Very Simple Sap Lines

[berkshires]

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.

Seems to me the best of all possible worlds would be 5/16 lateral lines from the top tap to the bottom tap, and then a 5/16 to 3/16 converter and at least 75 feet of 3/16 tubing (with no drops in it) down to a collection point.

Then all the lateral line with drops cut into it are on 5/16, and less prone to clogging, but you get the benefit of a sap column in 3/16.

Thoughts?