Kegging Set Up - Pressure Loss

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Chris17

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I’ve just set up a 2 19L corny keg set up with two taps in a fridge. I used the guide on the malt miller website, but seem to be having some issues with the gas lines.

I’ve got a 2L co2 cylinder which has a regulator fixed to it. I ran a length of 3/8 line to the regulator, which I then dropped to 3/16 to fit it through the drain hole on the fridge. Once back inside the fridge I increased back to 3/8 and used a splitter, with two lengths of 3/8 line connected to two grey gas disconnects. But I seem to having some issues with a leak somewhere along that. I’ve sprayed the full line, line reducers/splitter and regulator down with soapy water but can seem to find any bubbles.

I think there is a leak because I ran a short burst of gas from the cylinder last night. I then released most of it from the regulator using the release valve then turned the pressure up in the lines to about 20psi to ensure the remaining gas was in the lines. The cylinder was turned off so that the pressure would drop if there was a leak. I left it for about an hour and there was no change, but when I checked it this morning about 10 hours later, the pressure had completely fallen to 0psi. I’m just wondering if this is normal and if I should expect a small amount of seepage? The disconnects weren’t actually attached to any kegs, so will that have affected it?? If not, can anyone recommend how to find the leak because I’ve sprayed the full line down with soapy water while the gas was on and couldn’t see any bubbles?
 
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Tiny leaks are an absolute bind and that’s what you have!

I suggest that you go back through the assembly of your system but this time add a tiny smear of Vaseline to every joint before putting them together and repeating your test.
:hat:

BTW:
I use a Pastry Brush and a Fairy Liquid + water to check for leaks. I find that the foam I generate can last long enough to spot relatively small leaks.

Vaseline is non-toxic and doesn’t affect the taste of anything so I keep a jar especially for brewing.
 

Chris17

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Tiny leaks are an absolute bind and that’s what you have!

I suggest that you go back through the assembly of your system but this time add a tiny smear of Vaseline to every joint before putting them together and repeating your test.
:hat:

BTW:
I use a Pastry Brush and a Fairy Liquid + water to check for leaks. I find that the foam I generate can last long enough to spot relatively small leaks.

Vaseline is non-toxic and doesn’t affect the taste of anything so I keep a jar especially for brewing.

Cheers! I’ll give this a go tonight. Will the Vaseline just help to ensure all connections are fitted properly?
 
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I would say it's normal. Both of my kegerator, and my brewery setup does the same. You can expect some loss through the pipe walls.
Just try with much higher pressure, and try to submerge the fittings in water.
 

RoomWithABrew

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Leaks are a real and expensive pain.
You don't need to change the tube diameter. I use 4mm eva barrier tube throughout for gas and liquid.
If using push fit connectors ensure the tube ends are cut really square with a knife. They need ramming in a lot harder and further than you often expect. Once in give them a good tug to make sure the little ring is out.
Tubing and connectors do not like a tight bend after the connector, make sure no bend is occurring when you shut the fridge door.
Immersion is the best way to spot a leak for sure especially at 30 psi. Don't immerse the regulator though.
Do you mean a 2kg cylinder?

2 litres of CO2 gas in a cylinder is not going to get you very far, 2 litres of liquid CO2 will though.
 
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…. Will the Vaseline just help to ensure all connections are fitted properly?
I find that the Vaseline allows stuff to slide better so that things don’t stick, allows ‘O’ rings to seal better and then acts as a barrier between sealing surfaces.

Personally, I use fairly thick silicone tubing, almost no ‘Jubilee Clips’ (as long as there are ridges on the connections) and keep the pressure below 10psi.

Works for me!
:hat:
 

foxbat

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I wouldn't grease the o-rings in the JG connectors if I were you. You'll inevitably get it on the collar grips and risk the line popping out when you pressurise it. Inspect the o-rings inside the connectors for damage or trapped hairs that could come between them and the lines. Those o-rings are your gas seals. Any damage to them or debris under them and you have a leak. Likewise look for scratches on the part of the lines that would be under the o-rings.

Maybe you can reduce the number of JG connectors to just two? One 3/8-3/16 stem reducer on the regulator and another on the disconnect. There's no need for any 3/8 line at all on the gas side.

Finally, if your leak is from the disconnect poppet then you'll see bubbling if you hold it upside down and fill the inside with water.
 
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I wouldn't grease the o-rings in the JG connectors if I were you.

………

Er … as far as I am aware, no-one has suggested that “grease” should be applied to ‘O’ rings.

I recommend Vaseline for use as a lubricant for ‘O’ rings mainly because the ones found in brewing:
  1. Can have a less than perfect finish.
  2. Are often expected to seal between two plastic surfaces.
  3. Often have surface imperfections that will leak.
Unlike a hydrocarbon grease, Vaseline (a make of petroleum jelly) is non-toxic and can actually be eaten.
:hat:

PS
“Lubrication of O-rings is essential for the proper function and full-service life of the seal, but also to ensure the machine, motor, engine, or device in which it is placed does not malfunction from a blown seal.”

From:
 
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foxbat

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Er … as far as I am aware, no-one has suggested that “grease” should be applied to ‘O’ rings.
You know what I meant. Pedantry doesn't become you. wink...

The point is that with a JG connector - particularly the small 3/16" - it's very tricky to "lubricate" (happy?) the o-ring in such a way that you'll avoid also getting lube on the grip that's holding the line from popping out when pressurised, and you certainly will when you withdraw the line from the connector.

