Sap going backwards?

[Bolen Creek]

I have 300 taps that come through a 6ft ladder. The ladder is 3 1/2" pipes. I have 25 in vac at releaser and 22 inches past the ladder which is approximately 1,000 ft away. My problem is I my 5/16 lateral are flowing backwards about half the time on the other side of ladder they flow normal. We have a few 3/16 lines past ladder that all flow normal it's just the 5/16 going backwards. The ladders seem to be working good, anyone have any suggestions

[spud]

I have 300 taps that come through a 6ft ladder. The ladder is 3 1/2" pipes. I have 25 in vac at releaser and 22 inches past the ladder which is approximately 1,000 ft away. My problem is I my 5/16 lateral are flowing backwards about half the time on the other side of ladder they flow normal. We have a few 3/16 lines past ladder that all flow normal it's just the 5/16 going backwards. The ladders seem to be working good, anyone have any suggestions

You have a leak or loss of vacuum. This happens to everyone at times. This is why I use the CV2 spouts.

Spud

[Ultimatetreehugger]

Spud, what do you get for production numbers each year using cv2s? What level of vacuum do you like to run?

[Bolen Creek]

I will rewalk it tomorrow and see if we can locate a leak, this is a new install added onto a existing bush. The old part has CV 2 in it. We found it weird that the 3/16 lines were flowing the right direction and the 5/16 where going backwards. The mainline is probably 500 ft long past the ladder and all of the 5/16 were going backwards

[bill m]

Are you sure it was really going backwards? Could have been an optical illusion with the gas bubbles moving in a direction and give the appearance of the sap going backwards.

[Russell Lampron]

Sap flows backwards when there is more vacuum at the tree than from the vacuum source. If you put shut offs in the legs of the ladder you can shut one of them off to see it that helps or makes the problem worse. It's a possibility that you need to add another leg to the ladder to handle heavy sap flow.

I have a 10' ladder with three 5/16" legs on 17 taps which is probably too many legs for the number of taps. On low flow days I can see that the sap doesn't make it to the top. I never see the sap going backwards though.

[Chasefamily]

I have the same problem on one of my lines. I have 4 1/2" lines to lift 8ft or so. I have seen the sap flow backwards many times, then all of a sudden it will suck and go all at once. I am going to put in a shutoff in atleast 2 of the 1/2" lifters as i only have 112 taps on this line currently.

[blissville maples]

When your releaser if you're running vacuum is dumping or swapping sides you'll get a few seconds where the sap stops and even goes backwards a little bit. As soon as the releaser finishes it should resume, the proper direction away from the tree. this happens because for a split-second the tree has more vacuum than your main line, because the vacuum pump had to exhaust the air from the releaser dump.

Sometimes I see the ladders pulsing because the vacuum is rapidly changing, probably do to chugs of sap coming through the other section of main line causing sudden fluctuations that don't last long

[Chasefamily]

in my situation i am using and electric releaser. Late last night i installed 2 ball valves in my ladder so that i can shut half of it off if need be. It was starting to freeze when i did so, so i am hoping to be able to try it later today.

I have the same situation that Boleen Creek has. I have 28-29 inches at releaser (and the gauge is very steady), then 26-27 at this sap ladder. Alot of the 5/16 on this line will go backwards before it goes forward. at the very end of this run it switches to 3/4 line for about 500 ft and at the end of that there is one 3/16 line. the 3/16 continues to flow into the mainline. although when the 5/16 chooses to finally go, the 3/16 picks up speed and flows into main even faster

[n8hutch]

My guess is that you are getting pooling somewhere in the mainline and it is temporarily reducing vacuum past the pooling/sap blockage whatever you want to call it, then once the vacuum pulls the sap past the spot and the sap/air can pass each other the vacuum is restored past the blockage, your 3/16 line is not relying on the added vacuum to flow so it is not as effected by the surge in vacuum.

This pooling could be at your ladders or anywhere in the mainline.

This is why I reluctantly put a small leak in my system to keep my Ladders clear. Fiddled with the Ladder alot until I gave in and tried the leak.