Really dumb question about RO/DI systems

[telijah]

Right now, my system is under the sink, and I have a ball valve on the source line to turn the whole system on/off. I want to tap into the line pre-DI stage for drinking water, but not using a tank/storage system and also hooking up an auto shut-off system.

Now, if all I did was tap in the new line, I would have the problem of water running through and out the waste line and product line if I simply open the valve to the whole system just for drinking water. How do I logically do this? Initially, I just thought a valve pre-DI stage, a valve on the line for drinking water, and a valve on waste line would suffice, allowing me to simply keep the source water "on" for the whole system, and if I want drinking water, just open the valve on the drinking water line, and if I want to make RO/DI water, just open the other two valves... but is that OK for the other two lines to stay closed, essentially keeping the whole system under pressure all the time?

Not sure why I am struggling so hard with this at the moment, and it's making me feel really dumb at the moment.

 

[Mark Bianco]

If I am understanding you correctly you want to drink filtered, but not RO or DI water? If that is the case then all you would need is a Tee valve on the tubing before it enters the RO membrane.. If you wanted to drink filtered / RO water then the rejection water from your system need to be on and you could put the Tee valve there.

 

[Sonyardo]

It sounds like you need to get an auto-shut off valve for the RO filter. That will allow you to split the product line of the RO filter and divert one end to a ball valve for drinking water and one end to the DI filter. The waste water will only run when the when the water is flowing thru the DI filter or the drinking water valve. You can set the DI filter up with either a manual ball valve or a float valve on a storage container. Beware that float valves are not full proof and do fail in the open position from time to time. It's a good idea to keep water storage tanks in areas that an overflow will not cause water damage to the property.

 

[AlexAquaFX]

If you are looking to tap into your RO/DI unit for drinking water, I recommend a T after the RO membrane but before the DI. Then just add a ball valve to that line and you will easily be able to have RO water for drinking on demand. RO removes alot of contaminants including fluoride, so I recommend Ting in after the RO membrane and not before.

 

[ggsteve]

If you are looking to tap into your RO/DI unit for drinking water, I recommend a T after the RO membrane but before the DI. Then just add a ball valve to that line and you will easily be able to have RO water for drinking on demand. RO removes alot of contaminants including fluoride, so I recommend Ting in after the RO membrane and not before.

My RO drinking water system has a check valve after the "T" but before the bladder tank to the drinking water too.

 

[telijah]

OK, I said pre-DI, which is the same as post-RO, so we're on the same page. I guess a 3-way valve on the line between RO and DI would work, and would still just have to manually open the source each time I want to fill a container of drinking water... not terribly inconvenient I suppose. Should I still expect the flow rate from the RO drinking water line to be the same as the DI or product water line?

 

[telijah]

How do this look (original diagram from SectraPure and I chopped out the tank which has a float valve after the DI stage). I have this exact setup, minus the ASO valve and check valve, but would plan to install them in the same locations. The box in the upper-right corner would be where I think I could install the 3-way valve (provided it has an all-closed position) on the line after the ASO and before the DI stage. If left in the closed position, then NO water should flow anywhere, is this correct, since the ASO would shut the feed off on the line before going to the RO membrane...? Or would I need another 2-way valve to open and close the line just after the ASO and before the 3-way if the 3-way does not have an all-closed position.