ShatteredSerenity
I talk to God, but the sky is empty.
- Nov 24, 2024
- 6
I just thought I'd share a description of the gear I put together for inert gas asphyxiation with nitrogen and an exit bag. It's pretty basic since I felt it would be better to start with something simple and functional, then upgrade to SCBA/SCUBA or something else in the future if I have time and can obtain parts.
I'm located in a suburb in Washington State, and it was straightforward to find everything I needed either locally or online with 1-2 day delivery. For the things I needed to order online, I had them delivered to an Amazon Locker nearby to avoid any awkward questions since I live with my family.
Here's the tank, regulator, and hose:
The nitrogen tank was easy to buy at a local welding supply store. I had never bought compressed gas before so I was a little nervous, but everything went smoothly in the end. Before going to the store I did do some research into using nitrogen for home brewing in order to have a plausible cover story in case they asked what I was planning to use it for. I'm glad I did because they asked twice and the cover story worked flawlessly both times.
I tried asking about the purity of the nitrogen, and they just said said it was industrial grade (which doesn't mean much if anything). Then they asked what I was using it for, and I said I'm getting into home brewing. That got her chatting about a customer who gets little bottles of nitrogen for wine, and she said it works great for that so it should be perfect for my needs too. That didn't exactly help me satisfy my concern about purity, but it at least deflected her away from the topic of what I'm actually planning to use it for. I ended up tested the purity of the nitrogen myself with an oxygen meter and it contained 0.0% oxygen, which is about as pure as it gets for my purpose since all I care about is oxygen contamination.
When I went to buy the tank I asked what sizes they had in stock, so again they asked what I needed it for, and I responded that I was putting together a home brew system. The guy got interested so he asked what kind of beer, which stumped me (I rarely drink) so I just said my wife handles that part we hand't decided yet. They had 40 CF and 55 CF cylinders in stock, I was waffling between the 2 sizes but I ended up going with the 40 CF cylinder since it was shorter and easier to hide.
I decided to go with a combination pressure regulator and flow meter for simplicity. There are some very cheap regulators available on Amazon, but I was afraid they might be too cheap, and in particular I was concerned about it being too noisy. The regulator I chose was significantly more expensive, but not terribly expensive, and it's made by one of the main reputable welding supply manufactuers. It's well built, easy to adjust, and very quiet.
The flow regulator scales are calibrated for argon and CO2, not nitrogen, but the manufacturer provides a conversion table for a variety of inert gasses so that's not a problem. Nitrogen is lighter and less dense than argon, so for a given reading on the flow meter's argon scale, there will actually be more nitrogen flowing through the meter. According to the table below, approximately 1.19 times more nitrogen to be precise.
Most guidelines specify to use a 15 LPM flow rate to the exit bag, but the meter's scale is calibrated in units of SCFH (Standard Cubic Feet per Hour) instead of LPM, so you need multiply by the conversion factor 2.12 which produces a target rate of 31.8 SCFH. I rounded up to 32 SCFH for simplicity.
To get 32 SCFH of nitrogen flowing, we divide by the conversion factor 1.19 from the table below to get 26.9 SCFH on the argon scale. I stuck a piece of tape on the meter and marked it with a red pen to make it easy to set the target flow rate when I'm ready to use it.
The regulator did not include any sort of hose connection, just a 5/8" - 18 female outlet. I tried searching for fittings in the local hardware stores, but it turns out this is a pretty specialized connector type specific to inert gas, so I ended up having to go to a big gas supplier in the industrial part of town to find it. You'll probably want to order this online, unless they happen to stock it at the place you buy your nitrogen from (the welding shops I checked didn't have it either). The part you need is called an "inert gas nut and nipple." The kit they sold me came with a hose clamp, a 5/8" - 18 nut, and a barbed nipple sized for 1/4" ID hose.
I picked up 1/4" ID x 10 ft PVC clear vinyl tubing at the local hardware store. It's flexible enough and it doesn't have any smell, so it seems fine for this application. The hose clamp included with the inert gas nipple was too large for this tubing, so I also had to get a smaller one from the hardware store. I had to run the end of the tubing under very hot water for a while to soften it up enough to push on the nipple.
This is how nut and nipple look (if you shop online it may not include the hose clamp on the left, which is fine since it would proably be the wrong size anyways):
I bought an oxygen meter from an online store to test the gas. In the photo below the meter reads 20.1% oxygen in my house's ambient air. When I piped some nitrogen gas into the meter's inlet the oxygen reading went all the way down to 0.0, so I'm content with the purity of the gas in my tank. When the oxygen content droped to dangerous levels it started flasing red lights and beeping VERY loudly, which was super annoying and something you'll definitely want to watch out for if you use the meter with other people around.
