3/16" with minimal slope

[AndrewsofBow]

Just wondering on how the new tubing is working with only a 1-2% slope? My slope is man made, start high and end low, at best I have about 2% slope and am wondering if the new 3/16th would work.

[DrTimPerkins]

Just wondering on how the new tubing is working with only a 1-2% slope? My slope is man made, start high and end low, at best I have about 2% slope and am wondering if the new 3/16th would work.

Probably not a good idea. The only study I know of looking at 3/16" tubing on flat land (done in Canada) showed that there was a build up of backpressure and reduced sap yield.

[Cabin]

Probably not a good idea. The only study I know of looking at 3/16" tubing on flat land (done in Canada) showed that there was a build up of backpressure and reduced sap yield.

What about using 3/16 tubing for drop lines into buckets?

[DrTimPerkins]

What about using 3/16 tubing for drop lines into buckets?

Shouldn't be any problem doing that.

[Cabin]

Shouldn't be any problem doing that.

I know it shouldn't be a problem but is there a way to get some vacuum out of it?? Tap higher in the tree or something? My sugar bush is too spread out with almost all reds to put a tubing system in.

[DrTimPerkins]

I know it shouldn't be a problem but is there a way to get some vacuum out of it?? Tap higher in the tree or something? My sugar bush is too spread out with almost all reds to put a tubing system in.

For every ft of head (height), you'll (theoretically) gain 0.88" Hg of vacuum, however in this case it is somewhat of a false-gain, since you'll be losing that same amount of head pressure that exists lower in the tree by tapping higher up. Thus no, there isn't any real advantage to using 3/16" over 5/16" tubing in this way. As always, you just can't break the laws of physics.

[Cabin]

For every ft of head (height), you'll (theoretically) gain 0.88" Hg of vacuum, however in this case it is somewhat of a false-gain, since you'll be losing that same amount of head pressure that exists lower in the tree by tapping higher up. Thus no, there isn't any real advantage to using 3/16" over 5/16" tubing in this way. As always, you just can't break the laws of physics.

Well it would be nice to bend them once in a while. ;)

[johnallin]

Does tapping lower on the tree measurably increase pressure at the tap?

[Paul VT]

We did 3 runs of 3/16 this year. We put gauges on each of them. One has 7 taps on it and the drop from the last tap to the tank is only about 5 feet. But we are getting 13 inches of vacuum. And the one with the most drop has about 15 ft and we are getting 22 inches. Explain that!

[Thompson's Tree Farm]

Paul, where are you getting 13 inches of vacuum? At the last tap before the tank, or somewhere above that on the line?

[Paul VT]

Paul, where are you getting 13 inches of vacuum? At the last tap before the tank, or somewhere above that on the line?
The gauge is at the top of the line. From the last tap to the tank is only 5 ft of drop and the top tap to the tank is maybe 10 feet.

[n8hutch]

I have a run of 3/16 that doesn't have a whole lot of slope, maybe 1/8 inch per foot for 200' and then drops 10-12' after the last tap. The only time I have checked it & it wasn't running it was well below freezing, it has never stopped otherwise. Very happy with it so far. Going to put the Vac gauge on it tomorrow to see what I am actually getting. It has 17 taps on it

[sugarsand]

You may actually have more drop than you think, or possibly faulty gauges.

sugarsand