Method Exit bag and inert gas megathread

[ClownWorld2023]

Where are you from?

Europe.

 

[DeadHead]

Hate to be a nuisance asking retarded questions, but a while back I thought I made some notes (which I now can't find) - something to do with how the inlet pressure of the regulator relates to the bar of the nitrogen tank. If someone could kindly remind me what the relevance of this is and what I need to check for in terms of pressure before I buy the regulator, I'd appreciate it.
I have a 9l nitrogen tank at 137 bar. Thanks in advance.

 

[anonaon]

Not sure if this is what ur looking for but your regulator must be able to support the cylinder's working pressure. For examply, if you're cylinder operates at 200bar (2216psi) and your regulator is desgined for 150bar (2015psi), you'll need to bleed out some of the gas b4 using it with the regulator.

 

[ztem]

I buy the regulator

If you want to buy this regulator, buy it, that's the right regulator.

I use nitrogen and the GasMonkeys method, with Lung Demand Valve and SCBA!

My nitrogen bottle has 5 liters at 200 bar. How long will the contents last, assuming continuous breathing?

I feel like a broken record repeating what GasMonkey mentioned +10 times. Just search the word negative or positive pressure and see GasMonkey's posts, He repeated the same thing several times and now I'm repeating the same thing again. With on-demand systems(SCBA/SCUBA), how much gas you will consume depends entirely on your breathing rate before and after unconsciousness and when you stop breathing.With negative pressure, when your breathing(inhalation)stops, you don't create a negative pressure inside the mask, and as a result, gas consumption is zero. With positive pressure, when your breathing(inhalation)stops, the positive pressure inside the mask will no longer decrease, that's why we say on-demand system.Even if you assume that Slovakguy's cylinder was 6L/200bar, he consumed 678 liters of gas, a 5L/200bar is 1000L of gas.

warn due to the high pressure

You should silence the low pressure whistle.

 

[ClownWorld2023]

CO2 buildup not relevant for EEBD hood at all, because it's purged through the exhale valve?

Do I need to worry about stuff like the visor mask not sealing properly, and leaking exhaled air into the hood?

 

[DeadHead]

Not sure if this is what ur looking for but your regulator must be able to support the cylinder's working pressure. For examply, if you're cylinder operates at 200bar (2216psi) and your regulator is desgined for 150bar (2015psi), you'll need to bleed out some of the gas b4 using it with the regulator.

So if my tank is 137 bar, what must the outlet pressure of the regulator be?

 

[NoFutureAnymore]

So if my tank is 137 bar, what must the outlet pressure of the regulator be?

The regulator has to support a pressure equal or higher then 137 bar. That seems to be the general rule of thumb for all inert gas methods. A higher cylinder pressure can damage equipement, but lower pressure can't. If you think logically, the pressure will always go down in the cylinder while using gas. The second thing you have to look at are the connection sizes which have to match between equipement and cylinder.

 

[anonaon]

CO2 buildup not relevant for EEBD hood at all, because it's purged through the exhale valve?

Correct

Do I need to worry about stuff like the visor mask not sealing properly, and leaking exhaled air into the hood?

No, the hood's quite durable. Just dont crumple it in storage

So if my tank is 137 bar, what must the outlet pressure of the regulator be?

137 or above but dont worry about this. If your regulator is designed for its respective gas, it'll work. Otherwise welders would be out of jobs

 

[dustinspector]

What regulator would I need for a 125cu/ft tank of Nitrogen?

 

[Mare Imbrium]

What is the right size of an exit bag?

I have to sizes of oven bags - 43x45 cm, which is too small for me, and 55x60 cm, which is too big.

What is your opininion? Which size do you have?

 

[bythefire12]

I don't really understand how this all works despite reading for EEBD hood.

First, I need to find a place that sells a Drager hood.

Then I need a ACU-200 Regulator. The only one I found is argon/co2. Will that be a problem?

Then I need two couplers: CEJN, 1/4NPT, Series 344, and a male-male CGA-032 to 1/4".

The regulator connects directly to the nitrogen tank? Then one of those couplers connects to the regulator, and another to the mask hose? Then you connect the coupler coming out of the regulator to the one at the end of the mask hose?

