Check valve observations

[Mike in NY]

Pulled all taps yesterday, lost our sugar content the 30 of March. what I learned this yea;r those taps I put in January 30th ran fine till the end znd a lot of the tapholes are dripping today as I rince lines. I will use more of them next if not all taps cv.
#2) about 20 % 0f the check valves were leaking as I washed the lines out. Upon examination small wood chips (sawdust) were plugging the little black ball from sealing the tap against back flow. I guess my question is did I plug the taps backflushing the lines or were they plugged (not acting as one way valve) all season???
was a good year,looks like we made a few bucks to reinvest in some new stainless. ;>)

[maple flats]

Most likely the "sawdust" you see is really drill shavings. I like to anly tap when the sap is flowing and I let each hole flush the shavings. I won't say I get no plugging with shavings, but I do get very few that plug. If you tap before the sap flows you are not flushing the hole with sap flow and I'm not aware of any other approved method. I tapped 2/17 and I just came back from the woods. They are still running, but not very fast. The buds are likely to open here in a day or 2, then it'll be cleanup time.

[maple man-iac]

My observation this year is that check valves are useless. I tap 55O on vacuum at no less than 26 inches and 750 on gravity. I discontinued use of the cvs this year and my overall tap average is .55 gallon of syrup and still counting. Keep in mind I do run my vacuum 24 7.

[jasonl6]

I used CV's this year and for the last few, I tapped in mid January, pulled them Saturday/Sunday, most were still running, It's been warm so i was surprised any were running. CV's lengthen the season, it's been proved time and again.

Jason

[SandMan]

I tapped the last week of February, greater then 2/3rd's of my trees are still running (even today). Low sugar content at this point, so not boiling. I used regular seasonal taps and my season total was no different then the years I used CV's. I'm on tubing, all gravity. My sense is that CV's get a lot of credit that they don't deserve...at least on gravity systems! I gave up on CV's last year after using them for two years.

[sjdoyon]

We tapped second week of January, a full month earlier than last year with CVs. Had almost 8,000 gallons of sap come in yesterday at 2.5% and running even harder today. We compare our results to other sugarmakers in our area who don't use CVs, most of them are getting done this week and we are having trouble keeping up with the sap coming in.

[Sunday Rock Maple]

Tapped Feb 5th, this is week ten and it's running very strong as I'm typing this. Nothing against any other technology --- but I'm very happy with this one.

[DrTimPerkins]

My observation this year is that check valves are useless.

I discontinued use of the cvs this year.

These two statements combined make no sense. How could you observe they were useless this year when you did not use them this year?

[wdchuck]

Sap still running strong here and I was tapping in January, not because that was the best time to do it, but because thats when I had the time. Today was a gusher..... My father is still in denial about check valves. Keeps predicting that its over for the year. Eventually he'll be right.

[802maple]

We made 1275 gallons off 2750 taps with 5 year old health spouts, tapped Febraury 17 and finished yesterday because the sap went buddy at our Middlebury bush

[802maple]

Now waiting to see what happens at the Lincoln bush.

[themapleking]

I've been using the CV for 4 seasons now. Been ave. 20+ gal per tap, 20-22" vac. Cleaned lines today 1200 CV & 2/3 holes are still running, not good but they're still wet. Tapped the 2nd weekend in Feb. The biggest problem is on freezes the stubby spout likes to pop off. The fingers that hold the ball like to gum up with late season sap, plug up. The spout hole seems a hair smaller than a regular 5/16 spout.make sure your tap hole is cleaned out. Any debris will pug it up. Anyone who says they don't work! well I don't know what your doing wrong.
CV are a most for anyone that has a low sugar count, or wants more sap. They will give you more sap. More sap equals more syrup.

