Chasing a CO2 leak

[Off Balance Brewing]

Been chasing a leak for months. Burned through 2 5lb tanks in 2 months. Even bought a new dual regulator after giving up.

With the CO2 lines shut off, I turn off the tank and my regulator high pressure gauge loses about 30 percent over a day. No leaks detected by soapy water. Not sure how long this pressure should hold.

I open all three lines and submerge to check for leaks and don't see any. Pressure holds the same as above.

I've isolated one of my kegs for a leak. This keg holds pressure over days no drop. I hook it up the gas disconnect and the high pressure gauge drops to zero within two hours.

I think it could only be the gas post oring so I replace that. No help.

What am I missing???

 

[GilSwillBasementBrews]

nylon washer between tank and regulator?

 

[Off Balance Brewing]

I did stop using one with my new regulator. The regulator had a new oring at the tank. Should I still use a nylon washer? Just thought it would be another interface to leak at.

 

[GilSwillBasementBrews]

Try sticking one in and see if you’re still losing 30%/day.

 

[lumpher]

May not be the post o ring. The poppet valve ispring may need replacing. I have at least 2 kegs I need to do that for.

 

[Bobby_M]

Does the regulator have a main output shutoff valve? If so, when you close that and the tank valve, do you still lose pressure? You should be able to hold pressure in the regulator indefinitely or there is a leak somewhere. What are you using to tighten the nut to the tank?

 

[Off Balance Brewing]

So I don't think it's the poppet only because the tank holds pressure disconnected. I only lose pressure quickly when it's hooked up.

When I shut off the CO2 lines to the tank I do lose a little pressure. I will try adding the tank washer back and see if it helps.

Right now I tighten the tank nut with an 8 inch crescent wrench.

 

[Off Balance Brewing]

Does the regulator have a main output shutoff valve? If so, when you close that and the tank valve, do you still lose pressure? You should be able to hold pressure in the regulator indefinitely or there is a leak somewhere. What are you using to tighten the nut to the tank?

I'll try the adding the tank washer. I do have a small leak but nothing compared to what's going on with this mystery keg. Is it worth adding pipe tape to the tank?

 

[WesBrew]

THe crush washer needs to be in between the reg-nut and tank. Don’t just snug it or arm it. Lean on it with your weight. Something like 90ftlbs.
If you’ve isolated the keg, it’s most likely the largest opening if all else is in place. Keg lube on the lid gasket will help it seal. offset the lid alignment slightly too

 

[Beholder]

Have you checked the gas quick connect? This might be non-leaking when disconnected and leak when connected.

When I had a similar issue, I fortunately had valved manifolds, so could go keg by keg with open regulator, but closed tank, isolated it to one keg and confirmed with bucket test on the gas connected keg.

 

[Off Balance Brewing]

THe crush washer needs to be in between the reg-nut and tank. Don’t just snug it or arm it. Lean on it with your weight. Something like 90ftlbs.
If you’ve isolated the keg, it’s most likely the largest opening if all else is in place. Keg lube on the lid gasket will help it seal. offset the lid alignment slightly too

I'll try some lube on the lid seal but I would think it would lose pressure not hooked up to the tank. Seems to be fine unhooked. I'll up the tank torque too

 

[Off Balance Brewing]

Have you checked the gas quick connect? This might be non-leaking when disconnected and leak when connected.

When I had a similar issue, I fortunately had valved manifolds, so could go keg by keg with open regulator, but closed tank, isolated it to one keg and confirmed with bucket test on the gas connected keg.

Yeah I gave up on that and bought all new disconnects. I tried 2 different lines on the same keg and both lost regulator pressure with the tank off withing 2 hours.

 

[Off Balance Brewing]

Have you checked the gas quick connect? This might be non-leaking when disconnected and leak when connected.

When I had a similar issue, I fortunately had valved manifolds, so could go keg by keg with open regulator, but closed tank, isolated it to one keg and confirmed with bucket test on the gas connected keg.

Sorry I missed the last line. What was the bucket test? Filling up a 5 gallon bucket with water and submerging the keg upsidedown while connected?

 

[camonick]

Is it worth adding pipe tape to the tank?

No. Those are straight threads and tape won’t help. You need a gasket or o-ring.

 

[Beholder]

Sorry I missed the last line. What was the bucket test? Filling up a 5 gallon bucket with water and submerging the keg upsidedown while connected?

Yes, but needed a bigger bucket than 5 gal - used a kiddie pool to get good visual access. I first confirmed the bad line with pressure observation, since initial bucket test showed nothing as the leak was so minute. Had to watch the damn thing for long time before the smallest bubble came up.

I was ripping all the lines out hunting for the thing. Now I smile when I glance at my reg every now and again holding solid.,. I feel your pain.