The exit bag itself is a 19 in x 23.5 in (482 mm x 596 mm) turkey size oven bag. They were sold in 2 packs at the local grocery store. It's a decent thickness and reasonably flexible to cinch down around the neck. It's crinkly and certainly not the most luxurious headware for my last moments on earth, but if it comes to it this should get the job done.
I used a 1/4" elastic band from the local craft store to cinch around the neck, and I repurposed some spring loaded cord locks from an old backpack to set the neck band tightness. You want it tight enough to keep the gas in, but loose enough that gas can still flow out when you exhale.
I used 1" micropore tape from the local drug store to tape the bottom seam. It's flexible and adhered well to the plastic.
I live with family, so it's important for me to be able to hide the entire setup discreetly. Fortunately the 40 CF nitrogen tank is just short enough to fit in an old duffel I had laying around. It's nice to have a bag with an arm strap, because the full nitrogen tank is pretty heavy and awkward to carry.
My current plan is to ctb at a hotel in another city, and the rooms on upper floors require going through the lobby and taking an elevator, so it definitely will help to have the discrete duffel bag to lug the tank to my room without attracting attention. I was considering going with a 55 CF tank for extra certainty of enough gas for asphyxiation, but it would definitely require buying a taller bag, and I'd also really want something with wheels at that point.
Here's a breakdown of the materials and cost:
I'm not sure when exactly I'll ctb, but it removes uncertainty and eases my mind somewhat to at least have the means to do it in hand now.
The crinkly exit bag isn't particularly comfortable or elegant, and I would like to upgrade to a SCBA or SCUBA setup if I can source parts. I'm not sure it would be worth the extra effort and expense, though, considering that I'm only planning to be conscious in it for 30 seconds or so anyways. Upgrading my setup would give me something to work on if I decide to hold on to life a bit longer.
I'm located in a suburb in Washington State, and it was straightforward to find everything I needed either locally or online with 1-2 day delivery. For the things I needed to order online, I had them delivered to an Amazon Locker nearby to avoid any awkward questions since I live with my family.
Here's the tank, regulator, and hose:
The nitrogen tank was easy to buy at a local welding supply store. I had never bought compressed gas before so I was a little nervous, but everything went smoothly in the end. Before going to the store I did do some research into using nitrogen for home brewing in order to have a plausible cover story in case they asked what I was planning to use it for. I'm glad I did because they asked twice and the cover story worked flawlessly both times.
I tried asking about the purity of the nitrogen, and they just said said it was industrial grade (which doesn't mean much if anything). Then they asked what I was using it for, and I said I'm getting into home brewing. That got her chatting about a customer who gets little bottles of nitrogen for wine, and she said it works great for that so it should be perfect for my needs too. That didn't exactly help me satisfy my concern about purity, but it at least deflected her away from the topic of what I'm actually planning to use it for. I ended up tested the purity of the nitrogen myself with an oxygen meter and it contained 0.0% oxygen, which is about as pure as it gets for my purpose since all I care about is oxygen contamination.
When I went to buy the tank I asked what sizes they had in stock, so again they asked what I needed it for, and I responded that I was putting together a home brew system. The guy got interested so he asked what kind of beer, which stumped me (I rarely drink) so I just said my wife handles that part we hand't decided yet. They had 40 CF and 55 CF cylinders in stock, I was waffling between the 2 sizes but I ended up going with the 40 CF cylinder since it was shorter and easier to hide.
I decided to go with a combination pressure regulator and flow meter for simplicity. There are some very cheap regulators available on Amazon, but I was afraid they might be too cheap, and in particular I was concerned about it being too noisy. The regulator I chose was significantly more expensive, but not terribly expensive, and it's made by one of the main reputable welding supply manufactuers. It's well built, easy to adjust, and very quiet.
The flow regulator scales are calibrated for argon and CO2, not nitrogen, but the manufacturer provides a conversion table for a variety of inert gasses so that's not a problem. Nitrogen is lighter and less dense than argon, so for a given reading on the flow meter's argon scale, there will actually be more nitrogen flowing through the meter. According to the table below, approximately 1.19 times more nitrogen to be precise.
