Dow RO menbrane Mark E4 or Mark E8

[ethanclare]

Spoke with Dow today and they recommended the Mark E4 over the XLE4040. Is anyone familiar with this filter? Is it fairly new?

[Mathieu]

The Mark E4 is the 4'' version of the Mark E8. Better performance than the NF70-4040 and NF90-4040 with similar mineral rejection.

[Amber Gold]

Lapierre had some Dow Rep.s at their open house and they were very helpful. The Mark E4 and E8 were designed for sap, not water...different membrane material I guess...and these are the latest and greatest for sap concentration. Supposedly they don't pass any sugar or minerals, but I don't know how they flow in comparison to other membranes. Currently, these are only available from maple suppliers.

[802maple]

The simple answer is if one is faster then another on the permeate side , it is passing minerals or sugar of some kind.

[Amber Gold]

If that's the case, then why does the XLE (99% retention) flow faster than the NF-90 (85-95% retention)?

[gmcooper]

Amber Gold according to Dow info the XLE do not flow faster than NF-90. XLE has better retention and more surface area but is slower tha NF90. NF 270 fastest flow but has least retention of the 3. If I remember correctly the Mark 1 fall some where between NF 270 and NF 90 with better retention and also has more surface area. I have not seen the data but some must have it to compare where the new Mark E4 & E8 are flow wise.

[lew]

I can only tell you what my experience was with the Mark 8's this past season.. I have 4 8 x 40 membranes in a new CDL RO. I was able to take 1% and turn it inot 12% in a single pass with flow rates of 3.5 gpm concentrate and 26.5 gpm permeate. I could not find any passed sugar in the permeate. Not very scientific, but I reduced the permeate in the microwave by boing a cup down until there was almost none left then put it in the refractometer and it still read 0. I was very pleased with them. Also when runing the machine with 1% sap the highest pressure I achieved was 330 psi.

[Sunday Rock Maple]

We had a new Mark 8 membrane this year and were very pleased with it. Passed no sugar, ran on low pressure 300ish (like Lew said) and no issues or problems. It replaced a Hydranautics that passed sugar (unsure as to why) and was almost twice as expensive as the Mark 8.

[Greenwich Maple Man]

I have the Mark E8 . It works great. Passes zero sugar. I ran around 350 psi and had great flow. Hope this might help .

[Mark]

The XLE is way faster than the NF-90 because the NF-90 fouls out real quick. My NF-90's went in the trash after the first year.

[Amber Gold]

gmcooper - See the link below which is where I got my info. XLE's flow 2500gpd @ 100 psi and the NF-90's 1500gpd @ 70psi. When I put my XLE's in this season, I was getting ~270gph @ 250psi compared to 200 gph @ 200 psi on the 90's, but the 90's are pretty old is part of the difference.

http://www.americanro.com/1772776.html

I like the XLE's, but need to figure out why they passed sugar. To cut my losses, I'll be buying new membranes for 2013 and considering the XLE's or E4's.

[tuckermtn]

does anyone know what the price is for an 8x 40 mark E8? Lew- I assume those gph numbers are for your entire machine (vs. just one membrane) Does anyone have any expereince with flow rates and %s for a one (8 x 40) -membrane machine?

[Sunday Rock Maple]

About $900 for a Mark8 if I remember correctly from last year. We have an old Coster B300 and were getting 390 gallons total (of which about 90 gallons was concentrate at 8%) flow per hour on 2% sap at around 300 PSI. I think your machine would vary depending upon what you have for pumps.

[gmcooper]

gmcooper - See the link below which is where I got my info. XLE's flow 2500gpd @ 100 psi and the NF-90's 1500gpd @ 70psi. When I put my XLE's in this season, I was getting ~270gph @ 250psi compared to 200 gph @ 200 psi on the 90's, but the 90's are pretty old is part of the difference.

http://www.americanro.com/1772776.html

I like the XLE's, but need to figure out why they passed sugar. To cut my losses, I'll be buying new membranes for 2013 and considering the XLE's or E4's.

Ambergold I stand corrected. I had copied down the info from Atlantic RO and transposed them. Sorry about that.

