Page 1 of 1

Moar Power!

Unread postPosted: Sun Sep 26, 2010 3:56 pm
Author: HunterT
Recently I built a 20mm PVC cannon and it was disappointingly low on power. So I decided I want more power and to get this power I want I settled on replacing my PVC/ABS pressure tank with a steel air tank made from steel pipe fittings or something similar. Currently I'm using a 3/4inch Orbit Sprinkler Valve (http://www.amazon.com/Orbit-57100-4-Inc ... 318&sr=8-1). I figure the working pressure will be around 100-80 psi. I'm wondering if I can continue to use my PVC barrel and sprinkler valve. Also in the interest of making it even more efficient, I'm wondering if there is a ratio/formula for air volume to barrel size/length.

Many thanks

Unread postPosted: Sun Sep 26, 2010 4:17 pm
Author: Gun Freak
For the pressure you are using, which is low for use in pvc, the ratio 1:1 is fine. More will be louder and a little more powerful but 1:1 will be ok. Why did you upgrade to metal? PVC can hole 80-100 psi easily and some people use it up to 150 and beyond, and the metal only made it heavier. Yes, you can use the same barrel and valve. And, that link is broken...

Unread postPosted: Sun Sep 26, 2010 5:01 pm
Author: MrCrowley
I use 20mm PVC and 1" sprinkler valves up to 150PSI. I feel pretty comfortable at that pressure. No need for the steel chamber assuming your joints are solvent welded correctly.

Unread postPosted: Sun Sep 26, 2010 7:47 pm
Author: HunterT
Gun Freak wrote: Why did you upgrade to metal?

I have not upgraded to metal, yet. I was thinking about it.

It should be noted that my pressure tank is ABS with PVC endcaps. Currently I'm using about 30-40 psi in my pressure tank, because I just don't feel safe using a higher pressure. But could I take my current(PVC & ABS) pressure tank up to around 60 or 70 psi?

What kind of pressures could I get up to using my current sprinkler valve(modded) and a steel pipe air tank? Somewhere around 200psi? Could I fill it with a Schrader valve?


[/quote]

Unread postPosted: Sun Sep 26, 2010 7:54 pm
Author: Gun Freak
Don't go to 200 with that sprinkler. I would only use it at a max of 150. You can modify the diaphragm to use at higher pressure, but you gotta remember it is still plastic. And yes you could fill it with a schrader valve.

Unread postPosted: Sun Sep 26, 2010 9:46 pm
Author: Lockednloaded
200 psi won't break the valve, I have heard of people's diaphragms ripping, but I've used a sprinkler valve up to 200 psi with a stock diaphragm with no problems. I later switched out the stock diaphragm for a new so there would be no chance of diaphragm ripping

Unread postPosted: Sun Sep 26, 2010 10:59 pm
Author: HunterT
Gun Freak wrote:Don't go to 200 with that sprinkler. I would only use it at a max of 150.

What sort of valve would I use if I went higher than 200psi?

Unread postPosted: Sun Sep 26, 2010 11:13 pm
Author: jackssmirkingrevenge
HunterT wrote:What sort of valve would I use if I went higher than 200psi?


3/4" quick exhaust valve, perfect for a 20mm barrel.

Unread postPosted: Sun Sep 26, 2010 11:22 pm
Author: BeaverRat

Unread postPosted: Mon Sep 27, 2010 7:23 pm
Author: HunterT
Okay. Many thanks. Could I still use my PVC barrel on it?

Unread postPosted: Mon Sep 27, 2010 7:38 pm
Author: Gun Freak
HunterT wrote:Okay. Many thanks. Could I still use my PVC barrel on it?

Yes.