Most guidelines specify to use a 15 LPM flow rate to the exit bag, but the meter's scale is calibrated in units of SCFH (Standard Cubic Feet per Hour) instead of LPM, so you need multiply by the conversion factor 2.12 which produces a target rate of 31.8 SCFH. I rounded up to 32 SCFH for simplicity.
To get 32 SCFH of nitrogen flowing, we divide by the conversion factor 1.19 from the table below to get 26.9 SCFH on the argon scale. I stuck a piece of tape on the meter and marked it with a red pen to make it easy to set the target flow rate when I'm ready to use it.
The regulator did not include any sort of hose connection, just a 5/8" - 18 female outlet. I tried searching for fittings in the local hardware stores, but it turns out this is a pretty specialized connector type specific to inert gas, so I ended up having to go to a big gas supplier in the industrial part of town to find it. You'll probably want to order this online, unless they happen to stock it at the place you buy your nitrogen from (the welding shops I checked didn't have it either). The part you need is called an "inert gas nut and nipple." The kit they sold me came with a hose clamp, a 5/8" - 18 nut, and a barbed nipple sized for 1/4" ID hose.
I picked up 1/4" ID x 10 ft PVC clear vinyl tubing at the local hardware store. It's flexible enough and it doesn't have any smell, so it seems fine for this application. The hose clamp included with the inert gas nipple was too large for this tubing, so I also had to get a smaller one from the hardware store. I had to run the end of the tubing under very hot water for a while to soften it up enough to push on the nipple.
This is how nut and nipple look (if you shop online it may not include the hose clamp on the left, which is fine since it would proably be the wrong size anyways):
I bought an oxygen meter from an online store to test the gas. In the photo below the meter reads 20.1% oxygen in my house's ambient air. When I piped some nitrogen gas into the meter's inlet the oxygen reading went all the way down to 0.0, so I'm content with the purity of the gas in my tank. When the oxygen content droped to dangerous levels it started flasing red lights and beeping VERY loudly, which was super annoying and something you'll definitely want to watch out for if you use the meter with other people around.
The exit bag itself is a 19 in x 23.5 in (482 mm x 596 mm) turkey size oven bag. They were sold in 2 packs at the local grocery store. It's a decent thickness and reasonably flexible to cinch down around the neck. It's crinkly and certainly not the most luxurious headware for my last moments on earth, but if it comes to it this should get the job done.
I used a 1/4" elastic band from the local craft store to cinch around the neck, and I repurposed some spring loaded cord locks from an old backpack to set the neck band tightness. You want it tight enough to keep the gas in, but loose enough that gas can still flow out when you exhale.
I used 1" micropore tape from the local drug store to tape the bottom seam. It's flexible and adhered well to the plastic.
I live with family, so it's important for me to be able to hide the entire setup discreetly. Fortunately the 40 CF nitrogen tank is just short enough to fit in an old duffel I had laying around. It's nice to have a bag with an arm strap, because the full nitrogen tank is pretty heavy and awkward to carry.
My current plan is to ctb at a hotel in another city, and the rooms on upper floors require going through the lobby and taking an elevator, so it definitely will help to have the discrete duffel bag to lug the tank to my room without attracting attention. I was considering going with a 55 CF tank for extra certainty of enough gas for asphyxiation, but it would definitely require buying a taller bag, and I'd also really want something with wheels at that point.
Here's a breakdown of the materials and cost:
| Item | Source | Price |
|---|---|---|
| 40 CF compressed nitrogen cylinder | Welding supply shop | $204.65 |
| Inert gas flow meter regulator | Online | $126.76 |
| Oxygen detector | Online | $159.45 |
| Inert gas nut and nipple | Gas supply shop (can get online easily) | $10.16 |
| 1/4" ID x 10 ft PVC clear vinyl tubing | Hardware store | $4.69 |
| 19 in x 23.5 in (482 mm x 596 mm) turkey size oven bag | Grocery store | $3.99 |
| 1/4" elastic band | Craft store | $2.49 |
| 1" micropore tape | Drug store | $3.79 |
| plastic cord lock | Old backpack (can buy in craft store) | free |
Total | $515.98 |
I'm not sure when exactly I'll ctb, but it removes uncertainty and eases my mind somewhat to at least have the means to do it in hand now.
The crinkly exit bag isn't particularly comfortable or elegant, and I would like to upgrade to a SCBA or SCUBA setup if I can source parts. I'm not sure it would be worth the extra effort and expense, though, considering that I'm only planning to be conscious in it for 30 seconds or so anyways. Upgrading my setup would give me something to work on if I decide to hold on to life a bit longer.