[maple man-iac]

Dr. my observations were based upon the previous three or four years using them. My previous record yield per tap was .51 gallons per tap and that year the percentage of gravity taps was much greater than this year. I was completely tapped by the beginning of march and I'm still pulling a gallon per tap on my vacuum. I'm just not seeing the benefit to the check valve. My neighbors which use them have all been done for a week or two.

[Mark-NH]

My observation this year is that check valves are useless. I tap 55O on vacuum at no less than 26 inches and 750 on gravity. I discontinued use of the cvs this year and my overall tap average is .55 gallon of syrup and still counting. Keep in mind I do run my vacuum 24 7.

My understanding of CV spouts is consistent with your statements. If you run vacuum 24/7 then the cv spout is not needed. If you Never turn your vacuum off, you never allow sap or air to back flow into the tap hole. Right?

[maple man-iac]

My understanding of CV spouts is consistent with your statements. If you run vacuum 24/7 then the cv spout is not needed. If you Never turn your vacuum off, you never allow sap or air to back flow into the tap hole. Right?
That would be my conclusion Mark.

[DrTimPerkins]

Dr. my observations were based upon the previous three or four years using them.

Not what you said.


My previous record yield per tap was .51 gallons per tap and that year the percentage of gravity taps was much greater than this year.

It is not reasonable to compare sap yield from one year to the next. Each year is different.


I was completely tapped by the beginning of march and I'm still pulling a gallon per tap on my vacuum.

Flow can be quite variable for several reasons. Nearly ALL spouts in our testing are still running some, but it is very clear in our side-by-side comparisons that CV (both the original and new types) along with new spouts/new drops are significantly out-performing all other spouts we are testing at this time of the season, old spouts on uncleaned drops, new spouts on cleaned or uncleaned drops.....doesn't matter.


I'm just not seeing the benefit to the check valve.

That is fine. If you don't want to use them, don't use them. Research studies at UVM, Cornell, and even at Centre Acer show that they do work.


My neighbors which use them have all been done for a week or two.

Again, like comparing from one year to the next, comparing from one bush to another, or even from one section of a large sugarbush to another may not be valid if they aren't similar. One part could be a warm woods, another a cold woods.

[Mark-NH]

I am a believer in the CV's. Sap was running this weekend as we were cleaning our lines. This after it had not frozen all week. Our vacuums run off gas motors and we only power up when we think the sap will run. So there is a lot of starts and stops with our systems.

We also used the new 1 piece CVs in one bush this year and I prefer them over the 2 piece design. They were much less prone to vacuum loss because there is no joint were stubby meets tap. We have always chased vacuum leaks at this joint. The clear plastic is a welcome feature too.

[Dill]

CVs are actually causing me an issue with a landowner. I turned the pump off last saturday and pulled taps under vac this weekend. I tapped feb 16th, and turned the pump off for the 10 day freeze up and usually turned it off overnight.
Anyway almost all of my taps are still running, and quite hard with the cold nights we've been having. The old guy is convinced that we have to plug the holes cause he's never seen sap leaking this late.

[MillbrookMaple]

I would like to weigh in on the check valves. We have 500 check valves on stubbies and 1500 anti-microbial spouts (700 on stubbies and 800 one piece) in our sap bush. I found that both were working well when we pulled the taps due to budding. My observations were as follows. As far as leaks, the section with the 500 check valves on stubbies, I spent over half of my time chasing leaks at the trees. Then the section with the anti-microbial adapter spouts was much better for leaks but I still had to pound in taps every time I walked the woods. The section with the one piece anti-microbial spouts I had about 4 spouts that I had to fix for the whole season. As far as performance. I do find that the CVs are more prone to plugging with shavings. I really can't compare the performance of them since they both worked well till the end of the season and we were pulling around 1 gallon per tap a day at the end when the sugar content hit .7% The trees that the CVs were on did not run as well as the others for the season in general but the check valves were on 100% very old sugar maples and the other taps were mostly 10-15 " diameter trees and 75% red maples, so I don't think it is fair to even try to compare. The verdict is that I don't plan to buy anymore stubbies with adapters. I would imagine that the one piece CVs would be just fine. Because the CVs are more prone to clogging, if the price was the same I would buy anti-microbial spouts. Since they cost around $1 each and one piece CVs are .40 each. I will probably try 1000 one piece CVs next year (500 to replace the original stubbie adaptors and 500 new) to see what I think.

