4x40" Single Post Build - A few questions

[USinCA]

Hey Y'all,

I'm planning on expanding from 55 to somewhere north of 100 taps this year. The woods I tap has capacity for 300 taps in sugar maples. We only have time to boil on weekends, store sap cold in a milk tank. My little evaporator can manage 15gph, and we still managed 23 gallons last year.
I'm planning a 4x40 so I can RO to ~8% and boil at the same time. I have a schematic sketched up - I'll figure out how to upload the picture later. I know this is overkill for my current needs - but I should still have plenty of permeate to wash and rinse (I figure minimum 100 gallons needed).
I know this is overkill- but from what I've heard the smaller membranes don't like removing much more than 1/2 the water without fouling. I've also heard that building an RO that you can grow into isn't a bad choice, as long as there is enough permeate for washing/ rinsing.
Here's my plan as far as components:

y strainer
1/2 hp thermoplastic jet feed pump, or stainless 3/4 hp sprinkler pump (whichever is cheaper).
2.5 x 10" filter with pressure gauges on both sides (what micron rating?)
air bleeder post filter
low pressure switch post filter
procon 330 GPH, 250 psi pump w/ 1 1/2hp motor (overkill but I see no downside to more recirculation and flow over membrane, leaves room for a second membrane)
thermometer / temp probe and pressure gauge b/w HP pump and membrane
Stainless membrane housing w / 3/4" feed and drain ports - 1/2" Permeate port: https://www.maxwaterflow.com/4040-Stainless-Steel-Reverse-Osmosis-Commercial-Membrane-Housing-size-4x40_p_1274.html
RO Bucket 4" x 40" Membrane - or MES - or NF90? (RO Bucket's price is attractive)
drain valve at bottom of membrane housing
Recirc loop w/:
Pressure gauge & Air vent valve
0.1-5gpm flow meter (and needle valve? Does it need a needle valve)
check valve to prevent flow out concentrate line when starting feed pump
- loop tees in right before high pressure pump

0.1-5gpm flow meter on permeate line
0.1-2gpm flow meter on concentrate line
5 gallon bucket for a wash tank, put the inlet and outlet lines in the bucket and run.


Questions:
Starting with questions in the layout above
I figured I would buy either a 1/2 hp plastic jet pump, or 3/4" stainless - whichever is cheaper. But I'm leaning towards 1/2hp to keep power draw down - should supply plenty of pressure right?
Do I need a needle valve on the recirc. line? Or is it just controlled by the concentrate needle valve setting? Seems like I need a needle valve to increase pressure across the membrane - or the concentrate will just recirculate faster when closing the concentrate needle valve.
What pressure do you see in your recirculation loop? (what hose and fittings?)
Do I need a high pressure cutoff switch after the HP pump?
Membrane suggestions? Pro's cons?

Further questions:

Are there any components that tend to fail? The system should last many years right?
Are membrane housings standardized or do some membranes only work with certain housings?

I assume the connection between the HP pump and housing should be flexible to prevent any unwanted loads on the pump - what are you guys using for hose here? I'm picky about using food grade and stainless where possible, and must have 250psi pressure rating.
On that note, what hose and fittings are you using elsewhere?


I'll post a schematic as soon as I figure out how to... I can't upload an image in the message window at the moment- tips on doing that are appreciated too

[bmbmkr]

I bought a used Deer Run 125 in 2017 for the 2018 season, it worked great, single post 4x40 with a 5 hp Honda motor and a piston pump. I can't remember if i fed it with a Wayne sprinkler pump that year or not. My dairy tank is 3' off the ground, I may be just used gravity. That summer I bought a procon 330 and a 1 1/2 HP Leeson motor and added a second vessel.

I like the Wayne pump, i still use it to pump sap and permeate.

I bought 1/2" and 3/4" flexible braided hose, food grade from a local plumbing shop, It was made in china too, so whether you get it off amazon is up to you. I got my needle valves from E bay, they are 3/4" MPT in and 1/2" FPT out. I used a 3/4" tee to connect the two needle valves.

