Serving Pressure/Beer Line diameter

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Brewser
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Serving Pressure/Beer Line diameter

Post by Brewser » Mon May 13, 2019 12:46 pm

Hi, hope someone can help?

I have a corny keg setup with a beer tower tap. Most beers I brew are Ales/Bitters-such as Wherry/Courage/Directors etc (what I call English ales). As a result, I don't like a lot of carbonation, just bit of life!

The beer line I was using was 3/8 Outside Diameter ("OD"), which was useless. I then got advised to use 3/16 OD line, which has helped but this has results in a very slow pour (slightly more than a dribble). I don't want to increase the PSI too high through fear of getting a 'fizzy' beer. What PSI should I use?

If this is not possible, then is it possible to get a 3/16 Internal Diameter beer line?

Thanks in advance

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Kev888
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Re: Serving Pressure/Beer Line diameter

Post by Kev888 » Mon May 13, 2019 2:16 pm

It depends on the temperature, since temperature and pressure both affect how much carbonation is achieved. Also of course, it depends on your own preference. But as a guide, if we assume that your British-style ales are being kept at the classic cellar temperatures of around 12c then something like 7psi would be my choice (some might prefer closer to 10psi).

For cask like effects you might be tempted to go much lower, but that is more suitable for use with beer engine systems, which are different. Also if your cornies are old/second-hand ones that have had a hard life, you might find that their lid seal becomes unreliable if you go any lower than several psi.

You should be able to get a pretty decent pour rate at that, if not then possibly the line is excessively long (or partially blocked). Though it is also worth timing the pour and comparing to what you see in pubs and so on, as when you're judging it subjectively it might seem to take longer than it really is.

In a sense it is more important how carbonated the beer is than what pressure it is served at, since if it is already over carbonated dropping the serving pressure doesn't help much. The above 7psi at 12c will give you around 1.6 volumes of CO2 if left to reach equilibrium, which is fairly modest.
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Re: Serving Pressure/Beer Line diameter

Post by Brewser » Tue May 14, 2019 1:41 pm

Thanks Kev. That's really helpful. I would like to stick to cellar temps of 12/13c, but 7 psi with the thin beer line just dribbles out. I have invested in some wider beer line and will use the formula to determine pressure, to help decide what length of line I need - this is assuming that the lower the pressure, the shorter the beer line needs to be

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Re: Serving Pressure/Beer Line diameter

Post by Jocky » Tue May 14, 2019 4:14 pm

It sounds like you just need to shorten the run of 3/16" line that you have.
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Kev888
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Re: Serving Pressure/Beer Line diameter

Post by Kev888 » Tue May 14, 2019 8:02 pm

Yes, 12/13c and 7psi with 3/16" OD line should be a pretty good match, so like Jocky I wonder if it is too long; how long is the line?

Also (just to cover all bases) if you have flow-control taps have you checked that they aren't set to restrict heavily (as they may have been if you were previously using 3/8" line)?
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Re: Serving Pressure/Beer Line diameter

Post by stokie_spaceman » Thu May 16, 2019 11:00 pm

I've been fiddling with 3/16 line for a lager at 12 psi recently having used 3/8 line and a party tap (which are a useless combo unless you drop keg pressure to almost nothing). I read as a guide use 3 psi per ft pressure loss on 3/16 line. At 7 psi in the keg 2-3 ft sounds about right to me. Ere on the cautious side and start long. To extend the line use 3/8 with a JG 3/8 to 3/16 reducer. The smaller line really makes a big difference. My experience is limited on this but it works really well for the lager at 12 psi and about 6 or 7 deg c. I'm using 2m of 3/16 currently but need to chop back a bit as I was too cautious.

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