[Greenwich Maple Man]

My understanding of CV spouts is consistent with your statements. If you run vacuum 24/7 then the cv spout is not needed. If you Never turn your vacuum off, you never allow sap or air to back flow into the tap hole. Right?

Agree 100 % .

[Walling's Maple Syrup]

My understanding of CV spouts is consistent with your statements. If you run vacuum 24/7 then the cv spout is not needed. If you Never turn your vacuum off, you never allow sap or air to back flow into the tap hole. Right?When it freezes at night, most of the time the lateral lines freeze before the tree. The tree takes longer to freeze because it acts as an insulator. After pulling on it all day with vac., the tree is pressurized. If the lats. are frozen, then the vac. can no longer get to the taphole. the pressurized tree will then suck microbes back into the hole without cv's. Neil

[mellondome]

My observation this year is that check valves are useless. I tap 55O on vacuum at no less than 26 inches and 750 on gravity. I discontinued use of the cvs this year and my overall tap average is .55 gallon of syrup and still counting. Keep in mind I do run my vacuum 24 7.

If you run your vac 24/7, what do you expect a check valve to do for you?? that is like putting a mechanical releaser on non vacuum line.


When it freezes at night, most of the time the lateral lines freeze before the tree. The tree takes longer to freeze because it acts as an insulator. After pulling on it all day with vac., the tree is pressurized. If the lats. are frozen, then the vac. can no longer get to the taphole. the pressurized tree will then suck microbes back into the hole without cv's. Neil

so you are saying that the tree is over coming the 26" of vacuum that is between the ice in the drop line and the tap hole? Wouldn't that make an almost absolute vacuum in that section?

[DrTimPerkins]

The old guy is convinced that we have to plug the holes cause he's never seen sap leaking this late.

That's funny. You can tell the old guy that the trees will be just fine. :)

[DrTimPerkins]

If you run vacuum 24/7 then the cv spout is not needed. If you Never turn your vacuum off, you never allow sap or air to back flow into the tap hole. Right?

Actually, that is wrong. Running it this way will HELP (as will several things), but it doesn't totally solve the problem of backflow. Even with the vacuum running 24/7 (which is how we try to run the majority of our vacuum systems at UVM PMRC....vacuum was turned on at the beginning of season.....off at end of season), there are small pulses of backflow that occur whenever the releaser trips. There is also some backflow as lines freeze up at night, or anytime you get a leak, or open a valve (to ambient air pressure) in your system, or if the power goes out.....or any number of ways. You can reduce the incidence of backflow in many ways, but you cannot eliminate it. The CV is the line of last defense at the taphole.

As of this mornings measurements (and the numbers will change because the sap is still running here), 2 yr old uncleaned drops/spouts produced 22.8 gal/tap, new spouts on 2 yr old uncleaned drops produced 28.3 gal/tap (25% increase), and the CV2 on 2 yr old uncleaned drops produced 32.1 gal/tap (41% increase over old drops/spouts, and 13% increase over new spouts on old drops). This is on 20" Hg vacuum (we ran it at a lower vacuum this year as some people were suggesting that you needed high vacuum for CVs to work - obviously that is NOT the case).

[DrTimPerkins]

so you are saying that the tree is over coming the 26" of vacuum that is between the ice in the drop line and the tap hole? Wouldn't that make an almost absolute vacuum in that section?