The 330 Procon has 1/2 FPT in and out. I made sure my vessels had 3/4" ports, you mention expansion, if you ever bump up to the Procon 6 series, I think they are 480, 540 and 660-they have 1" NPT in and out. You want as much flow through your system as possible.

SS hose barbs and two quality SS clamps per barb. I got mine from NAPA and a local hardware store, the hose clamps on amazon and ebay are junk.

The needle valves- You have to have one for concentration whether you recirculate or not. I put two of em on a tee. When you start the machine, the concentrate valve is open and the recirc is closed. After you get some sap through and get all the air out maybe a minute or two ( Run your concentrate back to your sap tank while this is happening) you start to slowly close off your CONC needle valve, this increases pressure inside the system. You will see some permeate coming through at this point. Once you get up to 250 PSI or so, you can open the RECIRC needle valve and it will bleed off some of that concentrate back to the Procon feed line. The system pressure will drop when you open the RC valve, and then you can then close off the Conc Valve a little and increase the pressure again. You can adjust the two valves and monitor the Concentrate flow meter to get what you want, whether it is a certain brix, or match the speed of your evaporator. For a while, I had a flow meter between my head tank and flue pan float box so I can see what my evaporator is doing. I took it off because i was afraid it would stop up and burn my pans, but it was very handy to use for a couple of years, I leanred a lot about my air mix, firing times, what's goin on with concentrate comin in while I'm drawing off syrup. It really got me in tune with the machone, and I can run my RO to just out pace the evaporator and not worry about running the head tank over.

Keep in mind that 330 gph is 5.5 gpm and the 4" membranes have a max feed rating of 13 or 14 gpm. If you really want to save some time and money, go ahead and spring for a larger pump. 480 is 8 gpm, and 540 -9 gm 660 11 gpm. I've been runnin my 660 on a 2 HP motor up to 300 psi.

I ran a 660 on 4 4x40 with recirculation and it was grat. I just put a single 8" post on for this year. Wish I'd got the 660 several years before I did. One thing i DID do when i got the 660 was put a tee and a gate valve in between the 660 and the vessels, I'd open it when I started the machine, I had it running back to my sap tank also. Once my LP pump and procon 660 were running and pushed the air out of the system, I'd slowly close this valve so that the flow through the membranes at 11 gpm was introduced slowly. There is an occurrence called hydraulic shock that can damage the membranes. The extra valve and outlet let me slowly increase the flow through the system instead of all at once when you hit the switch.

5 micron is fine for your filter. You can get them in 24 packs cheaper than single. Mine came with a 4 1/2 x10 and i upgraded to a 2 1/2x20, but that was after going to the 660 and 800 taps.

I do have some stainless braided hose now, I got it from McMaster Carr, it is $$$ but worth it in my opinion.

I'd go with a larger flow meter on your concentrate line, 5 gpm on each is fine for a 330. You want as much flow possible through the machine until you start closing the conc valve so you don't get that hydraulic shock.

A bucket should work for your wash tank. I heat my wash water to 100F and I use a SS stock pot. I started with a 20 qt and now have a 44 qt, A step bit and bulk head fittings are pretty easy to use and rig up somethin that isn't goin to get soft with heat or react to acid/soap. Just my 2 cents.


I have about $6k in my 8" RO now, but it has paid for itself over and over. I have enough parts to build 2 2 post 4x40 machines and sell em and recoup a lot of my expense.

Good luck with it, if I can do it anyone can.

[USinCA]

Thanks for the reply, that's helpful

If it wasn't for the price jump between the 330 and 480 or 660 procon I would make the jump, but it's a huge difference here.
After checking a few datasheets I'm leaning towards a 3/4 hp stainless sprinkler feed pump- should be around 40 psi at 5.5 gpm - up to 60 psi at lower flows (ballpark numbers)

Not worried about pressure in the recirc. loop anymore either. If I put my needle valve at the top of the RO membrane, pressures after it will be roughly equal to pressure after the prefilter, and braided nylon hose will work fine.
I don't think I need a high pressure cutoff switch?

