Paintball CO2 tank thread size?

[Spudgun on Crack]

Alright, I found an old paintball tank and decided to use it as a small air tank for use in my pneumatic setup.

I took the valve off by soaking the tank it really hot water for 15 minutes then the thread lock gave way allowing me to twist the valve off with a pipe wrench.

Then to my surprise it was not a 1/4in npt thread like I had thought, I tried to measure the valve with a caliper but it came up as .45 inches which is not a commonly available size at homedepot.

Does anyone know what thread type and thread size paintball tanks are?

[STHORNE]

you could just dig up the ol' tap and die set and thread it yourself with the next smallest/common size

*cough* 3/8" *cough*

[Spudgun on Crack]

The tank thread is 3/8in npt or were you saying to thread it with 3/8in?

I can buy a threading set but I don't know where to get one, where would I look at homedepot if I wanted one?

[MrCrowley]

He means the threads are 3/8".

[STHORNE]

so why don't you just buy a 3/8"-1/4" reducer. They are like 85 cents at Home Depot.

And as of the tap and die set, Any hardware store has them for like 20-30 bucks.

[Spudgun on Crack]

YES!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I was hoping you would say they were 3/8in, I will go to homedepot tomorrow and buy a reducer.

[STHORNE]

lol, they are hard to find but I am 98% sure home depot has them.
Not sure what kind of pressure rating you want though....

[grumpy]

if you mean the threads on the tank itself, they are 5/8-18UNF-2B . hope that will help you out

[Spudgun on Crack]

No I meant the internal tank threads not the part that plugs into the paintball gun.

The pressure rating that I am looking for is 250psi because thats the max input pressure for this regulator that I am going to get.

[grumpy]

5/8-18UNF-2B is the internal thread size for the tank, not the pin valve.
here is tank manufacturers website with specs fo for the tank, these tanks do not come with the pin valve
http://www.catalinacylinders.com/paintball.html

[frankrede]

3/8" npt pipe threads can thread into a paintball tank easily and will seal with teflon if tightened enough.

[Spudgun on Crack]

I can tell for a fact the threads are not 5/8in, they have to be 3/8 because a 1/4in pipe almost fits and my caliper is accurate enough to tell me its less then 1/2in.

I think you found a differnt manufacturer of tanks, everyone can make there tank differnt but I think I have a standard pure energy tank that you can pick up at walmart.

[grumpy]

all paintball co2 tanks are threaded with the same size threads regardless of manufacturer. look on the neck of the tank and you will find a bunch of number and letters , in the second row there should be a letter the M followed by four numbers, this is the manufacturers number.

you can then take those numbers , go to this site and find the manufacterer of that tank (PMI does not make their own tanks). go to their website and check their spec. sheet and it will tell the thread size, and i gaurantee that they will be 5/8-18unf-2b.
http://hazmat.dot.gov/sp_app/approvals/ ... ymbols.htm

[Spudgun on Crack]

How is the thread 5/8in when a 3/8in pipe would not fit?

My c02 tank had a 3/8in thread but it was not npt threaded so I had to improvise.

So I took a dremel and sanded the threads off, then I got a 3/8 to 1/4in bushing wrapped it in teflon and put some 60 second epoxy on it. Then I twisted it into the tank with a pipe wrench. It was extremely hard to get in there but I got it all the way in after a lot of effort and then the epoxy set which made it rock solid. I then put more epoxy around the bushing and the tank for added safety. It should hold up to 250psi with no problems or leaks, the epoxy I used is rated for 1250 psi plus I screwed the fitting into the metal.

[DYI]

The 3/8" pipe would not fit a 5/8"-18UNF thread because a 3/8" pipe is 5.4/8" around.

The fitting should hold at 250 psi, but did you ever stop to wonder what that 1250 psi rating is? It sure as hell isn't a pressure rating. How could it be? The don't know what size of hole you'd be filling, and they don't know how thick the epoxy coat would be. I'd guess that the "1250 psi" is a tensile strength rating of the epoxy.