RO/DI and solenoid use question

[saf]

I am in the process of setting up my RO/DI unit to a float switch and solenoid so that I could leave it unattended. My question is where to incorporate the solenoid so that the water is turned off when it hits to float valve.

Another question is does the waste water continue to run even if the float switch turns off the "good" water?

thanks,

Scott

[Reefmaniac1]

By solenoid, I take it you mean the Automatic Shutoff Valve (ASoV)?

If so, here's the answer you're looking for:

"Looks very complex, but is really very simple. The water is simply traveling across the valve from left to right or right to left depends on how you look at it. Pure water travels across the top of the unit, the filtered water across the bottom. The valve has a top and a bottom. The top is the side with the (4) screws visible. The bottom has no visible screws and is marked in and out. The bottom of the valve is connected between the pre-filters and the membrane. Water from the pre-filters is directed to the ASOV(in). The filtered water continues from the out of the ASOV to the membrane end with only one connection, the membrane water inlet. So the bottom of this valve got in between the filters and the membrane. The top the side with the (4) screws connects across the pure water line, from the membrane pure water outlet. The pure water outlet of the membrane is on the membrane housing end with two connections. One connection goes to drain and the other is the pure water. The drain connection is not the one you want. Once you have located the pure water line, cut it and install the automatic shut off valve. Now the pure water path is interrupted by the ASOV as well."

[AZDesertRat]

You put the solenoid on the good water line so it shuts off when contact is made between the switch and water level. If you have an autoshutoff valve then yes the waste flow will also shut off.

[agoutihead]

well how does the water not continue to be made?

does the valve put enough pressure against the ro/di unit so that it just doesnt keep pumping water out?

i figured you would put this valve in the "main" line into the ro/di unit?

[manderx]

an autoshutoff valve uses the backpressure on the closed off 'good' line that goes to your tank to pinch off either the 'waste' water or the raw 'in' water depending on how you have it setup. though if you are using a switch and solenoid, the best place to put the solenoid if it's close enough is on the raw 'in' water. in this case any potential impurities from the solenoid(some have brass parts inside) are taken care of by the RO/DI, plus the unit isn't sitting there pressurized all the time.

[agoutihead]

yeah i like that idea best. put it right on the water main. thanks.

[AZDesertRat]

I prefer to keep my unit full of water and pressurized all the time to prevent any bacteria growth and to keep both the membrane and DI wetted as required. The autoshutoff valve does just that, once my pressure tank is full it shuts the flow off as well as the waste.

[agoutihead]

where is the best place to get one of these? ebay?

are there different kinds?

[agoutihead]

http://www.fishbowl-innovations.com/img/FAS_float01.jpg

what scares me about this setup, is that it has suction cups, and i know suction cups have the tendency to fail overtime from being in saltwater. so what happens if and when the suction cups stop working and the float valve just falls into the water?

[agoutihead]

????

[agoutihead]

bump

[AZDesertRat]

The 16th thing down on this page is an autoshutoff valve. It attaches to the RO unit and not the tank or water storage container. The 3rd and 4th things down are float valves that can be used in something like a rubbermaid brute trashcan or other vessel to stop the flow in conjunction with the autoshutoff valve.
http://www.buckeyefieldsupply.com/showproducts.asp?Sub=109&showspecials=109
Or for a more robust liquid level controller you would use an electric float switch like you pictured in conjunction with an electric solenoid and the autoshutoff valve. Places like autotopoff.com sell packages like that.

[DarG]

<a href=showthread.php?s=&postid=9996047#post9996047 target=_blank>Originally posted</a> by agoutihead
http://www.fishbowl-innovations.com/img/FAS_float01.jpg

what scares me about this setup, is that it has suction cups, and i know suction cups have the tendency to fail overtime from being in saltwater. so what happens if and when the suction cups stop working and the float valve just falls into the water?

My float is in a rubbermaid garbage can. The Suction cups are worthless. Put a small bead of silicone around both suction cups, just inside of the outside edge and then seat the float switch assembly where you want it in your water container. If it's going in your sump, just drop the water level a few inches for a day to give the silicone some time to cure. Do not press down on the suction cups to make them stick. Just seat them lightly so that the silicone makes good contact and smears just a little bit. My solenoid valve is on the supply water, before the first canister. Since it kicks on with even a small drop in the water level, the system doesnt sit dry for more than a couple of days. I'm always using my ro/di for something. Whether it's just a gallon or two to rinse out my filter bags twice or 3 times a week or refilling the container for my 2 part dosing pump, it's always something so the system never dries out.