Resource Inert Gas Experts Out There

[Kbeau]

In the US.

Time to start getting materials together. I think Inert Gas methods are intimidating for people because of the technical nature, most of us don't know anything about compressed gas, regulators, flowmeters etc.

As my starting point, I want to understand and get the Nitrogen tank.

Unless I'm mistaken, Exit recommends a 20 cu ft nitrogen cylinder type 0916-0145. I can find those online. Do they, or can they be purchased and delivered filled or do they have to be filled locally? If it costs $150-ish, it is probably arriving filled?

Do either the tank size or the LPM target change depending on which specific method you're using (e.g., plastic bag vs scuba/self-contained stuff)?

There are many posts on this topic but I get confused and hear different things. Any advice/knowledge here would be very much appreciated!

 

[devils~advocate]

In the US, getting a cylinder should be straight forward.
I would suggest getting the cylinder from a retailer. Go and visit them, tell them what you want.
You dont have to tell them what it is for, obviously.
But make up something... I told them I was using it for electronics & computer tests (non-oxidizing environments etc).

A 20 cf cylinder would work, but I'd recommend getting a 40 cf. This should be good for any method.
In my case, it was 40 cf of N (food or medical grade 99% pure).

Cylinder size is something to consider regarding the method. Just by intuition. Obviously I can't test this.
Exit Bag / Hood - is a constant flow system. The gas flows constantly without interruption....if one breathes in or not.
SCBA - is a controlled flow system. The gas flows based if one breathes in or not. It is much more efficient compared to the above.

For the hood method, since it is constant flow......the gas will flow into the hood even one is not breathing it in. Some of it will get wasted.
It is basically flooding the hood with inert gas & making it so no oxygen can enter the breathing area.
Intuition, suggests that one have as much quantity of gas as needed due to that some will get wasted.
Hence, getting the largest cylinder size you can afford and transport.

Ive made several visual diagrams of various systems.
I have more if interested.

Below is one that uses a hood. A home made exit bag would be the same principle.

 

[SummerSolesLongLost]

20 or 40 will both work, most say go with the 40 so you have some more room for testing and whatnot. That said people have done it with far less. You normaly buy in a store since shiping the gas is hard but if you call a local place they may be willing to drop it off at your house for a fee.

 

[Kbeau]

In the US, getting a cylinder should be straight forward.
I would suggest getting the cylinder from a retailer. Go and visit them, tell them what you want.
You dont have to tell them what it is for, obviously.
But make up something... I told them I was using it for electronics & computer tests (non-oxidizing environments etc).

A 20 cf cylinder would work, but I'd recommend getting a 40 cf. This should be good for any method.
In my case, it was 40 cf of N (food or medical grade 99% pure).

Cylinder size is something to consider regarding the method. Just by intuition. Obviously I can't test this.
Exit Bag / Hood - is a constant flow system. The gas flows constantly without interruption....if one breathes in or not.
SCBA - is a controlled flow system. The gas flows based if one breathes in or not. It is much more efficient compared to the above.

For the hood method, since it is constant flow......the gas will flow into the hood even one is not breathing it in. Some of it will get wasted.
It is basically flooding the hood with inert gas & making it so no oxygen can enter the breathing area.
Intuition, suggests that one have as much quantity of gas as needed due to that some will get wasted.
Hence, getting the largest cylinder size you can afford and transport.

Ive made several visual diagrams of various systems.
I have more if interested.

Below is one that uses a hood. A home made exit bag would be the same principle.

Thank you! I'm sure I'll hit you with a few follow-up questions!

 

[E5463656]

In the US, getting a cylinder should be straight forward.
I would suggest getting the cylinder from a retailer. Go and visit them, tell them what you want.
You dont have to tell them what it is for, obviously.
But make up something... I told them I was using it for electronics & computer tests (non-oxidizing environments etc).

A 20 cf cylinder would work, but I'd recommend getting a 40 cf. This should be good for any method.
In my case, it was 40 cf of N (food or medical grade 99% pure).

Cylinder size is something to consider regarding the method. Just by intuition. Obviously I can't test this.
Exit Bag / Hood - is a constant flow system. The gas flows constantly without interruption....if one breathes in or not.
SCBA - is a controlled flow system. The gas flows based if one breathes in or not. It is much more efficient compared to the above.

