3/16" As Gravity

[johnpma]

Question for the 316 guys. If you don't have the slope to create natural vacuum will 3/16" tubing and install it on more of a gradual slope sugar bush will the 3/16" then perform as a gravity system?

[maplefrank]

It will create the vacuum you have ed foe that slope. You will not get full capacity that you would with a lot of drop. But it would be more than running 5/16. So you you would gain more sap

[DrTimPerkins]

If you don't have the slope to create natural vacuum will 3/16" tubing and install it on more of a gradual slope sugar bush will the 3/16" then perform as a gravity system?

What % slope are you talking about?

[maple flats]

It's not the slope % but rather the drop from the T at each drop to the low end of the line. If a 3% slope (3'/100') is 1000' long the trees at the top will have full vacuum, those in the middle about half that. If a 20% slope 20' drop/100' is only 100' long you will not get full vacuum. Full vacuum is what ever the max is at your location (elevation above sea level and barometric pressure are both components).
Give us some information to answer the question.

[DrTimPerkins]

It's not the slope % but rather the drop from the T at each drop to the low end of the line.

Mostly correct, until you get to the low slope range at which point line friction overcomes gravity (elevation drop) and can even exceed it, creating backpressure.

It's kind of the same thing as when you fall on a steep hill you will tend to keep rolling down (unless you do something to increase your friction and overcome the force pulling you down), but on a shallow slope you just fall down and stay in place.

[johnpma]

What % slope are you talking about? maybe a 2% slope

[DrTimPerkins]

maybe a 2% slope

How many trees, and where are they positioned along the slope (near the end of the line, or mostly near the tank)?

[johnpma]

How many trees, and where are they positioned along the slope (near the end of the line, or mostly near the tank)? About 11 trees (mostly 8-10 inch diameter) spread out equally up to the tank

[n8hutch]

If you want all the sap you can get on gravity I would use 5/16 with that kind of slope, if all you have around is 3/16 and your not fussy with production then the 3/16 Will get you some sap. I saw a huge decrease year 2 on 3/16 tubing with marginal slope. Now I only use it on steep grades 7%-10% plus, it really was never intended for low slope situations.