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Sprinkler valve question
Posted: Sun May 10, 2009 12:29 am
by Mike_Hunt0420
How well do you think modding one of these would work?
http://www.sprinklerwarehouse.com/Rain- ... 100-gb.htm
I'm trying to work on a high preasure copper sniper.
Posted: Sun May 10, 2009 12:36 am
by Carlman
Probably decent enough but for that price you may aswell buy a qev if its a premade valve your after.
Posted: Sun May 10, 2009 12:40 am
by Mike_Hunt0420
tell me more of these qev valves. they premade just for spud guns?
Posted: Sun May 10, 2009 2:41 am
by inonickname
Mike_Hunt0420 wrote:tell me more of these qev valves. they premade just for spud guns?
I think you need to do some research.
A QEV is a quick exhaust valve which is pneumatically actuated. They usually have a piston valve while a sprinkler valve usually uses a diaphragm.
Basically a piston valve made to high tolerances
Posted: Sun May 10, 2009 10:14 am
by Carlman
Not true ion, diapragm qevs are made to just as higher tollerances as piston or shuttle qevs are.
Posted: Sun May 10, 2009 11:21 am
by Technician1002
Mike_Hunt0420 wrote:tell me more of these qev valves. they premade just for spud guns?
A QEV Piston or QEV diaphragm is a QEV only because of the ratio of the diameters and barrel sealing configuration. If the seal is small in relation to the diameter then the pilot pressure is the main mover of the valve. The valve speed is directly related to the rate the pilot is vented.
In a QEV, piston or diaphragm, the close diameter ratio increases the positive feedback on the valve as it opens, so the large area with a pressure change (barrel facing area) avalanches the valve open so the valve speed is no longer governed by the rate the pilot can be vented. It is designed to pop open when it opens.
I have a little write up on them on this other forum on QEV valves which goes into some of the math that makes them pop open.
http://www.crazybuilders.com/forum/showthread.php?t=18