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A small valve for a change

Posted: Mon Jul 02, 2007 10:30 am
by dongfang
Hi,

There's lots of talk of big valves .. but does anyone know about a smaller alternative to sprinkler valves? It's for the fuel in my jet hybrid gun project - butane and air will mix downstream[/] of the valves.

So, does anyone have an idea for a valve that can be triggered in the same way as a modified sprinkler (and in parallel with it), has moderate dead space and with a flow capacity of about 1/10 th of an 1" sprinkler valve? (of course the exact flow ratio of the two will be controlled by a ball valve in series with either the air or the fuel valve).

The only idea I have come up with is to use liquid fuel instead, and then use an automotive injector valve with some overpressure on the supply side .. but I'm not sure how good an idea that really is. And it's clumsy with one pneumatic and one electric valve.

Regards
Soren

Posted: Mon Jul 02, 2007 10:46 am
by spud yeti
I guess you could use a ball valve couldnt you? Or you could look at all the piston valve options. But I really dont know hybrids too well, so all this info could be wrong! :wink: Hope you find this helpful!

Posted: Mon Jul 02, 2007 11:09 am
by noname
Does it need to be electric so that the valves are triggered simultaneously? I don't know if you can get the same PVC fittings and everything where you live, but you could make your own inline sprinkler valve with as much (or as little) flow as you want.

Posted: Mon Jul 02, 2007 1:59 pm
by frankrede
1/8" QEV?

Posted: Tue Jul 03, 2007 1:04 pm
by boilingleadbath
I think that a 1/8" QEV would have about 1/50<sup>th</sup> of the flow of a 1" sprinkler. (I'm not sure weather the porting on them is 1/8" or closer to the ID of 1/8" pipe.)

Yeah, I could check, but I'm lazy.

(the amount of flow goes roughly as the diameter squared)

A 1/4" QEV, however, would be approximately correct. (regardless of the seat size nomenclature)
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Alternatively, one could construct some piston valves in tees with 1/4" pipe as the exit port.

Posted: Tue Jul 03, 2007 1:08 pm
by rednecktatertosser
I thought that QEV's were advantages over sprinkler valves because a smaller QEV had a higher flow rate than a larger sprinkler valve.