What about membrane and housing compatibility? Are all membranes compatible with all housings?
Membrane recommendations? Still leaning towards RO Buckets... How often do you replace membranes?

If it wasn't such a drive to southern Ohio I'd be making an offer on your pile-o-parts :lol:

Anyone have tips on posting photos??

[bmbmkr]

Yeah that was a big price jump! In all the different ways I've had my RO configured and all the drawings I've done, I never once considered putting the valve right on the post cap. Great idea. 3/4" nipple, 3/4" tee- (in/gauge/out) another nipple, another tee (in, recirc, conc) and you are set. I did have a 3/4" cross to consilidate these, but I could NOT for the life of me keep one side from leaking.

I have yet to put in high or lo pressure switches, It's on the list, but made it without them for the last 6 years. I have a rhythem of watching float pans, thermometers, RO gauges repeat, and I can hear the LP pump change pitch when my bulk tank is almost empty.

Membranes last a long time if you take care of them. Don't let em freeze or dry out. Do a benchmark test and write down your numbers and pressures and keep track of its performance.

I have not been able to post photos for a couple years now

I'm goin to put a 2 post backtogether this week while we are in the deep freeze, for days I won't be able to make enough permeate to run the 8". Maybe next year I'll get my other woods tapped and be back up to 8-900 taps...funny how life gets in the way of doin all the things you want, especially when you get a lil older.

Walk

[USinCA]

I'm sure I could get by without cutoff switches, but I'm a bit ADD, and I'll either forget, or my kids will distract me, and I will almost certainly screw up at some point. Cutoff switches are cheap insurance compared to blown pumps and lost time :)

I might pivot here, I have my eye on a used commercial 2 post unit for $700, it's a bit of a trip to have a look - might be worth it.

Thanks for the tips!

[Bricklayer]

Buying a used commercial unit is exactly what I did.
It had all the parts I needed to make it a maple RO.
I just had to re-plumb it all with bigger hoses and install a feed pump.
There was the odd brass fitting I had to replace as well. But more or less it saved me a ton of money.
Even just having the frame to boot everything to made my life a lot easier.
I got mine for $200. And it came with a $2000 webrol multistage high pressure pump. Costed me $100 to get it serviced and it was good to go.

[darkmachine]

I purchased a used commercial unit too, It was used for a restaurant's dishwasher. I changed out the pump, it was brass, and the membrane housings which were 2.5x40. It was a good starting point because i could look at how it was plumbed and substitute in new parts as needed. The only thing i still use left from the original is the needle valve and the frame, lol.

[USinCA]

I purchased the commercial unit - looks decent and came with a 150 gallon stainless tank, extra 1/2 hp stainless feed pump, 1hp goulds multistage ss pressure pump, 2 4040 housings etc, low pressure switch, flowmeters, tds meter, etc.
I want to re-plumb most of it to eliminate a few brass fittings and incorporate recirculation - which leads to my next two questions

Should I plumb as a single post? (cheaper, less high pressure fittings and hoses) since I'm not running many taps (~100, maybe 150)? Or go with the buy once cry once approach and plumb both in?

Anyone use sch 40 pvc to plumb pressure lines? 1" is rated at 450 psi working pressure - more than enough and much cheaper than stainless (but not as pretty). Is there any reason not to? Would it be too difficult to clean?

[darkmachine]

I used pvc hose barbs on my pump and membrane housings and then clear braided hose for all my plumbing, no issues running 200-250psi, Its way easier to route than rigid stainless.

[Bricklayer]

I used flexible stainless tubing from Falcon Stainless.
Can’t remember where I got them. But if you google it you will find them.
They are great. Have all different lengths and are threaded.
I’ve used the braided hose as well and as long as you have good barb fittings and properly install the clamps it works well.

[USinCA]

Thanks for the tip on the falcon connector - that looks like the best option to get from the pump to the membrane.

What size line are y'all running for recirc? 3/4 or 1/2"
The 1/2" needle or gate valves are much cheaper than 3/4