Pulling a spile for one minute, then replace it.

[TerryEspo]

I have seen that when my lines are full of sap, (beginning of the day). My Shurflo pump turned on and the sap flows slowly. But if I pull the farthest away tap on any lateral and clear the line, I then see the sap bubbles moving much better after I replace the tap. The lines never fill again with long sections of sap.

It seems the Shurflo cant pull a line full of sap (no bubbles) as good as when pulling sap/air. After pulling the spile the line now has sap bubbles moving rapidly along.

Is this due to low vacuum? Leaks?

I should state the first lateral closest to the pump does not need the tap pulled, it clears itself real good.

Any ideas?

Thanks.

Terry

[maple maniac65]

I am wondering if it is harder to see sap moving when the line is full verses sap moving with bubbles. A wet line full of sap has no turbulence.

[ennismaple]

Terry,

You want the sap moving slowly in tubing. When we check for leaks if the sap is barely moving in the lateral (like an inch a second) at the mainline and is maybe a 50/50 mix of sap and large bubbles - means there is no leak and you can keep walking. A line with a lot of small bubbles has a micro leak somewhere, likely on a fitting. A line with no sap in it has a ton of air getting in somewhere.

[ryebrye]

The shurflo is designed to pump liquid - and isn't designed to pump air, so it should actually do a slightly better job pumping when the column is full. It's just harder to see - but in the case your line is entirely full maybe you can look out the discharge side for evidence it's moving sap out?