Level ground gravity feed tubing

[Adirondack-Maple]

Does anyone have an idea on how to do a level ground gravity feed

[maple flats]

Welcome to the Maple Trader!
You have 2 options as I see it,
1. short runs using 3/16 and build a slope into the run, Maybe start at 6' high and slope down to 2' high, with a low container to catch the sap in. Then the highest tap will have about 4.4" of vacuum if the tubing going into the container is 1' high (actually .88x5) As the taps get lower, the vacuum decreases. The beauty of 3/16"{ tubing is at least 3 fold, the sap will not pass the gasses in the tubing, it thus generates some vacuum with each foot of fall, and it is cheaper to buy. If you try this method, it's best to keep at least 1-2% slope on the tubing (1%=1'/100') and have at least 12-15 taps on each line, too few takes too long to get enough sap in the line to get the gravity vacuum to work.
While this method will only give you minimal vacuum, it will help some.
2. Another method that some use is little short tubing drops, maybe 1 or 2 trees (1-4 taps depending on tree diameters) and feeding into a container on the ground.

For either method have a large enough food grade container, on a good run day a single tap can yield 2+ gal of sap, but 1 is likely closer to the average.
On both methods the tubing from the tap (the drops) to the lateral (the line connecting the drops and transporting the sap to a collection container, use 5/16 tubing from the tap to the lateral.

[Maple Man 85]

Does anyone have an idea on how to do a level ground gravity feed

Don't... Invest in a vacuum pump. For the amount of sap you'll gain in using a pump it will be a quick return on investment not to mention the headaches you'll save in sap freezing in the lines and separating or breaking fittings.