Most keg jumper lines have beverage ball lock disconnects at both ends. That way, the beer from one keg goes out through the beverage post of the server keg and into the beverage post of the receiving keg. In this way, the beer comes into the receiving keg from the bottom, avoiding frothing as much as possible. A few years ago, when I purchased a keg jumper line, it had a beverage ball lock disconnect on one end, and a gas ball lock disconnect at the other end. Descriptions of the product say that it can be used to push either sanitizing solution or beer from one keg to another. I can see the usefulness of it to transfer sterilizing solution from one keg to another, but how is it to be used to push beer from one keg to another without it foaming up as it drops from the gas post in the receiving keg?
It can not. You want two liquid (black) QDs on your jumper. Okay, for the sharp-shooters; if the beer was uncarbonated and the keg purged of oxygen it wouldn't hurt to have it enter through the gas post. I actually do this from time to time . . . but always keep it all black.
That's what I was afraid of. I'm not sure why they even bother selling ones with a beverage QD on one end and a gas QD on the other. The ONLY purpose I can see for that is for sterilizing the gas post on the receiving keg. Other than that's it seems useless. Besides, is it even worthwhile sterilizing the gas post? No beverage really touches that end.
Whoever put it together probably just thought to connect the 'OUT' from one keg to the 'IN' on the other. I guess that kind of makes sense if you don't know what it's used for.
I have the feeling that someone at the store screwed up and put a whole bunch of these together, then realized they messed up. Then they just sold them for a discounted price. I can always take off the gas disconnect and replace it with a beverage disconnect.
Connect a hose (any will do) to the gas disconnect and run the into a bucket or bowl of sanitizer. Easy way to do a closed transfer.
It'd go on the in post of the keg you are transferring into and allow the CO2 in that keg to be vented into the bucket of sanitizer. Maybe not necessary since pressure should always be pushing gas out, but If you don't vent the keg you're transferring into backpressure will build and stop the flow between the kegs.
If you don't have a PRV, this is an option, but other than that it's a just personal preference and how far you want to take measures to minimize O2. Either way there shouldn't be any issue of oxygen entering the keg since CO2 should be pushed out throughout the transfer.
