Low pressure issue

[gmcooper]

My WaterGuy Ro is giving me a few issues. I have been on phone with Bill a few times but still can't get enough pressure. Hoping someone on here might have the answer. I can't seem to get much over 125 psi with high pressure pump. The other issue I'm sure is related is I am getting way to much flow. At 125 psi and 1.6% sap I am running 3.75 gpm perm and 8 gpm conc. At those rates I'm not taking much water out. I have been recirculating from my head tank and can get to 8.5% but pressure still barely climbs to 140 with flows at 2.5 gpm perm and 7.5 gpm conc. Needle valve does not make a difference til the last 1/4 turn then still only bumps up pressure extra 5 lbs. Bill has had me run 2 full turns open the close 1/4 turn every 15 minutes. Next time I started 3 full turns open the 1/8 turn closed every 15 minutes. I have swapped membranes from one vessel to the other, still no change. I don't think I'm getting any sugar passing to perm as sap hydrometer floats right on zero in perm tank. I have run 3 days 800 gallons, 800 and 1200 thru it. Washed every night after running and rinsed. I'm wondering if there is a problem with needle valve or maybe membranes? The unit took a week to get here from OH. I know it spent more than1 whole day riding around on local route as driver ran out of time first day to stop here so it went out again next day. Could bouncing around on truck damaged something?
Mark

[sapman]

What is the minimum flow on the concentrate when you turn the valve all the way in? Do you have a separate membrane pressure valve? Obviously, as you turn in the conc. valve, the perm. flow should go up accordingly (though it drops off with time). How much pressure is the machine supposed to put out? Sounds like an issue to me.

[danno]

Tim's on the right track I think. Close that concentrate valve some, and pressure should start coming up.

[802maple]

I am assuming you have both a wash cycle and a concentrate cycle on the machine with a valve that switches it to either cycle. Dumb question but are you changing that? It sounds like it could be pushing sap thru the wash cycle.

[Russell Lampron]

Both of the issues that Tim and Jerry came up with were the things that first came to mind to me. On my RO there is a valve that needs to be switched from wash to concentrate and from concentrate to wash depending on what you are doing. When that valve is in the wash position it directs the wash solution through the concentrate side of the RO. That may explain the unusually high concentrate flow.

Maybe you can send a pm to one of the members that has a Waterguys RO on this site and have them tell you how they are running their RO. That may be more useful information than what you can get from the guy that builds them.

[gmcooper]

Ok with the concentrate valve turned all the way in (closed) I am still getting 7 gpm concentrate. My thought is that with that needle valve closed I should be getting no flow or barely any. On this unit there are no separate wash controls changing from one process to another is all manual valves (I have check multiple times to be sure each is in correct postion, these are all installed here and are after flow leaves the flow meter). In trying to figure the pressure issue out with the concentrate drain closed, wash cycle valve closed, and the ball valve to the head tank open as I close that one way down (almost fully shut) slowly the pressure does go up and conc flow drops, but that is putting all the pressure on the pvc pipe and fittings after conc. has passed thru needle valve and flow meter. I have looked over other brand units plumbed and running to check that I have things plumbed and routed correctly. I really think now that the needle valve is defective as it does not close off the flow of concentrate.

[802maple]

With other machines, the pressure valve will not affect the concentrate during wash mode because it bypasses the pressure valve control. I wonder if there isn't something wrong with the valving from the manufacturer.

[Brent]

Couple of questions
what size are the membranes ?
what is the Hp of the pump motors ?

My first suspicion is that the need valve to control the concentrate flow is defective. You should be able to pinch it down to zero or nearly zero. I can run mine at 0.1 GPM, not that I would, but it will do it.

[gmcooper]

My unit is rated for 300gph at 225psi. 2 NF270 4040 membranes. Feed pump is 1 hp and high pressure pump is 1 1/2 hp. These units are plumbed very simple and easy to follow. Not a lot of bells and whistles. I haven't taken apart the needle valve yet but there has to be an o-ring or something in there that is missing or damaged.
Brent as you mentioned yours you could turn down to .1 gpm conc flow if you wanted and mine closed tight only drops mine from 8.0 to 7.0 gpm.
Mark

[Brent]

Not good news.
On our 150 GPH rig which has 2 similar 4" membranes, the feed pump is 1 Hp and the Hi pressure is 3 Hp. You just don't have enough Hp on that rig. The 300 GPH rating might be valid for processing water at about 70 degrees but it will never do anything like that on cold sap. DOW says take off 3% for every degree celcius below the rated temp, which I think is 68F/20C. You could expect maybe 100 GPH at sap temps.

