CO2 Tank Leak

[slurms]

I have a CO2 tank that, when turning the tank knob, I hear a hissing sound. Seems like it's coming from the tank itself and not from the regulator. I assume this is possible but I never noticed it before, and I've been using this tank for the better part of 2 years at this point (albeit it's been opened and not moved really).

I recently moved houses so I had to take the regulator off and only noticed it when I was starting to set up my kegerator again. The regulator and lines seem to be holding pressure when I pressurize and close the tank. It also makes the sound when I used my other regulator, so it leads me to believe it's from the tank itself.

Anyone have any experience with this issue? The tank is still about halfway full so I don't want to waste it, but it's also pointless if it's just going to leak all out regardless.

 

[IslandLizard]

Make sure there's a fiber or plastic washer (1/16-1/8" thick) between the regulator and tank connection. Some regulators have a rubber washer/o-ring built in, but it could be damaged. The fiber washer need to be replaced more often (recommended every time) than plastic ones, as they're considered crush washers (single use).

Also, on my last (swapped) tank, I need to put 2 or 3 windings of teflon tape on the tank connector threads, as a lubricant. It's the only way to torque the regulator nut down enough to get a positive seal. That tank is almost empty and soon up for swapping again.

 

[slurms]

Thanks for the reply. These are TapRite regulators, and have the rubber (maybe plastic?) o-ring at the connection. I'll give the teflon tape a go and see if it's coming from the regulator/tank connection.

The funny thing is that the hissing might occur when the knob on the tank is in one position, but if I spin it to another position, it stops.

 

[IslandLizard]

The funny thing is that the hissing might occur when the knob on the tank is in one position, but if I spin it to another position, it stops.

Try with the valve all the way open. Some valves leak when not fully opened.

The teflon tape won't make a seal, the washer is meant to do that. But a thin layer of tape can make it easier to torque the nut down enough.

 

[slurms]

With the valve open all the way, it still sounds like it's leaking. But if I don't open it all the way tightly it seems to hold. It is a bit random in when I hear the leak. But I guess if it's not leaking when it's open, it should be fine. As long as it's not a danger issue...

In the mean time, I'll get it so I can't hear any leak and keep it on a scale to see if it is losing anything.

 

[Bobby_M]

The stem packing seal goes bad on these valves. I have a half a dozen tanks set aside for valve replacements.

 

[slurms]

My guess is that's probably what's going on here. Thanks for the info!

 

[IslandLizard]

As long as it's not a danger issue...

It could be a danger issue, depending where it is and how much it leaks.
CO2 can kill, say in a (small) room, while you're asleep or animals are asleep.

I'd say open it only when it needs to be operational, and until it stops hissing.
And yes, if you have one, keep it on a scale to monitor losses over time.

Do you own that tank? If swapped, return it to the place you got it from for a fresh swap.

 

[IslandLizard]

The stem packing seal goes bad on these valves. I have a half a dozen tanks set aside for valve replacements.

Ouch! Do you know what causes that?

I've read somewhere a tank valve should always be opened all the way, never left anywhere in between. Reason for that being, it compresses the valve packing in the top position, making a seal.
Or is opening all the way actually a bad thing, detrimental to that top packing over time?

 

[day_trippr]

Eventually age will cause the packing gland to dry out and lose compliance. Same with the upper and lower gaskets...

Cheers!

 

[MicroMickey]

One of my regulators is a TapRite. It too has an O ring at the joint but I still use a nylon washer at the joint. Give everything a slight smear of silicone lube when assembling as insurance.

 

[PCABrewing]

Ouch! Do you know what causes that?

I've read somewhere a tank valve should always be opened all the way, never left anywhere in between. Reason for that being, it compresses the valve packing in the top position, making a seal.
Or is opening all the way actually a bad thing, detrimental to that top packing over time?

The valve is designed to seat (back-seat) at the full-open position so you should open it fully and seat it just as when you close.
They are designed to not depend on the packing to prevent leaks with high-pressure gas.
Other high pressure tanks (oxygen) are also designed that way.
Fuel gas (Acetylene, Propane) valves are not designed to be fully open to achieve seal because they are typically lower pressure.
Those valves only get opened 1/4 to 1/2 turn.

 

[mashpaddled]

If you spray starsan or soap around the valve and the connection to the regulator, do you see bubbles at either? That would tell you if you have a leak at either seal.

I have a stainless CO2 tank that is real finnicky about both seals being just right. The valve needs to be snuggly open or it leaks slowly. If the regulator isn't screwed in perfectly, it will leak at the connection, even with the o-ring in place. My other tank has neither of these issues. When I hear the hissing of a slow leak with the stainless tank, it's usually at the connection to the regulator although it's impossible to hear a difference.

 

[bracconiere]

These are TapRite regulators, and have the rubber (maybe plastic?) o-ring at the connection

i hate those stupid things! that stupid rubber 'supper dupper' no washer needed o-ring, is right where the i don't know why it's there groove in the valve on most co2 tanks is! lol, use a nylon washer even with it....