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c02 adapter
Posted: Mon Oct 13, 2008 4:32 pm
by jonnyboy
I doubt their npt threads but its worthy to look into. As anyone seen these? The whole thing is 20 dollars and comes with a threaded 16 gram(?) tank. I found it at walmart. I might pick one up. Nothing epoxy can't fix/thread/seal/fill.

Posted: Mon Oct 13, 2008 4:57 pm
by jackssmirkingrevenge
That's an 88 gram cartridge as used by the crosman nightstalker:

Posted: Mon Oct 13, 2008 5:10 pm
by jonnyboy
Doh!

Can't believe I thought that was only 16. But what kind of threads are they? Looking around I just find the cartridges nothing about the threads. I imagine a 1/4 fitting encased in epoxy should seal it. I'll pick one up next time I go to walmart.
BTW I have had good success with locktite gel epoxy. It's quite thick so it doesn't seem down into an important part like an air inlet.
Posted: Mon Oct 13, 2008 7:10 pm
by VH_man
i wouldnt trust 1000 PSI to epoxy....... however much i trust it...........
Posted: Mon Oct 13, 2008 8:09 pm
by Lentamentalisk
it is actually never really going to get above 830psi, at room temperature, and when there is actually gas flowing through it it will probably be substantially colder than that. The problem is that the whole benefit of the adapter (correct me if I am wrong) is that you can unscrew it without losing all of the rest of the CO2.
Posted: Mon Oct 13, 2008 8:52 pm
by jimmy101
[quote="Lentamentalisk"]it is actually never really going to get above 830psi, at room temperature, and when there is actually gas flowing through it it will probably be substantially colder than that.
Ya, but leave it sitting in the sun for a while, perhaps laying on something dark colored and it'll easily get to >1000 PSIG. I wouldn't trust epoxy threads to take that kind of force.
I wouldn't think the threads would be all that unusual, you should be able to find the correct fitting (or tap or die).
Posted: Mon Oct 13, 2008 9:20 pm
by grumpy
you can find the adapters you would need to properly hook this up at palmers.
http://www.palmer-pursuit.com/cart/inde ... x&cPath=40
Posted: Tue Oct 14, 2008 6:47 pm
by jonnyboy
VH_man wrote:i wouldnt trust 1000 PSI to epoxy....... however much i trust it...........
C02 isn't 1k psi but someone answered the already. It's for my bbmg so it is just flowing through the barrel.
@grumpy
I didn't state it very well but what kind of threads are those?
Posted: Wed Oct 15, 2008 11:36 am
by jimmy101
jonnyboy wrote:VH_man wrote:i wouldnt trust 1000 PSI to epoxy....... however much i trust it...........
C02 isn't 1k psi but someone answered the already. It's for my bbmg so it is just flowing through the barrel.
Yes it has. An the answer is that the pressure in the tank must be considered to be
more than 1000 PSIG. Indeed, on a hot day of 90F the tank pressure is more than 1200 PSIG.
I would say that, for safety reasons, you should consider the tank to be at 2000 PSIG, which it will easily get to if you leave a full tank in a hot car for a while. Besides, many CO2 tanks have a popoff valve set at 2000 PSIG (not sure if the tank in the OP has a popoff).
Yes, the pressure will be much lower when the gas is flowing but the OP is about plumning to the CO2 cylinder. That joint will always have the full tank pressure on it.
Posted: Wed Oct 15, 2008 12:24 pm
by grumpy
@jonnyboy,
the only way you will be able to use that tank is to get this adapter.
http://www.palmer-pursuit.com/cart/inde ... 952ad0fd59
or you can find a local paintball shop and buy an asa to hook it up to.
burst disks used on co2 tanks are actualy designed to burst at between 2200 and 2800 psi. depending on manufacturer if you look at a burst disk on a co2 tank it will have 3k on it.
Posted: Wed Oct 15, 2008 2:12 pm
by jonnyboy
Thanks grumpy I'm not familiar with threads on something like that so I didn't know what I needed.
@jimmy
The parts will be subject to the pressure but seeing how its an open system the gas will just leave the barrel. Like in cloud bbmgs the internal pressure is significantly less than the inlet pressure.
Posted: Thu Oct 16, 2008 12:42 pm
by jimmy101
jonnyboy wrote:@jimmy
The parts will be subject to the pressure but seeing how its an open system the gas will just leave the barrel. Like in cloud bbmgs the internal pressure is significantly less than the inlet pressure.
That means the instant you screw the cartridge onto the adaptor the gun starts to fire. To stop firing you have to unscrew the cartridge.
In a cloud (or vortex) BBMG there is a valve. The volume between the valve and the compressed gas source is at the same pressure as the gas source. With a 120 PSIG compressor that volume is at 120 PSIG when the gun is not firing. With a CO2 tank that volume is at whatever the pressure in the tank is.
The fittings betwen the pressure source and the valve must be able to handle the source's maximum pressure. Trying to expoxy the CO2 cylinder's thread into a fitting (or a valve) means the epoxy has to withstand at least 1000 PSIG.
Posted: Thu Oct 16, 2008 2:14 pm
by jonnyboy
Theres going to be a blowgun there...
Posted: Thu Oct 16, 2008 2:17 pm
by Brian the brain
If the threads are the same ( and they should be!) as a 12 gram adapter, it should thread right into any 1/2" fitting.
I used a high pressure washer handle and it works great at those pressures.
Anything else basicly becomes a bomb...
Don;t mess around with 850 psi unless you know exactly what you are doing!
Posted: Thu Oct 16, 2008 3:37 pm
by grumpy
Brian the brain wrote:If the threads are the same ( and they should be!) as a 12 gram adapter, it should thread right into any 1/2" fitting
the adapter that comes with that tank serves two purposes,
1. when you screw the tank into the adapter it punctures the seal and opens the tank.
2. the adapter is also a pin valve, so when the seal is punctured all the co2 does not leak out.
3. to open the pin valve on the adapter you will need either an asa like on a paintball marker or the adapter from palmers.
a 12 gram adapter does not have the pin valve on it, and yes you can screw it into a 1/2 inch fitting, but the pitch on the threads is different than npt threads you need lots of plummers tape to seal the threads.
also most blow guns only handle 150 psi, and any valve you use may be frozen open by the co2.