 

[bracconiere]

i've had bad luck with the tap rite, oh you don't need a washer stupid o-rings....because the o-ring is supposed to seal right where a steel tank has a groove for a nylon washer to seal....so they MAY work for aluminum tanks, but not with steel ones....and i've never had a problem doubling down....

your kegs sound good, the only other thing would be, presurrize you lines totally unhooked, then shut them off at the reg, give them over night, then flip the shut off to on and see if you get a momentary hiss and drop, make sure it's not a leaky flare nut or barb or something.....

 

[balrog]

I'm with @WESBREW ; 8" crescent wrench isn't big enough, you need more torque to tighten regulator to tank. longer wrench handle. But I also suspect if I read you correctly in the first post, that shutting off tank and shutting off just below regulator, means you have isolated a leak between tank valve and below-regulator-shut-off-valves (which can leak.
You may have to submerge entire tank/regulator/lines into bath tub.

 

[JohnDBrewer]

Are you refilling the same tank or exchanging for a different one? The tank valve might be the issue.

 

[Off Balance Brewing]

Yes, but needed a bigger bucket than 5 gal - used a kiddie pool to get good visual access. I first confirmed the bad line with pressure observation, since initial bucket test showed nothing as the leak was so minute. Had to watch the damn thing for long time before the smallest bubble came up.

I was ripping all the lines out hunting for the thing. Now I smile when I glance at my reg every now and again holding solid.,. I feel your pain.

I'll have to try a bathtub and see if I can find it. Thanks.

 

[Off Balance Brewing]

i've had bad luck with the tap rite, oh you don't need a washer stupid o-rings....because the o-ring is supposed to seal right where a steel tank has a groove for a nylon washer to seal....so they MAY work for aluminum tanks, but not with steel ones....and i've never had a problem doubling down....

your kegs sound good, the only other thing would be, presurrize you lines totally unhooked, then shut them off at the reg, give them over night, then flip the shut off to on and see if you get a momentary hiss and drop, make sure it's not a leaky flare nut or barb or something.....

Yeah not sure I'm trusting the integrated oring. This is the first I've tried no washer in a while. I'll add it tonight.

So far the only time I hear a hiss opening is when I have the suspect keg hooked up. I'll try just charging the lines again after the washer add.

 

[Off Balance Brewing]

Are you refilling the same tank or exchanging for a different one? The tank valve might be the issue.

I have exchanged the tanks each time so I don't think it's the tank valve

 

[Off Balance Brewing]

I'm with @WESBREW ; 8" crescent wrench isn't big enough, you need more torque to tighten regulator to tank. longer wrench handle. But I also suspect if I read you correctly in the first post, that shutting off tank and shutting off just below regulator, means you have isolated a leak between tank valve and below-regulator-shut-off-valves (which can leak.
You may have to submerge entire tank/regulator/lines into bath tub.

I think I actually have 2 leaks. Tank off and line valves off I have a slow leak. Like 30 percent drop in the high pressure gauge. Hoping the tank washer and sitting on my 8inch wrench torque fixes that.

My big leak seems to be between a suspect keg only when hooked up, high pressure gauge drops to zero within 2 hours. Tank holds pressure alone and the lines charged and unhooked hold same as the above 30 percent drop over a day. Can't figure out the keg interaction leak.

 

[balrog]

I think I actually have 2 leaks. Tank off and line valves off I have a slow leak. Like 30 percent drop in the high pressure gauge. Hoping the tank washer and sitting on my 8inch wrench torque fixes that.

Could actually be the regulator itself, or any of the "valves" that are used to cut things off.

My big leak seems to be between a suspect keg only when hooked up, high pressure gauge drops to zero within 2 hours. Tank holds pressure alone and the lines charged and unhooked hold same as the above 30 percent drop over a day. Can't figure out the keg interaction leak.

Once I actually had a GAS leak on the LIQUID OUT side, between the flange of the dip tube and the O-ring upon which it sits. A little divot in the O-ring, allowed gas to escape between keg's headspace, under the O-ring, around the post threads, and out. It was a devil to find. Check all O-rings everywhere, including the PRV on the lid.

 

[bracconiere]

Check all O-rings everywhere, including the PRV on the lid.

"off balance" says the kegs hold pressure when not hooked up? but the reg still loses pressure? so the leak has be nearer to the reg? if my thinking is any where right on this.....

 

[Off Balance Brewing]

"off balance" says the kegs hold pressure when not hooked up? but the reg still loses pressure? so the leak has be nearer to the reg? if my thinking is any where right on this.....

Yeah I thought I had it narrowed down to the post oring since the keg holds pressure...but that didn't fix it.

