Chronic Foam Issue

[Colt85]

10 feet of 3/16 line at 10 psi and 40F is what I run with no problems. That said I have a couple ideas. 1 drop the beer lines off the kegs and let them hang. Heat rises! It only takes a couple degrees to upset the balance. 2. You have a really cool tower that is one big efficient heat sink! Copper tubes thru a large heavy thick chunk of pipe. It's like running your beer thru a wort chiller, but now your warming it instead of. Cooling. Remember it only takes a few degrees change to upset the balance! Here is a simple test. Buy a picnic tap and an extra chunk of beer line. Get 10ft. Hook it to your beer. Fill the line with beer and let it get cold for a few. If the problem goes away you know it has to be the construction of the tower. You could also pull the picnic tap out to the height of the taps to prove that height isn't the issue. Without that heatsink of copper and steel sucking the cold out of the line I bet the problem gets better! Also I see you have what look like flow control faucets. Are you sure they're the right ones? I know they make a creamer faucet for stouts. I know its a long shot but it was an idea. Either way good luck and keep us posted on the results!

Thanks! That pipe tower is actually stuffed with insulator, through which the copper/lines run, but you may still be right. If it was first couple pours and then smoothed out, I'd buy the tower temp argument but it's constant.

I had no idea there were "creamy" faucets! This is the model I'm using, what do you think?

http://www.amazon.com/gp/product/B0072KAC2M/?tag=skimlinks_replacement-20

 

[robfar]

Well I spent good money on good line thick walled line purchased at a brew supply so I should be all set there. More and more signs pointing to a leak at the coupler (great analogy btw). Here's what I'm working with:

http://www.amazon.com/gp/product/B002UZUSIM/?tag=skimlinks_replacement-20

with this connector:

http://www.amazon.com/gp/product/B0002EAJXW/?tag=skimlinks_replacement-20

The connector seems suspect as the contact between the "nut" piece and the "nipple" piece is just metal on metal. This seemed odd to me when I set it up. I even tried pulling an O ring off an old fuel injector and tried to get a better seal there but that just made it worse. Am I missing something or is this how they're supposed to be assembled? (see pic)

The seal is where the O-ring is squeezed between the "nipple" and the metal shank. The metal-on-metal is just providing the squeezing force. It's all correct in the drawing.

 

[MagicMatt]

I didn't see if you mentioned if you had played with the flow control on the faucet at all?

And I know 30ft may seem like a bit overkill, but it's just to aid in diagnosing the cause of the issue. Try 20' instead if you want. In fact, I would use 20' and hook up a picnic tap to it, that way you eliminate the tower and faucets altogether. If it pours fine with 20' and a picnic tap, then hook that same 20' to your faucets and try. If it foams, then you know it's something with your tower/faucets (cooling issue, flow control, etc).


And David, I find it very hard to believe that only 10' of line will cause your tap to stop flowing at an acceptable speed. What PSI are you at? I have a 32' line (3/16") in my keezer that is there in case I ever want to dispense soda (which is carbed much higher than beer), but when it's not being used for soda, I can hook it up to a keg and dispense my beer just fine at 38°F and 12psi. There is a slight decrease in pour speed, but it's certainly tolerable. Maybe 13 seconds.

Think about this: if adding line length caused the beer to stop flowing correctly, how in the world do jockey boxes (with either 50" of coils or ~30ft of line/cold plate circuit) work so well? I have one, and it pushes beer just fine with around 15psi, through over 30 feet of tubing (3/16" pvc line & 1/4"OD stainless), and I even double pass through my cold plate.

You mentioned that with 10' you were getting a pour "like from a bottle"....well this is exactly what you want! Why would you want your beer to come flying out of the faucet like a fire hose? The beer shouldn't "fill the tap" completely. You'd fill a beer glass in under 5 seconds that way.

 

[Rockn_M]

Thanks! That pipe tower is actually stuffed with insulator, through which the copper/lines run, but you may still be right. If it was first couple pours and then smoothed out, I'd buy the tower temp argument but it's constant.

