Beer Line Length and Pressure Calculator

I have a keezer in my basement with a tap in my kitchen and I just can't seem to get it right. I'm dispensing Yuengling Lager at 48 degrees, but anything near 19 PSI (as directed by the sheet) just shoots out foam.

Beer Line I.D.: 1/4"
Shank Bore ID: 3/16"
Height from Keg Center to Tap: 120"
Distance from Beer Out Connector to Shank: 144"
Length of Hose: 240"

It seems I'm not even close. Does anyone have any suggestions?

Bearcat Brewmeister said:

TA lot of folks use a set line length, then adjust pressure until it flows right. That is back asswards. You should set your pressure to the correct serving pressure for the beer style at the particular temperature you are at, then size your line (length AND diameter) to scrub off all of the excess pressure such that your beer flows correctly.

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I'm just in the planning stages of getting into kegging so bear with me, but I don't see the difference here. Having to keep and change out various different line lengths and diameters just to keep the pressure the same seems unnecessary. Again, it may be my lack of knowledge, but assuming you have set the line up to flow upwards to the tap, why is there a difference between increasing / decreasing the pressure vs. line length on the final output of beer? Isn't over/under carbonation due to line length or too high or low pressure the same thing (just different methods)?

Would a slightly over carbed beer due to line length taste any different than an over carbed beer (of the same amount) due to the pressure being too high? Assuming not (again - maybe my ignorance), I'd much rather just twist a knob than change out tubes just to hit a "proper" psi rating on my CO2 dial. Can someone educate me here?

mmonacel said:

I'm just in the planning stages of getting into kegging so bear with me, but I don't see the difference here. Having to keep and change out various different line lengths and diameters just to keep the pressure the same seems unnecessary. Again, it may be my lack of knowledge, but assuming you have set the line up to flow upwards to the tap, why is there a difference between increasing / decreasing the pressure vs. line length on the final output of beer? Isn't over/under carbonation due to line length or too high or low pressure the same thing (just different methods)?

Would a slightly over carbed beer due to line length taste any different than an over carbed beer (of the same amount) due to the pressure being too high? Assuming not (again - maybe my ignorance), I'd much rather just twist a knob than change out tubes just to hit a "proper" psi rating on my CO2 dial. Can someone educate me here?

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Line length does not cause over or under carbonation - the psi you set does. Over and under carbonation are relative terms based on the style of beer. A Belgian ale is properly served with much more carbonation than a Scottish ale. If you served a Belgian ale at proper Scottish ale carbonation, it would be too flat. If you served a Scottish ale at proper Belgian ale carbonation, it would be overcarbonated. The question you want to ask yourself is, "Do I want to drink the beer I brew at the carbonation level that is correct for the style?" For many homebrewers, the answer is yes, since for many beers, the bite or lack of from carbonation interplays with the flavors of the ingredients and is one reason we brew in the first place - to get the best tasting beer we can. If the answer is yes, you set your psi at the level that is correct for the style at the temperature it is at and the beer will be holding the correct carbonation. Then, it is just a fluid dynamics problem to get the beer to pour correctly. Beer will pour correctly if it comes out the tap around 1psi. For that to happen, you restrict the flow with beer line - the longer the line and smaller the diameter, the more pressure is removed (note - pressure removed, not carbonation). The calculator is doing the math for you to get from the pressure set for correct carbonation levels to 1 psi at the tap.

HeyNoPie said:

I have a keezer in my basement with a tap in my kitchen and I just can't seem to get it right. I'm dispensing Yuengling Lager at 48 degrees, but anything near 19 PSI (as directed by the sheet) just shoots out foam.

Beer Line I.D.: 1/4"
Shank Bore ID: 3/16"
Height from Keg Center to Tap: 120"
Distance from Beer Out Connector to Shank: 144"
Length of Hose: 240"

It seems I'm not even close. Does anyone have any suggestions?

