Question about co2 and beer gas

[oceanic_brew]

I have 4 kegs that have been under co2 at 12 psi in the fridge at god knows what temp heading up to a cabin this weekend. My friend works for a dispensing company and is borrowing a two tap jockey box that has some lengthy stainless coils inside which he tells me will need beer gas to push.

I understand that because of the amount of resistance in the lines a higher pressure is required to keep co2 in solution also that a mix of nitrogen and co2 is used since nitrogen doesn't dissolve as freely as co2, which would further carbonate the beer if not.

My question is do I completely vent the kegs of co2 and replace with beer gas once connected or can the beer gas push right in on top of the co2 at that pressure?

I admittedly do not 100% understand what's going on hahaha

Thanks

 

[LLBeanJ]

No need to vent the CO2 from the kegs.

 

[DrinksWellWithOthers]

Straight CO2 is fine for direct draw units (kegerators) and jockey boxes. Blended gases come into play with long draw draft units with longer draft lines.

 

[oceanic_brew]

Straight CO2 is fine for direct draw units (kegerators) and jockey boxes. Blended gases come into play with long draw draft units with longer draft lines.

There's 100 ft of coil in the jockey box per each tap.

 

[doug293cz]

What is the ID of the SS cooling coil tubing? The resistance to flow is a very strong function of the tubing ID. If you have 3/8", or larger, tubing, you won't need beer gas to push. If the flow is too slow at 12 psi, then you can turn up the pressure while serving, and then turn it back down, and vent, at the end of the session to prevent over carbing. Of course, it it is a long pouring session, perhaps no one will be in any shape to remember to turn the pressure down.

Also, if the beer is not in a cooler, you can use much higher pressures to serve and store without having to worry about over carbing. For example, if your beer was carbed @40˚F and 12 psi, and it will be sitting at 65˚F for storing and serving, then you would want the CO2 pressure to be 25-26 psi just to maintain the level of carbonation.

Brew on

 

[DrinksWellWithOthers]

There's 100 ft of coil in the jockey box per each tap.

Id estimate that the coils in my jockey box are around 100 feet too (one coil within another for each faucet) and I've only run it with straight CO2. A jockey box is for temporary dispensing meaning there won't be a long contact time with the CO2 and the beer.

If you're set on using blended gas I wouldn't bother venting the kegs.

 

[oceanic_brew]

Interesting!

Thanks everyone. I'm certain of what you are saying now.

If my friend wants to bring a tank of beer gas and run it on that I'll let him.

Especially since anyone who has a friend that desires a life requiring a tank of beer gas should consider themselves lucky.