For the hood method, since it is constant flow......the gas will flow into the hood even one is not breathing it in. Some of it will get wasted.
It is basically flooding the hood with inert gas & making it so no oxygen can enter the breathing area.
Intuition, suggests that one have as much quantity of gas as needed due to that some will get wasted.
Hence, getting the largest cylinder size you can afford and transport.

Ive made several visual diagrams of various systems.
I have more if interested.

Below is one that uses a hood. A home made exit bag would be the same principle.

can you dm me?

 

[Kbeau]

In the US, getting a cylinder should be straight forward.
I would suggest getting the cylinder from a retailer. Go and visit them, tell them what you want.
You dont have to tell them what it is for, obviously.
But make up something... I told them I was using it for electronics & computer tests (non-oxidizing environments etc).

A 20 cf cylinder would work, but I'd recommend getting a 40 cf. This should be good for any method.
In my case, it was 40 cf of N (food or medical grade 99% pure).

Cylinder size is something to consider regarding the method. Just by intuition. Obviously I can't test this.
Exit Bag / Hood - is a constant flow system. The gas flows constantly without interruption....if one breathes in or not.
SCBA - is a controlled flow system. The gas flows based if one breathes in or not. It is much more efficient compared to the above.

For the hood method, since it is constant flow......the gas will flow into the hood even one is not breathing it in. Some of it will get wasted.
It is basically flooding the hood with inert gas & making it so no oxygen can enter the breathing area.
Intuition, suggests that one have as much quantity of gas as needed due to that some will get wasted.
Hence, getting the largest cylinder size you can afford and transport.

Ive made several visual diagrams of various systems.
I have more if interested.

Below is one that uses a hood. A home made exit bag would be the same principle.

I don't know if you know the answers but a few questions: 1) The hood appears to be Allegro 9910 Tyvek (or a knockoff) I don't see any exhale valve/don't think it has one. Wouldn't we want a hood with an exhale valve so the CO2 leaves the hood to minimize any SI? 2) There is some text and numbers shown along with the regulator that I can't read. What is it instructing? My (tentative) understanding is that you fully open the nitrogen cylinder (with the regulator attached) and adjust the regulator/Flowmeter to be delivering 25 lpm nitrogen. Is that correct?

 

[devils~advocate]

I don't know if you know the answers but a few questions: 1) The hood appears to be Allegro 9910 Tyvek (or a knockoff) I don't see any exhale valve/don't think it has one. Wouldn't we want a hood with an exhale valve so the CO2 leaves the hood to minimize any SI? 2) There is some text and numbers shown along with the regulator that I can't read. What is it instructing? My (tentative) understanding is that you fully open the nitrogen cylinder (with the regulator attached) and adjust the regulator/Flowmeter to be delivering 25 lpm nitrogen. Is that correct?

1) Yes, the hood used in the example above is that particular brand and model. But it could be any other hood as well.
Im not sure if it has an exhale valve. I think these types of hoods work by using compressed air to displace any outside air or CO2.

2) Yes you are correct, full open cylinder. 25 lpm is the standard that is mentioned in this forum.
I think at the time I made this image, I was attempting to get regulator parameters for a scba system.
Most scba systems seem to use a higher flow....


This is what I have for the text....but ignore for a hood system.
If someone can compute the correct parameters, I can update this information for a hood system.

 

[txjambi]

Would two of these be enough to finish the job...

High Purity Helium Tank 99.99% (19g / 106 liters)

Helium Tank High Purity 99.99% Pure Made in Italy Our high purity helium tank arrives filled with 103 liters of compressed helium gas. The gas can be removed using our regulator or valve dispenser that attaches to the top of the tank. Tank Thread: M11 x 1.0 Regulator Thread: M11 x 1.0...

shopbvv.com

 

[devils~advocate]

Would two of these be enough to finish the job...

High Purity Helium Tank 99.99% (19g / 106 liters)

Helium Tank High Purity 99.99% Pure Made in Italy Our high purity helium tank arrives filled with 103 liters of compressed helium gas. The gas can be removed using our regulator or valve dispenser that attaches to the top of the tank. Tank Thread: M11 x 1.0 Regulator Thread: M11 x 1.0...

shopbvv.com

Not in my opinion. These are small.....103 Liters / 27 Gallons / 3.6 cubic feet
I'd say a minimum of 40 cubic feet or 1200 liters or 1.2 m3 size.
Bigger than this is always better.

 

[Kbeau]

Would two of these be enough to finish the job...

