PUTTING THE SYSTEM INTO SERVICE:
Clean and sanitize the mini-keg and bung/tubing.
Slide the Liquid Side bung down to bottom out against the retaining washer (I apply a bit of keg lube to the last 1/2” of tubing going into the bung, which might help to disassemble when empty).
Apply a bit of keg lube to the groove in the bung, and a little all around the shoulder.
Push the bung into the bottom port. I find it helps to get one small section of the groove in place, then move around from there. With the lube, it should seat pretty easily. I use a Popsicle stick or dowel to push around the center of the bung to help assure it is fully seated in the groove. Lift the flap around to double-check. After you do it once or twice, you will have the 'feel' for it.
You can add more sanitizer if you want, and can pull a little vacuum on the liquid out tube to suck out any excess sanitizer. It will get almost every drop. Close the tap if you keep a tap connected, and/or pinch clamp the hose.
Add priming sugar if you 'naturally carbonate'. I'm finding that ~ 60% of the normal bottling rate works well, and I don't know why it should be less, but I will get ~ 30 PSI at room temperature, which is in the ballpark on the CO2_volume/temperature charts. Fill with beer to ~ 1” from the top.
Insert the top bung/tube assembly the same as for the liquid side. Purge with CO2 if desired. Since I usually naturally carb, I just wait ~ 20 minutes to let the CO2 that escapes from racking push out the air.
For natural carb - close the gas side (see “Conditioning Options” below), keep in a warm (65F-75F) place for a few weeks. You can test the pressure with a gauge, expect ~ 30# at room temperature.
To serve, chill, connect a CO2 source at serving pressure (~ 10-12PSI), un-pinch and add a tap if you stored it w/o a tap. I generally just top off the pressure after pouring a pint. As the keg empties, the pressure will stay more steady with the extra head space, you can pour several w/o the pressure lowering much.
When emptied, release pressure, push the barbed portion of the tubing inside the keg using a dowel or Popsicle stick, so the tubing is looser in the bung. Then lift the lip of the bung, push in on the shoulder of the bung, work your way around and pull to remove the bung . If it is resisting, add a little keg lube as you work your way around, but this shouldn't be needed - just go slow and easy to avoid tearing the bung. They come out pretty easy for me, a little practice helps.
“Conditioning Options”: Since I'm putting Luer connectors on my tubing (1/8” Male Luer on the Liquid tubing OUT, 1/4” Female Luer on the Gas tubing IN), I just pinch clamp the small diameter liquid tubing, then 'close the loop' by connecting this to the Luer on the CO2 tubing (twist the tubing CCW a few turns to keep the Luer from untwisting itself).
I also have a pressure gauge connected to a Male Luer, so I can pinch off the gas tubing on the keg (I slip a slit piece of 1/2” ID braided hose over the tubing, and pinch it with a small Vice-Grips), and connect the pressure gauge to check pressure. Or just leave a gauge connected, or an air-stem - it's up to you. Or connect to CO2 to force carb. I'm using a paintball tank set-up.
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