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which valve to use for storing gas in bottles? Answered

I need to store gases(mainly hydrogen, generated from electrolysis)  in a bottle. I was thinking of getting a bicycle valve and attaching it to the bottle. The problem is I cannot find a bicycle valve anywhere online. Moreover, when a bicycle valve is opened the inside gas leaks out. Is their anyway of storing a gas in a (soda or soft drink) bottle? Which air valve should I use?

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petercd (author)2016-01-31

You DONT store gases from electrolysis-full stop.

The gas self ignites somewhere after 10psi, a cup full detonated will rupture both your eardrums causing permanent hearing damage...and you want to store a bottle ful.

Theres a reason why its used on demand only, its exceptionally dangerous to store.

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rickharris (author)petercd2016-01-31

I am just asking, because I don't know. Assuming the poster collects the gas from each separate electrode.e thy collect from the -ve electrode, won't this be hydrogen and if so why will it explode at 10PSI + ?

Hydrogen is stored commercially at much greater pressures than 10 PSI

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steveastrouk (author)rickharris2016-01-31

Its also not stored in plastic bottles....

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rickharris (author)steveastrouk2016-01-31

True, but why should hydrgen be unstable over 10psi

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petercd (author)rickharris2016-02-06

Not hydrogen risky at > 10psi, but mixed gases from electrolysis

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steveastrouk (author)rickharris2016-01-31

I don't think its unstable, in pure form, it can deflagrate when its mixed with oxygen.

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petercd (author)rickharris2016-02-06

Not hydrogen risky at > 10psi, but mixed gases from electrolysis.
All it needs is a spark and it has the perfect fuel/air ratio for combustion.
That catalyist spark can also originate from static as would be found in a plastic environment.
The speed of combustion of hydroxy also generates its own static component which bridges common gas arrestors for acetylene etc.
I havent yet heard of any 15yr old separating the gases from electrolysis, least of all one who is asking questions on this forum.

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Kiteman (author)petercd2016-02-01

I think what you mean is not to store the mixed gases. Oxygen or hydrogen alone will not ignite at all.

The main problem with storing quantities of hydrogen in the longer term is it's annoying ability to diffuse (leak) through most normal materials, even when there is no hole. A plastic bottle of hydrogen will, over a few hours or days, become a plastic bottle of some hydrogen.

(It's a similar thing to helium, which has atoms almost as small - think how quickly a rubber helium balloon goes down, thanks to the gas passing through the rubber.)

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petercd (author)Kiteman2016-02-01

Very correct on that issue regards mixed gases, I just figured a 15yr old wouldn't have equipment to isolate the 2 gases or the knowledge to want to separate them.

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Jack A Lopez (author)2016-01-31

I think ordinary plumbing valves will work, as long as you do not exceed the pressure, and also temperature, ratings for these.

I actually built an apparatus for storing hydrogen, made via electrolysis, and the valves I was using for this were ordinary PVC plumbing fittings. Also the bottle I was using for the storage space was a 2-liter PET plastic soda bottle.

Somewhere, I think I've got some pictures of this, and I will upload some of these, if I can find them.

Also I think the gas I was storing in the bottle was actually a mixture of hydrogen and oxygen, which is more dangerous than just hydrogen alone. I mean when I built the thing, my intention was to make just plain hydrogen, but I think the gas I was actually making was a mixture of hydrogen and oxygen.

BTW, part of my strategy for keeping this apparatus from exploding due to internal pressure (increasing as the electrolysis cell made more gas) was a pressure gauge (another ordinary plumbing fitting) installed at the top. The gauge let me know, at a glance, how much pressure was inside, and I never let it go over about 90 PSI, without emptying some of the gas out to relieve the pressure.

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user

OK. I promised pictures.

The method I used for adapting the 2-liter PET bottle was to glue its neck into a 3/4-inch PVC coupler using this stuff called "plastic welder epoxy". It also sometimes goes by the name of "plastic bonder epoxy". Two of its characteristics are that it is opaque, and it smells absolutely awful. In this way it can be distinguished from other weaker flavors of 2-part epoxy that do not work as well.

The other side of the coupler is attached in the usual manner, with PVC glue, to a 1/2-inch female NPT insert fitting.

The first two pictures are actually from like 3 years ago, spring of 2013. These pictures show the bottle and its glued-on adapter being filled with compressed air.

The last picture shows this bottle attached to the top of some plumbing which is the electrolysis apparatus. This picture was taken last night, and some of the other junk in my garage is visible in the background.

I was making gas with this thing as recently as last summer, but it has been in storage since then. The bottle seems to have collapsed, like it has less pressure inside than outside. Also it is covered with dust and a few cobwebs.

If anyone is interested, I'll see if I can get this thing fired up (so to speak) and making gas again.

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Kiteman (author)Jack A Lopez2016-02-01

If you left the bottle with any hydrogen in it, it will have less pressure inside than before, because the hydrogen will have diffused out through the plastic.

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Jack A Lopez (author)Kiteman2016-02-01

That's a believable explanation.

Everything goes somewhere.
https://en.wikipedia.org/wiki/Conservation_of_mass

;-)

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Downunder35m (author)2016-01-31

Apart from the obvious dangers you also face leaking through the material itself.
If you want a simple to use valve take one out of an old tyre, with the big rubber block on them it is quite easy to get them into a bottle or similar without using silicone to seal.
Be aware that unless you find a way to compress and liquify the hydrogen you can only store very little volume.
Depending where you are there is also the legal problem as you quite literally store a bomb waiting to go off....

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rickharris (author)2016-01-31

What sort of pressure do you intend to achieve?

1. You need to remove the air usually by filling the bottle with water and submerging the next under water.

2. You need to pipe in the gas you want to store under water to replace the water in the bottle, this way the bottle only contains the gas your trying to keep.

3. Getting this pressurized is now going to be the hard part. A soda bottle will safety hold perhaps 80 PSI, I would experiment with great care and find out how much they hold before exploding NOTE when a soda bottle explodes it does so with great and loud violence and scattering of plastic shrapnel so do it in a covered environment.

To get pressure you going to need some king of pump.

4. You best source for a bike valve is simple a bicycle inner tube, getting a tight fit in the bottle lid is going to be hard though.

5. There may be laws against keeping any amount of explosive gas in unsuitable containers in your home. So your neighbours may not be bast pleased.

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