Rebuilding an RO?

[Dill]

I'm looking at a spring tech that has sat in a barn for 5 years or so. Does Leader or any other company refurb ROs?

[maplwrks]

I think you will have more in it than it's worth.

[Bucket Head]

Do you know how to work wrenches and screwdrivers? If so, refurb it yourself. Whats wrong with it? What size is it? It worked five years ago? Or more importantly, what is the asking price? You might be able to have a decent machine with a little effort and money put into it. Give us some more details. Find out more info on it.

[Russell Lampron]

Like Buckethead said we need more info. What is wrong with it? How old is it? Is it new enough to have recirc? An old one without recirc isn't worth very much to start with. If it needs a main pump it may cost more than the RO is worth when you are done.

[Dill]

I know very little about it. Trying to go see it the last couple weekends. One of those friend of a friend deals. Its a small springtech. They used it for years and then bought a bigger one. Just unplugged this one and stuck it out in the shed. They are asking a grand for it.

[wiam]

I know very little about it. Trying to go see it the last couple weekends. One of those friend of a friend deals. Its a small springtech. They used it for years and then bought a bigger one. Just unplugged this one and stuck it out in the shed. They are asking a grand for it.

Sounds like worth a look, for the price could be worth the risk. If it has no freeze issues I would try it.

[802maple]

Most likely if it was drained well and been kept dry it will be fine. It might and most likely needs new membranes and the o-rings most likely will need replacing. Other then that they were old work horse, albeit slow ones but for a grand it might just work out for you

[WMF]

Leader used to build their own RO's from the late 80's to the mid 90's and they were the first Springtech's . They had fiberglass vessels and a Magikist piston pump. The smaller four inch machines did not have a recirc pump. The aluminum end caps can corrode but the rest of the machine is pretty tough. If it has an m-38E pump and it is not cracked from freezing it is worth $1000 all day long.

[wiam]

Leader used to build their own RO's from the late 80's to the mid 90's and they were the first Springtech's . They had fiberglass vessels and a Magikist piston pump. The smaller four inch machines did not have a recirc pump. The aluminum end caps can corrode but the rest of the machine is pretty tough. If it has an m-38E pump and it is not cracked from freezing it is worth $1000 all day long.

My Memtek has fiberglass vessels with aluminim end caps. Last season the end caps leaked by the O rings. I took them to a local hydraulic repair shop and they machined the corroded channels and put larger o rings. worked great this year. If it is a Magikist M-38 then that pump is still made. I can find a link if wanted.

[Bucket Head]

Can you get a photo of it and post here? The more experienced RO guys on here could probably tell what exactly it is, and somebody here may have even owned that model before. A photo might jog a lot memories here. Take your camera with you when you go to look at it.

[NH Maplemaker]

After last season I picked up an older spingtech Ro. They are very simple! There is a feed pump and a pressure pump some simple pumping. AS far as the menbrain towers go, mine have been replaced with three stainless steel one's . The menbrains were replaced with XLE from Atlantic RO.
When I was looking at this RO I called Leader and talked to Bob (there RO Guy) and he told me that parts are still very available for these RO's.
But as wiam said you should check the unit over very close for freeze damage!
As for Russ's comment about recirculation pump ,I don't know much about them except the older spingtech don't have them. This season I was running 2.5% sap through at 350 PSI and it was coming out at 10%! When done I did good rinse and it was good to go! So if this RO is intack, don't see how can go wrong for that price! JimL.

[wiam]

My old Memtek does not have a recirculation pump. It does recirculate though. There is a recirculation flow meter that reads 14-15gpm when concentrating. I usually multiply sugar content by 4-5 with no problems bringing flow back after a wash.
I would put new membranes in that machine. My choice would be xle's.

[NH Maplemaker]

I wish that I understood the recirculation part better! Like were the pump is located,and what is it recirculating? Water or sap or what? JimL.

[wiam]

I wish that I understood the recirculation part better! Like were the pump is located,and what is it recirculating? Water or sap or what? JimL.

Basically it is moving a lot of sap over the membrane. This keeps the membrane cleaner longer. Hope this makes sense.

[NH Maplemaker]

Yes,but it's just hard to figure out how with 2 pumps already running how more sap can be pushed in and out! But than again I didn' understand how the RO it self worked until I owned one! JimL.

[500592]

I think that he recirc pump I right in the housing and swirls the sap across the membrane and helping to stop fouling.

[PerryFamily]

Would the experienced RO guys say that the recirc pump is a necessity? Some of the private brand machines don't have them, as well as not haing the automation / safety shut offs. These units are significantly less money. I am sure there are advantages to these options but can your average larger hobby producer get good concentration of sap without them.

JMP

[802maple]

They are what make the machines that have them faster, all one has to do that has the recirc pumps is shut it off and you will instantly see what I mean. It also keeps the membrane from fouling as fast due to the swirling of the sap in the membrane. You can get good concentration with them just not as fast.

[500592]

It is if you want to bring sap up to 8% in one pass also I don't think one without a recirc pump could go over 20% I know mapl flats recyled sap in his ray Gingrich ro and brought it up to 18% but I think the flow rates dropped way down

[Russell Lampron]

I can do a lot more than what my RO is rated for because it has recirc. A buddy of mine has an RO without recirc and he has 2 membranes to my 1. Mine can put out the same flow rates as his even though his is rated for twice as much as mine.

[WMF]

I wish that I understood the recirculation part better! Like were the pump is located,and what is it recirculating? Water or sap or what? JimL.

The best way to understand what a recirc pump is doing is to look up " spiral wound membrane " and study how it is put together.

