SpudFiles

I'm looking to use a Paintball Co2 cylinder as an air tank on my next gun.

Probably will be a 12oz size like the one pictured. The thing is, I do not need the valve assembly that is screwed into the top of the cylinder.

These can be unscrewed and other things screwed in. I want to take out the valve and just screw in a nipple of some sort.

Now, is the thread in the cylinder a standard size, I estimate around 3/4 inch or is it a special size that only the proper valves etc will screw into?

Has anybody done something like this? Any help appreciated.

are you hoping to use your gun for high pressures because that tank would be pointless at standard pneumatic pressures.

spudgunnerwryyyyy wrote:are you hoping to use your gun for high pressures because that tank would be pointless at standard pneumatic pressures.

other than the fact that it looks really damn cool. I read someplace that you can use it with 3/4 threads. Some people deem this unsafe though, because it doesnt thread in to far.

Place the tank in a vice, grab a wrench. and use some muscle. If it is properly built, it is going to take some effort to remove. As far as the thread sizes, I've screwed a 3/8" npt nipple into the threads, but I am unsure if those are the right sized threads.

Oh, and this tank can hold a lot of pressure. You shouldn't waste your effort on using this only to put 100 psi in it. I have yet to experience it but I heard it makes for one helluva hybrid chamber.

mopherman wrote:

spudgunnerwryyyyy wrote:are you hoping to use your gun for high pressures because that tank would be pointless at standard pneumatic pressures.

other than the fact that it looks really damn cool. I read someplace that you can use it with 3/4 threads. Some people deem this unsafe though, because it doesnt thread in to far.

3/4" is way too big. Like I said, I put a 3/8" nipple into one. it screwed in about two good turns, then got hard. I used the wrench and tightened it on down but I have yet to test mine for pressure holding, etc.

Not that pointless. Will be using at around 200psi. Not that high, but it's nice to know that I have something that will safely handle these pressures.
It saves me having to construct my own tank, it's lightweight and has a nice finish. Better the a sodastream one eh, except the price...oh well.

hubb017 wrote:

mopherman wrote:

spudgunnerwryyyyy wrote:are you hoping to use your gun for high pressures because that tank would be pointless at standard pneumatic pressures.

other than the fact that it looks really damn cool. I read someplace that you can use it with 3/4 threads. Some people deem this unsafe though, because it doesnt thread in to far.

3/4" is way too big. Like I said, I put a 3/8" nipple into one. it screwed in about two good turns, then got hard. I used the wrench and tightened it on down but I have yet to test mine for pressure holding, etc.

my bad. i was confused about the thread sizes for a sec. have you been able to get that nipple to seal?

Yeah I havn't seen one in person so was only guessing the size from the pictures I have seen.

mopherman wrote:

hubb017 wrote:

mopherman wrote: other than the fact that it looks really damn cool. I read someplace that you can use it with 3/4 threads. Some people deem this unsafe though, because it doesnt thread in to far.

3/4" is way too big. Like I said, I put a 3/8" nipple into one. it screwed in about two good turns, then got hard. I used the wrench and tightened it on down but I have yet to test mine for pressure holding, etc.

my bad. i was confused about the thread sizes for a sec. have you been able to get that nipple to seal?

I haven't tried to seal it. I was just trying to see if the nipple I had would fit into the tank. I'm sure with enough teflpn, it would seal. Maybe even some of that Loktite stuff.

Frankrede used a paintball tank on his hybrid, not sure what size he used but you could check.

Edit: he used a 3/8" nipple, so I guess that what works

If you're only using 200 psi, why not just use normal steel pipe. The small opening on the CO2 tank won't be very good for flow.

Because a piece of steel pipe will be a lot heavier and doesn't look as good. It would be reduced to a 1/2 inch pipe anyway so not that big a difference.
On the sodastream cylinder that Iam currently using, it only has a 7.5mm opening in the top with external 3/8inch threads. It still works very well.
A 3/8 inch nipple should have an internal diameter of at least 9mm. It should have high enough flow rates for what I'm doing.

I modified the pin valve on a 20oz tank to fit a shader in it, i fill it and use it to fill other things through the same shrader valve. Maybe you could do the same, although this wont give you much air flow, you could use it as a secondary tank like i did.

I also feel that is is better to use something that has a pressure rating far above what you are going to use it for because i just don't trust pvc even though it is quite safe if used properly.

Why not take a drill and just drill the whole pin thingy out of the center? Kinda rough, but then you would have standard ASA threads and a relatively large flow rate.

Those are not standard size threads on the Co2 tanks. I read somewhere you can buy an adaptor though to go from this special thread to NPT. It's used on the Co2 filling stations.