You need to clarify what you mean by "no flow".I'm not understanding your question / or what your trying to achieve. In a static condition with water in the valve body, the valve will be closed. When the solenoid opens to exit water downstream, the valve will open and there is flow. When the solenoid closes, your flow gradually slows until it is closed and there is just static pressure on both sides of the diaphragm, the upper side having more force than the other thereby holding it closed. I guess what I'm saying is that if there is water pressure in the valve, it will be closed and there is no flow????

Sorry--I've haven't explained this well. By 'no flow' I mean no water present at the valve--it would have all drained out leaving no flow and no pressure.

What I am trying to do is set up a system using two electronic valves where I can fill two connected 3 foot vertical sections of 4 inch pipe, hold the water in the pipes for 8 hours and then empty the system completely that night. The filling would be under pressure from a pump through valve #1 but the emptying would be by gravity with a second valve plumbed lower than the 4" pipes. I can see how the emptying valve would open all right assuming it is the 'low flow' kind but there would be no force to close it. I need to have it closed the following day to refill.

I may have to get the valves, etc and experiment. I was hoping there was an electronic valve that operated by a different principle. I am trying to come up with a way to raise and lower a small animal door by flotation--the site is 500 feet plus from power.

Thanks for your help.

Let me see if I have this right. You have a pump that supplys water thru valve#1 to fill both interconnected tubes.It should also fill to Valve#2 which is electically closed and the solenoid plunger will be on its seat.This second valve is lower than the tubes. So, when your ready to let the water flow valve #2 opens. You'll need sufficient head pressure to make the valve open and of course a valve designed for low,low flow. I assume you will have a timer to open and close both valves. Set the control timer so that the valve is electrically off shortly after the tubes drain. The next day valve #1 opens and water flows and fills the tubes, then on to the valve #2. the valve may sputter and flow water for a very short time until both the upper and lower chambers are full of water and then the hydraulic differential between the upper and lower part of the diaphragm should cause it to close. The fact that you have a pump supplying the pressure is helpful. THe faster the water flow into the valve the better. Think of it this way. When you install a new piping and valve system and initially start it up, everything is dry. As the piping fills and the valves fill the hydraulic forces in the valve should take over and close it. The valve seals itself shut once you have enough force on the upper part of the diaphragm to do so. So, unless I'm missing something here, you should be alright. THe one thing that does worry me is if your going to have enough flow to open valve #2. There has to be a differential within that valve for it to open. You may have to tinker with this a bit, especially with the head pressure above valve #2. Try it, let us know

Yes, you've got it right. Thank you for an excellent explanation. I'm going to set it up using an Irritrol 3/4" ultraflow 700. They claim a flow rate as low as 1/2 gpm which I think should work. This project will take some time but I'll let you know.

How about this,

Your first fitting from the pump at the first pipe can be a one-way valve or small backflow preventer. That will fill the pipe and when you shut off the pump with a timer it would hold the water in the pipes. You didn't say how long you need the pressure to remain or have water in the pipes. But you could have a pvc pipe with small holes in that would eventually leak the water out. The pump pressure would overwhelm the tiny holes in the pipe at first filling the tubes and then slowly drain it out. You wouldn't need any valves unless you want to keep the water in the pipes longer. If so,than provide smaller holes and a longer drain time. What are you trying to achieve? That would help members to figure out what are good suggestions. Aloha

THe irritrol ultra flow is a good choice.Says in the current manual that it can operate at as little as .1 gpm. You're not going to get much better than that. Pressure range is 10-150 psi. You may need to elevate the tubes accordingly to maintain that pressure throughout the entire empying cycle. If the #1 valve is below the tubes, then the supply piping will hold the water between the tubes and valve after it drains. If it is higher or nearly level, then do as lehua13 suggested and add a small check valve where the pipe enters the tube. After you get it going, we would like to know how it worked out for you. good luck

Here is what I'm trying to do--no laughing now or comments about having too much time on one's hands.

I want to open a door to a chicken pen to let them out in the morning and close up after dark. The expense of running power is prohibitive so a commercially available door opener is out. I have water at 60-80 psi and lots of left over plumbing parts from other projects. I figure to use toilet bowl floats which fit nicely inside 4 in pvc. The float would sit on the bottom of the vertical pipe (where the water would enter) and have a rod running to the top of the pipe where it would attach to a small aluminum frame/hardware cloth door. The door would run in a heavy critter proof channel, sides and bottom, and of course there would be one pipe for each side. I've already tested the door/frame and the floats float it easily. The assembly would slide up and down as the water enters or leaves the pvc pipe. Hope that is clear. I realize that friction and weight will be critical but initial test seem to show it will work. I am also concerned about using a battery operated controller but they seem to be some better ones on the market these days.

