Without using a beer engine or gas what can I expect, if not using those methods is even possible!
Yes, it is possible to serve from a faucet/tap.
BUT:
In the olden days what they would do was knock out the bung on the barrels and cover it with a cloth so the air could get in and allow the beer to flow.
This would work great if the whole barrel was consumed but if not the beer would oxidize a bit.. THINK an Air pump on a keg of BUD... the next day the ber is pretty flat and funky.
So if you drink it all up no problem.
If not you need to purge the "air" from it and replace it with CO2.
I at the Great Dane Brewery it looked like to me that they set up CO2 lines going to there "casks"... I guess probably just a little pressure to fill the headspace.
Having never used one;;; I don't know how those kegs are setup to equalize the pressure but there must be some method; since you will get to a point where the preassure is equal and the beer will stop following.
If this method lets air in you need to replace it with CO2, or purge when done drinking.
You could when finished drinking turn the thing on end and push CO2 in through the faucet to take up the headspace and then server again...
DPB