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Is the keg at 48 degrees as well? If you have temperature variation from the keg to the tap, that is a recipe for foam.

My keezer is set to 48 degrees, and I left it overnight, so I would assume it equalized out by now. To cool the beer lines, I have a 6 gallon metal bucket of water being pumped through copper alongside the beer lines. This is all wrapped in a foam insulation. The starting temperature for the coolant is 54 while the keezer is at 48. I can pour four pints in a row that are 99% foam. If it were a matter of temperature, I would have thought that the beer would start to cool the lines by the last pint. Is there anything I might be missing?

HeyNoPie said:

My keezer is set to 48 degrees, and I left it overnight, so I would assume it equalized out by now. To cool the beer lines, I have a 6 gallon metal bucket of water being pumped through copper alongside the beer lines. This is all wrapped in a foam insulation. The starting temperature for the coolant is 54 while the keezer is at 48. I can pour four pints in a row that are 99% foam. If it were a matter of temperature, I would have thought that the beer would start to cool the lines by the last pint. Is there anything I might be missing?

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Not sure what to tell you. Many will recommend that you turn the pressure down. That may indeed stop it from foaming, but at 48 degrees in the keg, CO2 does not want to go into solution so with lower pressure settings, you eventually will be drawing non-foamy flat beer. Is it possible the keg was over carbed to start with? Possibly try shutting off the gas and bleeding the keg pressure a few times over a few hour period, then turning the gas back on.

I can certainly make it colder if that'd help. I only raised the temperature because that was what the spreadsheet recommended. I'm only on my second keg and basically wasted most of the first as well. Towards the end of that, I had the beer at 40 with the pressure a little over 8PSI and that basically worked.

I've dropped the temperature a bit and I'll try bleeding it like you mentioned

HNP, check out this thread from the MicroMatic beer forum. Hopefully that will help. It appears to me that you've got it to warm. Also appears that you may not have your 10ft rise cold enough.

For shorter runs usually a fan can be hooked up to cool the beer line but I don't know if there's one big enough to keep 10ft. cool. Glycol may be your answer but those setups can be quite pricy. Dig around in the MM forums and I'm sure you'll find plenty of alternative suggestions and or answers to your specific issue.

Thanks for the thought. I'll poke around there some more. I turned down the temperature a bit and that does seem to help (40% foam instead of 100%).

I apologize if I'm hijacking your thread and I'll create a new one if it makes sense, but can someone help me better understand the relationship between CO2 pressure and temperature? I thought that colder beer could contain more CO2, but the output of the spreadsheet seems to indicate that the beer should be warmer and more pressurized in my case. I interpreted my foam as CO2 breaking out of the beer, and since colder beer can contain more CO2, I would want my beer colder. I suspect one of my fundamental understandings is very wrong, so feel free to correct me

Now, for any of you that want the CORRECT length of hose based upon the principles of physics, mechanical engineering, and fluid mechanics...

l = 1800*d/Q²*(p-0.44h),

where:
l = hose length (ft)
d = hose ID (in)
Q = flow rate (gpm)
p = gage pressure of barrel (psi)
h = height difference between middle of keg and faucet (ft)

So if you've got a keg that you'd like at 12psi, the faucet is 2ft above the middle of the keg, you're using 3/16" tubing, and you'd like a flow rate of 0.7gpm:

l = 1800*0.1875/0.7²*(12-0.44*2) = 9.5ft.

(If the faucet is above the keg, h is positive; if the keg is above the faucet, h is negative.)

brian1 said:

Now, for any of you that want the CORRECT length of hose based upon the principles of physics, mechanical engineering, and fluid mechanics...

l = 1800*d/Q²*(p-0.44h),

where:
l = hose length (ft)
d = hose ID (in)
Q = flow rate (gpm)
p = gage pressure of barrel (psi)
h = height difference between middle of keg and faucet (ft)

So if you've got a keg that you'd like at 12psi, the faucet is 2ft above the middle of the keg, you're using 3/16" tubing, and you'd like a flow rate of 0.7gpm:

l = 1800*0.1875/0.7²*(12-0.44*2) = 9.5ft.

