Perhaps you could test the bag by inflating it with your breath, as if it were a balloon? Was the elastic really snug around your head as you were inflating the bag? But I'm guessing.

Ten minutes is a very long time. The two minutes it ought to take can feel like an eternity, but that's a different matter.

 

[dyingispeaceful]

I'm pretty sure that Kilopascal translates directly to bar, so 16500 kPa is 165 bar. If the tank is rated for 300bar / 30000 kPa you have almost half the pressure you should have. That could be a possible reason. Also I can't find any other information on the regulator regarding pressure rating. Other than that I really don't have any other idea why this shouldn't work.

Here in germany we have a tüv certification for each component to guarantee that the work together.

The tank is rated 16500 kPa on the website but 300 Bar on the bottle. Yes, this is quite inconsistent and is worrying me a bit but thanks for pointing it out.

@Soul @TiredHorse

I tried to test the exit bag on a steel bottle(instead of my head). I tightened it to the extreme. The bag FILLED in about 1.5 mins.I thought that(and supported by your comments) that the elastic prolly wasn't snug around my head(touching my forehead and above my ears). So I proceeded to test if that indeed was the problem.

BEFORE, the elastic seemed to fit really well on my head(not very tight and definitely not loose). It was quite easy to pull down later(but that of course didn't work)
So I gradually started tightening the elastic around my head and stopped after 2 mins. The next 6 attempts all failed but the bag seemed to have filled more.
In my 7th try, the bag filled in just about 2 mins. Here, the elastic was so tight that it hurt(just a little bit though, although I did get elastic marks on my forehead). When time came to pull down, it was DEFINITELY IMPOSSIBLE TO JUST PULL IT DOWN. I had to stretch it from both ends around my ears and then pull it down(after crumpling the bag). Pulled down, it seemed to be quite tight, but I could still put up to 3 fingers quite easily from around my neck, not so easily from the side(putting 1 was easy though). Obviously it was colliding with my nose(in my method's defense some people have told me I have a big nose, but they're from China so....). Anyways, after loosening the elastic ALOT, I was able to remove the bag and noticed it had teared from the front(prolly because of my need to stretch it to pull it down because it was really tight around my forehead).

This is my only try that filled the bag in 2 mins. However, it tore the bag as well and I can't afford that in my final attempt. My tightening increments were also gradual and not that sudden. My head is also quite average sized. What do you think is going wrong? Is it supposed to be that tight? If you have tried attempting it(at least TiredHorse has), how easy or had it is for you to pull the bag down? How much do you have to stretch it?

 

[Roger]

Argon is heavier than air and will leak from bottom of bag ?

 

[TiredHorse]

Wow! Well, I guess that revealed the problem, but I'm surprised at how much trouble the bag gave you.

If you have tried attempting it(at least TiredHorse has), how easy or had it is for you to pull the bag down?

For me, using the same size bag (I think; the largest size the market carried, anyway), it was easy to pull the bag down. I had the elastic band below my ears to begin with, and just above my eyebrows (like a shower cap), but it certainly wasn't so tight that it hurt or left marks, and there was plenty of room left for me to pull it down over my face.

I don't know what to say.

With the elastic band all the way loose, how much room do you have to pull the bag down? Could it be that you need a larger bag, or is it specifically a drawcord problem?

 

[dyingispeaceful]

Argon is heavier than air and will leak from bottom of bag ?

That's what I've been thinking as well. Maybe it would have be much more simpler with Nitrogen.

With the elastic band all the way loose, how much room do you have to pull the bag down? Could it be that you need a larger bag, or is it specifically a drawcord problem?

With the elastic band all the way loose, there is PLENTY of room to pull the bag down.

I don't know If I need a larger bag. My head fits perfectly and I have quite some space when I don't tighten it, and still some when I tighten it like in my first try(where the gas was prolly going leaving). What do you think?

I don't think it can be an elastic problem as it is fitted perfectly along the edge of the bag. It tightens and loosens quite well too. I'm using 10mm elastic. Following is the link: ebay.com.au/itm/322135311459 But what do you think?

 

[TiredHorse]

What do you think?

I'm afraid I simply don't know. I used almost the exact same elastic --3/8"-- in what is probably the exact same bag, and didn't have any trouble. I doubt your hair or its styling could have any effect on how the bag fits, could it?

