5lb co2 depleted in 3 months

[rayhwong]

Hi,
I set up my pressurized co2 system 3 months ago and now the c02 tank is empty. There must be a leak right? I am using silicon tubing. Is that the source?
How can i check for a leak?

Thanks.
Ray

[bharada]

Ray,
To check for leaks spray every connection (tank to regulator, base of bubble counter, top cap of bubble counter, hose-to-bubble counter, hose-to-checkvalve, hose-to-reactor) with Windex. If you have a leak you will see the Windex start to bubble.

When I first set up my 40g tank, the 5# tank I hooked up to it ran for only a little over 3 months before the tank pressure dropped under 850psi, indicating that the liquid CO2 had been used up and only gaseous CO2 remained. I now have a 10# tank and the tank pressure hasn't budged in 6 months.

I was, and still am using regular vinyl airline tubing, although I have gotten some black CO2 tubing from AquaBotanic last week which I plan to install once the barbs for my check valve (I have a Milwaukee regulator on my 125) come in. I've read that silicone tubing was the least desirable type of tubing to use for CO2.

[Thooshe]

I had the same problem. I used thread tape on the bottle to regulator connection and it has been in operation for 10 months. You can get thread tape from a hardware store for about a buck and it should be enough to last you for a loooonnnnggg time.

[glass-gardens.com]

I run a 2.5 pound tank on a 75, lasts a good 3 months with a very high bubble rate so I'd guess you have a problem. The silicone will tend to harden from CO2 exposure which first has the affect of deteriorating the physical connection at the regulator and reactor and leaking. You could cut off an inch at either end and that will be a temporary fix. You should get a good CO2 rated tubing. That would fix that deficiency if that's the problem.

If you look at the mating surfaces on the regulator and the tank, you'll see that in reality, the threads have nothing to do with the seal other than to provide the force to hold the mating surfaces together. The only thing that seals the connection is the washer that came with your regulator. If the gas were to leak past the mating surfaces, the threads would be sealed with tape but the gas would leak past the collar that holds the nut on so taping the threads won't stop leaks.

If the connection is leaking, it either isn't tightened down enough or there is something preventing the washer from being perfectly compressed between the mating surfaces. Could be a scratch or gouge in either of the surfaces, dirt, anything. Tighten the connection more or better, replace the washer, check the surfaces and then crank it back down.

The reason some people seem to have success stopping the leak by taping the threads
is due to the fact that when they put the tape on, they are essentially lubricating the threads so they tighten it more than it was without tape without realizing it. The problem is, the tape can flake and wreak havoc on a regulator. I realize that to the average person, it seems like they are tightening the regulator enough, even too much, but you have to remember, you're also tightening it to stop something that's running almost 1000PSI. If you're really paranoid about busting the stem or something, try a bit of silcone applied to the threads to lubricate them.

[Bonsai_Swamp]

As mentioned above, a soapy water spray will bubble quite nicely if it hits a leak. Just be sure to get it on both sides of the cylinder connecting nut. Most likely the leak will appear on the cylinder side of the nut.

The face seal is a horrible concept for high pressure systems; the engineers must have been running out of ideas when they got to CO2. Use a new washer, tighten the nut, test for leaks, and after the system has been running for a few days and the temperature has stabilized go back, re-tighten, and test for leaks again just in case something moved.

And if the regulator gets bumped - re-tighten and test for leaks.

Nothing like the feeling of dumping $25 worth of CO2 in a few weeks because that #@!#/&!! washer started leaking.

Glass-Gardens - I assume you are referring to silicone grease, not silicone sealant?

[rayhwong]

Wow thanks for the great advice. I am already using thread tape. I think the connection isnt tight enough. I was afraid I was going to break something during the tightening.
I will get a refill and check for leaks after the next setup. Thanks again!

[Rex Grigg]

As stated the use of Teflon tape on the cylinder to regulator threads is a lousy idea. Unless you want a new regulator. What you need is a monkey wrench. You are not going to break anything. It's all brass and steel. As I recall the nut is supposed to be tightened to the range of 50 foot pounds of torque. And then after you have opened the valve on the cylinder you need to give it another bit of torque. Don't be girly men here use some force.

[rkundla]

Originally Posted by glass-gardens.com

If you look at the mating surfaces on the regulator and the tank, you'll see that in reality, the threads have nothing to do with the seal other than to provide the force to hold the mating surfaces together. The only thing that seals the connection is the washer that came with your regulator. If the gas were to leak past the mating surfaces, the threads would be sealed with tape but the gas would leak past the collar that holds the nut on so taping the threads won't stop leaks.

If the connection is leaking, it either isn't tightened down enough or there is something preventing the washer from being perfectly compressed between the mating surfaces. Could be a scratch or gouge in either of the surfaces, dirt, anything. Tighten the connection more or better, replace the washer, check the surfaces and then crank it back down.

Excellent observation!

I now treat my CO2 tank and regulator like you are supposed to treat your alloy wheels on your car. Tighten the nut as tight as you can without breaking anything, then 24 hours later, tighten it again.

I think this process allows the teflon/nylon washer to stabilize after the initial tightening, then the second tightening helps seal it even more.

[ThomE]

I used loctite instead of thread. But I agree. The o-ring should really do all the work.

[unirdna]

Originally Posted by Rex Grigg

What you need is a monkey wrench. You are not going to break anything. It's all brass and steel.

This simple solution is what worked for me. Plyers don't cut is - what does, is a solid crank with a proper sized wrench.

On a side note. IME, you can expect a 5lb tank to last 6 months or so, running 60bpm.

[rayhwong]

I unscrewed the nut today and it wasnt tight at all. That must of been the source of the leak. Also some thread tape spilled out into the washer and cylinder junction and did not create a solid seal. I wish I knew this earlier!
I also didnt have a monkey wrench so I used two sets of vices to tighten it.
Rookie mistakes.......

I notice the washer now is a bit imprinted with the shape of the cylinder junction where it was pressed against. Will this be ok? Do i need a new washer?

[bharada]

Probably should get a new washer.

[glass-gardens.com]

You should be able to get a new washer from the place you get your gas.

They're cheap, like $0.20, I make it a habit to replace them every fill.

[Rex Grigg]

Many places that fill tanks can also install a permanent seal. It's a brass piece that screws into the outlet of the CGA 320 valve and has a 'O' ring on the face. I have one in each of my tanks and it works great.

[Bonsai_Swamp]

Originally Posted by Rex Grigg

Many places that fill tanks can also install a permanent seal. It's a brass piece that screws into the outlet of the CGA 320 valve and has a 'O' ring on the face. I have one in each of my tanks and it works great.

That sounds like the Bodok seals we use to replace the goofy stock plastic seals on the little emergency oxygen jump kits. The stock seal is similar in concept to the fibre CO2 washers and is even less reliable. (Just what you want on emergency equipment - fiddling with the regulator because it's leaking during use!)

http://www.999supplies.com/popup_image.php/pID/1328

I agree - harass your gas suppliers until someone sells you one of these. They need a lot less pressure to seal and are infinitely more reliable.