What are your RO pressures and flow rates?

[madmapler]

I was looking at some older posts where guys were talking about running their 8" membranes at around 250 to 300 psi. I run my 2 post at around 500 because that's what the guy I bought it from told me. They are xle 440s. My membranes have been through the course this season and aren't doing all that great. At 500 psi, I start out with 14 gpm permeate and 4 gpm conc. with 40 degree sap. It drops quickly and soon is at 4 gpm conc. and 8 gpm. permeate. where it pretty much stays at and slowly drops a little lower as I recirculate it. I thought it would be interesting to hear to hear how other ROs perform. Mine is an old memtec with a separate recirc. pump.

[Sunday Rock Maple]

I was looking at some older posts where guys were talking about running their 8" membranes at around 250 to 300 psi. I run my 2 post at around 500 because that's what the guy I bought it from told me. They are xle 440s. My membranes have been through the course this season and aren't doing all that great. At 500 psi, I start out with 14 gpm permeate and 4 gpm conc. with 40 degree sap. It drops quickly and soon is at 4 gpm conc. and 8 gpm. permeate. where it pretty much stays at and slowly drops a little lower as I recirculate it. I thought it would be interesting to hear to hear how other ROs perform. Mine is an old memtec with a separate recirc. pump.

We have two Mark E8's also at 500 PSI on an HC2. Our numbers are similar in that we hold the concentrate steady at 8% out at 4 gpm (with 1.8% sap in at 44 degrees) and average around 13 gpm permeate for 17 gpm total flow.

[blissville maples]

have u tried acid wash, the high pressure is ok, downside is packs membrane more and should use acid

[gmc8757]

We have two Mark E8's also at 500 PSI on an HC2. Our numbers are similar in that we hold the concentrate steady at 8% out at 4 gpm (with 1.8% sap in at 44 degrees) and average around 13 gpm permeate for 17 gpm total flow.

I'm just curious...what if you ran your setup at 250psi? What do you think your flow rate and/or concentrate percentage would drop down to?

I'd be interested in knowing what a single post 8" would do with a procon pump rated at 250psi. I know it would depend on whether a recirc pump was involved, so let's say no recirc pump. Any idea or guesses?


Sent from my iPhone using Tapatalk

[madmapler]

have u tried acid wash, the high pressure is ok, downside is packs membrane more and should use acid

If you're asking me if I've done that then yes. I soap washed then acid then soap again. I'm washing now after every 3000 gallons and I think I'll get through the rest of the season if I'm careful. Not much of it left anyway I think. I am really surprised they are doing as well as they are. They got frozen solid a few days before the season began and I recently overheated them tremendously.(150deg.+)

[NH Maplemaker]

Joe at Atlantic RO ( God rest his soul) told me that the XLE run better at 300 PSI! That's were I run mine.

[Ontario Ian]

I have a single post cdl 600gph. I run just a hair under 500psi with 2gpm, I think 7gpm permate (don't pay much attention to this flow) with h20 membrane.

[gmc8757]

I have a single post cdl 600gph. I run just a hair under 500psi with 2gpm, I think 7gpm permate (don't pay much attention to this flow) with h20 membrane.

What percent concentrate are you getting at 2gpm?

[Quabbin Hill Farms]

Yes Joe also told me that the XLE means Extra Low but if I run mine at 300 I don't get much concentration. I called him for some advice last year and his wife told me he was sick , but I didn't know he had passed away. He was always helpful and fun to talk to.

[Ontario Ian]

What percent concentrate are you getting at 2gpm?
12-14% depends on sap %

[gmc8757]

Thanks for the info Ian.

Quabbin, what do you get if you run at 300psi?


Sent from my iPhone using Tapatalk

[madmapler]

Yes Joe also told me that the XLE means Extra Low but if I run mine at 300 I don't get much concentration. I called him for some advice last year and his wife told me he was sick , but I didn't know he had passed away. He was always helpful and fun to talk to.

xle's can handle up to 600psi. Joe was a great guy. Without his adapters, we will no longer be able to use the xle's unless you already have them. His nephew said the design died with him.

[Quabbin Hill Farms]

Maybe 4% but not much more

[gmc8757]

Maybe 4% but not much more

No kidding? So you will only bring sap up to about 4% running at 300psi on an 8 inch membrane? I'm looking at putting an ro together..contemplating going up to an 8". I see the housings are rated at 300psi,450 and 600. If you told me you got great results at 300, I may have stopped there, but looks like I should bump up

[Quabbin Hill Farms]

I have three 4"x 20" membranes in my unit. I normally run it at 500 psi and that gets me to around 6. This is an old unit 1980 era so it will normally double whatever the raw sap coming in is.

[Quabbin Hill Farms]

Sean guess i was lucky I had him make me three adapters before he got sick.

[madmapler]

Sean guess i was lucky I had him make me three adapters before he got sick.

I've got 2. Problem is, I'm going with a 4 post next year. I plan on holding on to them . Maybe seeing if I can get them made. Your numbers for concentrating sound pretty realistic.

[ennismaple]

I was getting just over 9 GPM permeate and 3.5 GPM concentrate flow rate yesterday at just shy of 400psi which works out to 750 GPM processed. If we are re-circulating back into the sap tank we can run 9 and 9 for several hours at about 250psi. After a few hours the concentrate flow rate goes up as well as the pressure.

We do a rinse every 4 hours which brings the performance back. I can't imagine how bad it would have been plugged up had I not rinsed it twice yesterday!