"Pumping system inverse slope"

[Thompson's Tree Farm]

Dominion and Grimm have a "pumping system inverse slope" listed on page 9 of their 2008 catalog. Anybody know just what it is and what it is supposed to do? I want to move sap from one remote extractor location to a second remote location. They are 1200 feet apart and there is an elevation difference of 12-15 feet. No electric available. Will this do it. I currently pup it with a gas powered pump but would like to have the sap all consolidated when I get there.
Thanks,
Doug

[royalmaple]

Doug-

That lifter is meant to do exactly what you are looking for. It goes into an open tank that has sap in it. It has a float on it and when the float actuates it opens up a flapper and a vacuum line attached to the unit draws the sap up into your system to another location / releaser.

I don't know the specs on it but that is the idea anyway.