Running membranes in series

[Bricklayer]

I'm trying to wrap my head around how to plumb my membranes. I'm going to be running 2 4" x40" xle 4040's. I wish I could post a sketch but my iPad dosnt seem to have any sketching apps. My pump is mounted vertical so my feed from the pump has a 1" fitting to pump head then tees to a 3/4" line to membrane and the other side of the tee is 3/4 also and that gets the recirc line. From there I go to the first membrane mounted vertical I will be feeding from the bottom of membrane casing. At the top of first casing my concentrate gets fed to top of other membrane. My question is how do the permeate lines get connected neatly. The permeate out line is top of one and bottom of other. Do the lines need to be equal to even pressure or does it matter. The pressure going into the second membrane is obviously going to be lower then what's going into first membrane. Is there a booster pump needed in between membranes? I plan on switching membranes every other cycle to keep them equal. I tried looking on the site for pictures but not a lot of them show the complete diagram of a 2 membrane in series plumbing schematic.

[wishlist]

Tie all the permeate line together at one end . Permeate can feed out either end. On my 3 membrane unit I feed the first membrane at the bottom and tee'd all the permeate lines on the top .

No booster pump between membranes .

[Bricklayer]

So the permeate can exit the same end as the concentrate goes in?

[Urban Sugarmaker]

So the permeate can exit the same end as the concentrate goes in?

Yes! It does not matter which end. Just plug the opposite end.

[Bricklayer]

With this setup what way does the brine seal ( o ring end) go into the housing?

[mellondome]

Always put the oring in the end that you will put the membrane into the housing. Don't push the oring the entire length of the housing.

[seandicare]

just my 2 cents....don't run permeate lines into one....keep them separate and run them into your collection tank......that way you can test them periodically for sugar, and if one membrane is leaking sugar you'll know which one instead of having to check each membrane

[Bricklayer]

All my cannisters are vertical and my feed lines and concentrate line connections will all be at bottom of cannisters. All top caps of cannisters will be capped of with a plug. So oring goes down in this case on both membranes?

[mellondome]

Are you going to physically install / remove the membranes from the bottom? Most would do this from the top, in which you would put the oring on the top.
For the permeate lines, are you putting in a flow meter for permeate? If so, where are you locating it? If only 1 meter, you will need to plumb the permeate together before the meter. Another option is to put a meter on top of each membrane, then flow them through a common pipe to your collection tank.

[Bricklayer]

I have a permeate flow meter so my lines will be connected. What is the purpose of the oring on the membranes? If it really doesn't matter what end the go on?

[Clinkis]

Somebody correct me if I'm wrong but I believe you need to feed the membrane at the end with the brine seal. They are designed to have pressure on that side which make it seal. At least that is what I did on mine.

[Bricklayer]

This is the info I found on the xle 4040. Could not find any info on how it goes in series or parallel. Or if the brine seal goes on pressure side or outlet side. In my case my feed side and outlet side are the same end so this is why I'm a bit confused.
http://i1070.photobucket.com/albums/u495/bottenhof/Mobile%20Uploads/2016-04/4C15BE8E-E637-4A65-9AA5-DA3DCE02F629_zps6ika1oyj.png (http://s1070.photobucket.com/user/bottenhof/media/Mobile%20Uploads/2016-04/4C15BE8E-E637-4A65-9AA5-DA3DCE02F629_zps6ika1oyj.png.html)

[Urban Sugarmaker]

I went through this same confusion setting mine up. Basically, it does not matter which end the brine seal is located. What does matter is its orientation. You want the "U" facing the incoming flow. The brine seal is also known as a "U-cup". If your membrane is vertical and will be supplied raw feed from the bottom, you could insert the membrane in from the bottom (if you can tilt the unit) and U-cup could be on the bottom with the U facing the floor. Or, you could flip the membrane over and insert it into the canister from the top, but now you have to remove the U-cup, turn it over and re-install so the U is again facing the floor. Of course this all assumes you are feeding the membrane from the bottom. If feeding from the top, then opposite would be necessary.

[wiam]

All my cannisters are vertical and my feed lines and concentrate line connections will all be at bottom of cannisters. All top caps of cannisters will be capped of with a plug. So oring goes down in this case on both membranes?

Concentrate has to come out opposite end from sap coming in.

[Bricklayer]

Finally found a kids drawing app to sketch it out. This is the way I think it has to be plumbed to work. If there is a better way with less tubing let me know
http://i1070.photobucket.com/albums/u495/bottenhof/Mobile%20Uploads/REVERSEOSMOSIS_zpszarckm8a.jpg (http://s1070.photobucket.com/user/bottenhof/media/Mobile%20Uploads/REVERSEOSMOSIS_zpszarckm8a.jpg.html)

[gmc8757]

I think you want one more needle valve on the recirc line?


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[wiam]

I think you want one more needle valve on the recirc line?


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Both my Memtek and my Seprotech are plumbed similar to the drawing. Neither had any valve in the recirculation line.

[Bricklayer]

Very primitive drawing I know. Sorry about that. I do have a needle valve on the recirc line. Forgot to mark it. And I forgot to mark the orientation of the brine seal oring end of the membrane. But I would assume the oring would be at the inlet side where the sap feed enters on #1 and where the concentrate enters on # 2 so basically at the top of the membrane housings?

[Tweegs]

FWIW, this is how mine is set up.
The valves are electronically controlled but could be manual.

14231

[WVKeith]

Bricklayer, maybe the simplicity of the drawing does not show it, but I would think that you would want to make sure that the re-circulation line goes into the inlet side of the high pressure pump.

[Bricklayer]

It does. My drawing is very basic. The recirc line goes to a needle valve first then a flow meter then a tee that is on the inlet of the hp pump.

[Bricklayer]

Found this info on the Dow website. Tons of info there if you look deep enough
http://dowac.custhelp.com/app/answers/detail/a_id/452/kw/O%20ring