(If the faucet is above the keg, h is positive; if the keg is above the faucet, h is negative.)

Click to expand...

Or, you could use the calculator which is based upon the principles of physics, mechanical engineering, and fluid mechanics. Using a flow rate of 1 gallon per minute, typical for a draft system, the answers come to approximately the same as the formula above (very minor differences due to rounding of parameters or assumptions on friction factors).

Free spreadsheet to use without any condescending caps - cheers!

"Free spreadsheet to use without any condescending caps - cheers"

Thanks. That's about what I figured. Admin, feel free to delete my account.

brian1 said:

"Free spreadsheet to use without any condescending caps - cheers"

Thanks. That's about what I figured. Admin, feel free to delete my account.

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Personally, we'd all like to learn here. So for the OP who authored the spreadsheet, why not unprotect the damn thing so we can see the formulas and better our understanding of the ideas behind beer line length. I don't understand the infatuation with protecting stuff so others can't see how you did what you did. I mean it's a "free" spreadsheet, right? Why not let us see the workings so we can tweak and so on? Gah! I don't get it.

I can produce every equation, reference, and assumption used and/or made throughout the derivation of my aforementioned mathematical relationship; however, doing so would certainly be too... well, condescending. "Cheers."

brian1 said:

I can produce every equation, reference, and assumption used and/or made throughout the derivation of my aforementioned mathematical relationship; however, doing so would certainly be too... well, condescending. "Cheers."

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That wasn't directed to you. It was directed to the OP who authored the spreadsheet. Personally, I feel you have been open with your methods, and in this hobby, we need that. I think it's the openness and sharing of ideas, tools, and such that have advanced this hobby.

jgourd said:

Personally, we'd all like to learn here. So for the OP who authored the spreadsheet, why not unprotect the damn thing so we can see the formulas and better our understanding of the ideas behind beer line length. I don't understand the infatuation with protecting stuff so others can't see how you did what you did. I mean it's a "free" spreadsheet, right? Why not let us see the workings so we can tweak and so on? Gah! I don't get it.

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Much of the instruction I have had and feedback received over time pertaining to application design in spreadsheets is to make the user interface as clean and error proof as possible, and to that end, I typically protect sheets. There is no intent to specifically hide or protect any proprietary method or short change the hobby here - from a formulaic standpoint, nothing is "invented" in any way - the formulas are freely found in any engineering fluid mechanics textbook or by the poster a few replies up. This is just meant to be a tool that is a time saver from having to look up constants and manually plug numbers into a standard formula. Feel free to use the tool or the formula - the results are roughly the same.

In OpenOffice, just uncheck Tools>Protect Document>Sheet...

944play said:

In OpenOffice, just uncheck Tools>Protect Document>Sheet...

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The new OpenOffice won't unprotect Excel by default anymore; you still need the password. When I do my spreadsheets, I just put a blank password (it achieves the OP's intended result--removing potentially confusing stuff or "clutter"--without requiring an actual password to unprotect them if I want to--thereby having the choice to do so without being restricted by the designer). But I found a workaround. Save the Excel file as OpenOffice calc. Save back as Excel and it gives you the option to strip the password protection. Then unprotecting works just fine without a password. And I got the formulas. And now any password protected Excel spreadsheet can be easily "broken."

Bearcat Brewmeister said:

Much of the instruction I have had and feedback received over time pertaining to application design in spreadsheets is to make the user interface as clean and error proof as possible, and to that end, I typically protect sheets. There is no intent to specifically hide or protect any proprietary method or short change the hobby here - from a formulaic standpoint, nothing is "invented" in any way - the formulas are freely found in any engineering fluid mechanics textbook or by the poster a few replies up. This is just meant to be a tool that is a time saver from having to look up constants and manually plug numbers into a standard formula. Feel free to use the tool or the formula - the results are roughly the same.

