Natural Gravity Vac?

[Indiana-Jones]

We have ran 300 feet of black 3/4 mainline, reduced to 1/2 blue tube for the remaining 2oo ft of the way up a ravine with very steep sides. There is 10 to 15 % grade up this main. There are maybe 50 taps coming in on 8 laterals dropping down over the sides, some may be 45 degrees coming down.

So, what seems strange is where the black pipe drains into the storage tank the sap trickles out at a slow but constant rate. But, we drilled a hole for a new saddle about 75 ft up from the drain end and the sap squirted 2 ft in the air. I'm guessing that something is keeping the pipe from emptying out

Tomorrow I'm going to put a vacuum gauge at the top and see. I wouldn't have thought that you could pull a vacuum on 3/4 pipe.

[briansickler]

Sounds like the black line is plugged. If it was vacuum locked, when you drilled that hole, it should have vented the line and allowed it to drain out the bottom end. Just my thoughts. Good luck.

[unc23win]

Thats what I was thinking its plugged or frozen below where you drilled the hole.

[Indiana-Jones]

In the morning I think I will unplug the top end and see if the tube empties. This black pipe is new and the spot where the plug up would be is in the middle of a 1100 ft roll.

But...I have made a few trespassers POed.

Thanks for the replies and I will report back.

[Indiana-Jones]

This morning the sap had quit flowing and the tube was empty, so it would not have helped to open the top. We did push about 60 feet of 5/16 up the line and felt no obstruction. So the saga continues.

Today was our first boil of the season, went through about 250 gallons of sap in 6 hours.