SpudFiles

So one day my friend and I decided to make a spud gun. In the the end it turned out to work great. I am planning on moving to a Pneumatic or electric valve, so I can get a higher flow rate. I have done quite a bit of research on the right valve but I am just not sure which way to go. I dont know what to do because I cant use the traditional sprinkler valve due to the fact that I am going to higher pressures that are around 160-170psi, also because it doesn't release the tank fast enough. I have taken into consideration an electric ball valve but they are just way to much money. I am considering making a piston valve but from my knowledge the input and output are at a 90 degree angle and my launcher looks like so...


What valve should I go with?

you could make a coax piston, where the barrel is inside of the chamber, but that would not be something you could adapt your gun to, you would have to build a completely different one

Maybe attach a union after the ball valve, before the barrel, and use a burst disc.
Even with a burst disc (made from aluminum foil, painter's tape, or the pressure you mentioned maybe plastic soda material(?)) It will still have restriction. You could get a smaller diameter barrel and use the barrel for a second chamber...a double barrel! 8)
Seems like the easiest solution.

How about this? 4way 2" pvc coupler


lol one r

On a budget, to keep the inline form, a large ball valve is a big improvement. Often they are configured so when they open, the handle is pushed forward, the recoil pushes the launcher to the rear and helps open the valve.

Walapu's design above would work, but the difficulty of sealing the sides of the piston is not an easy task. Often a larger diameter piston is needed to provide a flatter surface to form a seal on the valve seat. Due to the number of seals required, they have high friction. Overall, this is not popular for high pressure as when they have tight enough seals to hold pressure, the movement is very stiff. In low pressure high volume applications not requiring a super leak proof seal, they work well such as motorcycle throttle pistons.

Well in the end I am just going to stay with the ball valve :/ Thanks everyone for your ideas and comments.

You could make a 1.5" porting Tee valve piston for under $30 if you shop smart... and you'd have alot more power. like prolly more than you could handle... so it's prolly too powerful actually.

mobile chernobyl wrote:You could make a 1.5" porting Tee valve piston for under $30 if you shop smart... and you'd have alot more power. like prolly more than you could handle... so it's prolly too powerful actually.

Air cannons have the advantage of adjustable power. With lighter projectiles a 2 inch valve on the 700 cu in launcher is not hard to handle with spuds, apples, etc at pressures up to 80 PSI. It gets it's kick when using larger barrels and heavy loads and then even I need a little bracing.

2 inch barrel with 1-1/2 inch valve will be no problem for spuds and apples. Kids at church camp fire my 2 inch ported piston apple cannon all the time at 60 PSI.