Click to expand...

I understand your point. But some of us who have an insatiable desire to constantly learn about our hobby (even the mathy stuff) want to see how you used those equations. We enjoy leveraging others' work to skip the work of correlating formulae (we want to see how someone else did it). The same goes the other way in that we also work through math and formulae to facilitate some sort of calculation for others.

i just want to say, brian1's formula is more accurate than the spreadsheet, at least for me.

i have a wheat beer on tap. 37F, 20psi for about 3.4 volumes. 3/16" line, 5" shank, 24" height difference.

your spreadsheet gives me 93 inches, about 7.75 feet. I have 10' on there right now, and I have to turn the reg down to 8psi to get a decent pour. pouring at 20psi on 10' gives me nothing but foam. 7.75 feet would be useless.

brian1's formula gives 16 feet, which, while I haven't tried that yet (waiting on beer line...) seems much more reasonable...

motobrewer said:

i just want to say, brian1's formula is more accurate than the spreadsheet, at least for me.

i have a wheat beer on tap. 37F, 20psi for about 3.4 volumes. 3/16" line, 5" shank, 24" height difference.

your spreadsheet gives me 93 inches, about 7.75 feet. I have 10' on there right now, and I have to turn the reg down to 8psi to get a decent pour. pouring at 20psi on 10' gives me nothing but foam. 7.75 feet would be useless.

brian1's formula gives 16 feet, which, while I haven't tried that yet (waiting on beer line...) seems much more reasonable...

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I agree, this thing seems to return a bit too short. Really irritating the spreadsheet is protected too. I'll probably get around to making a spreadsheet that biases longer (using the formula here) and post it in a day or two, I won't lock it either that should help if anyone needs to change the assumed resistances of specific line diameters as well.

By way of example, I have an IPA on tap with a picnic faucet right now, 38 degrees, 9 PSI for 2.3 volumes, this thing is calling for 41" of line. I've got 60" on there now, will foam too much still, not horrible but still way too much to be acceptable. About 1/2 the glass is foam.

TheYoshi said:

I agree, this thing seems to return a bit too short. Really irritating the spreadsheet is protected too. I'll probably get around to making a spreadsheet that biases longer (using the formula here) and post it in a day or two, I won't lock it either that should help if anyone needs to change the assumed resistances of specific line diameters as well.

By way of example, I have an IPA on tap with a picnic faucet right now, 38 degrees, 9 PSI for 2.3 volumes, this thing is calling for 41" of line. I've got 60" on there now, will foam too much still, not horrible but still way too much to be acceptable. About 1/2 the glass is foam.

Click to expand...

The spreadsheet was created quite a long time ago and I do not recall the password. If I manage to come up with it, I will go ahead and unlock it. Like I said earlier, no intent on hiding anything here - they are standard engineering formulas - I just have always had a habit of protecting sheets for error proofing purposes. I think the formulas in use are similar to other posts, but with some differences in constants and where they are combined.

Therefore, if I get the sheet unprotected, the recommendation for modifying the spreadsheet would be to change the coefficients assigned to the diameters of beer line (the coefficients relate to material smoothness). These were standards that were pulled off of a fluid mechanics table listing several materials, but even minor differences in the coefficients, which could exist among the different manufacturers of beer line, would cause big differences when you are at the fringes (i.e. very low but more so, very high pressures). I assume that is why this sheet works for most people but a few site some issues with it.

The formula should result in beer that pours at about 2 ounces per second, so that is a good double check for line length. There is no guarantee that this flow rate will result in no foam however, since there are other factors that can contribute to foam such as line temperature, dips in the line (not feeding up for the entire length), force carbonating at higher than serving pressure, etc.

