National Homebrew Club Ireland

Brewing Discussions => Equipment & Chemicals => Topic started by: vinyljunkie on November 18, 2018, 04:17:17 PM

Title: Air in Beer Line
Post by: vinyljunkie on November 18, 2018, 04:17:17 PM
I have a 3 keg kegerator I built for a tall fridge. I'm having some foaming issues on two of my lines (the two kegs at the back of the fridge).

- There is air in the beer line of the two kegs at the back of fridge.
- The back of the fridge has ice on the wall of fridge.
- There is no fans in the fridge.
- The therm probe is in a bottle of water sitting on the shelf beside the kegs at the front of fridge.
- I have 3/8 to 3/16 reducers, the 3/16 line is 4.5 foot long and flow control intertaps
- The beer pours 90% foam for first half a pint then pours perfect.

I'm wondering if anyone has come across this? Do I need to install fans to move the cold air around or is it something else?

Title: Re: Air in Beer Line
Post by: mick02 on November 18, 2018, 08:40:54 PM
I have had this issue before. The problem in my case was a gasket in the disconnect. I didn't out it back properly when I reassembled it after cleaning. If I were you I'd start at the keg and work your way towards the tap tightening everything you can.
Title: Re: Air in Beer Line
Post by: johnrm on November 18, 2018, 09:02:22 PM
The coldest part of your fridge is going to be at the bottom there the bottle is.
A fan would be good to distribute the air and regulate temps.
Consider a standoff to keep the kegs of the back of the fridge. A piece of wood should suffice, maybe slot it in to one of the vacant shelf spaces.
Title: Re: Air in Beer Line
Post by: pob on November 19, 2018, 09:09:27 AM
Quote from: vinyljunkie on November 18, 2018, 04:17:17 PM
- The therm probe is in a bottle of water sitting on the shelf beside the kegs at the front of fridge.

Why is it in water?
For a serving fridge you just want it cool, not as precise as a ferment fridge.

Probe should be free capturing air temp. Maybe tape it to the side of the fridge about 3-5cm from end, with probe sticking out. That is probable cause of your ice on back wall.
Title: Re: Air in Beer Line
Post by: johnrm on November 19, 2018, 02:54:50 PM
In water buffers the temp at the probe.
Ice build up means inefficient cooling - should be corrected by installing a fan.
Title: Re: Air in Beer Line
Post by: vinyljunkie on November 19, 2018, 05:36:07 PM
Cheers for the replies, I will apply all suggestions. Tighten all connections, tape probe to measure air temp rather than in the bottle and place something in back of fridge to stop the kegs sticking to back wall.

Just on the fan, what should I be looking to install? I assume a PC fan? Wire it to the STC 1000 where the fridge is installed on cooling?
Title: Re: Air in Beer Line
Post by: vinyljunkie on November 19, 2018, 08:40:07 PM
Quote from: mick02 on November 18, 2018, 08:40:54 PM
I have had this issue before. The problem in my case was a gasket in the disconnect. I didn't out it back properly when I reassembled it after cleaning. If I were you I'd start at the keg and work your way towards the tap tightening everything you can.
Ive tightened everything, from tap back to keg posts. The keg itself is air tight.

Im wondering could it be the post gasket needs replacing?

There are small bubbles rising up the beer line from keg and either forming air pockets halfway or up at the connection to the back.of the shank. When i pull a pint the air pockets dissapear then start forming again immediatly.
Title: Re: Air in Beer Line
Post by: mick02 on November 19, 2018, 08:42:45 PM
Quote from: vinyljunkie on November 19, 2018, 08:40:07 PM
Quote from: mick02 on November 18, 2018, 08:40:54 PM
I have had this issue before. The problem in my case was a gasket in the disconnect. I didn't out it back properly when I reassembled it after cleaning. If I were you I'd start at the keg and work your way towards the tap tightening everything you can.
Ive tightened everything, from tap back to keg posts. The keg itself is air tight.

Im wondering could it be the post gasket needs replacing?

There are small bubbles rising up the beer line from keg and either forming air pockets halfway or up at the connection to the back.of the shank. When i pull a pint the air pockets dissapear then start forming again immediatly.
Aye, looks like something is not airtight alright. If you connect that beer line to a different keg does the problem disappear? If so it's probably your liquid post, if it follows your line it could be the disconnect.
Title: Re: Air in Beer Line
Post by: iBrau on November 20, 2018, 07:51:06 AM
If you eliminate all the gaskets and still have foam formimg in the line after pulling a pint then check the liquid dip tube inside the keg. I don't know how it happened but one of my kegs had pin-hole damage to the top of the liquid tube. I was seeing bubbles rising out of the keg exactly as you described.
I sent a mail to TheHomebrewCompany with a photo of the damage and they posted a replacement straight away.
Title: Re: Air in Beer Line
Post by: vinyljunkie on November 20, 2018, 08:18:15 PM
So frustrating, I'm trying multiple combinations.

I think it has to be the keg, I can see the bubbles rise from the black disconnect as soon as it's connected. I replaced the gasket on the out post, I thought that had worked but again started to see bubbles form after a few minutes.

I need to spend time at it to really investigate hopefully at the weekend.

I'm wondering are all liquid posts the same, I seem to have three different types.
Title: Re: Air in Beer Line
Post by: mick02 on November 20, 2018, 08:42:36 PM
Quote from: vinyljunkie on November 20, 2018, 08:18:15 PM
So frustrating, I'm trying multiple combinations.

