Vacuum line on ground. Bad idea?

[raptorfan85]

I have a back section of woods tubed that I want to add vacuum to. The only power source is 1200 feet away and I can't run a gas engine in that spot. Would it be a bad idea to just run a vacuum line on the ground to the releaser? It would save a lot of work hanging wire.

[TapTapTap]

I have a back section of woods tubed that I want to add vacuum to. The only power source is 1200 feet away and I can't run a gas engine in that spot. Would it be a bad idea to just run a vacuum line on the ground to the releaser? It would save a lot of work hanging wire.

It will work so long as no sap or moisture accumulates in the lines which can create a blockage. Then you'll get no vacuum when it freezes (and even when it's not frozen if there's too much to be moved by the vacuum) and likely will overwhelm your moisture trap at times.

Therefore, the only way to do it trouble free is to set the line at a constant downward pitch to the releasor or back to the moisture trap which means only one high point and no sags. You should be even more diligent about slope than with your sap lines. If you have sags because of the land topography, then I suggest tees with valves to allow moisture to be drained off - which can only be done with the vacuum off unless you install a moisture trap at each sag.

Ken

[DrTimPerkins]

It will work so long as no sap or moisture accumulates in the lines which can create a blockage.

Ken is absolutely right. When we started doing a lot of research on chambers for sap yield measurements in the 1990s, the vacuum lines were initially run aerially. These were not used to transport sap...just vacuum (air), but not tied to wire except at widely spaced intervals, so there were some sags. After a few sap runs we had no vacuum until a few hours after the regular main. In checking things out, we found that we had condensation in the pipe which froze in the sags. We had to run new line and wire tie it just the same as regular lines. Lesson here is to NOT a line unless it is graded properly so it will drain...even if it is just a vacuum (air) line. We do sometimes run 5/16" vacuum lines a short distance without worrying about grade, but these will thaw quite a lot faster than a mainline.

[raptorfan85]

Thanks for the info guys. Looks like I'll be running some more wire.

[ennismaple]

Dr Tim is right - you'll still get moisture in that line no matter how perfectly your releaser is functioning. One day this season I had one remote releaser 500 feet from the vacuum pump that would not build vacuum, even after it hit +5C. I tore the releaser apart - all good there; the moisture trap at the releaser - all good, went back to the pump and took the other moisture trap apart and it definitely was functioning properly. I then walked the entire line from end to end checking if there was a kink, blockage, anything... I found the problem 10 feet from the vacuum pump where a chunk of ice had been sucked back towards the pump and had completely blocked a PVC union in the 1.25" vacuum line - it was a perfect plug and was in the shade so it wasn't melting quickly. That ice cube sized blockage cost me a bunch of sap and time.

[One tap short]

Run some wire and save yourself the headache of a vacuum line filled with sap/moisture in a sag.