I need a part, but i dont know what its called...

[maryjanesjungle]

Lets say for arguments sake i had a aeroponics grow and my reservoir HAD to be placed higher then the sprayer. Obviously if there was a power outage i would have one hell of a flood on my hands. So my questions is,.. is there such a thing as a shut off type valve that would allow for water to be pumped through it at a certain pressure level or higher, but shut off if water preasure went below that certain pressure level? I would like to use 1/4" tubing too btw,.. so something that would fit inline with that if possible. Do they make such a thing?

 

[green_thumb...]

try looking for a low pressure shut off valve

 

[maryjanesjungle]

hmmm,... not finding anything. Man this is driving me nuts, i know they (whoever the hell they are) has gotta make such a thing... i mean it's just a 1/4" in line valve that allows water through at a certain pressure but not at a lower pressure,.. anyone know what im talking about?


idea:,...
hey if i just ran more line above the top water level in the res then is below it would that keep from draining the res if the pump pumping water back up into the res shut off?

 

[jm420]

A check valve will allow theflow one way and not let it go the opposite direction

 

[wastekan]

Have yet to see one for a 1/4" line...How big is the line feeding the 1/4" line? perhaps with some adapters or creative engineering you could work in http://www.dripworksusa.com/store/freeze.php..

 

[oldschoolfarmer]

anti-siphon valve would do the trick. Any plumbing store will have one, just tell the guy at the store "I'm setting up a recirculating aquarium but don't want it to leak back out of the pump hose" he'll set you up. Or if you're searching online, "anti-siphon valve" brought up a bunch of good hits. RC stores sell them for gasoline planes and such:

example: http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXLYW7&P=FR

 

[Blunt_69]

This is what i would do.
Use a sub resevoir that sits below your aero setup. Using a pump and a level shut off valve, pump water into main rez from sub rez. You may need a good pump to keep up with outflow water supplied by the misters."

All areoponics ive seen run raised buckets, My senario introduces plenty of flood potential, as well as anything that isnt using gravity to it's benifit.. Even a valve can fail leaving a sensitive system like aero open for disaster..

 

[maryjanesjungle]

Thanks oldschoolfarmer, i think the phrase anti-siphon valve got me a little more on the right path, but i still don't know if that'll work. Let me better explain my system, (it's a little like what you were describing Blunt_69)..

Ok so the my res (which is an air tight sealed pressurized container mind you) is above my sprinkler head, and i have a sub res under the sprinkler head like Blunt_69 was talking about. The water pump is in the sub res which pumps up into the res (thus why its pressurized) and that pressure pumps out water to the sprinkler head. It's a perfect circulatory system with no leaks but if heaven forbid the the power were to go out the built up pressure in the res AND the fact that it's above the sprinkler head makes it keep squirting for a few minutes (till the pressure is gone) then just dripping because it's above (till negative pressure is created in the res) then it finally stops. But in that amount of time the sub res will over flow. And no there is no way to increase the sub res size to that of the res so it could hold all the volume of water.

So anywho,.. again what i need is a valve that allows water through it at say for the sake of example 10 PSI, but also NOT allow water through THE SAME DIRECTION (i don't need a back flow stopper kind of thing) at say 5 PSI. See the valve i need has to stop flow in the same direction it also allows it, not in a reverse direction.

On howstuffworks.com i read this about anti-siphon valve's,..

"An anti-siphon valve is nothing more than a one-directional valve. It can be as simple as a spring-loaded flap that lets water flow in only one direction"

Now although it's for air not water i found this on an aquarium site and if that little red thing in the valve were spring loaded that would do the trick i bet,.. but i cant tell if it is from the pic but i think its just a normal check valve and not what i need.

Anyone know where to find what i need?


EDIT:
heres a spring loaded one, but i don't know if the pressure i got is enough to let it close at the right time...

 

[Me2]

An anti drain valve is what your after, you`ll need one with a pressure rating to match your system.
I use them on my fogging heads,they wont open unless they see at least 58psi and they close automatically when the pressure drops to 26psi.

 

[maryjanesjungle]

I think an anti drain valve would do the trick if you could find one with a low enough pressure rating.
I use anti drain valves on my fogging heads,they wont open unless they see at least 58psi, they close automatically when the pressure drops to 26psi.

YES! That's what i think i need man,.. something that allows water through at a higher psi and not lower psi,.. where do i find them with 1/4" in/outlets? boy one that was adjustable would be the shit,....

 

[Me2]

They have a male and female end so they plug inline with the fogging head, i guess its around 1/4" on the male end, it could be 8mm though. The lowest pressure model in the range i use opens at 1.5 bar (~22psi) and closes at 0.7bar (~10psi) which may be too much. I guess a lower pressure version should exist.. somewhere.

At least you know what your looking for :wink:
Can`t find a pic but they are Netafim AD15, anti drain valves. Not expensive..maybe 75c each.
You may have to uprate your pump to make use of them if its underpowered but thats no bad thing for aero.

 

[yamaha_1fan]

http://cgi.ebay.com/1-4-Electric-So...h=item300297942253&_trksid=p4634.c0.m14.l1262

solenoid valve. Not sure if this would work in your application. Basically the valve would close when the pump turned off, and open when the pump turned on. It would have to be connected to the same timer the pump is on.

The problem you have with a pressure valve is finding one that is going to meet your exact pressure requirements

 

[Me2]

A solenoid could be a useful safety measure. They are normally closed so it would have to be powered up all the time which may reduce the lifespan. If it dies it shuts off the water.

The adv really is the best bet if your pump is upto it. The issue of the water pressure ramping up and down would be replaced by a very sharp instant on, instant off.