I lube my keg poppet o-rings, post o-rings, PRV o-rings but not those in the JG connectors.
 

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I diligently sprayed everything on my first keg setup and still lost all my CO2 through a slightly malformed o-ring on the corny post.

Always inspect and lightly lube o-rings with food grade keg lube now...
 

RoomWithABrew

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I'm in the don't apply any lubricant to facilitate the push fit connectors, John Guest or Kegland types. Make sure the line is cut square and rammed in far enough. The kegland duotights have an arrow on them to show the seating level. So measure this distance and mark the pipe before shoving it in. They can often feel secure when partly in, the drawn line also lets you know if any of them slip out, which doesn't happen in my experience.
My keg fridge has 6 duotight T and 3 inline regulators and the associated connections to kegs. Touch wood not leaking, it can be done.
I lubricate the orings on keg posts etc with food grade silicone lubricant, do not use silicone lubricant on silicone orings. Most orings are not silicone unless specially ordered.
 

JockyBrewer

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I found the tiniest of leaks on one of my secondary regulators thanks to Buffalo Leak Detector Spray (Buffalo Leak Detector Spray 450ml - The Malt Miller).

I lubricate keg o-rings routinely - a tiny smear of silicone grease every time they're cleaned. I wouldn't lubricate John Guest or Duotight fittings - if they've become leaky then it's better for them to go in the bin.
 
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Leaks are a pain. In my setup I used to run lines around bends but I found that doing this causes JG fittings to leak if there is a line under any tension going into them. I switched to straight lines with connectors to go around corners which seemed to solve the problem.
20220607_180435.jpg
 
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Doh!!

I’ve just realised that (without leaks) a “60 litre Sodastream” bottle of CO2 will last me +/- two months.

As the keg is full of carbonated liquid when I start (I add sugar to the brew after transferring it to the keg) the 5psi pressurisation is there until all the liquid has gone.

What brought this on?

Well, I’ve just renewed my first Sodastream bottle since restarting brewing at the end of March. During these two months, I had a major cock-up (when I accidentally pressurised a keg to 30psi), discovered a CO2 leak and consumed 3.5 x 10 litre kegs of beer.

Not bad, in view of the history! The cost of replacing the Sodastream bottle was £13 or 25p per day; which is nearly half the daily rate of what my energy supplier charges me, just to have an electric meter in my home!
:hat:
 
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@Dutto
At 5psi you could actually run a keg ferment under pressure and then put inline regulator on it to keep your beer kegs carbonated.
You'd hardly need to use the sodastream at all.
“If I knew that when I started ….. !”
:(

Your right of course; which is why I try and minimise the CO2 usage by carbonating the kegs as part of the Conditioning.

It takes two to three minutes to drop the pressure off the top of a keg before fitting the tap, but it means that the keg can normally be tapped the next day.

BTW, I’ve also seen the price of the “ferment under pressure” FV’s and I would need 4 of them (+regulators) to replicate what I manage at the moment!

So maybe my original comment should have included “…. and I was really well off ….”
:D:D
 

RoomWithABrew

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Ahh @Dutto

I think you misinterpreted my statement a bit.
You ferment and naturally carbonate in the kegs as you do now.

You get another keg ( think of it as your sodastream cylinder ) and in that you put some, sugar, yeast and water, maybe some nutrient. This will ferment and produce CO2, put an inline regulator on the gas line coming out of the gas producing keg and then run that line as your gas supply to the kegs. In a corny keg you could easily generate about 60 psi and safely contain it.


Not suggesting you pressure ferment your beer at all.
 

foxbat

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Ahh @Dutto

I think you misinterpreted my statement a bit.
You ferment and naturally carbonate in the kegs as you do now.

You get another keg ( think of it as your sodastream cylinder ) and in that you put some, sugar, yeast and water, maybe some nutrient. This will ferment and produce CO2, put an inline regulator on the gas line coming out of the gas producing keg and then run that line as your gas supply to the kegs. In a corny keg you could easily generate about 60 psi and safely contain it.


Not suggesting you pressure ferment your beer at all.
Problem is you have to purge the keg supplying CO2 first or you'll be forcing a CO2/air mixture into the beer. Mostly air to begin with, then trending to more CO2 content as time passes.
 

foxbat

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Doh!!

I’ve just realised that (without leaks) a “60 litre Sodastream” bottle of CO2 will last me +/- two months.

As the keg is full of carbonated liquid when I start (I add sugar to the brew after transferring it to the keg) the 5psi pressurisation is there until all the liquid has gone.

What brought this on?

Well, I’ve just renewed my first Sodastream bottle since restarting brewing at the end of March. During these two months, I had a major cock-up (when I accidentally pressurised a keg to 30psi), discovered a CO2 leak and consumed 3.5 x 10 litre kegs of beer.

Not bad, in view of the history! The cost of replacing the Sodastream bottle was £13 or 25p per day; which is nearly half the daily rate of what my energy supplier charges me, just to have an electric meter in my home!
:hat:
Sodastream bottles are a really, really expensive way to buy CO2. Your bottle is costing you £31.70 per kilo of CO2. Adams Gas, which is far from the cheapest, work out at £4.85 per kg. There are others on here that are paying half the price that Adams Gas charge for a refill.
 

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