Sap from up to 8 individual taps enters the small blue lateral line which then delivers it to the 3/4" mainline
Maple sap flows down the mainline towards the releaser
Here is what the vacuum manifold looks like when sap is flowing. The lines are just starting to thaw, as you can see in the hole closest to the camera. This is the sap flow from 650 taps.
Since maple sap flows best when the night time temperature fall below freezing, down into the low twenties at night, ice routinely forms in the sap lines. In this video clip, you can see the beginning of the flow as the sap is just starting to be pulled past the ice. This is causing a surging, sporatic flow of sap.
When the vacuum tank fills up, it triggers a float valve that releases the sap inside. Each release is 4 gallons of sap, or enough sap to make about 12 ounces of syrup. When we were having our best runs this past season, the tank would release every 1:50 seconds, which translates to about 130 gallons of sap per hour. Since we were collecting sap from 650 taps, we were getting about 1/4 gallon of sap per tap hole, per hour.
Back before we had our tubing and vacuum collection system, we used to collect sap from bags that hung from the tree. There are many methods of collecting sap, but we found the sap sak holders and bags to be a good method for us. However, it did require a lot of time and effort. Each of the bags can hold up to 4 gallons of sap. While it is true that they don't fill up completely each day, they need to be emptied on a daily basis to get fresh sap. On average, a person can collect about 50 bags or buckets of sap per hour, so when we had 670 bags to collect, it required a lot of help and time. In this video, you can see how the sap looks very watery when it comes out of the tree. It is only about 2% sugar.