Excel and OpenOffice both allow protecting of sheets without passwords (just leave it blank). That's what I do to prevent accidental erasing of a formula. But unprotection is simply done in case one wants to change something. There's also an option to hide formulas. One would only do that if they wanted to keep others from seeing what was done. Cheap IMHO.

Kind of sad that people get on a poster for protecting or even hiding formulas. If you don't like what the poster has done for the forum for free on their own time then get off your lazy ass and make your own. Anything else makes you look like a freeloading dink IMO.

CPooley4 said:

Kind of sad that people get on a poster for protecting or even hiding formulas. If you don't like what the poster has done for the forum for free on their own time then get off your lazy ass and make your own. Anything else makes you look like a freeloading dink IMO.

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Indeed many of us have and have shared it many times over. And others have come to critique and make corrections. And we all learn something. Isn't it great when we openly share things without silly protections how things get much better much more quickly. Open source all the way!

So say it that way without the unnecessary bs. He'd either agree and unprotect, offer the explanation above that he doesn't have the password anymore, or do nothing. Either way it's his work that he spent his time on and offered here for free for all to use. Those that don't like it or disagree with him can just make their own on their own time and offer it here for free for all to use. All the information is readily accessible to anyone that wants to take the time to do so.

TheYoshi said:

I agree, this thing seems to return a bit too short. Really irritating the spreadsheet is protected too. I'll probably get around to making a spreadsheet that biases longer (using the formula here) and post it in a day or two, I won't lock it either that should help if anyone needs to change the assumed resistances of specific line diameters as well.

By way of example, I have an IPA on tap with a picnic faucet right now, 38 degrees, 9 PSI for 2.3 volumes, this thing is calling for 41" of line. I've got 60" on there now, will foam too much still, not horrible but still way too much to be acceptable. About 1/2 the glass is foam.

Click to expand...

To unprotect spreadsheets and unhide formulas just get OpenOffice (it's free). Open the Excel document, save as OpenOffice document, close, open the OpenOffice version of the document, resave as Excel document. It will complain about the protection. Just check to remove all protections and you're done. You can then close and reopen the newly saved Excel document. The sheets will be unprotected and formulas unhidden.

Bmpvevpxgpvsswp

Bearcat Brewmeister said:

There is no guarantee that this flow rate will result in no foam however, since there are other factors that can contribute to foam such as line temperature, dips in the line (not feeding up for the entire length), force carbonating at higher than serving pressure, etc.

Click to expand...

have you had success pouring wheat beers carbed and served at 20psi using 7 feet of line?

my setup is pretty standard, my lines are coiled on top of the keg. yes it's probably warmer on top, but maybe a degree or two. i have perlicks and a 5" shank.

Request a little patience for a newby: what is the volume of CO2? Is this the volume of my CO2 tank? If so, aren't compressed gasses typically measured in weight, not volume? Bottom line, it looks like a great tool, I'm just not sure how to use it because I can't figure out what my input should be for CO2 volume. Sorry for the novice questions...

Josh1 said:

Request a little patience for a newby: what is the volume of CO2? Is this the volume of my CO2 tank? If so, aren't compressed gasses typically measured in weight, not volume? Bottom line, it looks like a great tool, I'm just not sure how to use it because I can't figure out what my input should be for CO2 volume. Sorry for the novice questions...

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Volume of CO2 is the amount of co2 dissolved in solution (beer). AKA, an English Mild will have less volumes than an American light Lager. AKA less carbonation.

IrregularPulse said:

Volume of CO2 is the amount of co2 dissolved in solution (beer). AKA, an English Mild will have less volumes than an American light Lager. AKA less carbonation.

