SpudFiles

Does anyone know the performance comparison between a 1'' moded sprinkler valve and a 3/4'' Q.E.V. ?
I can get a 1'' sprinkler valve, blowgun, and everything to attatch them for $20. The cheapest Q.E.V I could find were $50. Just trying to figure out if it's worth it.

if you pay $50 for a 3/4'' QEV then you are getting ripped off, but to answer your question a 3/4'' QEV will out proform a 1'' sprinkler valve. its not a dramatic increase in power, but it is noticable.

a 3/4'' QEV isnt worth much more than $25, but even that is a little high.


edit-

I know how the sprinkler valve works. Doesn't a Q.E.V. work the same way?

they work simularly, yes, but a QEV is set up slightly differently and has more flow, even though it's outlet is smaller.

I found a website where they were selling Q.E.V.'s for $30 a peice, but you had to buy 10 minimum. Anyone know where to get them for a good price?

www.mcmaster.com if you live in the US. They probably ship to Canada too, but im not sure.

How about international? Here in Singapore I only know Fasternal but it sells aluminium or zinc QEVs at around 35 a piece.

flamerz14 wrote:How about international? Here in Singapore I only know Fasternal but it sells aluminium or zinc QEVs at around 35 a piece.

Fastenal is the only place I could find around where I live, but they are expensive, 140 dollars for a 1" qev: http://www.fastenal.com/web/products/de ... ku=0443032
You're probably better off finding one off of ebay.

I recall being shown some comparison done between a modded 3/4" sprinkler and a 1/2" QEV some months back- I think it was on spudtech...
Hang on, I'll use the fancy new spudfiles tool bar to find out...

Here we are:

For the velocity figures;

3/4" Pneumatically modded sprinkler valve, 40 CI chamber, 5' CPVC
barrel, 100 PSI, shotgun slugs for projectiles (425 grains):

376.8 fps
402.2 fps
389.6 fps
359.4 fps
413.7 fps

Average: 388.3 FPS

1/2" Quick Exaust Valve, 40 CI chamber, 5' CPVC barrel, 100 PSI,
shotgun slugs for projectiles (425 grains):

529.6 fps
487.5 fps
498.1 fps
507.9 fps
563.2 fps

Average: 517.3 FPS

3/4": 388.3
1/2": 517.3

That's a major change in energy, over ³/₄ more, just for changing the valve. I think that might well be more than worth it.