9 replies to this topic

[Maeric]

I was making up some designs for an airtank, and I was wondering how big should it be in terms of Ci (cubic inches)

I have some designs for 4000ci (Yeah, overkill I know.), 1000ci, 750ci, 350ci, and 250ci. None of these are completely accurate, because I don't know the volume of the elbows, except the 1000ci one has on piece of 6 X 36" PVC. And for 200psi PVC (just an example) what is the maximum psi for compressed air? (For all of you that don't know, the PSI rating on PVC is for liquids.)

[Carbon]

It really depends on what you want to do with it, and how many shots you hope to get. At least, assuming you want multiple shots with a 4000 cubic inch tank. Also, you'll need to balance out air volume versus the tradeoff of time spent filling. Big volume is lots of shots, but takes forever to fill.

As far as max PSI, general consensus seems to be around 120 PSI, with most using 80-100.

[MoonMaster]

I could be totally wrong on this, but I'm pretty sure that I'm not, or else I would not be posting. Psi is a measure of how much force (in pounds) can be applied to a specific area ( 1 square inch). Now I could be wrong, but I don't think it really matters how that force is applied ( through liquids or gases. So that means that you could fill your tank up to 200 psi (if it is made of 200 psi pvc), but the general consensus for darts I heard was aroud 70 Psi.

[Carbon]

I could be totally wrong on this, but I'm pretty sure that I'm not, or else I would not be posting. Psi is a measure of how much force (in pounds) can be applied to a specific area ( 1 square inch). Now I could be wrong, but I don't think it really matters how that force is applied ( through liquids or gases. So that means that you could fill your tank up to 200 psi (if it is made of 200 psi pvc), but the general consensus for darts I heard was aroud 70 Psi.

One would think that, but it's not true...sched. 40 PVC tends to fail well below it's liquid pressure rating when used for air. Here's an interesting link discussing the dangers. They specifically say not to go above 100 PSI, and that it really shouldn't be used for above-ground installations, if at all.

What makes it particularly bad is that when PVC fails, it fails explosively, sending shards of plastic everywhere.

Edited by Carbon, 21 December 2007 - 04:15 PM.

[sn1per]

So PVC explodes...

[Lynx]

So PVC explodes...

Yes, and one good way to protect yourself is to put a piece of denim around the air tank because denim is EXTREMELY strong. My friends at a major research facility (Batelle) gave me the suggestion!

[Maeric]

I'm not sure if i said this, but the goal here is to make a fairly large air tank (CS's was about 350ci I think), and to get multiple shots out of it, say, for a Magstrike or a titan (at least 25).

And yes, I'm not going over 1/2 of the pressure rating for safety, and I would like to hear from Capitan Slug for sure. I want to make more of an sharpshooter rifle out of the Titan (semi-auto), so I need a lot of compressed air, considering that CS's got 10 shot from a Titan.

[Matt31]

To put things into perspective for you, I have a 2 foot long, 3" diameter tank and i get about 12-20 shots off per filling. Of course this is also with a fairly low pressure(30-35 PSI) and an inefficient system(I'm wasting a decent amount of air, per shot)

[CaptainSlug]

I'm not sure if i said this, but the goal here is to make a fairly large air tank (CS's was about 350ci I think)

No, my tank is 145ci at 90psi. Which was plenty for around 80 shots using a magstrike.

Realistically you cannot make a low pressure tank that will be able to supply more than 10-15 shots for a gun such as a Titan. The amount of volume used per shot is simply too high for a low pressure tank to supply. You would have to go with a high pressure tank. A 45c 3000psi tank regulated to a 35psi output pressure will give you around 600 shots using a Titan.

Edited by CaptainSlug, 21 December 2007 - 07:13 PM.

[Maeric]

So, I'm thinking of going for a 550ci tank (two pieces of 36" x3" PVC) at 90psi. This I'm thinking could get me a fair amount of shots, even with a large gun. The main two guns I am planning this for is my Titan and my Hornet. And possibly my AirMav, and a Magstrike when I get one.

It's decided then! Thanks guys!