An 8 inch membrane has over 400 square feet of surface area for water to be forced through. The flat sheets of membrane material are folded into envelopes and one side is glued to and has a fluid connection to the permeate tube in the center of the membrane. The envelopes are then wound spirally around the permeate tube.

When you look at a membrane from the ends you see the edges of the envelopes. A recirc pump applies a high flow rate of sap from one end of the membrane to the other which breaks up the boundry layer of very concentrated sap on the membrane surface as the flow is 90 degrees to the sheets of membrane material.

Contrary to what some heavily advertised RO assemblers say, plumbing the outlet of the RO back to the feed tank is not a substitute for an expensive highly engineered recirc pump integrated into the membrane housing.

[NH Maplemaker]

This may be a stupid question, but is there one recirculator pump for all the menbrains on the RO? Is ther any way to add one to an older RO? JimL.

[WMF]

Old school machines have one large recirc pump for multiple membranes. This was found to be better than none but the friction losses in the pipes connecting the membranes together led to the first membrane in series having good recirc flow but membranes downstream had less and less.

This is what was so revolutionary about the Lapierre patent. He integrated a separate pump onto the end of each housing and his machines were the first to have great recirc flow.

CDL raised the bar even higher by integrating the recirc pump inside the housing which eliminates the shaft seal which has always been a potential problem and is why it is hard to simply take an off the shelf pump and add to a plain RO. There are not many pumps out there that the housing and shaft seals can withstand up to 500 psi without catastrophic failure. The seals alone for external recirc pumps are several hundred dollars.

[PerryFamily]

At what point in time would you say that the recirc pumps were "standard" equipment on the big name manufacturers units? early 90's, 2000's?

When looking for a used RO, are there any units to simply stay away from for whatever reason? Un reliable, performance.....And anything specific to look for on a used unit.



Any info is appreciated

JMP

[Bucket Head]

I don't know when they became "standard". I have a 1991 Airablo 250 and it does'nt have a recirculation pump. I was told that it does somehow recirculate with how the machine is plumbed. With that said, I'm not sure if thats true or not since I am not familiar with RO plumbing. This is the only RO I've owned so I can't compare it to anything else. Maybe some of the more experiened guys on here could explain how/if theres reciculation without a third pump. I can tell you I have not had the fouling troubles that some folks have had with the ones that were not made by the large maple equipment companies.

[WMF]

The Airablo machines I have seen , at least the 8 inch models do have recirculation but they are a bit of a hybrid between the old school RO's and the newer recirc pump on the housing RO's.

The Airablo pressure pump has an additional separate pump section which instead of making pressure is plumbed to the housing and provides high recirculation. You can see these ports on the pressure vessel. The advantage of this is one less pump but the disadvantage is the pump is separate from the housing and suffers from the same friction losses of old RO's. They at least do use the space between the OD of the membrane and the ID of the pressure vessel for part of the recirc path which helps with the friction loss.

[Bucket Head]

WMF,

Thanks for the plumbing explanation. I would have to go look to see just how many outlets or ports my pump has and see where they lead to. Although I have two 4" membranes not an 8" one, so maybe those are completely different? If my poor memory is working right tonight, my high pressure pump has two ports on the side, one of which is the feed line, and the other attaches a manifold which connects it to one of the pressure vessels, I think just one of them? The other fitting goes out the end (bottom) of the pump. Again, I'd have to take another look at it to be sure.

[Daren]

Dill....I picked up an old used springtech mini elite 125 gal/hr machine at the end of last season and got it up and running for this past season (what there was of it). I know it was not used for at least two season prior, and think it was most likely 3 years prior. I did have some problems and not knowing anything about RO, sacked up and took it apart. After finding out that the pump housing was literally broken, I took the pieces to Leader and they welded it back together for a waayyyyyyyyy less than I thought. The mechanical "RO guy" was very helpful in explaining how this system worked and I was able to put it all back together by myself. After I put the pump system and some new lines on it, I fired it up and once I started to bring up the pressure, I found some leaks in the brass pressure fittings. More trips to the hardware store. After replacing those...a bit of a pain in the butt, but very doable....it ran fine. Even with a very small machine like this, I cant believe how much more fun it was to boil concentrate. I was taking 1.2 to 1.5% to 6.5% at a rate that would stay ahead of my evaporator. If I had the time to start the RO and go putter for a while before firing, I was bringing it to a bit over 9% on a single pass running at 275 to 300 PSI. Had to keep checking to make sure the pressure was not going up too much for the first 30 to 45 minutes, but then it stabilized so it didn't need baby sitting so much. Mine shuts off with high pressure and with drop in feed pressure. I paid three times what your guy is asking, so as long as the pumps work, I cant see how you can go wrong. It can be cleaned and with a new membrane, even a slow machine will be worth that much. I still used the old membrane although I have a new one on hand just in case. Mine does not have a recirc pump, but it does "recirculate" some within the membrane on the concentrate side by directing flow through a second port on the side of the membrane housing. I run mine for 3 1/2 to 4 hours, then rinse for 20 to 30 min and go right back to concentrating. I wash after each day with soap. Came back to my first 200 psi check values for flowrates. The permeat flow starts to drop off a bit by the 3 hour mark but watching over a gallon per minute get removed while boiling 30 gal per min....a 350 gallon run is gone in 4 hours start to finish as far as boiling goes. My units is one of the oldest onces I think, so that old technology still gets r done! Plus, leader was awesome, helpful and friendly. I want to get a spare pump to have on hand just in case of failure due to the age, but then again....there is no sure thing as far as failure goes, even with new stuff. Hop this works out for you.