RO Issues

[BRL]

23052
23053
23054

Hey Everyone, I built this RO and I can't get it to work. On start up Concentrate needle valve is fully open, recirc needle valve fully closed, turn on low pressure pump and most of the flow is coming out of the permeate line?? (at 40psi I would think this shouldn't be flowing at all???) I am feeding the membrane from the bottom, flow arrow on membrane is pointing up, U-cup seal at the top with the seal in this direction /\. Sap enters the bottom in the outside port, drain valve in the center port. Condensate exits top outside port and permeate exits top center port. Am I missing something here? Membrane is a 4x40 from RO bucket. High pressure pump is a goulds gb20. I'm only running a single membrane right now, I was thinking the pump might be to much for a single membrane but the low pressure pump is pushing through. Sap enters at 2% and comes out at 2%. Any ideas or tips appreciated.

[BRL]

Picture shows sap entering the top I changed it to entering the bottom.

[ronintank]

23055
this is a standard diagram for ro flow

[eustis22]

pump on either side of the filter? pressure gauge on concentrate o/p line?

[Maples Maple]

BRL,
ronintank provided a standard diagram for a RO with recirc.
It would be helpful if you posted a diagram of our system. Include the filter location, pumps, each needle valve and the pressure gauge locations.
That way people of the forum can give you some feedback.

BTW, it looks really nice. I hope you get it working correctly.

[BnSmaple]

Not positive but I think your membrane is in upside down….I just built 2 for friends this year and the o ring seal on outside of membrane has to be on same side as the intake to housing

[Bricklayer]

Things to check.

1. Membrane seal must be on the feed side.
2. Feed inlet is the outside most input on the housing the other end will be your concentrate out line.
3. Your permeate line is the middle input on the housing. Whatever end you are using as your permeate out line. The other end must have a plug in the housing cap.

[blissville maples]

Check the u cup seal, that's a huge culprit of this symptom. Shouldn't matter how you pressurize the membrane top bottom side shouldn't matter. Some membranes are not directional, CDL being one. I would crank down concentrate valve til pressure is up you may be using it as simply a pump and not be concentrate if pressure not up.

[eustis22]

Does anyone ever place the membrane housings so that the concentrate/permeate ports are uppermost? how about sideways? asking for a friend.

[craigwade2005]

Does anyone ever place the membrane housings so that the concentrate/permeate ports are uppermost? how about sideways? asking for a friend.

Mine is set up that way. Feed comes into the bottom, with a plug on the other port.
Concentrate and permeate are both our of the top.
Lots of other designs run their housings horizontal as well.

[BRL]

Finally got the RO figured out yesterday. All I can say is wow! And we are only running one membrane right now. So the problem was I messed up the permeate o-rings when I slide the membrane into the cap. Running it at 250psi with .6gpm concentrate going to the evaporator, 1.5gpm permeate, and recirculating over 5gpm (flowmeter only goes to 5, should be better with 2 membranes). Here is a clip of the first run yesterday.

https://youtube.com/shorts/8nW_GJW9KPI

[ronintank]

Glad to see you up and running.