I had no idea there were "creamy" faucets! This is the model I'm using, what do you think?

http://www.amazon.com/gp/product/B0072KAC2M/?tag=skimlinks_replacement-20

Try adjusting the creamer knob on the facuet.

 

[Kwitty]

Well I spent good money on good line thick walled line purchased at a brew supply so I should be all set there. More and more signs pointing to a leak at the coupler (great analogy btw). Here's what I'm working with:

http://www.amazon.com/gp/product/B002UZUSIM/?tag=skimlinks_replacement-20

with this connector:

http://www.amazon.com/gp/product/B0002EAJXW/?tag=skimlinks_replacement-20

The connector seems suspect as the contact between the "nut" piece and the "nipple" piece is just metal on metal. This seemed odd to me when I set it up. I even tried pulling an O ring off an old fuel injector and tried to get a better seal there but that just made it worse. Am I missing something or is this how they're supposed to be assembled? (see pic)

There's no beer and touching anywhere near that part of the coupler. The sealing point is between the sanke tap and the bottom of the nipple. That's why the seal goes there. The only other place to leak at that connection is the hose on the nipple. That nut needs to firmly and flatly hold down the nipple flange. If you put something inbetween it, it could compromise the seal of the flange to the sanke tap. More chance it'll make things worse!

 

[Colt85]

I didn't see if you mentioned if you had played with the flow control on the faucet at all?

And I know 30ft may seem like a bit overkill, but it's just to aid in diagnosing the cause of the issue. Try 20' instead if you want. In fact, I would use 20' and hook up a picnic tap to it, that way you eliminate the tower and faucets altogether. If it pours fine with 20' and a picnic tap, then hook that same 20' to your faucets and try. If it foams, then you know it's something with your tower/faucets (cooling issue, flow control, etc).


And David, I find it very hard to believe that only 10' of line will cause your tap to stop flowing at an acceptable speed. What PSI are you at? I have a 32' line (3/16") in my keezer that is there in case I ever want to dispense soda (which is carbed much higher than beer), but when it's not being used for soda, I can hook it up to a keg and dispense my beer just fine at 38°F and 12psi. There is a slight decrease in pour speed, but it's certainly tolerable. Maybe 13 seconds.

Think about this: if adding line length caused the beer to stop flowing correctly, how in the world do jockey boxes (with either 50" of coils or ~30ft of line/cold plate circuit) work so well? I have one, and it pushes beer just fine with around 15psi, through over 30 feet of tubing (3/16" pvc line & 1/4"OD stainless), and I even double pass through my cold plate.

You mentioned that with 10' you were getting a pour "like from a bottle"....well this is exactly what you want! Why would you want your beer to come flying out of the faucet like a fire hose? The beer shouldn't "fill the tap" completely. You'd fill a beer glass in under 5 seconds that way.

Yes, plenty of adjustment with the flow control, including starting with the flow completely off followed by gradual increase. Even at a slow dribble all I get is foam.

Anything wrong with splicing in a new section of line with a nylon barb coupler? To change the line completely I have to disassemble the entire tower and it's quite labor intensive.

 

[Colt85]

The seal is where the O-ring is squeezed between the "nipple" and the metal shank. The metal-on-metal is just providing the squeezing force. It's all correct in the drawing.

Good to know, thanks robfar

 

[MagicMatt]

Anything wrong with splicing in a new section of line with a nylon barb coupler? To change the line completely I have to disassemble the entire tower and it's quite labor intensive.

It might work in a pinch, but I wouldn't use it as a permanent line. Any turbulence caused by the coupler could allow the CO2 to come out of solution even more.

Instead I would recommend just using a picnic tap as I mentioned earlier. This is just a test anyway, so no need to connect to the taps. If it works with the picnic tap and you get no foam, you can then go through the trouble of connecting it to the tower as you have proof it should work fine. If you go this route and do eventually connect the longer line to the tap and it doesn't work for some reason, that would 100% indicate something with the faucets/tower.

 

[Colt85]

It might work in a pinch, but I wouldn't use it as a permanent line. Any turbulence caused by the coupler could allow the CO2 to come out of solution even more.