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Now that makes a whole more sense. Thanks for the help.

brian1 said:

Now, for any of you that want the CORRECT length of hose based upon the principles of physics, mechanical engineering, and fluid mechanics...

l = 1800*d/Q²*(p-0.44h),

where:
l = hose length (ft)
d = hose ID (in)
Q = flow rate (gpm)
p = gage pressure of barrel (psi)
h = height difference between middle of keg and faucet (ft)

So if you've got a keg that you'd like at 12psi, the faucet is 2ft above the middle of the keg, you're using 3/16" tubing, and you'd like a flow rate of 0.7gpm:

l = 1800*0.1875/0.7²*(12-0.44*2) = 9.5ft.

(If the faucet is above the keg, h is positive; if the keg is above the faucet, h is negative.)

Click to expand...

Perhaps I am having a complete brainfart, but I am not seeing the same results with this equation to the excel sheet. Plus, no matter how I order the equation, I do not get 9.5 ft. Using the equations available on other sites and entering the numbers provided above, it works out to be 3.7 ft to 4 ft (depending on the equation), which does match the excel sheet. What am I not seeing here? Can someone order the equation so that I can see what is in the numerator and denominator? Finally, there is a box after the 'd', is this a power (2, or 3 perhaps)?

Thanks.

I don't have the excel sheet in front of me and haven't looked at it in quite some time. However, my guess is the difference in flow rate. Most commercial setups plan for a flow rate of 1 gallon per minute which is a bit strong for most homebrew setups. Don't know if the excel sheet is set up with 1 gallon as the default or not, but more than likely that is the culprit.

I just ran a scenario based upon your number. When I use a flow rate of .7 I get 9.7 feet of line recommended. When I use a flow rate of 1 I get 4.75 feet of line recommended. That's assuming a diameter of .1875" line.

If you'd like you can shoot me your email via pm. I have a kegging calculator/how to built into my Brew Chart. It's not in my published version as I'm still upgrading, but I'd be willing to send it to you ahead of time so you can see what I'm talking about. My kegging calculator allows the user to control the flow rate and diameter of line so that they can dial into their system better.

cp

Anguslow said:

Finally, there is a box after the 'd', is this a power (2, or 3 perhaps)?

Thanks.

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Shame that it has taken this long for someone to reply to your question about the "square" Angus. Since the formula is dealing with flows through a circular tube I would hazard a guess that the "square" is actually meant to be the symbol for squared (i.e. ^2 as you would enter it in excel). I think the formating of the forum probably didn't like using superscript and just blanked it out.
Hope it works out for you.

uh, CP responded to him within an hour

motobrewer said:

uh, CP responded to him within an hour

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Sorry, should of been more specific about the lack of reply for what the "square" in the formula was... hang on, my reply was specific about that...

mattd2 said:

Shame that it has taken this long for someone to reply to your question about the "square" Angus.

Click to expand...

CPooley4 said:

So say it that way without the unnecessary bs. He'd either agree and unprotect, offer the explanation above that he doesn't have the password anymore, or do nothing. Either way it's his work that he spent his time on and offered here for free for all to use. Those that don't like it or disagree with him can just make their own on their own time and offer it here for free for all to use. All the information is readily accessible to anyone that wants to take the time to do so.

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"No good deed goes unpunished."

As another poster said, wow, gonna need a lot of line for my Heff! Regarding different lengths of lines for different styles: Changing line at the tower every time I change styles will be a PITA, so I'm planning on changing the length of the line by splicing on or removing a section of line to meet the line length requirement. I'm going to use some sort of nipple to make the connection. I assume I add the length of the nipple to the shank length? Being that it is a constriction at this point and offers resistance it should be taken into account, no?

Ok for every one on here doing this calculator, it isnt much but if you are doing a home brew/ kegerator a foot of restriction is alot. That equals 3 pounds of restriction in the system. So every 4" of 3/16" restrication line is equal to 1 pound of restriction in the line.
Also I do understand why you want to measure from the middle of the keg?? Where is the beer being sucked from?? Not the middle. It is being sucked from the bottom. Micro Matic is the only maker of these stems and valves, and you want to measure from the bottom of the keg to the faucet.