Paintball Tank to NPT for Medium Pressure Reservoirs

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mark.f
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Tue Mar 29, 2011 9:55 pm

Been searching, and have seen a lot of posts with people suggesting to others to either force a 3/8" pipe nipple into the end of the bottle or use a drill and pipe tap to tap the end of the cylinder.

There's an easier way, although I've yet to try it.

The internal threads on a paintball tank are 5/8"-18tpi (unified fine threads). These are the threads exposed after removing the pin valve.

Now, you may be at a loss for how to convert these threads to NPT threads, but take a look at this:

It's a simple 45 degree SAE flare adapter, for 3/8" OD tubing to 1/4" NPT male. Less than 2 bucks, and should be a fairly common part. The flared side is 5/8"-18tpi UNF.

Problems:

Thread engagement is shorter than the pin valve used, so I would personally limit pressures to somewhere mid-range, around 400-500 PSI max.

Orifice through the fitting is rather small so it would be best suited as an air reservoir.

That's about all I wanted to say. Rather limited application, but slightly useful nonetheless.
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clemsonguy1125
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Tue Mar 29, 2011 10:05 pm

Thanks, was thinking about the best way to do this earlier today.
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Hubb
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Wed Mar 30, 2011 6:23 am

Paintball ASA adapters usually have 1/8" NPT threads already built into them. If one doesn't mind the restriction, that is also a viable option, while not having to worry about removing the pin valve from the tank.
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mark.f
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Wed Mar 30, 2011 7:43 am

Very true. I guess it's just whether or not you have that style adapter available to you conveniently or whether or not you want a permanent connection (can't be taken off) or not. Keeping the pin valve (obviously) lets you remove the tank from your gun while pressurized.

Unless you build a hammer valve into the other end of your 3/8" flare fitting, in which case it would be like a Girandoni or Condor system. :D Albeit limited to 500 PSI until you find a better connection (longer thread engagement).
turner
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Mon Apr 11, 2011 5:24 pm

just simply use any Asa they convert to 1/8npt. flow shouldn't be a big problem if your just filling your gun. http://www.ansgear.com/Paintball_ASA_Sale_s/808.htm
cannon monkey
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Mon Apr 11, 2011 6:19 pm

3/8 flare fitting fits in the threads on the bottle it's self that is if u can get the valve off of it
most big random like i ever seen
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