I usually use starsan for bubble detection on the kegs and soapy water on the regulator. I might have to bite the bullet and use soap on the kegs...always makes me nervous

 

[bracconiere]

Yeah I thought I had it narrowed down to the post oring since the keg holds pressure...but that didn't fix it.

I usually use starsan for bubble detection on the kegs and soapy water on the regulator. I might have to bite the bullet and use soap on the kegs...always makes me nervous

do you use flare nuts on your gas lines?

edit: and do you use a manifold?

 

[IslandLizard]

Hoping the tank washer and sitting on my 8inch wrench torque fixes that.

The last 2 tanks I got (filled swaps), I've been putting 3 wraps of teflon tape on the tank's threads. Not for making a seal but to reduce friction when torquing the regulator nut on it. I could not get the main connection leak free without the tape. I use a super heavy 16" adjustable wrench, which has an awesome leverage and grip (even without a glove).

Can you slide a heavy duty steel tube over your 8" wrench for some needed extra leverage, or some other extension? My cars' lug nuts are torqued with a 3' steel pole over the lug wrench.

 

[bracconiere]

Can you slide a heavy duty steel tube over your 8" wrench for some needed extra leverage, or some other extension? My cars' lug nuts are torqued with a 3' steel pole over the lug wrench.

well groove or not kiss a rubber o-ring good bye!

 

[IslandLizard]

well groove or not kiss a rubber o-ring good bye!

Not necessarily. Creating a positive seal is the objective, and the regulator should not twist (much) when torquing the nut to do so.

 

[bracconiere]

Not necessarily. Creating a positive seal is the objective, and the regulator should not twist (much) when torquing the nut to do so.

smooshing is a thing too, not just twisting? unless you're replacing that tank o-ring every swap? damn, thanks for that! you just reminded me i think there's a special thing for tanks to use those o-rings...

something like this that screws into the cylinder valve?

https://www.amazon.com/Valve-Stopper-Permanent-Washer-Insert/dp/B07KCLB2FY

 

[Off Balance Brewing]

do you use flare nuts on your gas lines?

edit: and do you use a manifold?

I don't use flare nylon washers. I use plastic disconnects, I thought you only needed those for metal to metal connections. I can try adding those but I don't notice a leak when they are submerged.

 

[Off Balance Brewing]

smooshing is a thing too, not just twisting? unless you're replacing that tank o-ring every swap? damn, thanks for that! you just reminded me i think there's a special thing for tanks to use those o-rings...

something like this that screws into the cylinder valve?

https://www.amazon.com/Valve-Stopper-Permanent-Washer-Insert/dp/B07KCLB2FY

Isn't this the same that's on the end of new regulators with the oring?

 

[bracconiere]

I don't use flare nylon washers. I use plastic disconnects, I thought you only needed those for metal to metal connections. I can try adding those but I don't notice a leak when they are submerged.

but the flare might be loose? and you're right with the plastic QD you don't need a washer...but still the nuts can get loose over time...double check they are all tight?

 

[Off Balance Brewing]

The last 2 tanks I got (filled swaps), I've been putting 3 wraps of teflon tape on the tank's threads. Not for making a seal but to reduce friction when torquing the regulator nut on it. I could not get the main connection leak free without the tape. I use a super heavy 16" adjustable wrench, which has an awesome leverage and grip (even without a glove).

Can you slide a heavy duty steel tube over your 8" wrench for some needed extra leverage, or some other extension? My cars' lug nuts are torqued with a 3' steel pole over the lug wrench.

Man I've never needed to tighten them that much..maybe that's why I have a slow leak. I tried adding the washer tonight and gave the wrench a heavy torque. I'll see if that helps...or I'll flip over another 14inch box wrench to leverage it.

 

[bracconiere]

Isn't this the same that's on the end of new regulators with the oring?

i think that one screws into the tank? but they make an insert like that, that is just solid metal. that's what i was looking for, to use with the regs with the rubber o-ring?

 

[Off Balance Brewing]

but the flare might be loose? and you're right with the plastic QD you don't need a washer...but still the nuts can get loose over time...double check they are all tight?

I did...but will again

 

[bracconiere]

I did...but will again

how old is the regulator? i find mine only last about 5 years before starting to leak from the internals....

 

[bracconiere]

@Off Balance Brewing can you shut the lines off with a shut off at the reg it's self? to see if the reg is leaking i'd kill then lines on mine and shut off the tank too...then i'd know it was leaking from the regulator's internals?

 

[Off Balance Brewing]

i think that one screws into the tank? but they make an insert like that, that is just solid metal. that's what i was looking for, to use with the regs with the rubber o-ring?

Interesting. You think it's just a better seal surface on the tank for the washer to seal to?

 

[Off Balance Brewing]

how old is the regulator? i find mine only last about 5 years before starting to leak from the internals....

6 months old...but I'm not impressed. Been having creep problems.