RO/DI ASVx2? - Drinking & Topoff help please..

[Anonymous]

Just curious what a good (if possible) configuration might be for hooking up two pressurized reservoirs (with shut-off valves) to one RO/DI system.

All I currently have is a basic RO/DI system with fiber prefilter, carbon prefilter, RO membrane and a single DI chamber.

I'd like to hook up a 3-5 gal pressurized drinking water reservoir AND a 3-5 gal pressurized topoff reservoir and have them both capable of shutting off the source to the RO.

Effectively, this (quick rough drawing) - but I'm not entirely sure where to put the ASV(s)..

Also... - Both feeds will have to punch up from the basement to the main level and the feed running to the top-off will be about 40' away. - Will one (or both) need a booster pump after the reservoir as well?


Many thanx!

Norm

 

[Anonymous]

I would think having two pressurized canisters would just put twice the backpressure on your membrane really yanking production down.

Something I used to do was have it all go to a canister after the RO membrane, then tee the output of the canister to carbon for drinking or DI for tank water, since the tank water is top off it really doesn't need a huge supply of it at any one time, and if I need to drink it then I have an ample supply for that as well.

I yanked the system when I moved all my tanks downstairs, plus the water occasionally would constantly produce waste water and really cheese me off, if I turned off the supply of water to the RO unit (thinking this would fix things) then the pressurized canister would end up emptying over night.

 

[Anonymous]

As usual, let me start off with an insult or two.

:wink:

I would think having two pressurized canisters would just put twice the backpressure on your membrane really yanking production down.

Pressure does not double like electric potential. The pressure is the same if identical reserviors are used. Don't read too much into series/parallel configuration.

Now for the two cents:
sfsuphysics configuration is typical, that is, have the bladder tank being feed by the RO, and when RO water is needed, a tee will go to a carbon post filter for drinking, or a DI for RO/DI water. This is the most logical configuration.

Since you have two bladders, I would connect them together if you have no other use for the spare one. This way, you will have good 6-10 gal of RO water when you need to make a small water change or when making a bucket of fruit punch for the football team.

 

[Anonymous]

:lol:

Ok, so better to have post-processes after the reservoir(s). - Makes sense and makes installing ASV a lot simpler too!

Thanx!

 

[Anonymous]

damn hydrodynamics... I would think that if two lines each of equal pressure, fed into a third since the force at each line is (say 15psi x .0001 in^2), feeding into a 3rd line then you'd have twice the force for the same line size hence doubling the pressure. But you have to go complicate the matter *sigh*