Am I even in the right ballpark? I've never worked with any of this stuff.

 

[ztem]

Cylinder<->Regulator<->CGA-032 to 1/4" NPT<-> Drager CEJN 344 with 1/4" NPT"<->Hood

Will that be a problem?

Never.

The regulator connects directly to the nitrogen tank?

Y.

 

[bythefire12]

Does anyone know good places to get the Drager hood?

 

[ExpiredLion]

The bouncing ball flow meter that I have attaches at an angle to my regulator. Is it safe to slightly tilt the tank in order to get the flow meter to be totally perpendicular with the ground and adjust the rate that way? Since otherwise I would think the flow rate is not going to be accurate if it is tilted and having gravity act on the ball at an angle.

I'm unable to upload a picture but essentially it is one of those test tube looking flow meters like this https://www.wtfarley.com/assets/images/other flowmeters/nf-1b21.jpg and the regulator looks like this https://m.media-amazon.com/images/I/61OKqxZf3qL._AC_UF894,1000_QL80_.jpg

 

[ClownWorld2023]

What is the right size of an exit bag?

I have to sizes of oven bags - 43x45 cm, which is too small for me, and 55x60 cm, which is too big.

What is your opininion? Which size do you have?

I had ordered multiple sizes myself. My 43x55 bags fit best.

Does anyone know good places to get the Drager hood?

What region? US , EU ?

 

[Mare Imbrium]

Thanks for information.
For me seems 43x55 cm small, maybe because my seam is broad.
55x60 gives a good space for nose and mouth.

 

[ClownWorld2023]

Thanks for information.
For me seems 43x55 cm small, maybe because my seam is broad.
55x60 gives a good space for nose and mouth.

If pre-filled properly then that should work fine.

 

[Mare Imbrium]

Will you use this bag for your ctb?
Did you already made a "blackout test"?

 

[ClownWorld2023]

Will you use this bag for your ctb?
Did you already made a "blackout tesr"?

I will most likely use an EEBD hood.

I did not do a blackout test yet.

 

[Mare Imbrium]

Is for you the exit bag too unsecure?

 

[DeadHead]

Correct


No, the hood's quite durable. Just dont crumple it in storage


137 or above but dont worry about this. If your regulator is designed for its respective gas, it'll work. Otherwise welders would be out of jobs

It's not, it's a argon reg that I'd be using with a nitrogen tank. Vendor claims you can't use the reg for nitrogen, but as far as I know you can

 

[ClownWorld2023]

Is for you the exit bag too unsecure?

Yes I rather use something more straightforward.

Too much ambiguity involved with the plastic bag.

 

[ztem]

I don't recommend the Drager PSS rescue hood anymore.Two people bought it and have problems with the hood's exhalation valve.From now on, only use hoods that have an internal mask like the Chinese(used by EM's customers and Vizzy and bennydiazapine) or Drager Saver CF or 3M Scott.

 

[MG_39]

I don't recommend the Drager PSS rescue hood anymore.Two people bought it and have problems with the hood's exhalation valve.From now on, only use hoods that have an internal mask like the Chinese(used by EM's customers and Vizzy and bennydiazapine) or Drager Saver CF or 3M Scott.

Do you know if the 3M Scott male coupler is the same as Dräger PSS? (And yes I know I can cut it off and use a barb fitting on my regulator instead, or cut it off and replace the male coupler.)

I can't find any information about the 3M Scott coupler except that it's a CEJN 340 series, my female coupler for my regulator is a Rectus though, and struggle to find good data sheets. But I know I have the correct female coupler for Dräger PSS.

 

[ztem]

my female coupler for my regulator is a Rectus

That's compatible with the 3M Scott.

if the 3M Scott male coupler is the same as Dräger PSS?

The plug of those two hoods are not the same, the Drager's plug is CEJN 344 and the 3M Scott's plug is CEJN 340 and both of them are compatible with the Rectus 95KS coupler.

 

[MG_39]

That's compatible with the 3M Scott.