You still should be able to close down the concentrate flow much lower that you said you could. I'd be asking Bill for a new flow contol gauge/valve.

[Kev]

you could have a bit of gunk on the needle seat...

[gmcooper]

Did some testing tonight and found my problem is in fact with the flow control valve(needle valve). I did take it apart and end of the valve has some damage and it appears to not seat all the way in to close off flow. I did use a ball valve to regulate pressure and brought things up to 210 psi with conc at 3.5 gpm and perm at 4.0 gpm. It did go up more when I closed it tighter but the ball valve was really screaming from the pressure so i backed of to 210 psi.
In the morning I will be on the phone for a new valve.
Mark

New valve is being shipped out. Bill thinks it's possible the valve had water left in it from testing and froze in shipment.

[gmcooper]

Problem solved! New flow control valve came today and works just like it should. Not sure why but the original valve does not close tight and the threads bottom out before its even close to seating in tight. Have run close to 7000 gallons sap thru unit and have been recirculating to 8-9%.

[802maple]

Glad to see it is working for you, If you have to use a ball valve again for some odd reason don't worry about it screaming it won't hurt anything.

[gmcooper]

Thanks for the info 802. My main concern was the ball valve was creating a vibration at 225 psi and I was concerned about pvc fittings cracking with pressure and vibration. It did work in a pinch but wouldn't want to rely on it everyday.
Mark

[mountain man maple]

Are you having any problems with permeate flow rates dropping off yet? I rinsed my 5000 model as paper work said but after concentrating sap to 10% a couple of times my flow rates on permeate dropped considerably. At end of season could only get 2 gpm max out of permeate. Now I am told I should have been washing with soap or acid when flow rates started to drop 10-15%. Anyone else experiencing this problem? I believe my only option now is to have membranes professionally cleaned to get flow rates back because I have no pure water to wash or rinse with.

[gmcooper]

Mountain man
I have been washing then rinsing after every day. Not sure I have been getting temp hot enough on wash cycle but my flow rates are still good and held up tonight. Some where around 8000 gallons so far this year. When talking with Bill when mine had issues he said I would need to wash much more often than the directions call for.
Mark

[maple connection]

That sounds to me like it is by passing somewere. It sounds like its not the membrane if you changed it. Make sure the u cup o-ring on the membrane is the right way and on the right end of the membrane. But, if your not passing sugar it should be right. Next, check the all the valves to make sure they are off. It sound like its in a wash cycle. I hope you can get your problem resolved.
Good Luck,

[mountain man maple]

What are you using to wash with the Ro sanimembrane or the citric acid? Bill also told me I would have to wash more than average... which seems to be the standard with ALL RO's to wash every day they are operated.

[gmcooper]

Mountainman
I am using sanimembrane (powder) to wash. I picked up some at Bascoms after my unit showed up. I have citric acid and preservative they call for. I ran up over 10% conc last night and I'll see if it has any effect later.

[PATheron]

Mountain Man- Had bascically same problem last three years. By the end of season flow rates terrable. This is what Ive found. Ive always been light in the ro department for the sap I get. Ive always had big declines by the end of the year. I send them out they come back like new and then they decline through out the year. This year I make sure that I wash it with soap everytime Im done with it after I make each batch of syrup. I always let it go till it kicks off on high temp. Ive even added a heating element in my older machine and run that to high temp. I rinse it with a lot of perm. I happen to have two 1500 gallon tanks and rinse each two post machine with 1500 apiece, probly not necessary. Now my big trick. I think Ive always messed my machines up becouse I couldnt filter my sap good enough. This year I bit the bullet and spend 500 apiece on lapierre canister filters for each machine. They have two foot square filters inside. They are as far as Im concerned THE BEST MAPLE THING I HAVE EVER BOUGHT!!!!! I dont know why they dont come with every new machine and I dont know why leader, cdl and any other equipment dealer doesnt copy them and sell the same thing. My cdl machine has had no decline this year what so ever. I recirc for several hours and when its ready to send to the headtank at 15 or sometimes 17% or more I rinse the machine back into the sweet and then it takes me five minutes to shut down and change the filter. The feed pressure goes through the roof and I send it to the head tank and start boiling. Throw it in the washer and ready for next time. They are just awesome. The other thing Ive found too is if I recirc instead of pinching it right down the membranes hold up way better. Its way easier on them. If you over do it like I do you probly make darker syrup but its the only way I can do the volume I do with the time available. Anyway thats my experiances. Theron