3/16” on natural vacuum - how many taps is too many?

[bobanlou]

I have an 800 foot long 3/16” natural vacuum line with 36 taps on it. The top tap is 140 feet in elevation above the collection tank, and the lowest tap has 50 feet of elevation. Too many? I ran an experiment with a gallon jug of water. I removed the top tap from the tree, filled the 800 foot line by siphoning water into it, and then timed how long it took the gallon of water to be siphoned through the line. It took 7 minutes and 12 seconds. That’s 8.33 gph.

It seems to me that 8.33 gph woul support more taps than 36. 36 taps flowing a total of 8.33 gph equals 0.23 gph per tap. Which is more than I’ve ever gotten on my best flowing day.

I invite people to check the logic of my experiment and to challenge my conclusion.

[Bucket Head]

I have a line longer than that with a little over forty taps on it. However, it is coming down a mountain side, so that helps.

I remember taking in a presentation by Professor Tim Wilmot, the originator of the 3/16 research, and he said he had a line with 37 taps on it and it showed no signs of it being overloaded. I don't know if he ever experimented to see just how many would overfill the tubes capacity.

Steve

[maple flats]

On a lease I had about 5 yrs ago (the landowner now taps it himself) I had one line that had 45 taps on it. Fairly level on the top section on that lateral and most of the taps ( about 5' fall in 600 feet of lateral), but very good drop in elevation on it's way to the mainline. The flow was very good, but I never tested it to see if 2 laterals of about 22 each would be better.

[DMF]

I have one line over 1,000' with 35 taps on it. 80' change in elevation.

[bobanlou]

Does anyone have a feel for gph of sap from a tap under high vacuum on a good sap running day? The best I got this year was 0.13 gph, but this wasn’t a good running year for my location in western Maine. If I knew max flow per tap. I could divide it into 8.33 and get an estimate of how many taps the line would support on a max flow day.
Bob

[DMF]

Does anyone have a feel for gph of sap from a tap under high vacuum on a good sap running day? The best I got this year was 0.13 gph, but this wasn’t a good running year for my location in western Maine. If I knew max flow per tap. I could divide it into 8.33 and get an estimate of how many taps the line would support on a max flow day.
Bob

I don't have a high vacuum set-up. I used 3 lunchbox style soda pumps last year with 3 collection tanks. I have one days' data and I don't remember if it was a high flow day or not. For this snapshot in time, the three pumps were pumping a total of 34.17 gallons per hour. I had approximately 309 taps being pumped which works out to 0.11 gph per tap. I really need to track this better next year; I didn't track this once for all of this past season.