This is my vacuum releaser. I built it from 12" PVC watermain that I pulled out of the garbage pile at a local construction company, aluminum that I bought at my local metal supply company, lexan that I bought and had machined at a local plastic supply company, and blumbing that I bought on Ebay, Amazon, AliExpress, and at local hardware stores. The large white pipe and the clear check valves are from CDL.
I spent the day today cleaning everything, replacing a couple of o-rings, and putting the machine back together. I had a big vacuum leak that it took me a while to find but I eventually managed to get the main releaser chamber down to 26.5 inhg.
What is it for?
It’s like an airlock. The whole system is under vacuum. The vacuum sucks the sap in from the trees and it fills the top chamber. When the top chamber is full valves change that isolates the vacuum pump and releases vacuum in the upper chamber by letting air in. That forces a check valve in the tubing from the trees closed so the tubing stays under vacuum. Then, the weight of the sap pushes another check valve open and lets the sap run into the lower chamber. When the sap has all run out of the upper chamber the valves reset and it starts sucking sap in from the trees again while a pump pumps the sap from the lower chamber into a IBC.