CO2 Leak Hunting

[Jayf19]

I am leak proofing my kegerator and would like to know if I should investigate the following further or not.

I've put my regulators at 40 psi and closed the gas to see if there were any leaks, after about 8 hours disconnected from the gas, the high pressure side dropped from 60 to 56 (as shown below). Should this be considered a slow leak?

 

[MMP126]

That doesnt seem like a concern. That little change in pressure could be from a temperature swing in your house.

What I do, or did, was to open each section of the system one at a time, and use a spray bottle of soapy water to spray each connections. If it bubbles up, you have a leak to fix. Works great!

 

[Jayf19]

Thanks; I've lost a few CO2 tanks to stubborn leaks that I couldn't find with the spray bottle technique (last time was behind the CO2 shutoff valve handle) which makes me somewhat paranoid every time I change something on the gas side of my setup.

I'll leave it overnight but the temperature swing would make sense.

 

[Vale71]

That doesnt seem like a concern. That little change in pressure could be from a temperature swing in your house.

To get that amount of pressure drop you'd need a temperature decrease of 20°C and that's unlikely in a temperature controlled home environment. I'd say he has a leak even if quite a slow one. I'd wait at least 24 hours to get a better assessment.

 

[Jayf19]

Dropped by another 4points overnight. I'll tighten everything up a tad more and re test.

 

[CaptMogul]

@ $ 42.00 a pop for a 20lb tnk a small leak can cost some serious change. A leak @ the gas connection, @ the keg is very hard to find even with @ spray of soap. IMHO

 

[bruce_the_loon]

Is the gas outlet valve closed? Even if it is closed, it might be worth leak checking the gas lines beyond the valve in case the valve isn't sealing properly.

 

[TennBrewer]

I used a balloon or a rubber glove to seal around each gauge and the tank valve. If there's a leak, the balloon inflates. I found a leak coming from a faulty pressure gauge this way.

 

[day_trippr]

^clever^, especially wrt gauges. I'll have to remember that trick...

Cheers!

 

[Jayf19]

Is the gas outlet valve closed? Even if it is closed, it might be worth leak checking the gas lines beyond the valve in case the valve isn't sealing properly.

I'm testing everything individually, so far I know I don't have any leaks anywhere between the CO2 to the primary and to the secondary. I'm at the point where I'm testing the lines going from the secondary regulator to the individual kegs.

I used a balloon or a rubber glove to seal around each gauge and the tank valve. If there's a leak, the balloon inflates. I found a leak coming from a faulty pressure gauge this way.

That is brilliant, I have bulkheads on my kegerator walls and was wondering how I could submerge them in water to identify small leaks.

 

[bracconiere]

^clever^, especially wrt gauges. I'll have to remember that trick...

Cheers!

???? i thought you never had a deflated co2 tank? lol

 

[Tom R]

Somethin like this might help. I use Starsan.
45804 - Hercules 45804 - Megabubble Leak Detector, 16 oz. (w/ sprayer) (supplyhouse.com)

 

[day_trippr]

???? i thought you never had a deflated co2 tank? lol

Your thought is correct. I have 3 CO2 systems and a beer gas system and none of them leak.
But I shall remember that neat trick for others dealing with problems in the future...

Cheers!

 

[HopSing]

You may want to try isolating the gas side components. Disconnect the CO2 line that goes from your regulator to your distribution block and retest. If the pressure drops at the same rate, then the leak is likely in the regulator assembly (gauges, connection to tank, regulator itself, etc.). If the pressure does not drop, then check the next component in the system by disconnecting everything that it is connected to it other than the CO2 feed line. For example, turn off valves or disconnect all lines on the CO2 distribution block then repeat the test of pressurizing the system and turning off the CO2 tank. If it loses pressure, then the leak is likely in the distribution block. If no pressure is lost, then turn on or reconnect each keg valve one by one and repeat the leak down test.

