The Future of Tapping is Here. Our Clear Check Valve Spout has everything the efficient producer needs: check valve technology, plus the visual benefits of clear, polycarbonate material. Available in both 3/16" and 5/16" sizes.

The Leader Check Valve Adapter was invented by Dr. Timothy Perkins, Director of the University of Vermont's Proctor Maple Research Center. Co-designed and co-tested with Leader Evaporator and the Proctor staff, this spout has revolutionized maple sugaring, extending the season and leading to substantial increases in maple sap production.

There are circumstances where sap can reverse its flow in a tubing system and return into the maple tree's tap hole. It could be caused by leaks or outages in a vacuum system, or even natural freezing and thawing cycles. Such reversals can (1) cause bacteria from the plastic tubing system to be introduced to the tap hole, and (2) allow harvested sap to be re-absorbed into the maple tree.

Bacteria is how a tree closes down a tap hole, and that brings an end to the maple season. Bacteria from the tubing system can accelerate this process. And, as a tap hole begins to close from this natural process, sap runs will continually shrink, regardless of weather conditions. This is one of the reasons why new maple sap tubing systems almost always out-produce systems with years of use, and why, the older a system gets, the tougher it is to reach the high production numbers that so many maple syrup makers are looking for.

By introducing a check valve system at the tap hole, we can effectively eliminate the backflow of sap from the tubing system, increasing sap production in two ways:

Sap that leaves the hole during short sap runs cannot be pulled back by the tree as it freezes.
Contaminated sap from the tubing system cannot be pulled back into trees during the natural freezing and thawing cycles, each time a mechanical releaser trips, leaks occur, or vacuum pumps are shut off.
Extensive testing of Leader Check Flow taps and adapters showed a very strong effect in extending the sugaring season. It allows maple syrup producers to tap their trees earlier, so not to miss the early sap runs, also knowing that the tap holes they drilled are not going to dry out and stop running prematurely. In fact, for the last two weeks of the season, the check valve adapter will continue to run like a freshly drilled tap hole.

Leader Clear Check Valve Spouts - 5/16"