Instead I would recommend just using a picnic tap as I mentioned earlier. This is just a test anyway, so no need to connect to the taps. If it works with the picnic tap and you get no foam, you can then go through the trouble of connecting it to the tower as you have proof it should work fine. If you go this route and do eventually connect the longer line to the tap and it doesn't work for some reason, that would 100% indicate something with the faucets/tower.

Good plan, I like it! I'll give it a shot.

One thing I just noticed, the the nipple at the top of the D coupler is within about 2 inches of the bottom of the lid of the keezer, so when the lid is closed, the line takes an immediate 90 degree bend. Guts tell me that's probably not good, what do you think?

 

[djonesax]

And David, I find it very hard to believe that only 10' of line will cause your tap to stop flowing at an acceptable speed. What PSI are you at?

10PSI as previously stated.

Think about this: if adding line length caused the beer to stop flowing correctly, how in the world do jockey boxes (with either 50" of coils or ~30ft of line/cold plate circuit) work so well? I have one, and it pushes beer just fine with around 15psi, through over 30 feet of tubing (3/16" pvc line & 1/4"OD stainless), and I even double pass through my cold plate.

Not sure about the jockey, never built one or really looked inside one. Looking at this one in the link though, it uses 50' 5/16 OD tubing which has a resistance of about .5 PSI. So over 50' that would drop roughly 25PSI and the instructions clearly say to start out at 30PSI to push the beer through.

http://www.kegworks.com/single-fauc...ctid50COIL-S&gclid=CKO-3sr1rcYCFdgHgQodQlUMGQ

You mentioned that with 10' you were getting a pour "like from a bottle"....well this is exactly what you want! Why would you want your beer to come flying out of the faucet like a fire hose? The beer shouldn't "fill the tap" completely. You'd fill a beer glass in under 5 seconds that way.

No, this is not what "I" want, this causes the pour to be turbulent, "I" want it to fall out of the tap but a nice solid pour. I said before that I am getting a 10.45 second pour with 5' of line at 10 PSI, at 35 degrees.

Anyway, your system works for you and thats great, I'm not trying to start an argument. I'll take a video of the pour later to show what I mean.

David

 

[djonesax]

I was going to question the flow control on the tap too, the picnic tap seems like a good test.

The other thing I was thinking about is the cleanliness of the tap. I had a beer that kept pouring foaming once so I took the tap apart and there was some nasty gunk in it. It's embarrassing to admit but I scrubbed it all clean and no more foam.

Also, check this out on youtube at the 1:45 mark, could this be your issue?

[ame]https://www.youtube.com/watch?v=KIlj1Bq3BUc[/ame]

David

 

[MagicMatt]

Anyway, your system works for you and thats great, I'm not trying to start an argument. I'll take a video of the pour later to show what I mean.

I agree that if your system works the way you want, you have little reason to change it. But the reasoning behind WHY it works is a bit flawed, as unfortunately the internet is full of misleading information regarding resistance in general. As I mentioned earlier, line resistance is completely dependent on flow rate. This means that all of these numbers that you (and others) are quoting like "5/16 OD tubing which has a resistance of about .5 PSI" is completely false as a generalization as a key piece of information (the flow rate) is missing. You cannot say that a given type of line has a specific number as a resistance without taking flow rate into account; it's just incorrect to say so. You have to account for the flow rate, and that flow rate has to be ~1gal/min in order for those quoted resistance numbers to mean anything at all. Otherwise those numbers are complete garbage.

Without going too deep into fluid dynamics (as even I don't have an expert level grasp of it), here's a basic formula for fluid resistance (R):

R = (change in pressure) / (flow rate)

Therefore, without factoring in the flow rate, you cannot calculate resistance.

Furthermore, to calculate the "change in pressure" (we'll call this deltaP), you actually need the flow rate as well. The formula to calculate pressure change is:

deltaP = (128uLQ)/(pi*(d^4))

where:
u = viscosity
L = line length
Q = flow rate
d = line diameter
pi = the mathematical constant Pi.

