Calculating beer line length

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stz

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Hello HBT.
Apologies if this is a repeat, but .. I guess it makes life easier for me to put it in my own thread? I get pretty rubbish pours on my keg system. I thought that flow control taps would solve everything, but it doesn't seem to have. So ...

I want smack bang in the middle of the 'safe' zone for carbonation levels. This is 8 psi at about 30-34F (I'd rather have beer too cold than too warm and it is easier to work with as low a pressure as possible). So I need to overcome 8psi of pressure. Using 5/16" line with a restriction value of 0.4psi per foot and an average height of 2' I have ..

8 (pressure) - 1.5 (height) 6.5 / 0.4 (restriction per foot) = 16.25' of line required to balance.

I did originally have a few feet of 3/8" line which gave pretty poor results. I've just 'upgraded' to about 12' of 5/16" which is ... well still pretty poor tbh.

Is there any way to overcome this without spending any more money? I could run the system at a lower pressure? But then my beer wouldn't be carbonated enough? I could carbonate higher then reduce to serve? But I'd be fiddling with the regulator and the beer would go flat over time. I could reduce the temperature to 30F and reduce the pressure slightly in the hope of fudging it with some middle ground (will likely do this), but feel I should be able to solve everything by just backing the flow control off to almost nothing?

Anything I'm missing? Also everybody rates 3/16" and I can see why with the restriction values, but this is really difficult for me to fit to my taps without an expensive lego like arrangement of push fit. The 5/16" and 3/8" I have laying around.
 
The nuclear option would be order pairs of reducers for all lines and 15' of 3/16" though I'd be looking at $12 or so per line. I'm thus kind of loath if I can bodge something. I looked up this bev seal ultra and it quotes even lower resistance so I'd need even more of it? Primary benefit seems to be ease of cleaning and no off flavours compared to regular line? I doesn't seem to be what I need.

I used the calculator you posted and it seems to think I want 70+ feet of 5/16" for a 10 second/pint pour. This strengthens the argument for 3/16" line. I understand to achieve a longer pour without flow control your only option is to increase the line length to increase the resistance. Because I can decrease the flow rate it makes it seem like I need to set it to 2-5 second/pint to get it down into realistic ranges (20'+) which seems very fast and also completely counterproductive. I'd assume the faster pour would fob less and I'm guessing it is a quirk of the calculator, IE it assumes that a slower pour has greater resistance in the lines.

The flow control taps also seem like they don't work as well as they should. I feel if I back them off I'm increasing resistance therefore a slower pour should fob less and be equal to a longer line length. If I open them fully I decrease it so a faster pour should fob more. Using the calculator it would seem that I'm aiming for a 2-5 second pour with my current line length and this is way to fast, like not even on the same planet.
 
Nobody uses 5/16" ID line unless they're sending beer a really long ways. Heck, it's rare for anyone to use 1/4" ID line.
Do yourself a huge favor and switch all your lines to 10 feet of 3/16" ID tubing (if solid PVC like the virtually generic Bevlex 200).
You'll be stunned how much better your system dispenses...

Cheers!
 
Yes all fair points, just something a cheapskate like me didn't want to hear. I reduced pressure to 6psi overnight and chilled the kreezer down to 30F and I still just got a pint which was 40% foam with about a 20 second pour. I've ordered reducers and 10m of line. While not the cheapest solution, it'll stop me going crazy, also I can serve beer at more sensible temperature.
 
Well I made the change and have had some time to play and figure it out.
Now with 16' of 3/16" I need at LEAST 12psi to serve at anything above a pointless trickle. This means I cannot really keep the beer at 0C any more.

Keeping the keezer at 4C (much better average serving temp for me) allows me to dispense at 13-14psi at a slow/steady speed with the compensator tap FULL open to give a perfect pint with half an inch of tight head though it is quite slow and this is moderate to high carbonation.

To be honest I can keep it at 7C and 16psi and still get a great pour at a faster rate. 7C is also very acceptable as a serving temperature. Bottom line is I didn't need 16', the math works out and I probably only needed 10', but it is nice to have some flexibility as I can use different temperatures based on style. If I want a lightly carbonated beer I'm going to have to dispense slowly at 12psi and 8C.

Can't think of times when I'd want a lightly carbonated super cold pour? That is about all I can't do now without cutting line down. Nice to not use to much energy. Not so nice to have liquid in the keezer. Keeping it close to 0C means little liquid/mould growth, not so with 8C!
 
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