Balance tank needed?

[jrmaple]

Is a balance tank needed for the old Surge pumps if I have a moisture trap? What is the benefits to the balance tank if using it for sap? Thanks

[BreezyHill]

You can live without it.
Benefits: the pump pulls on the balance tank so when a surge of sap or gases enter the system the system will have less of a drop in vacuum level.
If you use a mechanical releaser, when the releaser finishes dumping the vessel will be at zero inches of vacuum. The sudden drop in vac level will allow sap to flow backwards in the tubing system until the releaser and the tubing system are at the same vacuum level. When the releaser is higher than the tubing the sap comes back to the releaser.
If you install a check valve on the tubing entrance to the releaser you will isolate the tubing system and reduce the sap surges.
This is when the balance tank pays off. When the balance tank is at say 24" and is four times the size of the releaser, a moment after the releaser closes, the vac level will be at 19.2 and climb back to 24" quicker, than a trip from 0 all the way back up to 24".

Then factor in that the sap in the closed tubing system was flowing into the system reducing the vac level and factor in any leaks that the system may have and the tubing system will likely be closer to 22 or 23 than still at 24".

More time at 24 is more sap in the bucket so in my opinion balance tank all the way.

My system is a electric releaser so no drop except for surges of sap. My system has 5 gallons of moisture trap and another 3.7 gallons in 3" line to the pump. Before this upgrade I had a small balance tank that was only 2x of the mechanical releaser...what a difference!

The old system ran vac on the tubing all the time thru a priority system so surges were minimal.

Ben