So as the line length increases, flow rate decreases, which actually causes the change in pressure (deltaP) to decrease. Plugging this in to the above basic formula for line resistance, if deltaP is decreasing and flow rate is decreasing (both due to lengthening the line), then the ratio of deltaP/Q (i.e. resistance) will decrease exponentially. Hence "line resistance decreases exponentially as flow rate decreases".

In the most simple terms I can think of, consider the following equation:

x = 2 + y


What you are basically doing by saying that 3/16" line always has a resistance of 2psi/ft, is the same as saying that in the above equation, "x" is always equal to 6. You are completely ignoring that a part of the equation "y" is variable, and are treating it as a constant. The only way for x=6 is if y=4; there is absolutely no other way to make it true. Similarly, the only way for 3/16" line to have a resistance of 2psi/ft, is to have a flow rate equal to 1gal/min. If that flow rate changes, then the resistance cannot be "2psi/ft".


For the record, I'm not trying to argue either. I just want to help prevent the spread of misinformation regarding these flawed ideas of how resistance and line balancing work. I hear too many people saying things like "too long of lines will cause problems/foaming/etc", which couldn't be further from the truth. Sure, eventually you'll reach a length where the pour is unbearably slow. But changing your lines from 5' to 10' for any reasonable serving pressure >10psi will have minimal effect on flow rate.

I'm not trying to be an expert here, just explain things as much as I comprehend them. Perhaps someone more knowledgeable in this area can contribute better examples. I have a degree in mathematics, but fluid mechanics delves more into the realm of physics, of which it's been a while for me.

 

[MagicMatt]

I was going to question the flow control on the tap too, the picnic tap seems like a good test.

Also, check this out on youtube at the 1:45 mark, could this be your issue?

Ha, instead of posting that last long post, I could have just as easily referenced the video you posted. When he turns the flow control up, he is increasing resistance (the same way that adding line length would), and it causes no foaming problems whatsoever. Conversely, it decreases foam production. This disproves the theory you posted in the other thread you linked to previously, where you stated "If you have 10' of line and 13psi, and its trickling out, that will cause foam too."

 

[Colt85]

I was going to question the flow control on the tap too, the picnic tap seems like a good test.

The other thing I was thinking about is the cleanliness of the tap. I had a beer that kept pouring foaming once so I took the tap apart and there was some nasty gunk in it. It's embarrassing to admit but I scrubbed it all clean and no more foam.

Also, check this out on youtube at the 1:45 mark, could this be your issue?

https://www.youtube.com/watch?v=KIlj1Bq3BUc

David

Thanks for the suggestions and the vid! Yeah, disassembling and thorough cleaning was the first thing I tried. No dice so far

 

[Rockn_M]

Thanks for the suggestions and the vid! Yeah, disassembling and thorough cleaning was the first thing I tried. No dice so far

Do you have or can you get another faucet to see if you get the same foaming?

 

[djonesax]

Ha, instead of posting that last long post, I could have just as easily referenced the video you posted. When he turns the flow control up, he is increasing resistance (the same way that adding line length would), and it causes no foaming problems whatsoever. Conversely, it decreases foam production. This disproves the theory you posted in the other thread you linked to previously, where you stated "If you have 10' of line and 13psi, and its trickling out, that will cause foam too."

Thanks for that explanation, I get what you mean about the flow rate now and how its related to the resistance.

The thing that doesn't make sense to me and maybe you can explain this. I get a 10.45 second pint with 5' and when I add that flow rate into the calculator you mentioned, it said I needed a 9.2' line to get the same flow rate that I am already getting with 5'. It seems like that might mean that 5' is all I really need and the extra 5' I added has little affect since I have already reduced the flow rate to a rate where there is little resistance. BUT, I fiddled with the calculator and I found that it thinks that with a 5' line I'd have a flow rate of 7 second pints which isn't what I have. So my real world example and the calculator don't jive.

Also, just to show what I was talking about. I took 4 crappy videos.

