Author Topic: Torpedo Keg - leaking issue  (Read 844 times)

Offline Jefferson Coastal

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Torpedo Keg - leaking issue
« on: April 17, 2022, 05:45:04 pm »
I have a nice looking Torpedo keg, and this is my first keg to develop a leak.  Not sure where looks like the lid.  The PRV appears to be welded into place so cannot replace that.

Wondering if anyone else has issues with leaking Torpedo kegs?

Online BrewBama

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Re: Torpedo Keg - leaking issue
« Reply #1 on: April 17, 2022, 08:02:26 pm »
I’ve had to apply keg lube to the lid seal to ensure it doesn’t leak on the one I have.

Offline tommymorris

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Re: Torpedo Keg - leaking issue
« Reply #2 on: April 18, 2022, 07:35:11 pm »
If it’s leaking gas you can spray starsan on the seals (lid seal, posts, poppets). The spot with the leak should grow a bubble.

Offline redrocker652002

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Re: Torpedo Keg - leaking issue
« Reply #3 on: April 19, 2022, 12:14:13 am »
I think you can buy new gaskets for those can't you?  Asking cause I honestly don't know. 

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Re: Torpedo Keg - leaking issue
« Reply #4 on: April 19, 2022, 06:09:09 am »
Yes, I replaced all my black gaskets with red silicone. But I still had a leak around the race track seal. Keg lube did the trick.

Offline purduekenn

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Re: Torpedo Keg - leaking issue
« Reply #5 on: April 19, 2022, 06:45:19 am »
I’ve had to apply keg lube to the lid seal to ensure it doesn’t leak on the one I have.

Agree. I also use keg lube on the keg post o-rings.

Offline Richard

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Re: Torpedo Keg - leaking issue
« Reply #6 on: April 19, 2022, 08:35:08 am »
Yes, I replaced all my black gaskets with red silicone. But I still had a leak around the race track seal. Keg lube did the trick.
If you have a scratch in the metal you can have a leak even with new o-rings. Keg lube is a good idea in all cases.
By the way, silicone is a nice gasket material but it is highly permeable to oxygen. Buna-N is actually a better choice for kegs.
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Offline MNWayne

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Re: Torpedo Keg - leaking issue
« Reply #7 on: May 19, 2022, 10:06:33 am »
I replaced all my "big oval lid" seals with seals available from Williams Brewing.  They offer a gasket that's slightly thicker and slightly softer than normal.
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Offline Andy Farke

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Re: Torpedo Keg - leaking issue
« Reply #8 on: May 21, 2022, 12:13:06 pm »
If you have a scratch in the metal you can have a leak even with new o-rings. Keg lube is a good idea in all cases.
By the way, silicone is a nice gasket material but it is highly permeable to oxygen. Buna-N is actually a better choice for kegs.


Out of curiosity -- are there good data on the amount of oxygen ingress for a cornie keg under pressure? I know there is some minor ingress via bottle caps (adding up to major ingress over time), but I'm curious if the surface:volume differences swamp out any effects in a keg during typical duration of storage. I would certainly consider swapping out my lid gaskets, if the cost:benefit ratio is worth it. My kegs are usually stored cold (<33 degrees) for 2-4 weeks at most, served fairly cold (~40 degrees), and finished within 1-2 months.
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Offline Richard

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Re: Torpedo Keg - leaking issue
« Reply #9 on: May 21, 2022, 08:34:16 pm »
If you have a scratch in the metal you can have a leak even with new o-rings. Keg lube is a good idea in all cases.
By the way, silicone is a nice gasket material but it is highly permeable to oxygen. Buna-N is actually a better choice for kegs.


Out of curiosity -- are there good data on the amount of oxygen ingress for a cornie keg under pressure? I know there is some minor ingress via bottle caps (adding up to major ingress over time), but I'm curious if the surface:volume differences swamp out any effects in a keg during typical duration of storage. I would certainly consider swapping out my lid gaskets, if the cost:benefit ratio is worth it. My kegs are usually stored cold (<33 degrees) for 2-4 weeks at most, served fairly cold (~40 degrees), and finished within 1-2 months.

