What brand is the valve? I bought a RainBird at first and had the exact same problems as you. I then bought an Orbit WaterMaster (sold at Lowes and Home Depot too) and never had a problem since.

I found it with a search:

Valve type: Barrel sealing
Piston seat diameter: 1.2"
Piston diameter: 2"
Piston mass: .8oz
Flow efficiency: 23%
Pilot volume: 1.1 in3
Dead volume: 2.2 in3
Vent Diameter: .1" (.2" if you modded your blowgun)

The guy that wrote this is a genius! GGDT says my ...

Oh, I thought that was referring to only a barrel sealing piston valve. So, if I'm using an unmodified 1" Orbit WaterMaster sprinkler valve, how should I adjust the following settings?

- Piston Dia
- Piston Mass
- Vent Dia
- Pilot Vol

Thanks! That was the problem.

Clyde, I don't see an option for pilot valves. I have the following options: Chamber Seal, Barrel Seal, Burst Disc, Hammer and Generic in version 4.4. What version are you using?

frankrede, the projectile goes 40 yards with a t-shirt stuffed tightly in the bottom ...

GGDT shows my Projectile never cleared muzzle but it actually went 40 yards. I know I'm just entering something wrong. Does anyone know what it is? I have attached a capture of GGDT.

My gun consists of:

Chamber is 4" sch 40 by 12 " long, pressured to 80 psi => inline 1" sprinkler valve actuated by ...

lukemc,

Is there a way to remotely / electronically activate a piston valve? I haven't read much into piston valves yet but I'll check them out.

Hi,

I'm having a hard time picturing this. Do you mean attach a sprinkler valve to a blow gun that is attached to a modified sprinkler valve, or somehow attach a solenoid directly to the blow gun?

Jackss,

Can you point me to a thread where this is done? I did a quick search but haven't found it yet... I'll keep looking.

I'm using electronically operated valves so I can activate them remotely. These valve seemed interesting because they are rated up to 800 psi and the 3/4 350 psi model is $50... I just can't seem to find dealer that sells a 1" model.

I'm looking for a good high pressure (250 psi +), 1", metal, electrically operated valve for an air cannon. Are there any good options other than sprinkler valves which all seem to max out at 150 psi? Will the 1" and 3/4" valves used in air suspension systems work.. like these http://www ...

BCannon;
I am willing to help you but please, provide info for asked questions.
1) What barrel diameters, and what schedule pipe for each?
2}What is the weight of each of your projectiles?
3) What is the cannon configuration? Inline or over under?
4) Chamber size should be at least 18 in at 4 ...

The objects I'm shooting are no more than 10 inches long. With a 4" diameter barrel (18" long), 1" sprinkler valve and 4" chamber (12" long) pressured to 100 psi, the 3" diameter object is launching 25 yards with a rag stuffed in the bottom of the barrel. This is perfect my situation... I just want ...

I think the expanding foam idea will work great for my situation. Thanks!

Now, does anyone have any suggestions for keeping the foam plug from coming out of the barrel? I only want to shoot objects 20-40 yards so distance isn't a priority. Ideally I would like to reduce the end of the barrel so ...

Anyone have any ideas of how to shoot multiple sized objects out of a cannon with a 5” barrel? The objects I’m shooting range in size from 1” to 5”. I’m just stuffing a rags in the bottom of the barrel for now but there has to be a better solution. Has anyone built a plunger type system? Thanks for ...