Our maple woods do not have a lot of topography, so gravity flow is not an option. Sap is drawn from the trees under vacuum to pump houses, then is pumped to centralized storage tanks. To understand the layout, picture a center point with lines radiating out in a semi-circle. At the center is the building housing the reverse osmosis (RO) equipment. This is designated pump house 1, but we usually call it the RO house. The central storage tanks are adjacent to the RO house. Lines extend from this central point through the woods to the west, south and east, forming the semicircle. Six pump houses, sometimes also called stations, are located along that grid, and serve as intermediate sap collection points.
Pump houses contain a stainless tank, Lapierre sap extractor, and a pump. The size of the tank, extractor and pump are based on the requirements of the pump house and is influenced by factors such as the number of tapped trees along the lines feeding into the pump house.
Pump house 3 is not only the smallest building, but also the shortest distance from the RO house. Sap is drawn from approximately 200 trees. Our experience with this pump house last year, in which the vacuum pressure was low, spurred us to rethink the setup and look for improvements.
The first thing we changed was the storage tank. It had a plastic tank that we wanted to replace with stainless for ease of cleaning. Lincoln and Logan took the frame holding the tank apart then cleared out the tank and lumber. That provided the opportunity to do a thorough cleaning in preparation for the new tank. The second step was to assemble a sap extractor to improve the vacuum pressure. We had the basic unit but had to order several parts to get it operational. Due to the number of taps, the extractor is smaller than the units in the other pump houses.
After the stainless tank was in place, the rest of the build could begin. A frame was built to hold the extractor above the tank. PVC pipes with control valves were installed on the back wall as part of the vacuum system and lines were connected to the extractor.
The last piece to making this work was the addition of an immersible pump inside the tank. The pump has an attached float that rises with the level of the sap. When the float reaches 90 degrees it triggers the pump to turn on, sending sap through a flexible hose up to the main line that exits the pump house and runs all the way to the storage tank. In the picture you may notice a separate hose attached to this line that points down into the tank. Its purpose is to drain sap back from the main line into the tank at the end of the day, preventing sap from freezing in the main line overnight.
The extractor and pump are working beautifully. The trees connected to pump house 3 are tapped and the vacuum is strong. This is a satisfying reward for the work that Karl, Lincoln, and Logan put into design, problem-solving and construction.