The CO2 pressure in the keg is irrelevant. What matters is the partial pressure of oxygen inside and outside. Temperature does make a difference, and the permeability is lower at lower temperatures. I haven't worked through all the numbers since I have butyl rubber now and won't ever switch to silicone, but you can try to work it out for yourself. I suspect that for a month at 40F the ingress of oxygen is not significant, but that is just my gut feeling. Do a Google search on "oxygen permeability nitrile vs silicone" and get results like these:
https://imageserv5.team-logic.com/mediaLibrary/99/D116_20Haibing_20Zhang_20et_20al.pdf "The Permeability Characteristics of Silicone Rubber"
https://www.marcorubber.com/o-ring-permeation.htm "O-ring permeation chart"

You can take the formula from the O-ring permeation chart and plug in a coefficient that is 10-50 times higher for silicone compared to Buna-N and see if it matters.
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Offline Andy Farke

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Re: Torpedo Keg - leaking issue
« Reply #10 on: May 21, 2022, 08:51:53 pm »
If you have a scratch in the metal you can have a leak even with new o-rings. Keg lube is a good idea in all cases.
By the way, silicone is a nice gasket material but it is highly permeable to oxygen. Buna-N is actually a better choice for kegs.


Out of curiosity -- are there good data on the amount of oxygen ingress for a cornie keg under pressure? I know there is some minor ingress via bottle caps (adding up to major ingress over time), but I'm curious if the surface:volume differences swamp out any effects in a keg during typical duration of storage. I would certainly consider swapping out my lid gaskets, if the cost:benefit ratio is worth it. My kegs are usually stored cold (<33 degrees) for 2-4 weeks at most, served fairly cold (~40 degrees), and finished within 1-2 months.

The CO2 pressure in the keg is irrelevant. What matters is the partial pressure of oxygen inside and outside. Temperature does make a difference, and the permeability is lower at lower temperatures. I haven't worked through all the numbers since I have butyl rubber now and won't ever switch to silicone, but you can try to work it out for yourself. I suspect that for a month at 40F the ingress of oxygen is not significant, but that is just my gut feeling. Do a Google search on "oxygen permeability nitrile vs silicone" and get results like these:
https://imageserv5.team-logic.com/mediaLibrary/99/D116_20Haibing_20Zhang_20et_20al.pdf "The Permeability Characteristics of Silicone Rubber"
https://www.marcorubber.com/o-ring-permeation.htm "O-ring permeation chart"

You can take the formula from the O-ring permeation chart and plug in a coefficient that is 10-50 times higher for silicone compared to Buna-N and see if it matters.


Very cool -- thank you!
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Offline Richard

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Re: Torpedo Keg - leaking issue
« Reply #11 on: May 22, 2022, 03:05:36 pm »
OK, I ran the numbers and my gut feeling was very wrong. Beverage grade CO2 is 99.9% pure, so I looked at how long it would take for the oxygen permeating through the O-ring to equal 0.1% of a 1-liter headspace. At that point the oxygen entering through the O-ring would equal or exceed the oxygen already in the CO2. That seemed like a reasonable value to use as a threshold. The time for that to occur with a Buna-N O-ring was only about 9 days, so silicone would be 1-2 days. Both are way shorter than a month, so even Buna-N O-rings will not keep beer oxygen-free for months. Considering that both are so short I'm not sure it matters a whole lot that one is a lot shorter than the other. If Buna-N were 10 months and silicone 1 month then I think it would really matter, but not 10 days to 1 day.
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Offline Andy Farke

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Re: Torpedo Keg - leaking issue
« Reply #12 on: May 22, 2022, 05:30:48 pm »
Interesting -- thank you, Richard!
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Offline dm2020

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Re: Torpedo Keg - leaking issue
« Reply #13 on: July 19, 2022, 03:45:55 pm »
This may not apply for your keg - but, I've had (2) 2.5 gal torpedo kegs and both had the gas side dip tube "flared" end come off. It appears it was not a flared end on the tube, rather a 2-pc tube being the tube and flange.
Thus, it created "an opening" that the o-ring could not / would not seal.

I didn't trust the liquid side tubes to seal, and replaced both (G & L) with conventional one-piece tube with a flared end.
Again  - YMMV.

Offline soymateofeo

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Re: Torpedo Keg - leaking issue
« Reply #14 on: July 23, 2022, 10:58:47 am »
I have used starsan to find bigger leaks but it did not help me with smaller leaks.  I went through a lot of CO2 before I switched to dish soap solution in a spray bottle.  It turned out to be on the gas side post. I changed all of the gaskets since I had them. (dip tube, keg post, poppet)  It seemed to do the trick but I always use keg lube.  My recent fail was using amazon plastic liquid/gas connects.  absolute garbage.  Anyway, after I spray with dish soap solution, I sprayed with starsan to rinse the soap away. There was no effect on the beer with weird soap flavors.