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1/2" QEV or 3/4" sprinkler valve
Posted: Tue Dec 09, 2008 9:40 pm
by LCTChamp
I am planning on building a small bore pneumatic gun. I plan on using a .40 caliber blowgun as a barrel so I can use darts. I wont be using pressure over 100psi because my only source of pressure is a bike pump at this moment. At about the same price which would be a better valve to use the 1/2" QEV or 3/4" sprinkler valve? How would a attach the blowgun barrel to the gun? Epoxy?
Posted: Tue Dec 09, 2008 9:50 pm
by FishBoy
QEV i would guess, at least for that barrel.
Posted: Tue Dec 09, 2008 9:52 pm
by LCTChamp
Is there a specific reason for that choice?
Posted: Tue Dec 09, 2008 9:57 pm
by Velocity
QEV's have several advantages over sprinkler valves:
1) More durable construction
2) Greatly improved opening times
3) Better flow
A think a 1/2" QEV will have greater flow than a 3/4 sprinkler valve...it will be close anyways.
Posted: Tue Dec 09, 2008 10:01 pm
by LCTChamp
What kind of epoxy would I use to attach the barrel?
Posted: Tue Dec 09, 2008 11:11 pm
by jook13
Read the epoxy packages. It will usually state what it is designed to bond to.
Posted: Wed Dec 10, 2008 12:47 am
by jon_89
I would just go for the sprinkler if you are using blowgun darts. I use a blowgun barrel with a sprinkler and I can shoot a dart 30 feet and go through a .5 inch plank.
Edit: That was using only 30 psi, 1 inch by 5 inch chamber, and a 24 inch barrel.
Posted: Wed Dec 10, 2008 7:28 am
by psycix
Besides the way faster opening times and the metal construction allowing higher pressures, the QEV will probably have about the same flow of the sprinkler.
QEV is way better.
Posted: Thu Dec 11, 2008 12:10 am
by jon_89
I agree with everybody on the QEV if you intend to use different barrels such as a marble barrel but as stated above for blowgun darts a sprinkler would work fine. Today I put a dart through a 2x4 at 140 psi.
Posted: Thu Dec 11, 2008 1:18 am
by POLAND_SPUD
my answer is.... 3/4 QEV
forget about sprinkler valves QEVs are the way to go.... oh yeah and notice the fact that 3/4" QEVs are only a little bit more expensive than 1/2" ones..
Posted: Sat Dec 13, 2008 4:09 pm
by LCTChamp
Sorry I didn't reply sooner, but I've been busy.
Psycix the metal construction doesn't really matter like I said in the original post I can only go to 100psi.
Posted: Sat Dec 13, 2008 4:14 pm
by Ragnarok
I was about to respond with a link to some tests that were done on Spudtech's forums between these two valve sizes, but the archive seems to have done a runner... link's dead.
The QEV won out by a pretty large margin though.
If I were you, I would seriously consider Poland_Spud's recommendation. A 3/4" QEV will be an even better choice.
Posted: Sat Dec 13, 2008 4:16 pm
by Gippeto
If you're going to buy a valve, assuming that the costs locally are near each other or not of concern (When does that ever happen?) I would say, get the qev.
It will have a wider range of applications (for future re-use) than the sprinkler valve, and you won't have to mod it either.