The plug of those two hoods are not the same, the Drager's plug is CEJN 344 and the 3M Scott's plug is CEJN 340 and both of them are compatible with the Rectus 95KS coupler.

I'm sorry, but I'm confused what you mean. CEJN 340 = DN 6.2mm, CEJN 344 = DN 7.4mm
The DN for Rectus 95KS coupler is 7.4mm (Or is the difference between them the bore?)

Of course this is not a problem, since I can just replace the hose barb with a Rectus 95SSTF*DIA* But still curious how both 340 and 344 could fit 95KS.

 

[ztem]

I'm sorry, but I'm confused what you mean. CEJN 340 = DN 6.2mm, CEJN 344 = DN 7.4mm
The DN for Rectus 95KS coupler is 7.4mm (Or is the difference between them the bore?)

There is no problem using a 7.4mm coupler with that plug.Two people used it and had no problems.

Of course this is not a problem, since I can just replace the hose barb with a Rectus 95SSTF*DIA*

Never do that.The reason you buy that hood is that you don't need to modify the hose. if you want to modify the hose, there are cheaper hoods to buy. You just need a Rectus 95KS (If you are in Europe , with G1/4 or G3/8 thread ‌depends on the outlet thread of your reg).

still curious how both 340 and 344 could fit 95KS.

Because of its design.

 

[MG_39]

There is no problem using a 7.4mm coupler with that plug.Two people used it and had no problems.

Never do that.The reason you buy that hood is that you don't need to modify the hose. if you want to modify the hose, there are cheaper hoods to buy. You just need a Rectus 95KS (If you are in Europe , with G1/4 or G3/8 thread ‌depends on the outlet thread of your reg).

Because of its design.

If 6.2mm and 7.4mm is the nominal flow diameter, and the male exterior dimensions is the same, then they will most likely be interchangeable yes. Otherwise they will NOT, and it would be insanely stupid to not replace the barb fitting (which isn't rocket science)

Tbh, skipping the coupler and just use the correct size hose barb instead is certainly not a bad alternative. I have never ever had a connection like that leaking with any kinds of gas, even though I replaced bottles for oxygen, acetylene, mison, argon A LOT of times. Sure I never had a CEJN coupler (For compressed air, never used for gas) leaking either when NEW, but a lot of old ones that started to leak. But it feels like it just adds one more thing that could potentially cause problems, even though it's very unlikely.

 

[ztem]

If 6.2mm and 7.4mm is the nominal flow diameter

Yes that's the nominal diameter (ID) , aslo known as the basic flow size.

and the male exterior dimensions is the same, then they will most likely be interchangeable yes. Otherwise they will NOT

The Rectus 95KS acts as a universal socket for both plugs.

and it would be insanely stupid to not replace the barb fitting (which isn't rocket science)

You are confusing concepts, there's no need for this or this or this or this, you just need this and that's it.

skipping the coupler and just use the correct size hose barb instead is certainly not a bad alternative. I have never ever had a connection like that leaking with any kinds of gas

I never said that modifying the hose (using teflon tape for NPT/BSPT connections, hose clamps, barbed fittings...etc) is bad , In fact, I have said several times in the past that there is nothing wrong with using them because some people think that using these things just adds another point of failure but what you are constantly thinking about is nonsense, you want to modify a plug and play setup and that would be insanely stupid, the hose is long enough and has a ready to use plug. Again, you just need to connect the coupler's thread to the reg's outlet and then connect the hood's plug like this to it and that's it , I can't explain it simpler than that. But as I said before, do whatever gives you peace of mind , higher flow rates AKA 40LPM, bigger cylinders, with or without barbed fittings, with or without couplers..etc , when and how you want to CTB is not my concern and business.

Sure I never had a CEJN coupler (For compressed air, never used for gas) leaking either when NEW, but a lot of old ones that started to leak. But it feels like it just adds one more thing that could potentially cause problems, even though it's very unlikely.

Another mental gymnastics, you only want to use it once and you don't even need to think about it leaking even if it's a cheap and low quality coupler.

 

[Dmoore3232]

Would these EWOT masks work? How does the CO2 get let out? Where does that go?