10 Foot Warm Tap
10 Foot Cold Tap
5 Foot Warm Tap
5 Foot Cold Tap

In the 10 Foot Warm Tap video you can see what I mean by its trickling out. It eventually fills the tap and pours right but the initial turbulence still seems to produce more head than desired. The 5 Foot Cold Tap video produces the least amount of head.

David

View attachment 10footWarmTab.MOV

View attachment 10FootColdTap.MOV

View attachment 5FootWarmTap.MOV

View attachment 5FootColdTap.MOV

 

[MagicMatt]

Thanks for the videos. For what it's worth, the 10 second pour looks perfectly acceptable and appropriate for a homebrew installation. You say it trickles, I say nay. I'm assuming the different levels of head between the two (10 and 5 seconds) was because they are different beers. But if you play them side by side, there's virtually zero change in the amount of time it takes to reach the same level.

So while it may look different to you coming out of the tap, there's no real noticeable change in pour speed (even though you would think that doubling your lines would double your resistance).

 

[Kwitty]

Colt 85. I looked at the tap on Amazon and it indeed looks to be flow control. Your in the clear. However I've never used one so I can't comment on it much. Not sure how the creamer taps work either. I just know they look similar with the valve on the side. Good luck!

 

[djonesax]

Thanks for the videos. For what it's worth, the 10 second pour looks perfectly acceptable and appropriate for a homebrew installation. You say it trickles, I say nay. I'm assuming the different levels of head between the two (10 and 5 seconds) was because they are different beers. But if you play them side by side, there's virtually zero change in the amount of time it takes to reach the same level.

So while it may look different to you coming out of the tap, there's no real noticeable change in pour speed (even though you would think that doubling your lines would double your resistance).

Its hard to tell in the video but the 10 foot line is definitely a couple seconds slower for a full glass. I timed them on my phone last night with the same tap and beer

We'll have to agree to disagree on the length because I still think its a little too long since it just doesn't seem to have enough flow speed to fill the tap like the shorter line. Look at the picture to see what I mean and see how the turbulence is creating more head. I will admit that length is not as as drastic a difference as I was expecting but the previous shorter line definitely poured better in my opinion. Later on tonight I'll shorten that 10' line to 8' and see if I like it better.

Thanks,

David

 

[Colt85]

Do you have or can you get another faucet to see if you get the same foaming?

Picnic tap is in the mail, will report back

 

[PapaO]

Nice tower but I think part of the problem is how it is cooled. To test this, pour a pint of seltzer and take the temp. Then pour another and take the temp. Keep doing this until you get the same temp on two pints. This will tell you how good your tower cooler works and the temp of the beer in the other keg is. Now with commercial kegs you have to know how many volumes it was carbed at e-mail the brewery and ask. Now you have the only two things you need to balance your system. Use this chart to set the psi. http://www.kegerators.com/carbonation-table.php Forget Line calculators there useless for a home system. They are for commercial systems with remote draw. Now if you have your keg in the basement and tap in your bedroom on the second floor then it will come in handy. Line length is used to control the flow only not to balance your system. Now if your system is balanced I would check the Coupler. On a D Coupler it could be the check ball #2 is stuck. Remove it you don’t need it if your shutoff has backflow preventer on it. Or your Probe Seal #4 is bad and letting co2 from the head space get into the beer line.

http://www.micromatic.com/draft-keg-beer/keg-taps-couplers-pid-7485E.html

 

[gnef]

what shanks are you using, and do they have elbows for the tubing? Do you have any spare faucets that you can check with?

I don't want to insult you, but did you check to make sure that the tubing is truly 3/16" ID?

Have you fully dissasembled the sanke coupler and checked for debri, cleaned it, etc?

