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Expansion Tank?

Posted: Wed Jul 07, 2010 11:13 pm
by HunterT
You now those tanks that are in a water system. They have a rubber bladder inside them charged with air. Then water is pumped around the bag and the bag provides water system pressure. I have gotten a hold of one of those and the bag is busted. It is rated for 150psi and I was wondering if it would be safe to use for a pneumatic spud gun?

Posted: Wed Jul 07, 2010 11:15 pm
by jackssmirkingrevenge
An accumulator?

Image

Depends, is the outer tank rated for 150 psi or the bladder?

Posted: Wed Jul 07, 2010 11:28 pm
by HunterT
No I don't think so. It says on the tank. The tank itself is steel. The bladder inside is bad.

Posted: Wed Jul 07, 2010 11:33 pm
by jackssmirkingrevenge
If so, provided there's no corrosion, it should be fine.

Posted: Thu Jul 08, 2010 12:05 am
by HunterT
Okay.
Thanks :D

Posted: Thu Jul 08, 2010 8:29 am
by metalmeltr
It should be ok but be careful the steel is not very thck, maybe 1/16", I have punctured one with my air cannon and a nail dart at 200psi

Posted: Thu Jul 08, 2010 8:38 am
by Hubb
metalmeltr wrote:It should be ok but be careful the steel is not very thck, maybe 1/16", I have punctured one with my air cannon and a nail dart at 200psi
That's not really saying much. If the launcher is well made, there should be absolutely no problem putting a nail through just about anything at that pressure.

In fact, it became a second hobby of some members here a while back to put homemade darts through coins.

Posted: Thu Jul 08, 2010 8:44 am
by metalmeltr
Hubb wrote:
metalmeltr wrote:It should be ok but be careful the steel is not very thck, maybe 1/16", I have punctured one with my air cannon and a nail dart at 200psi
That's not really saying much. If the launcher is well made, there should be absolutely no problem putting a nail through just about anything at that pressure.

In fact, it became a second hobby of some members here a while back to put homemade darts through coins.
I's just a ball valve cannon(it's in the pnumatic showcase) I was just saying that the metal is thin and not to trust it at exteamly high pressure.

Posted: Thu Jul 08, 2010 1:16 pm
by Biopyro
I have one of these, and use it for a water cannon, for which it is perfect. Bear in mind that the bladder will be using a good portion of your volume, and that the air going into the schrader is not what is fired.
As you can see in JSR's diagram, you would just be compressing atmospheric air to fire from the water section, with the air you pump in to the nitrogen compartment.

Posted: Thu Jul 08, 2010 1:36 pm
by Technician1002
In his the separation between the air and water burst.

Posted: Thu Jul 08, 2010 1:39 pm
by Biopyro
Well it's good to see that I've forgotten how to read while I've been away! In that case you just need to bear in mind the possible volume taken up by rubber.

Posted: Thu Jul 08, 2010 1:47 pm
by Technician1002
I am surprised nobody mentioned the valve in the bottom of the tank in the drawing. The tank can intake a pressure surge quickly, but it is bled back out at a snail pace to prevent damage to the plumbing. When you want a blast of air, this is not a good thing to have in your tank.

Posted: Thu Jul 08, 2010 1:49 pm
by Biopyro
The one I have doesn't have the valve at the bottom. Without a nozzle, it will exhaust my 3L tank of water in under 10 seconds.

Posted: Thu Jul 08, 2010 10:12 pm
by HunterT
Neither does mine.