Very Simple Sap Lines

[DrTimPerkins]

I read a lot of articles and they all said to have a long, steep run after the last tap...

That is the optimal configuration, but not always possible in some settings.

[DrTimPerkins]

"almost never" denotes an exception. Could you describe that exception and what the circumstances would be for it?

When you're cleaning/draining lateral/drop lines at the end of the season and wish to evacuate all the liquid from them.

[Sugar Bear]

I read a lot of articles and they all said to have a long, steep run after the last tap, as Sugar Bear had said. I am going to buy more tubing on Wednesday and I am rethinking how I will set up my lines.

I will also buy the single handed 3/16” tool at CDL. I did check out the tool at Mapletech tools and they did reply to me about shipping costs, but by the time it came across the border and the exchange, it was not any cheaper than CDL.

I still wonder about setting the lines up at the beginning of November before the snow flies, especially if some people leave them up all year round. We do have squirrels and chipmunks, but they are not overly active after November.

6 years ago when I started with gravity tubing I don't know what I would have done. And even with this great website I would have done the wrong thing.

But for today and as for myself and I was you .....

If you have good slope in your grove and you have sugar maples in your grove I would use 5/16" tubing. Run straight as possible down the slope with 7 to 10 taps or so each. Avoid zig zags by using multiple separate lines parallel to each other. Final runs as straight as possible of uninterrupted tubing (Fairly CRITICAL) on each run should be at least 75 feet long and drop at least 15 to 18 feet in that 75 feet ( CRITICAL). You can angle 2 lines into one collection barrel. My experience is that two of these such lines with 7 taps each going into one 55 gallon barrel will overflow that barrel in short order when the trees are dealing. But you can do more if your tank is bigger then 55 gallons.

All runs must be sealed tightly. No leaks. Try a gauge or two for your peace of mind. If no sap column builds you might have a bad leak. If it is not a big column you might have a slow leak. If you are around 15 to 20 inches of mercury or more you a functioning as designed. This assumes prime time and the trees are dealing. At trickle time a functioning as designed system just may not function nearly as well. Perhaps only 5 to 8 inches of mercury. Be patient, nature delivers a Royal Flush only on its terms.

The length of your sap column is formed by two forces.

The number of taps on the run and the pitch of the final run.

Given the same number of taps on a run. The steeper the pitch of the final run the shorter that sap column will be because more gravity is acting on it because it is steeper. But it will actually generate a bit more vacuum as a longer sap column on a less steep pitch. But the differential increases as the slope diminishes. If your sap column is 10 times as long with a final run on level ground. Well guess what? No nothing. Taps with back pressure. Ouch! vent the system. Do something else. Take down the lines. Put up buckets. Call God!

Its all baby physics.

1) Be ready to boil.
2) Consider a home built RO.

Otherwise be prepared to be very frustrated with your taps on tubing unless you have a pump.

[Biz]

Sugar Bear, are you saying you can get 15-20" of natural vacuum using well set up 5/16" lines? 3/16" lines will get you good natural vacuum with some drop but 5/16" lines cannot develop as much vacuum. Curious how this works. I use all 3/16" lines and get good vacuum and sap production out of my gravity 3/16" lines. Even better for lines with the pumps.

Dave

[Sugar Bear]

Sugar Bear, are you saying you can get 15-20" of natural vacuum using well set up 5/16" lines? 3/16" lines will get you good natural vacuum with some drop but 5/16" lines cannot develop as much vacuum. Curious how this works. I use all 3/16" lines and get good vacuum and sap production out of my gravity 3/16" lines. Even better for lines with the pumps.

Dave

I got 17 inches last year on a 5/16" run which had 7 sugar maple taps ( albeit frisky taps) . Had decent slope throughout. Not a cliff but decent slope. I want to say about 5 pitch ( 25 feet out and 5 feet down ) at the sap column location.

I have not used 3/16" and have been told and read that it generates vacuum through a broader range of geography then 5/16" but has clogging problems and sanitation problems much more readily then 5/16".

Even so I plan to set up a 3/16 gravity run this coming season. On Red Maples.

[Sugar Bear]

Correct. As long as the bottom taps don't overload the lines, or as long as you don't have to cross a long flat stretch of ground, it would be fine to add them. They will not get any/much of any benefit of natural vacuum if there is little drop beyond them to the point of sap exit from the line, but it won't hurt either.

Tim

If the sap column formed from the higher taps rises above the three lower taps. Which in my case it did and in most cases I suspect would, won't that create back pressure into the three lower tap holes ( reverse vacuum ). I mean the sap in the column then want's to go to 4 places. Those 4 places being the collection barrel, and into the three lower tap holes that are "on column" thus cutting down the flow rate of the three lower tap holes.

It seems to me that a sap column should never reach or encroach on a tap drop.

Let me know where I am confused please.

Rob

[Biz]

Interesting, perhaps you have an ideal setup for the good vacuum. I do not have clogging problems on my 3/16 lines but had an issue with sanitation once, the next year after I decided not to bother cleaning the lines. Now the lines get cleaned every year, and I try to do drop replacement every 2 years, line replacement every 4 years or when I see too many moldy spots.

Dave

[Sugar Bear]

Interesting, perhaps you have an ideal setup for the good vacuum. I do not have clogging problems on my 3/16 lines but had an issue with sanitation once, the next year after I decided not to bother cleaning the lines. Now the lines get cleaned every year, and I try to do drop replacement every 2 years, line replacement every 4 years or when I see too many moldy spots.

Dave

My setup is not ideal but decent and suspect that I could get a fair amount more then 17". I started out last season ( after I fixed the leak at the gauge connect ) getting around 6 to 8" and then went to around 13" and peak run gave me 17". What are you able to get on 3/16??

[DrTimPerkins]

Sugar Bear, are you saying you can get 15-20" of natural vacuum using well set up 5/16" lines? 3/16" lines will get you good natural vacuum with some drop but 5/16" lines cannot develop as much vacuum. Curious how this works.

5/16" tubing will develop natural vacuum if installed properly. This has been known for some time. https://ecommons.cornell.edu/bitstre...=1&isAllowed=y It is more difficult in some ways, requires more taps per lateral line, is less consistent, and the vacuum will "collapse" at certain times and not persist well during low or no flow periods, but it certainly can be done.

3/16" tubing will develop natural vacuum much faster and will retain it far longer during a flow. This is because the internal diameter of 3/16" tubing is small enough that a column can develop (due to cohesion of water) and be held within the tubing. That's not the case with 5/16" tubing, in which the water (sap) column will naturally drain unless maintained by continuous flow of sap.

The biggest advantage with 5/16" natural vacuum systems over 3/16" is that there is less clogging.

[DrTimPerkins]

If the sap column formed from the higher taps rises above the three lower taps. Which in my case it did and in most cases I suspect would, won't that create back pressure into the three lower tap holes ( reverse vacuum ).

I am not entirely sure what you mean. If the sap column rises higher in the lateral line than the lower taps (which should only happen if the drain end gets blocked, the tubing at the end with the lower taps is on flat ground or below the lateral line at that elevation, there is a clog or blockage in the line restricting flow, or the line is seriously overloaded with taps), then the problem is with the installation somewhere.