With your manbrane passing some sugar is it possible it was a seal that leaked?
Mark

[tuckermtn]

About $900 for a Mark8 if I remember correctly from last year. We have an old Coster B300 and were getting 390 gallons total (of which about 90 gallons was concentrate at 8%) flow per hour on 2% sap at around 300 PSI. I think your machine would vary depending upon what you have for pumps.

I would guess your coaster and my Memtek might be two birds of a feather. I have a 5hp magikist piston pump and a recirc pump with one 8"membrane. I typically have been getting 350-400 gph through my NF 270. My system is ment to be run at higher pressures- like up to 500 psi- as the old membranes used to need more umph to concentrate. Could I run a mark8 at these higher pressures or is it just going to clog up too fast?

-Eric

[wiam]

I have 2 xle4040s in my 250 gph memtek. I run pressure at about 400 and flow stays around 180 when taking 2% to 8%. flow will drop about 4 hrs in.

[lew]

tuckermtn, yes that was for all four membranes, brand new.

[Amber Gold]

GM-I pulled the membranes out a few times and checked the o-rings. The first time, I found a partially torn o-ring, but the problem didn't get any better. Lapierre had Dow rep.'s at their open house. There first thought was the taped membranes aren't rated for the pressures we run them at. Also, when I pulled the membranes out the first time, they were deformed...membrane had a bulge in it. I'm not sure why a deformed membrane would pass sugar...membranes still in one piece, unless it stretched it out and made the pours larger...not sure. I'm guessing a fiberglass wrap is rigid and can handle higher pressures.

[Sunday Rock Maple]

Eric,

Sounds like they are alike. I have the same Magikist and used to run at 550 PSI. The new membrane will only go to 330 max, I think the new design doesn't need the higher pressure to work.

[wiam]

GM-I pulled the membranes out a few times and checked the o-rings. The first time, I found a partially torn o-ring, but the problem didn't get any better. Lapierre had Dow rep.'s at their open house. There first thought was the taped membranes aren't rated for the pressures we run them at. Also, when I pulled the membranes out the first time, they were deformed...membrane had a bulge in it. I'm not sure why a deformed membrane would pass sugar...membranes still in one piece, unless it stretched it out and made the pours larger...not sure. I'm guessing a fiberglass wrap is rigid and can handle higher pressures.

My xle membranes are tape wrapped and I have had no issues running them about 400psi. Was the membrane deformed or just the tape? The tape on mine looked bad after 1 season but the membranes still tested ok when factory cleaned.

[Amber Gold]

William, hard to say because they were full of water. I'd say the membrane was deformed.

[Brent]

gmcooper - See the link below which is where I got my info. XLE's flow 2500gpd @ 100 psi and the NF-90's 1500gpd @ 70psi. When I put my XLE's in this season, I was getting ~270gph @ 250psi compared to 200 gph @ 200 psi on the 90's, but the 90's are pretty old is part of the difference.

http://www.americanro.com/1772776.html

.

When they print a spec running at 40 degrees with sugars, I'll start to get concerned about splitting hairs on performance. I have been told by someone well known to many Traders that the only difference in normal and "maple" membranes is that they are only available to maple equipment dealers, and have a different model number, and higher prices. The XLE4040s give me about 20% more throughput than the original "maple" membranes that were in our rig.

[Amber Gold]

For what it's worth, Dow says the membrane in the E4 and E8's is specific to maple sap.

[sapman]

So does anyone have an opinion on Hydranautics PVD1. I hear easy to clean, no sugar passage when taken care of properly, and flow rate holds up better than others after concentrating for awhile.

[Brent]

PVD-1s are what was in my Airablo when it was new. I think its 10 year old technology, maybe more.
Call Joe at Atlantic RO he'll tell you the real story. I think he said it was a common membrane marked
with a special model (PVD-1) and sold that way exlusively to the maple RO manufacturers.

[sapman]

I did talk with Joe a lot about the pvd1. Said he used to sell them, til they wouldn't let him anymore. Thing is, everyone I know who has one, loves it. Flow rates stay up betterand very easy to clean.