HPA Tank Air Source

[whoa044]

WARNING
The ASA adapter threads are very close to, but do not perfectly match those of a 1/2 NPT pipe threading. Unless if you are going to epoxy glue the two fittings together, I would NOT recommend attaching them together!

I really don't know if you guys know about this since I haven't been on for a while, but here it goes:

So I like to go paintballing, and if any of you play paintball, or have seen it, you may have caught a glimpse of one of these:


It's a remote line that can go from the paintball HPA tank, to the paintball gun. The HPA tanks, which have a safety limit of 4500 psi, weigh roughly 2 pounds.
Anyway, this connector, just so happens to be 1/2 inch NPT threaded.


Now, 4500 psi will not be flowing through the coil, because the HPA tank has a regulator. The regulator comes standard at about 850psi output pressure (to my knowledge).
Here is an example of an HPA tank, and it's regulator:



68 cubic inch (most common) 4500psi tanks will cost in the range of $130 to $200. And getting them filled often would be hard to do unless if you play paintball, or know someone that has a 4500psi compressor. These things are GREAT. They are very light, last many shots (depending on chamber volume), and can easily be carried around, or attached to the gun itself.

I built a very simple pneumatic, with a solenoid valve. The valve was rated to 140psi, but it worked at 400psi just fine haha. Anyway, the chamber was a 1" diamater, 8" long steel pipe, and I could shoot it ALL day. I'm not sure how many shots with a larger pneumatic the tank could provide, but you could do the math. The amount of air inside a 68cubic inch tank at 4500psi is equal to 150psi at 2040ci, or 33.4 liters at 150psi, but you can easily use a compressor in a 150psi situation.

To imagine how much air be put into a 68ci tank, imagine an 8.8 gallon tank filled to 150psi. There are even 122ci tanks, which can almost double your "air carrying capacity"
I would highly recommend using one of these as an air source for your gun if it's powered by 200+ psi.

Some remote lines have a slide check at the quick disconnect end. And ALL remote lines, at the part where the tank screws in, have a knob that twists to open/close tank flow.

A good HPA tank: Guerrilla Air HPA Tank
A good remote line, with slide check: Remote Line w/ Slide Check

[Lockednloaded]

Don't ever put 400 psi behind a whimpy plastic solenoid rated for 140 psi, get a metal valve

[MrCrowley]

Judging by the fact that he said solenoid valve and not sprinkler valve and the rating is 140PSI and not the more common ~125PSI for sprinkler valves, I assume he is using a brass valve which are more commonly rated for 10bar or ~140PSI. I could be wrong though, just guessing.

[Gun Freak]

There are cheaper tanks, for example, this one. You could buy two of these tanks for less than the one you linked and it would give you 96ci as opposed to 68.

[whoa044]

Crowley is right. The solenoid is brass.

And you can buy a 122ci 4500psi rated tank, getting you more for the money. Scuba tanks would work too, but they are quite heavy


edit: Two of those tanks at 3000psi is equal to a single 64ci tank at 4500psi. It'll be more expensive, but it'll weigh 4 times as less (2lbs compared to 8lbs of the 2, steel tanks). a 122ci 4500psi tank would be best. Largest volume and highest pressure

This is just an idea for an air source of over 200psi

[ramses]

Have you considered a regulator? or are you looking at "low pressure" tanks where the internal regulator puts out 450 instead of 900 PSI?

Bear in mind that the fiber wrap tanks do expire after 10 years (I think) to the point where they are not allowed to be re-hydrotested. Metal tanks do not expire like this, but do still require hydrotesting.

[Hubb]

...
Anyway, this connector, just so happens to be 1/2 inch NPT threaded.
...

That fitting is an ASA adapter. It is not 1/2" NPT threads and should not be used as such. If you use that in 1/2" NPT, you are just asking for problems later on down the line. And anything remotely related to a problem involving pressures these tanks put out is something most would probably like to avoid.

[Lockednloaded]

The connector on the other hand, has 1/8" NPT threads that can be easily adapted to 1/2" NPT

[whoa044]

Have you considered a regulator? or are you looking at "low pressure" tanks where the internal regulator puts out 450 instead of 900 PSI?

Bear in mind that the fiber wrap tanks do expire after 10 years (I think) to the point where they are not allowed to be re-hydrotested. Metal tanks do not expire like this, but do still require hydrotesting.

This thread is just letting other people know that HPA tanks can easily be used as a source of high pressure air. On my pneumatic guns though, I would just have a 1/4 inch valve on the gun, restricing air flow when I don't need it. 800psi is flowing through the valve, so I have to be careful. IMO composite fiber tanks are better: Lighter, and are rated for higher pressures. I think 10 years is a good length of time for a small tank

That fitting is an ASA adapter. It is not 1/2" NPT threads and should not be used as such. If you use that in 1/2" NPT, you are just asking for problems later on down the line. And anything remotely related to a problem involving pressures these tanks put out is something most would probably like to avoid.

The pressure the tanks put out is 800psi. imo I think an epoxy weld is good enough to connect a NPT to an ASA adapter. The ASA adapter has threads which appear to be identical to NPT threading. With teflon tape, it screws into a 1/2 NPT threaded fitting perfectly.
Not so long ago I epoxy glued it.

Oh, and ASA is 0.822in OD with about 12 TPI. 1/2 NPT is 0.84in OD with 14 TPI.

[whoa044]

Oh, and oddly enough, my tank puts out far more than 800psi (the common regulator output)
The dial on the gauge of my metal pneumatic goes up to 1000, and I know for sure it goes over 1,200psi. Didn't want to go any higher as it might damage the gauge.


I think these tanks are perfect for small metal pneumatics (burst disk pneumatics, specifically). And because these tanks can output 800psi (1200+ in my case), a small burst disk gun can work quite well. I have a 1" burst disk gun that currently works. It's shooting .50 caliber lead bullets as of now.....

[Hubb]

Oh, and ASA is 0.822in OD with about 12 TPI. 1/2 NPT is 0.84in OD with 14 TPI.

Just because it can be done doesn't mean it should be. Calling these threads the same is misleading at best, especially for those who are not familiar with with them. No one is disputing your knowledge on the subject. In fact, it seems that you are quite knowledgeable about it. But you must remember that others here may not be.

[whoa044]

Alrighty, updated the original post

[mobile chernobyl]

I had an HPA setup on my one copper gun which used a 92ci 4500psi tank as the resevoir and stepped down immediately to 850psi at the tank - it then ran into a low pressure regulator where it was adjustable between 150 and 300ish psi. This setup is shown below:

This worked well however it was slow to fill up the entire gun, so I nixed the low pressure regulator and fed it directly into the gun using the on/off ASA as the throttling valve to back it off close to my fill pressure. With this setup I could of hit the full 850psi had I wanted to, but 300 was adequate for me This is shown below:

[whoa044]

Never thought about buying a macro line for a direct feed... The setup looks good: nice and simple
Don't you love the look of a gun of just bare metal and mismatching colors? Gives it a "strong/rigid" look. Everything I build is like that

And I don't even bother with regulators. If I'm using a solenoid (right now it's burst disks), then I just close the valve before it gets over 300psi, like you do.


Have you hydrotested that tank lately? Just wondering because I haven't seen a crossfire regulator on any *new* tanks. Last one I saw was on my first composite fiber tank heheh >.>

[mobile chernobyl]

you are required to hydro these tanks every 5 years, I had it hydrod under a year ago

Cross fire is not that old of a reg - Of course I've been playing paintball for over 10 years now.