Balancing a cobra tap/picnic faucet?

From what I'm reading, usual keg pressures range from 10-12psi for most styles and balancing requires similar resistance to the end of your faucet for foam-free pours. OK, got it.

Now, I understand that you usually get about 1 PSI drop per foot of 3/16" beer line. I also read that most shank/faucet combos give you an additional 4-5PSI drop. That means a 6 foot run of 3/16" line is about right.

I also read that cobra/picnic taps are basically no-drop meaning I'd need about 10 feet of 3/16" line to balance. This got me thinking, what is the PSI drop of 1/8" line? I can certainly force it onto the barbs with a little hot water and cussing.

What says the group?


Also, one tag along question... if going with 3/16", which style would you choose for you beerline from these two choices:

*****This clear PVC tubing has the highest strength and abrasion resistance
of any PVC tubing we offer, plus it remains flexible at low
temperatures. Use with water, air, food and beverage, and ethylene
glycol. Material is FDA compliant. It can be sterilized with gas. 3/16" ID with 1/32" wall thickness, 160psi max. $.16/ft.****** mcmaster 5006K36

or

******Easily monitor what’s flowing through your line—this PVC tubing comes in clear as well as a selection of transparent colors
so you can easily identify different lines within your system. Also known as vinyl, PVC is the most common plastic material for
low-pressure conveying applications. Use with water and air; clear tubing is FDA CFR21 175.300 compliant and can also be
used with food and beverage. All tubing can be sterilized with steam (autoclaving) and gas. Not rated for vacuum. 3/16"ID, 1/16" wall, 45 PSI max, $.14/ft******
mcmaster 5233K53

I'm pretty sure the pressure drop/ft. of line is usually rated near 2. I've seen it as hight as 2.7 I think, depeding on the brand. I would call the manufacturer and see if you can get that info for sure and that should help you balance it perfectly.

EDIT: http://northernbrewer.com/tubing.html this line from NB is rated at 2psi/ft for sure.

The height of the tap vs. keg is also a factor. http://kegman.net/balance.html


Those hoses you posted are not especially for beer. Beer line has very thick walls which somehow prevent foaming moreso than other beverage lines. I got mine from Austin Homebrew and run 10psi, 5 ft lines, and shanks to ventmatic faucets. I get too much foam. Still manageable, but the first pour especially is about 1/2 foam which settles to 3/4 glass of beer.

5-6 ft of 3/16 thick-walled beer line with a picnic tap will be fine if your regulator is set at ~12 psi. That's what I've got now

... until I build my kegerator.

lil sparky, your kegging but don't have a kegerator? i'd like to keg but i'd rather not deal with the kegerator just yet. whats your set up? (sorry to hijack!)

We've got an extra refrigerator, but it's not one I'm allowed convert. I've got everything set up just like I would with a full frig type kegerator, except I'm using the picnic faucets instead of faucets in the door. I just took some of the drawers out and set the kegs in there. I'll be getting a Sanyo to convert soon, though.

thing is with a picnic tap, you have to be careful using it. if you want to use it outside, the tubing will warm up fairly quickly, so if you don't do a constant pour, each glass will be mostly foam. if you can keep the lines refridgerated, this isn't a problem.

also, you want 3/16'' ID smooth bored, thick walled, beverage grade tubing. usually the OD is 7/16, i believe.

gnef said:

thing is with a picnic tap, you have to be careful using it. if you want to use it outside, the tubing will warm up fairly quickly, so if you don't do a constant pour, each glass will be mostly foam. if you can keep the lines refridgerated, this isn't a problem.

also, you want 3/16'' ID smooth bored, thick walled, beverage grade tubing. usually the OD is 7/16, i believe.

Click to expand...

Is it that the lines warm and expand, affecting the pressure? If so, would using braided lines help? Just curious.

you are half right. the lines warm, but it isn't the pressure you are directly worried about, it is the co2 coming out of solution due to the temperature difference. when the lines are warm, the co2 comes out of solution much more readily, and this spells foam.

gnef said:

you are half right. the lines warm, but it isn't the pressure you are directly worried about, it is the co2 coming out of solution due to the temperature difference. when the lines are warm, the co2 comes out of solution much more readily, and this spells foam.

Click to expand...

Makes perfect sense -- thanks! I hadn't realized that before.

I was looking at the Mcmaster.com tubing and most of their clear PVC is listed as beverage grade/FDA approved so I'm wondering exactly what the difference is with the 1/8" walled beerline everyone is selling for 55-60 cents a foot. If it's rated at 50psi and above, is there anything about it that would not cause enough pressure drop? Maybe it deforms too much?

I'd pick the first one from Mcmasters. Now, if you got a kegerator and your planning to keep the cobra tap hooked up and inside the kegerator at all times, there should be no worries. They do drip after pouring. What I do is place a folded up paper towel on top of the keg for the tap to rest on and drip onto. Also make damn sure that the trigger is not right up on the door side, because it might open it up and then you have a huge, huge mess when you open the door the next time. I keep my brews, all ales, around 10 to 12 psi. Sometimes they can be a little foamy, but when you pour, stand up and hold the tap at eye level, that helps some. Or you can do this, drop the pressure down to about 5 psi and crank back up later. But once it's fully carbonated, I noticed that leaving the regulator at 5 psi pretty much maintains carbonation. Again, the key word is previously carbonated.