Connecting corny keg to jockey box

[csprague]

I've searched the threads endlessly, and those of other forums, and have come up with no answers here. As far as I can tell, I'm only the second person in the history of the world whose tried to use a corny keg with a pre-fab jockey box

The problem: The back of the jockey box has the standard 7/8-14 shanks that connect to 50-feet of 5/16 OD SS tubing.

Like all pre-fab jockey boxes, the fittings assume you'll be connecting to a sanke keg, and that would indeed be a simple matter of getting some 3/8 ID tubing, some 3/8 tailpieces and 7/8-14 nuts and washers.

Problem is, how do you connect this to a corny keg? Most of what I've read strongly recommends 3/8 for resistance/foam control, but obviously, you can't fit a 3/8 ID tube onto a 1/4" ball lock barb.

How do people do this? Simple double-barb adapter and a very short length of 3/16 hose on the keg side? Or can you just run 3/16 tubing all the way to the jockey box and use a 1/4" tailpiece? What effect would that have?

Help!

(thanks)
Chris

 

[ozzy1038]

Why not get a brass barbed fitting and connect it that way?

 

[csprague]

What do you mean?

 

[JRems]

You are over thinking it. Just use the standard ball lock connector with 5 feet of 3/16 or 1/4" line to a 1/4" Barb tailpeice.

 

[csprague]

I had considered that, but how many PSI would I need to push that with? 3/16 ID vinyl tubing has a resistance of 3psi/ft. 50-feet of 5/16 OD tubing has about .5psi/ft, for 25psi. The faucet and shank add about 3psi more.

So using 5' of 3/16 ID vinyl beer tubing, I'm looking at a staggering 43 PSI!

By using 3/8" tubing, at a mere .2psi/ft, the beer line only adds 1psi, not 15. Seems like enough of a difference to make it worthwhile to look for a solution that allows 3/8 tubing.

Chris

 

[csprague]

Source for my line resistance numbers:
http://www.beersmith.com/blog/2011/07/14/keg-line-length-balancing-the-science-of-draft-beer/

 

[ozzy1038]

Try the 3/8 tubing and use epoxy mix tip inserts in the keg to add the resistance you need to get a good pour. https://www.homebrewtalk.com/f35/cure-your-short-hose-troubles-100151/

 

[JRems]

Use 1/4" like I said and it will be fine, I have a jockey box with 50 feet of 1/4" stainless and 6 feet of 1/4" vinyl line to the keg. I don't think that chart is right or I would need over 100 psi. It pours great at about 40 psi. Your tubing has much less restriction, even with 5 feet of 1/4" line I bet you will only need 20-25 psi

 

[csprague]

For what it's worth, I ended up finding, and ordering, this:

http://www.midwestsupplies.com/barbed-swivel-nut-1-4-flare-3-8-barb.html

This will make it easy to use low-resistance 3/8 line.