Once there is ice in the dropline or lateral line or mainline, the vacuum level in the system on the pump side is no longer relevant. It then becomes the vacuum (or positive pressure) level in the tree that influences the movement of liquid at the taphole, spout, and any unfrozen part of the dropline. The tree during the freeze phase will go from whatever pressure existed in the stem before the freeze (positive pressure or slightly negative if there hadn't been a freeze for some time) to a negative pressure or suction, which pulls water from the soil through the roots into the stem. However, if there is unfrozen water in the spout or dropline, it will also pull it from there into the tree. This was one reason the dropline was developed, to reduce the ability of the tree to take up sap from lateral lines.

[Moser's Maple]

Dr. Tim
are you doing a comparison between the cv2's and the cv1's, or plan to in the future???????

i read you have a 25% increase from new spout to old spout..this isn't a cv1 correct????
just curious if the cv2's are out preforming the cv1's?????

[Moser's Maple]

nevermnind Dr. Tim I just read another thread......you explained yourself there quit clearly there.....guess i should read all threads before asking questions. sorry to take uo your time.
by the way is there a possibility of a polycarbonate cv adaptor in the future or would that be just a waste of time??????

[DrTimPerkins]

....is there a possibility of a polycarbonate cv adaptor in the future or would that be just a waste of time??????

That would be up to Leader Evaporator. If that is something you might be interested in, I'd let them know.

[jimbison]

could some one please give me some sugestions as last yearwent to all new stubbies and cv's new cv's this year started tapping Feb.14 by the end of March all lines had dried up except one that I had added in mid march checked the holes and they were all black except the last ones tapped in mid march and they had some spots in them when tapping took spouts from bag they came in to taphole run 20" vacuum on wet dry system 1400 taps just 300 gallons all dark thanks for any help

[inthewoods]

As of this mornings measurements (and the numbers will change because the sap is still running here), 2 yr old uncleaned drops/spouts produced 22.8 gal/tap, new spouts on 2 yr old uncleaned drops produced 28.3 gal/tap (25% increase), and the CV2 on 2 yr old uncleaned drops produced 32.1 gal/tap (41% increase over old drops/spouts, and 13% increase over new spouts on old drops). This is on 20" Hg vacuum (we ran it at a lower vacuum this year as some people were suggesting that you needed high vacuum for CVs to work - obviously that is NOT the case).

Doc, are these numbers (by that I mean gallons per tap) usable sap during the season, or total sap (even the nasty/buddy sap after the buds break)?

On a separate note, I read your brief article about dual-line combo in the latest Maple News, and I am very excited about this new technology. You stated a 15-20% increase in sap yields. Is that above our current high yields on high vacuum? So what you're saying is, if I currently have a 50-60% increase in yields on my high vacuum over my pails, I can add another 15-20%? So the total yield would be 65-80% over the pails?

[Moser's Maple]

Yes!!! would definitely be interested in a polycarbonate adaptor. My thoughts are as follows.....we switched over some taps this year with the cv2's, and I liked how they stayed tight to the tree, but what I liked the most was how easy it was to find a vacuum leak with them. I also like the cv1's becasue of the ease of being able to keep the stubby on year round and when tapping time comes it's just a matter of inserting the cv1 in the hole and attaching the stubby to it. I realize with this 2 part system you have a greater chance of leaks, but with a polycarbonate adaptor, many producers that may not want to cut off the spout each year would be able to keep their stubby's, but also have the advantage of being able to trace a leak by just looking at the tap. Have your cake and eat it too......maybe?????

[DrTimPerkins]

Doc, are these numbers (by that I mean gallons per tap) usable sap during the season, or total sap (even the nasty/buddy sap after the buds break)?

Total usable sap to date and still running. Hasn't turned buddy yet.

[DrTimPerkins]

...read your brief article about dual-line combo in the latest Maple News, and I am very excited about this new technology. You stated a 15-20% increase in sap yields. Is that above our current high yields on high vacuum?

Yes, correct. We are finishing our final testing with dual-line/modified spout this year, and will be talking about it more, starting at the Leader Open House in a couple of weeks.