CO2 Leak in Keezer

I've had 2 CO2 tanks run empty. The first time I thought the tank wasn't filled properly. The second time I know it was full. I didn't even manage to go through 2 kegs between the 2 tanks. I am 99% certain there is a leak.

I think I may be missing a washer on one of my CO2 lines. I also don't have a washer on my regulator. I think that is the problem. I thought I'd post in case there are any other possibilities however.

Any other tips?

Jeeze, fix the obvious stuff (no gasket on the regulator/tank coupler? Really??) and then come back for help...

Cheers!

I picked up the gasket for the regulator and they mentioned using teflon tape on threads. So I'm assuming I should get some of that too before I get the tank filled and hooked up?

Did they actually suggest using tape on the regulator/tank coupler?

Interesting. That's a flare coupling that absolutely does not utilize the threads to seal. At all. So the only use for tape there would be to prevent galling, but I don't think I've read of anyone galling the threads on a CO2/tank coupler.

I have two CO2 systems, neither has tape on any of the flare fittings, from tank to kegs. I say don't put tape where tape is not part of the seal...

Cheers!

I was thinking he meant the tape was for the threads on the co2 disconnects but I may be mistaken. So do you not use Teflon tape at all then?

Use PTFE tape on tapered threads (NPT) only. Not on the regulator (CGA fitting) and not on a flare fitting. Where a fitting screws directly into a regulator or wye with NPT threads, yes. As shown here:



Not having a nylon washer in a metal-on-metal flare connection can definitely cause a slow leak.

zachattack said:

Use PTFE tape on tapered threads (NPT) only. Not on the regulator (CGA fitting) and not on a flare fitting. Where a fitting screws directly into a regulator or wye with NPT threads, yes. As shown here:


Not having a nylon washer in a metal-on-metal flare connection can definitely cause a slow leak.

Click to expand...

I did not understand the entire first part of your post about all the different fittings.. BUT - the part about the washer... I just lost an entire tank of C02 in a week on my first keg as well. And my regulator, nor my tank came with a washer to go between the two. You happen to know where I might pick one up? Are they standard sized or sized differently for different size C02 tanks?

Some regulators have an intergrated o-ring instead of the washer. Does yours? If not, the washer can be bought online at tons of places (google "CO2 washer") or probably at a homebrew shop. You can also stop by anyplace that fills the tanks (welding or fire shop). They're dirt cheap. And yes, they're a standard size. I've heard of people punching out their own or even using cardboard in a pinch...

With all that being said, the nylon washer I was referring to is in an MFL connection. Lots of people don't think about the need for a washer since corny QDs with MFL fittings have them integrated. But for all-metal MFL fittings (like on a sankey coupler) you need the washers. Without it you'll have a tiny leak that's pretty hard to detect.

Make a soap solution good enough to blow bubbles with and spay on all your connections. A Starsan solution can also be used but make sure that it will bubble up. I do this every time connect a new CO2 tank just to make sure that I tightened the regulator down and that anything connected to my regulator has not been jostled. You should check you Kegs for leaks I spray Starsan on the keg lid and posts after I pressurize it to 30PSI to seal.

+1 on the soap. I use water and Dawn dish soap in a spray bottle.

As mentioned above, never use teflon tape on a flared/compression fitting. Never. You should however take them apart and check that the plastic inserts are present and accounted for. That's what makes the seal on those fittings.

Goes without saying you need to get a washer for your regulator.

Also goes without saying but make sure you're seating the keg gasket by ramping up to higher psi (20-30 psi) and then backing down to serving pressure. Which also brings up the point to check your keg o-ring and quick connects. (again on the soapy water)

So I believe I have determined the source of my leak to be a bad regulator. I have tried another, and pressure will hold over night if I crank it up to 30 and shut off the tank. My question is, should the regulator stay at 30 indefinitely while the tank is off? If the pressure goes down after a while (days or weeks) does that still indicate a small leak?

I got frustrated and didn't revisit this for a while, but now I have two batches that could be kegged.

I have a primary reg with one body reserved for purging carboys and kegs and setting keg lids. I keep that reg set at 30psi and just close the shut-off. The low pressure gauge stays pinned at 30psi for months.

But there's no keg connected, no beer to absorb CO2. Just a reg hooked to a tank with both ends closed tight.
Cheers!

If there is no leak, pressure should not change. If there is a slow one it will drop slowly. If it is connected to a non carbed or undercarbed beer for the pressure you have it set on the pressure will drop though as the CO2 dissolves into solution.

I'll add that some CO2 tanks can leak from the valve unless it's fully open. So if you shut off the tank, the regulator may slowly drain. This doesn't necessarily mean there's a leak.

^ Almost. I've yet to read of anyone getting a tank that didn't hold gas when its tank valve was totally closed tight (Wait for it - there'll be an "Actually..." soon enough ) But I have read multiple instances of folks who got a swapped tank with a bad valve stem packing, which would still be tight when closed, but leaked gas if partially opened - and often the leak stops if the tank valve is opened fully to the stop...

Cheers!

Sorry, I meant the regulator, not the tank.

If the tank valve is fully closed with the (pressurized) regulator attached, the gas can flow back around the stem packing and make you think your reg leaks. Someone here posted a diagram a while back, I'll see if I can find it...


Edit: here it is, from this thread

^ Ah, gotcha. Yeah, that could conceivably happen...

Cheers!

The "packing" or gland nut on the tank can be "snugged up".........

Working in the power plant bidness', we would always adjust the packing on valves, (water, steam, gasses, etc...), for leakage, ease of opening and the like.

If anyone gives a d$@n, any valve of this type should be fully opened, and then backed off only slightly from it's stop, which USUALLY gives you a good sealing spot on the valve stem, for it's packing, o-ring, etc.. to seal against.

A leak there should be easy to spot and isolate, however, don't back the gland / retaining nut off more than 1 turn when messing with a pressurized vessel!

day_trippr said:

^ Ah, gotcha. Yeah, that could conceivably happen...

Cheers!

Click to expand...

Yep, happened to me on my first tank. Made diagnosing the location of my leak a bit more difficult.