ASOV and float valve

[ramsey]

Hey Russ,

I'm wondering if there's any type of maximum length from an ASOV/RO unit to a float valve. I currently have an ASOV hooked up to a container in my garage but I'm thinking about hooking up 2-3 more connections to various top-off containers (and have solenoids on a timer). Is there a limit to how far I could run a line? The longest will probably be about 20' or so. I know the ASOV works by pressure so I want to make sure it'll still work.

Thanks man.

[BuckeyeHydro]

You should be fine. The ASOV works off pressure, rather than the volume of water in those lines. To the extent possible try not to run those lines uphill. You lose about 0.5 psi of Net Driving Pressure for every 1 foot those lines go uphill.

Russ

[ramsey]

Thanks Russ. I'll give it a shot. One of the runs is going to the second floor of my house but that'll be from the RO unit.

Solenoid > RODI > T > float valve in ATO container

Do you think losing some pressure would be ok if it's happening after to RO unit?

[BuckeyeHydro]

Not sure I follow. My post above was referring to lines running uphill after the membrane.

Russ

[ramsey]

Yeah, that's why I'm asking. My RO unit is in the garage but one off my top off containers is on the second floor so it will have to go up one story after the DI. Hopefully that's more clear but if not, I'll call you Monday.

[BuckeyeHydro]

If it has to go up 10 feet, that would equate to 4.3 psi. So if your feedwater pressure is good - say 65 psi, then your net driving pressure would be reduced to about 61 psi by the head pressure alone. No big deal.

But if your feedwater pressure is low - say 42 psi, that would reduce the net driving pressure to about 38 psi - that might be a big deal.

Remember that the effects of reduced pressure on rejection are more acute at the lower end of the pressure scale. See the example below from a 75 gpd RO membrane.
http://i224.photobucket.com/albums/dd293/BuckeyeFS/256fe891-aae3-416f-8e99-bc14ac32a7ab_zps2bfaba53.jpg (http://s224.photobucket.com/user/BuckeyeFS/media/256fe891-aae3-416f-8e99-bc14ac32a7ab_zps2bfaba53.jpg.html)

[ramsey]

Perfect Russ, exactly what I needed! My feed is about 60 psi so I should be good. I might consider a booster pump too. Thanks again man!