piston valve help

[sp1ke]

i am making a piston valve for my latest sniper rifle and have been having some trouble

i cant find any hose barbs that will work, what can i use instead of a hose barb for my gun?

i know that there are threads that talk about this same question so you dont need to tell me i cant seem to find an adequate answer so thats why im asking. and yes i know how to search and use google.


the T is 1/2" with a 1/2" nipple that houses my hot glue piston with a neoprene sealing face. I have an elbow at the bottom of the T that connects to a 1/2 ball valve that connects to a foot long 1" chamber. I plan to pilot and fill it with a blow gun.

[Gun Freak]

First off, might want to upgrade the blowgun pilot if the volume between the piston and the blowgun is large... And also for the barb problem... you can just put a cap with a nipple to connect it or a threaded plug and drill a hole in it to put the barrel through and the piston would seal directly into the barrel. What size is your barrel? I'm guessing half inch... If it is then this method might not work. But if you up the T size to 3/4 then it will.
Hope this helps,
~Gun Freak

[Crna Legija]

a blow gun will be plenty for a 1/2 inch tee i use it on a 1 1/4 inch .
if you can solder cut the threds off a fitting and solder pipe in to it.
the pic above is wrong the barrel need to come 1/2 way in to the tee .

[FighterAce]

You could get a 1/2 - 3/8 or 1/2 - 1/4 reducer with threads on the outside, grind off the hexagonal pieces for the wrench and screw it into the Tee with the 3/8 or 1/4 side pointing to the piston. Thats what I did and it works great.

[Gun Freak]

the pic above is wrong the barrel need to come 1/2 way in to the tee .

Sorry, I drew it in 2 minutes.

[ramses]

I will have to pull a tech and direct you to my piston hybrid...

except I have no pics of the valve...

Anyway, I was facing the same issue as you, and I decided to use copper fittings. Basically what you need is a copper pipe to MPT the same size as your tee, a copper reducer to one copper size smaller than the thread adapter, a short length of both sizes of copper pipe, and a threaded adapter to your final barrel size, or just leave it copper out the tee.

• File out the ridge in the reducer that keeps you from sticking the pipe all the way through.
  
  Flux, lightly screw the MPT thread into the tee, and push the barrel size pipe into the tee as far as you want it, keeping in mind it will go in further when you use a wrench.
  
  take the copper parts out, and solder it all together. There are a bunch of tutorials out there about soldering pipe.
  
  Thread that back into the tee, and you're done!

When I upgrade my hybrid for MOAR flow, I'll take pictures and put it on the wiki...