High Purity Helium Tank 99.99% (19g / 106 liters)

Helium Tank High Purity 99.99% Pure Made in Italy Our high purity helium tank arrives filled with 103 liters of compressed helium gas. The gas can be removed using our regulator or valve dispenser that attaches to the top of the tank. Tank Thread: M11 x 1.0 Regulator Thread: M11 x 1.0...

shopbvv.com

I don't think so. What exactly is your method?

 

[devils~advocate]

I don't think so. What exactly is your method?

I guess they are proposing an inert gas method...I would assume a hood method with helium.

The cylinders linked in their message are too small. They are only 3.6cf or 106 liters each.
These won't last long.....two of them would last about 10 minutes maximum (assuming 20 lpm flow)
And that is assuming everything is perfect.

Recommend at least 500 liters.....just for time purposes. The larger the cylinder the more time allowed.
Im not familiar with UK or EU cylinder sizes....maybe someone can elaborate.

One needs as much gas flow for ctb due to hypoxia.
So I'd say at least 15-20 minutes of flow...at 20 lpm minimum

 

[Kbeau]

I guess they are proposing an inert gas method...I would assume a hood method with helium.

The cylinders linked in their message are too small. They are only 3.6cf or 106 liters each.
These won't last long.....two of them would last about 10 minutes maximum (assuming 20 lpm flow)
And that is assuming everything is perfect.

Recommend at least 500 liters.....just for time purposes. The larger the cylinder the more time allowed.
Im not familiar with UK or EU cylinder sizes....maybe someone can elaborate.

One needs as much gas flow for ctb due to hypoxia.
So I'd say at least 15-20 minutes of flow...at 20 lpm minimum

Yes, I was wondering if it's bag or hood which affects the flow rate, although this would be too little irrespective I think. I'm also concerned if they have done enough research or are going a little too impulsively and risking a failure. I don't know how you control flow rate on these little cylinders, and managing 2 of them at the same time.

 

[devils~advocate]

Yes, I was wondering if it's bag or hood which affects the flow rate, although this would be too little irrespective I think. I'm also concerned if they have done enough research or are going a little too impulsively and risking a failure. I don't know how you control flow rate on these little cylinders, and managing 2 of them at the same time.

I thought the way a bag and hood functioned was the same (?) Same about of internal volume etc. I may have them confused.
The bag is hand made while a hood is manufactured (?).

But yes having two cylinders connected together in series would be a challenge...if one is not familiar with fittings etc.
I agree, recommend getting a larger cylinder and take that possible problem of two working together out of the equation.

 

[ocean2200reef]

Hello, I am going to ctb this Monday using the oceanreef scuba mask with nitrogen, my nitrogen is %100 pure, I was just wondering if anyone know how to test the connections for leaks when using ocean reef mask, I wanna do the soapy water and hiss test but idk if your supposed open the valve all the way or just a little and for how long? Also am in the usa and the adapter for it has to be to pieces that your screw together and my pieces won't screw all the way, there is still a few visible threads and I made sure I purchased the correct ones.

 

[Kbeau]

Hello, I am going to ctb this Monday using the oceanreef scuba mask with nitrogen, my nitrogen is %100 pure, I was just wondering if anyone know how to test the connections for leaks when using ocean reef mask, I wanna do the soapy water and hiss test but idk if your supposed open the valve all the way or just a little and for how long? Also am in the usa and the adapter for it has to be to pieces that your screw together and my pieces won't screw all the way, there is still a few visible threads and I made sure I purchased the correct ones.

Unfortunately I don't know much about SCUBA/masks. If you don't get a response here I'd repost on the Inert gas Megathread

 

[Jay_AU]

I'm finding ebay sellers in my country with 2.2L Nitrogen, including a regulator and hose, for around $100 AUD. The claim is 9/lpm for around 30 minutes. Rather than fool around with one regulator and two tanks, two regulators and two tanks seems like a better option, as I can no doubt find a t-splitter to join both hoses (Im presuming I would need to buy 2 x 2.2L tanks, as the flow rate may not be enough with a single unit.

 

[devils~advocate]

For the threads on metal fittings... you can use PTFE thread seal tape. Its sold in all hardware stores.
There is also pneumatic thread sealant. Its in a liquid form that goes on the threads and seals them up air tight once the fittings are connected.

PTFE thread seal tape is a white stretchable tape that doesnt btw have an adhesive


Pneumatic thread sealant is a red bottle. Search on web, you'll see the brand.