I think it has to be the keg, I can see the bubbles rise from the black disconnect as soon as it's connected. I replaced the gasket on the out post, I thought that had worked but again started to see bubbles form after a few minutes.

I need to spend time at it to really investigate hopefully at the weekend.

I'm wondering are all liquid posts the same, I seem to have three different types.
As I mentioned in a previous post, the gaskets in my disconnect were the problem. Stick a straight head screwdriver into the to of the disconnect and tighten it up and see if it makes a difference
Title: Re: Air in Beer Line
Post by: vinyljunkie on November 20, 2018, 08:46:53 PM
Just done that now - no immediate sign of bubbles. Will check it in ten mins and see how it is.

Had my hopes dashed before :)
Title: Re: Air in Beer Line
Post by: vinyljunkie on November 20, 2018, 08:54:43 PM
Yea again no luck, bubbles slowing rising up line and collecting at BSP fitting to shank.

The fact that I have two lines with the same issue is strange.

So with your lines its solid beer from keg to shank no bubbles?
Do you force carb?
Title: Re: Air in Beer Line
Post by: mick02 on November 20, 2018, 09:01:14 PM
Quote from: vinyljunkie on November 20, 2018, 08:54:43 PM
Yea again no luck, bubbles slowing rising up line and collecting at BSP fitting to shank.

The fact that I have two lines with the same issue is strange.

So with your lines its solid beer from keg to shank no bubbles?
Do you force carb?
Yeah I force carb and my lines are free from bubbles. You have a leak somewhere you just need to figure out where. Try spray starsan on the disconnect/liquid post/jubilee clip and see if you're getting any bubbles. I'm assuming this is the first time this has happened? When you day that you're getting the same in two different lines, are these lines connected to different kegs? If they are connected to the same keg then that's where the leak is, if it's connected to different kegs and you're still seeing bubbles then I'm stumped
Title: Re: Air in Beer Line
Post by: Sorcerers Apprentice on November 20, 2018, 09:19:55 PM
Quote from: vinyljunkie on November 19, 2018, 05:36:07 PM
Cheers for the replies, I will apply all suggestions. Tighten all connections, tape probe to measure air temp rather than in the bottle and place something in back of fridge to stop the kegs sticking to back wall.

Just on the fan, what should I be looking to install? I assume a PC fan? Wire it to the STC 1000 where the fridge is installed on cooling?
I used my daughters laptop support cooler fan, she had dropped it and it had broken the USB connector, I soldered the cable to a power supply and it makes a huge difference to my fermentation fridge
It's like this one
https://goo.gl/images/4swQjM

Sent from my SM-G950F using Tapatalk

Title: Re: Air in Beer Line
Post by: vinyljunkie on November 20, 2018, 09:20:38 PM
Connected to different kegs ehich is makinh me think its something to do with temp of fridge or psi on regulator. Will play about again tomorrow to see if i can come to a solution.
Title: Re: Air in Beer Line
Post by: Will_D on November 21, 2018, 11:12:06 AM
Surely in a pressurised system what we call a leak results in the pressurised stuff (beer, gas, etc) exiting the system into the surroundings (which by definition are at a lower pressure).

If you are getting gas in the lines there are maybe 2 sources:

1. The gas is coming out of solution  from the beer and is rising to the top of the line. Cause would be contaminated beer line causing nucleation (ie bubbles in champagne glasses form on the glass's micro scratches.

2. There is a leak in the dispense post inside the keg (above the beer level) allowing gas from the top of the keg to enter the beer line when you pull a pint (and lower the pressure in the line)

If you keg is fairly full lay it on its side with the dispense tub at the bottom. That way the dispense post is submerged in beer. Pull some bee and see what happens.

HTH

Will
Title: Re: Air in Beer Line
Post by: vinyljunkie on November 21, 2018, 11:20:59 AM
Hi Will, thanks for your reply.

I raised the PSI on the reg by 5 PSI this morning. It seems to be doing the trick, I've read so much online over the last few days. I'm fairly certain it was to do with the balance between PSI and Temp.

I'll leave it over the weekend pours and check again.
Title: Re: Air in Beer Line
Post by: vinyljunkie on November 21, 2018, 09:38:14 PM
One thing I don't quite get - so If I burst carb at 30 - 40 psi for two days;

1 - I don't vent?
2 - I set reg at 15 PSI so for 2.5 vols as per force carb chart for around 6 celsius https://www.homebrewsupply.com/wp/wp-content/uploads/2016/02/carbonation_cart.png (https://www.homebrewsupply.com/wp/wp-content/uploads/2016/02/carbonation_cart.png)

I assume thats correct?

Then you have the line length calculator; https://www.brewersfriend.com/2009/07/18/getting-a-good-pour-kegged-beer-co2-line-length-and-pressure/ (https://www.brewersfriend.com/2009/07/18/getting-a-good-pour-kegged-beer-co2-line-length-and-pressure/)
L = (P -(H x .5) – 1 ) / R
5 = (15-(1.5 x .5) - 1 ) / 2.7

I should have 5' of 3/16" beer line, other calculators I've seen online suggest 10'-12'

My beer line was 6', I reduced it to 4.5' recently to increase flow rate. Maybe I need to go longer an go for 6'.