hmmmm?

[Three Saps Sugar Shack]

how long does your vac run before it takes its full effect on the tree? after about 5 min i notice a 50% increase in flow, will it flow harder the longer the vac is on? how long before max flow is reached?

[venus_amos]

I've observed that depending of sap flow and lateral length. it can take up to 3 hours to get max vacuum on taps.

[Haynes Forest Products]

Max vacuum AT the tree or IN the tree? When I turn on my Vacuum system If things aren't all froze up my guage is at the max reading within minutes. Then as the day progresses I'm sure there are fluctuations. I have never sat and watched the variations thru out the day.

[venus_amos]

For an example, I've already check on a very long 5/16 line with 63 taps. From start, 10:30 a.m. 21 in. Hg on releaser:

at the end of line

11:00 : 13 in.Hg
12:00 : 19 in.Hg
13:00 : 22 in.Hg
14:00 : 26 in.Hg

Vacuum top to 26 in.Hg until frozen.

On this day, sap flow was average, checking method was snap drop with vise-grip pliers before removing spout, put gauge on spout, remove pliers, check vacuum, re-snap drop with pliers before removing gauge, replace spout, remove pliers. Doing that for don't break vacuum column on line, responsible on backflow to tap.

[danno]

I'm thinking you had some real ice in your lines. With no ice, I will have full vac at the end of my line within a minute of turning the vac on, unless I have ice blockage. I'm running the same Sihi as you - you're doing great if you can get 26" at the end of your lines. I can get 25"ish at the releaser, 24"ish at the end of my lines.

[venus_amos]

That was last year with my vp76 non-flood on new tubing installation. Watching for have no leaks. When I've checked vacuum, I've walked the 5/16 line to be sure to find no ice. I have 1400 taps installed on this method. It work very well but it needs to be very meticulous on leaks.

In my post, I forgot to tell my 5/16 line is 1000 feet long

[Three Saps Sugar Shack]

but my gravity lines hav stopped flowing... vac still pullin sap...

[3rdgen.maple]

Venus am I reading this correct? You have a 1000 foot 5/16 lateral with 63 taps on it? If it is that is the problem. Strive for 5 and keep it under 200. Now if you are saying you use 5/16 for mainline at 1000 feet long that right there is your problem. You need a bigger mainline to get max vac to your trees. If I am not understanding this right then disregard everything I said.

[venus_amos]

3rdgen, your reading is correct. my new installation has an average of 42 taps on each 5/16 lines. my neighbor has tested this installation mode since many years. In his bush, one side with very long 5/16 lines and the other with a conventionnal installation (10-15 taps on 5/16 lines). Each sides are connected in their own electric releasers with water meter. Year after year, performance of each sides is similar. Before installing my new tubes, I was 10 main lines of 400 to 500 feet. Now I have only 2 main lines of 300 feet each,

A year before, I was testing one 5/16 line to see performance because I was sceptical. Now, nothing gonna make me change my installation : low cost in maintenance and high performance. Also, if there is a power failure, the sap flow will be higher than a conventional system. We have lived the last year. With my new pump, this season, I hope to get between 15-20% more sap