PDA

View Full Version : Funny vacuum problem


Vtmbz
03-10-2016, 03:36 PM
Yesterday was a good run here. I have 6 lines of 3/16 vacuum, all were showing sap flowing.

So I put vacuum gauges on three of the lines and they all stopped running and are still not running, while the three without are running even as we speak. I don't think it's leaky gauges, but they read zero vac.


???
DrTimPerkins
03-10-2016, 04:00 PM
So I put vacuum gauges on three of the lines and they all stopped running and are still not running, while the three without are running even as we speak.

When you cut into the line to install the vacuum gauge, the sap, which creates the vacuum, ran out of the line. Thus zero vacuum until the trees produce enough sap WITHOUT any vacuum to start the process of building vacuum again. The lines you did not cut into did not lose vacuum, and therefore are still running. If you (or others) need to cut into a 3/16" line for repairs or to install a gauge another time, use Vise-Grips to pinch off the line on the downhill side. This will stop the flow out of the line. Then when the repair is done, take the Vise-Grips off and you'll still have vacuum.

One way to "jump start" the flow again would be to take a pint of sap and a small funnel of some sort and pour it into the line at the top, then quickly reconnect the line before the sap all runs out.
Vtmbz
03-10-2016, 04:17 PM
Interestingly, I clamped the line and observed that the air bubbles were not moving, but I guess it wasn't clamped enough. The lines are all dry. What surprised me most was the sap didn't start back up.
RiverValleySugarhouse
03-11-2016, 06:19 PM
Could be because it hasn't frozen at night. Same with a powered vacuum pump sap will run for awhile after no freeze up but you shut the vacuum pump off you will lose the sap flow and not get it back till it freezes. I know guys now getting sap and it hasn't frozen at night in three nights now. Gravity has been dry for 2 days. I shut mine off when sap flow went way down. I have seen it the other way I have went down and just had sap drip drip into tank with no freeze up and started vac and you could watch the laterals slowly fill up with sap and then start trickling in with a half an hr. Hope this makes sense