CF Tank Thread Size Help, please.

[ctshooter]

I'm trying to understand the different thread sizes for SCBA and paintball tank. 

My understanding for US spec threading is that SCBA tanks are 7/8-14UNF and paintball tanks are 5/8-18UNF.

I'm seeing some of the carbon fiber tanks from China which list a M18 x 1.5 - are these threads compatible with the paintball 5/8-18UNF? There are many CF tanks available in middle sizes (3L) which I'm looking into but confused what will work with what safely.

 

[Centercut]

No, the US sizes are not compatible with the metric sizes. You are correct about the SCBA and Paintball tank thread sizes. You would need to buy a separate tank valve in M18*1.5 to use one of the metric tanks. I'm assuming you'll fill the tank yourself since if its not DOT (US) then no paintball or SCUBA shop will fill it for you.

 

[Bluecup]

If you go with the us scott type valve the fill adapter you will need is the Cga347

 

[ctshooter]

Thanks - I do fill myself so that is not a concern. There is some concern with the quality of these tanks, but with the threading becoming an issue I'll just stick with US made tank threads. I already have some very nice tank valves from JoeB so I would want to be able to re-use them.

 

[hollowpoint]

Good call. 

It's my personal preference and I'm sure there will be plenty of people waiting to disagree, but I'll take a 15+ year old Scott/Interspiro/Draeger SCBA tank over a brand new Chinese cylinder.

 

[steve-l]

I would like to point out that it isn't necessary to charge the gun to 4500 psi just because you can. Most guns have a max rating of 250 bar or less anyway. Even if they do have the higher pressure rating, it isn't a problem to charge them to a lower pressure. Sometimes it makes a lot of sense. In my case I never charge my FX Crown higher than 230 bar. This allows me to use two new aluminum SCUBA 12 liter tanks and I charge the guns from them. I recharge the tank about once a month. I still get 4 magazines between gun fills even at the reduced pressure.