Any thoughts are greatly appreciated.

Ian

Now that is one unique idea!!. As the floats rise they are lifting the door. Thats what I call "makin do with what you got". A battery operated controller should not be a problem. Remember. sprinkler water valves are electrically ACTIVATED but HYDRAUICALLY OPERATED.

Hi Water,

Interesting application. Just curious. Where does the water go after the gate opens and closes? I know chicken poop and water mixed sure create a stink. What makes them go back in after dark? What about the mentally impaired chicken that doesn't know better than to go in after dark? Are you enticing then with an automatic feeder in the pen? I actually saw an automatic system from Australia used in Hawaii for moving cattle from one paddock to another. Quite ingenious. Aloha

The water will be piped into a nearby hedge row away from the pen. Chickens become attached to their inside roost and will make for it when it starts to get dark--no need to entice them.

Hi water,

How about a closed system with two pipe chambers and two small recirculation pumps(water fountain pumps) on a 24v battery with solar trickle recharge. One pump moves the water from the storage pipe to the lifting chamber and one pumps the water back out into the storage chamber. You could make the pipe chambers bigger so they don't fill up and trap air at the top for added pressure to help empty the chamber. Viola no automatic valves or controller. Just the pumps anf timer that runs off the car battery. Then you don't have to deal with getting rid of the water but only once in awhile one it gets ugly. Aloha

I'm sure that would work. I've also seen reference to using a car battery and a solar panel to operate an actuator to open and close the door. If my idea doesn't work I may give solar/battery a try.

Hi Water,

When you get your gate working, post a diagram of what you can up with for inspiration to others. Good luck.

Will do--and maybe some photos if I get really inspired.

After several false starts I finally got this project completed and it is now operation but in 'beta' mode--I still check it regularly.

The photo shows the two main parts during construction--the float chamber with attached door frame and the floats and door itself. The frame the door slides in is made of two 2x4's spaced to accommodate the door. Only the intake valve was attached at this time. The wood frame is attached to the 4 in pvc by plumbers tape at the bottom and screws at the top. The two 3/4in elbows are the overflow. I tried to keep the plumbing symmetrical to insure equal force in both chambers.

http://i206.photobucket.com/albums/bb67/ianamke/th_P424008.jpg

Oops! Let's try this

http://i206.photobucket.com/albums/bb67/ianamke/th_P4240009.jpg

Maybe this will work.

http://s206.photobucket.com/albums/bb67/ianamke/?action=view&current=P4240008.jpg

Hi Water,

Looks great. Larger picture please to see detail or a link to a YouTube video showing it working with the chickens. I smell a patent pending. Well done. JMHO Aloha

That link goes to photobyucket and there are two sort videos there plus other stills which I hope you can access. If not I'll try and post them separately. Obviously i haven't done this before.

But on with the story. It turned out that the drain valve (an irritrol 700) even when operated manually was exceedingly slow in closing the door. At about that time I discovered that I would have to use special solenoids with a battery operated controller. The whole idea was to do this on the cheap with left over and scrounged parts and it was starting to lose some of its appeal--especially as some controllers only worked with their valves or so they said. Fortunately, I discovered a new on the market low pressure timer that works on zero pressure.

http://www.dripworksusa.com/store/btimers.php#TLP It's about half way down the page.

I built the door using a piece of hardware cloth sandwiched between two aluminum screen door frames and then covered with a sheet of aluminum flashing. Friction caused by the moving rods that support the door gave me the most trouble. I used threaded rod and it would have been better to have bought steel rod and threaded the ends myself. I ended up inserting coppers sleeves in the wooden disks that close the tops of the tubes and fitting 1/4 inch plastic irrigation tubing over the threads. With a bit of grease it works like a charm. I'm quite pleased with how it has worked out but it was only possible because I already had most of the materials.

Waterouzel

Water,
Glad you shared your project with us, and its apparent success. nicely thought out. very unique." Making due with what you got"

Hey Water,

Coolest thing I have seen on this website. Congratulation. You have earned your hydraulic engineering degree in one project. Show a university engineering professor the vids and pics and he will eat it up. JMHO Aloha

Thanks guy--don't know about the engineering degree but it has been fun. I couldn't have done it without your help and encouragement. Now if I can just come up with a way to keep wild turkeys out of my vineyard--water cannon maybe?

Waaterouzel

H2O,

battery powered motion sensor hooked up to a solenoid valve hooked up to a pressurized hose. Well maybe.

Aloha.