 

[Colt85]

Nice tower but I think part of the problem is how it is cooled. To test this, pour a pint of seltzer and take the temp. Then pour another and take the temp. Keep doing this until you get the same temp on two pints. This will tell you how good your tower cooler works and the temp of the beer in the other keg is. Now with commercial kegs you have to know how many volumes it was carbed at e-mail the brewery and ask. Now you have the only two things you need to balance your system. Use this chart to set the psi. http://www.kegerators.com/carbonation-table.php Forget Line calculators there useless for a home system. They are for commercial systems with remote draw. Now if you have your keg in the basement and tap in your bedroom on the second floor then it will come in handy. Line length is used to control the flow only not to balance your system. Now if your system is balanced I would check the Coupler. On a D Coupler it could be the check ball #2 is stuck. Remove it you don’t need it if your shutoff has backflow preventer on it. Or your Probe Seal #4 is bad and letting co2 from the head space get into the beer line.

http://www.micromatic.com/draft-keg-beer/keg-taps-couplers-pid-7485E.html

Thanks for the suggestions PapaO. I've done the first bit, first pour is around 42, subsequent pours quickly even out to ~38. Not ideal but I believe my problems are much greater than tower cooling as I can fill pitcher after pitcher of cold foam.

Ok, I'll find out about CO2 in the commercial keg. So, say it's carbed to 2.5 volumes, then I'd set the psi to ~10 since I'm at 38 degrees? This is currently where I'm at temp/psi-wise.

I've already disassembled and cleaned the coupler a few times but I'll try again. I'm using this one, brand new: http://www.amazon.com/gp/product/B002UZUSIM/?tag=skimlinks_replacement-20

Are some brands more reliable than others? Think it's worth replacing the whole thing?

 

[Colt85]

what shanks are you using, and do they have elbows for the tubing? Do you have any spare faucets that you can check with?

I don't want to insult you, but did you check to make sure that the tubing is truly 3/16" ID?

Have you fully dissasembled the sanke coupler and checked for debri, cleaned it, etc?

I'm using these shanks: http://www.amazon.com/dp/B00829HNWE/?tag=skimlinks_replacement-20

They've got barb fittings and I've got line secured with hose clamps.

No insult taken! Anything's fair game at this point. Yes the line is 3/16 ID.

I've disassembled and cleaned the coupler twice now with no change in performance. I've got a picnic tap on the way to test weather the faucet is the culprit.

 

[gnef]

What is the sharpest bend that the tubing has to make? If it is pinched at any point, it could cause the symptoms that you describe.

Looking at your pictures, the highest likelihood of pinching would be right at the barb from the shank.

A quick test could be to remove the shank and faucet from the tower, reconnect all the tubing, and see if you can serve the beer through it that way (I might even recommend drilling a 7/8" hole in a piece of wood to mount it so that you don't have to hold the shank and faucet).

 

[Colt85]

What is the sharpest bend that the tubing has to make? If it is pinched at any point, it could cause the symptoms that you describe.

Looking at your pictures, the highest likelihood of pinching would be right at the barb from the shank.

A quick test could be to remove the shank and faucet from the tower, reconnect all the tubing, and see if you can serve the beer through it that way (I might even recommend drilling a 7/8" hole in a piece of wood to mount it so that you don't have to hold the shank and faucet).

gnef, it's actually a fairly gentle bend at the back of the shank. Now that I think about it, though, a suspect spot is the where the line attaches to the D coupler. The top of that barb is about an inch from the bottom of the keezer lid, so, with the line attached, the beer makes an immediate 90 degree turn out of the keg. Maybe I can cut a recess into the lid to ease that

 

[day_trippr]

Before you cut anything maybe you can lean the keg over enough to give a decent bend radius (really you only need a couple inch radius for 3/16" ID beer line) and give it a try.

It would sure explain a lot though if you've been literally crimping the beer line nearly closed all this time

Cheers!

 

[Colt85]

Before you cut anything maybe you can lean the keg over enough to give a decent bend radius (really you only need a couple inch radius for 3/16" ID beer line) and give it a try.

It would sure explain a lot though if you've been literally crimping the beer line nearly closed all this time

Cheers!

Ugh, * face palm * I'll give it a shot!

 

[gnef]

If that turns out to be the problem, you may need to get one of the low profile d couplers with the horizontal connections.

 

[Colt85]

If that turns out to be the problem, you may need to get one of the low profile d couplers with the horizontal connections.

Didn't know they existed, thanks for the tip!