Question for guys with Ray's RO

[heus]

I did the initial rinse on my 375 3 membrane with 300 gal of soft water. Manual said to set flow as high as possible. Should there be water coming out the permeate hose when rinsing? Flow meters said 8gpm concentrate and around 2 gpm on the permeate side. I assumed that when you crack the pressure valves all the way open you would only get flow from the concentrate side.

[maple flats]

If you have 2 gpm you have flow. I'd adjust the pressure setting to get closer to a 50/50 ratio for rinsing. To adjust this just turn the knob that controls the pressure, back the pressure off to get both flow meters near equal.
Then, when concentrating you want to crank the pressure up to just under 275 PSI. Watch that pressure, it will slowly rise and should be set to shut down on high pressure at about 295-300 PSI, you want to back it off as it climbs. For the first few minutes I check every 3-4 minutes, after that I check every 15-30 minutes. If it climbs too high the RO will just shut down if you don't adjust occasionally. It won't take long to really love running an RO.
If you would like a copy of a real printed manual for Ray's RO, send me your email in a PM. I just sat down and made up the whole manual, 1 sentence at a time from his hand written original. Then I numbered the pages and have a table of contents. My copy is kept in a loose leaf notebook and each page in in a protective sleeve. This makes it far easier to use. My RO from Ray is a 250 but the only difference will be 1 more membrane and likely the pump and wash tank sizes.

[heus]

Dave, so when Rays manual says "adjust the valves for maximum flow" he's talking about 50/50? I had the valves backed out all the way. So in other words, yes it's normal to get flow out the permeate line during a rinse? I have Rays manual but I guess I'm not understanding it clearly.

[mellondome]

With washing / rinsing ANY ro, you want to flow across the membrane surface as fast as possible. That would mean very little pressure. You should have a high flow on the concentrate side with ss little as possible on the concentrate side.

The purpose is to flush off the surface that plugs up...which is the concentrate surface. If you try to run 50/50, you are just holding the "dirt" in place. Think about it like the surface of an air filter.. pushing air across it will clean it... pushing through it will just leave it the same. Unlike an air filter.... don't push backwards on a membrane

[heus]

So 8gpm flow on the concentrate side and 2gpm on the permeate side would be acceptable then? It was only running at around 50 psi with the pressure valve all the way open. I assumed that I would not be getting any water at all from the permeate side since Rays manual only mentions sending the water from the concentrate line down the drain.

[TunbridgeDave]

Lowest pressure and highest flow possible for rinsing across the concentrate side. Not sure why 50/50 is being suggested but that's wrong.

[Moshers Maples]

I just got one of Rays 125 expandables and need some help. I see two valves on the concentrate side, how do I set them for flushing and for normal running? It looks like one valve controls concentrate flow to the head tank, what does the valve going back to the pump do? I haven't turned it on yet and don't want to damage anything do to my lack of understanding. Thanks

[jcyphert]

My guess would be the valve going back to the flow tank is your re-circulation valve. This valve allows you to let the concentrate make a second pass on the membrane to rise your brix more. You'll get higher concentration but lower flow.