I have found CO2 leaks in the distribution block valves, keg connectors, keg posts, keg lids, keg PRV's, etc.. Without isolating each component it is difficult to narrow down your focus. Also don't rule out multiple leaks. It happens!!

Good luck.

~HopSing.

 

[esdill]

Close all of your valves (primary regulator outlet, secondary inlet, secondary outlet, etc.). If there's a leak overnight, then it's somewhere in the primary regulator (gauges, etc.). If no leak, then open the first valve in line, if there's a leak overnight then it's between the first valve and the second valve. If no leak, then open the next valve in line ... and continue the process until you can sectionalize where the leak actually exists. Once you find the section that has the leak, find the leak and repair it. I had a hairline crack on the back side of a brass coupling between two of my secondary regulators that was not visible to the naked eye ... once I had sectionalized where the leak existed I was able to find the crack.

 

[JohnDBrewer]

I had an annoying leak for the last several months finally found it. The valve only leaked when not completely open. Open all the way or closed, even mostly close no issues but if it was not fully open the valve leaked.

 

[Mad Mann]

Glad to hear there is so much info on gas leaks. My experience is on-going and have tried everything from spraying and looking for bubble to complete submersion. I found multiple leaks to include one of the gauges that I replaced. Still leaked and I discovered it was a small beverage line leak that turned into a bigger issue now resolved. However still have a small CO2 leak. As the above comment suggested, I will try the manifold and see what happens.

 

[Jayf19]

Thanks for all the tips, this is what I generally do when I make changes to my setup and what I've been doing since this weekend.

You may want to try isolating the gas side components. Disconnect the CO2 line that goes from your regulator to your distribution block and retest. If the pressure drops at the same rate, then the leak is likely in the regulator assembly (gauges, connection to tank, regulator itself, etc.). If the pressure does not drop, then check the next component in the system by disconnecting everything that it is connected to it other than the CO2 feed line. For example, turn off valves or disconnect all lines on the CO2 distribution block then repeat the test of pressurizing the system and turning off the CO2 tank. If it loses pressure, then the leak is likely in the distribution block. If no pressure is lost, then turn on or reconnect each keg valve one by one and repeat the leak down test.

I have found CO2 leaks in the distribution block valves, keg connectors, keg posts, keg lids, keg PRV's, etc.. Without isolating each component it is difficult to narrow down your focus. Also don't rule out multiple leaks. It happens!!

Good luck.

~HopSing.

 

[Jayf19]

It seems that my leaks are coming from the Duotight (plastic) > MFL connections (stainless). Has anyone had similar issues where they had to install a plastic flare on the stainless MFL connections?

I recall seeing elsewhere that day_trippr uses EVA Barrier / Duotights.

 

[bruce_the_loon]

Poking around on the net a bit has most sites copying the sales blurb from somewhere with a line that there are special instructions for flare fittings which aren't in the blurb.

Williamsbrewing.com has a note that stainless steel MFL connectors will need some teflon tape to make sure the seal is good and has a video which may or may not be relevant.

https://www.williamsbrewing.com/Hom...Tight-8mm-System/DuoTight-8mm-To-Female-Flare
Hope it helps a bit.

 

[day_trippr]

fwiw, most of my 1/4" FFL connectors are John Guest, I reckon I have nearly 40 of them in service, while I have only 5 Duotights, all on my regulator outputs.
None of them have flare washers or tape. None of them leak...

Cheers!

 

[Bobby_M]

My process and recommendation for connecting Duotight fittings to metal MFL devices is to put a light layer of keg lube on the tip of the MFL and the threads, hand tighten the DUOtight on, pressurize and test for leaks. If it's bubbling, tighten 1/8th turn. Done.

 

[Jayf19]

My process and recommendation for connecting Duotight fittings to metal MFL devices is to put a light layer of keg lube on the tip of the MFL and the threads, hand tighten the DUOtight on, pressurize and test for leaks. If it's bubbling, tighten 1/8th turn. Done.

I like that, thanks Bobby!