Maybe @Roger is right and it's a question of Ar being heavier than the N2 I used? That doesn't feel right, though. I have difficulty accepting that that much Ar would leak out that fast.

I am baffled.

 

[dyingispeaceful]

@TiredHorse @Honigwaffel @Soul @Roger
So I seemed to have solved my problem and will point out 2 mistakes I noticed I had made. Hopefully, others can avoid them.

1) I didn't fold the bag inside out during the process of attaching the hose to the exit bag. I just inserted my hands inside the bag and taped the hose(wrong way). I believe folding the bag inside out is very important as it's quite difficult to stick the hose while putting our hands all the way in the bag, and even if one does, there is a great chance of bag getting crumply and tight(because of the surface not being completely flat while taping and/or taping micro alpha sheets of the bag together).

2) With the new bag that I created and incorporating the process I mentioned in step 1, I found it a lot helpful to position the bag like a shower cap as mentioned by TiredHorse. This definitely helped me as I didn't have to stretch the bag before pulling it down because first I was placing it above my ears(but my new bag seemed to have a lot more space as well). This might not apply to everyone but I guess there is no harm in following this rule as it makes pulling the bag down a lot easier.

I've don't 5 trials now and all have passed.

 

[TiredHorse]

Five trials, all passed, is reassuring news. I'm glad you had such success in troubleshooting --and thank you for posting your discoveries!

 

[Soul]

Thank you for the update - I hope there's some argon left after all the experiments!

 

[Honigwaffel]

Thank you @dyingispeaceful for the update. These are exactly the information this forum needs, very useful for the community. Five succesful tests is wonderful news, I'm glad it's working now for you. All the best

 

[dyingispeaceful]

Thank you for the update - I hope there's some argon left after all the experiments!

Approx 75 L of Argon were left. I did another 2 trial runs and let the rest escape. Got the bottle refilled this afternoon :)

I'm pretty sure that Kilopascal translates directly to bar, so 16500 kPa is 165 bar. If the tank is rated for 300bar / 30000 kPa you have almost half the pressure you should have.

Could someone comment on this? My tank is rated as 16500 kPa but 300 bar. It lasted approx 40 mins but I'm still wondering about the inconsistency. @TiredHorse?

 

[Soul]

Just curious: Could a soul fill a bathtub with argon and lie down in it instead of using an exit bag? With sufficient sedatives to fall asleep before SI made the soul climb out? Would a set-up like that endanger the neighbours? (And purely in the realm of Inquiring Minds Want to Know: Would argon go down the drain if one unplugged it afterwards?)

 

[Superfluous]

Just curious: Could a soul fill a bathtub with argon and lie down in it instead of using an exit bag? With sufficient sedatives to fall asleep before SI made the soul climb out? Would a set-up like that endanger the neighbours? (And purely in the realm of Inquiring Minds Want to Know: Would argon go down the drain if one unplugged it afterwards?)

No, a Soul would fail with this method. Firstly, when a Soul enters the bath, they would create turbulence. Secondly, a Soul would exhale CO2, which I believe is more dense than argon, and the act of a Soul breathing would also create turbulence. Finally, we would miss a Soul

 

[TiredHorse]

Could someone comment on this? My tank is rated as 16500 kPa but 300 bar. It lasted approx 40 mins but I'm still wondering about the inconsistency. @TiredHorse?

I'm afraid I'm no use here. I have no idea why a tank would be rated both X and 1.8X. But I'm both US and old school --I still think in terms of PSI-- so I may be missing something obvious.

 

[Superfluous]

I'm afraid I'm no use here. I have no idea why a tank would be rated both X and 1.8X. But I'm both US and old school --I still think in terms of PSI-- so I may be missing something obvious.

I also spent some time researching the specific cylinder you have, and just couldn't find the specs. Makes no sense to me. Wish I could have been of more help.

 

[dyingispeaceful]

I also spent some time researching the specific cylinder you have, and just couldn't find the specs. Makes no sense to me. Wish I could have been of more help.

Thanks and no worries. As long as it works fine, its good.

 

[RememberWhatUCameFor]

https://www.quora.com/Is-argon-heavier-than-air

argon is indeed havier then air in opposite to helium


should argon even been used with a bag then? a mask would be probably way better then

 

[johndoe1954]

didn't fold the bag inside out

Why does this matter?

What type of bag you using?

 

[justamortal]

thankyou very much