discussing details about the 'nitrogen hood' method

[lastNamePicked]

I came across a few questions regarding certain details of this method. Obviously, mistakes done during the process can be fatal in this case.

Q1: Why does the 'hood' not pop due to a constant flow of gas (15 litres/minute recommended) ?
Q2: 400 litres of gas are recommended as minimum to guarantee death. is there a possible drawback using an even larger gas cylinder (2000 litres) ?
Q3: The 'hood' is tightened around the neck to ensure the gas is not leaked. At the same time, it must not be too tightened to ensure remaining carbon dioxide is leaked. How firm should it be exactly ?
Q4: How fatal are small holes possibly in the plastic bag ?
Q5: Can someone give the dimensioning of the tubing used for this case ? (15 litres/minute) ?

Thank you in advance.

 

[TiredHorse]

Q1: Why does the 'hood' not pop due to a constant flow of gas (15 litres/minute recommended) ?

The neckband of the hood should be elastic, allowing the flow of inert gas to escape, carrying with it the CO2 you exhale.

Q2: 400 litres of gas are recommended as minimum to guarantee death. is there a possible drawback using an even larger gas cylinder (2000 litres) ?

No, there is no drawback to using a larger cylinder.

Q3: The 'hood' is tightened around the neck to ensure the gas is not leaked. At the same time, it must not be too tightened to ensure remaining carbon dioxide is leaked. How firm should it be exactly ?

Use an elastic drawcord drawn snug, but not so tight that you can't still get your fingers under it. The prefered protocol is to don the hood like a shower cap, with the elastic cord below your ears and then around your forehead, and to allow it to inflate with inert gas before pulling it down over your head. If the elastic band is tight around your forehead, it'll be at the right snugness when you pull it down and settle it around your neck.

Q4: How fatal are small holes possibly in the plastic bag ?

You want to make sure the bag does not have any small holes. That excess ventilation will throw off any standard inert gas flow rate calculations.

Q5: Can someone give the dimensioning of the tubing used for this case ? (15 litres/minute) ?

Whatever size fits on the hose barb of the flowmeter/regulator; size is not critical.

 

[Jen Erik]

Q1: Because there is not an airtight seal around the neck.

Q2: Size or weight of the cylinder containing the larger quantity of nitrogen could be a drawback. Larger quantity of gas means larger, heavier cylinder.

Q3: Check the PPeH for a description.

Q4: Bags with small holes will not allow for proper inflation. I personally would find another bag without any holes.

Q5: It will depend on the regulator device used. Check the PPeH.

 

[lastNamePicked]

with a flowrate of 15 litres per minute the nitrogen is emitted into the tube with a certain pressure. in the description of the tube it says that it can be used with a pressure of 20 bar. how can you calculate to which pressure the gas is emitted into the bag with 15 litres per minute ?
on the regulator is says '4,5 bar l/min'. does that mean that 4,5 * 15 = 67,5 bar pressure is needed for the tube to withstand ?
unfortunately, i cannot find information on tubing in the PPH when it comes to nitrogen flow regulators. can someone give details on this please, maybe even link an appropriate tube.

 

[stbdchick]

There's no direct conversion from something like liter/minute to pressure; liters per minute is given for folks using the Mad Dog nitrogen flow regulator, which seems to me to be much simpler than most. I bought mine off Amazon and had to read the manual and play with it a bit to figure it out.

Here's my thoughts: too high a pressure may blow the bag, so that's to be avoided. Put the bag on your forehead, turn the gas up very slowly, until the bag inflates. That's the right pressure to use. I've done a trial run and a failed attempt, and this seemed to work for me.

You just need the "air" you're inhaling to be all nitrogen; given that nitrogen is lighter than CO2, the inflated bit of the bag will be all nitrogen, and continually push the CO2 out of the bottom of the bag.

 

[lastNamePicked]

doesn't the material of the tube matter ? for silicon tubes it says that they are only suitable for a pressureless flow of gas. if the gas is flowing with a rate of 15l/minute doesn't that pose a pressure on the tube ? i cannot find any specifications for tubing anywhere and I don't wanna miss out on anything.

 

[stbdchick]

There's a whole lot more detail in this thread, which I am currently reading: https://sanctioned-suicide.net/threads/exit-bag-and-inert-gas-megathread.8393/page-10