Where is my regulator leaking?

[Belgian Samurai]

Hi,

I have installed this new regulator per the instructions (my first time), but the pressure is dropping ever so slowly. I opened up the CO2 tank nozzle slowly and got the regulator pressure set to 12psi and locked that knob in place. The CO2 tank is wide open now. I made up a warm soapy cup of water and using Q-tips, swathed all of the threads and there are no bubbles, yet the regulator now shows 10psi within about 5 minutes.

Where should I be checking specifically? Or what tip would you give me to isolate this leak?

Thanks!
Belgian Samurai

 

[IslandLizard]

Is your tank valve all the way opened, until it stopped turning?

There's nothing (kegs) attached to the output of the regulator? Is that little shut-off valve/knob on the bottom of the regulator all the way closed? In that case the pressure should not change, even if there's a tiny leak, as the tank keeps supplying CO2.

Some regulators have a little creep, there's a tiny needle valve inside the regulator that lets CO2 through.

To test for leaks, you set it at 12 psi (or whatever) with the tank open. Then you close the tank, all the way. Tanks should always be operated fully open or fully closed, never in between.
If that pressure drops there's a leak. But how long does it take to drop a few psi? Minutes or hours?
Realize, there's only a (relatively) small amount of CO2 in that whole regulator assembly, so it doesn't take much for some (or all) to leak away.

 

[Belgian Samurai]

Oh, that's good to know! @ operate fully open or fully closed, but never in between

So, the pressure guage read 12psi when CO2 tank was fully opened. The reading on the guage dropped to 10psi in 5 minutes.

Oh, then you said to fully close the CO2 tank after setting it at 12 (or whatever) psi. Okay, I will try that tomorrow and will report back.

Thanks!

 

[day_trippr]

fwiw, with an open cylinder, observing a 2 psi drop on the low pressure gauge without essentially emptying the tank such that the high pressure gauge would be at the bottom stop would indicate to me a temperature change effect and not actual gas loss...

Cheers!

 

[kiwipen]

Some regulators have a little creep, there's a tiny needle valve inside the regulator that lets CO2 through.

Could you elaborate on the creep part? I don't understand.

 

[IslandLizard]

Could you elaborate on the creep part? I don't understand.

Creep is when the pressure you've set changes a little, either up or down. Can be due to a variety of reasons, such as changes in temperature, but also a variety of mechanical causes.

That small needle valve inside the regulator limits how much CO2 is being let through from the high pressure chamber (tank side) to your low pressure system (the regulator output). That knob you turn to dial in your pressure regulates a spring-tensioned rubber diaphragm to which that needle valve is attached. It's all mechanical.

 

[Belgian Samurai]

Ok, I'm back at it this morning. I had fully shut off the CO2 tank last night, so before I gave the pressure regulator a 2nd chance today, I loosened the coupling nut attaching the regulator to the tank and re-tightened it. Then fully opened the CO2 tank and set the regulator to 12 psi. Fully closed CO2 tank.

At the 5:00 minute mark, it had lost about a 1/2#.
At 15:00 minutes, the pressure guage reads 14#...and is now 15#.

Since ambient temperature was mentioned, I have a space heater running across the room to warm up this place and yes, it's pointed in this general direction at about 12ft/4m. But I only run it when I'm down here working. Did I just isolate the cause? This basement is somewhere between 64°-74° depending on time of year. I removed the CO2 tank from the keezer due to the cumbersome weight when full and loading it into the keezer.


At 20:00 minutes: the pressure guage read 19#. I have rotated the heater to blow away from the gauges.
The pressure guage is still climbing (21#) and I guess this is due to the ambient temperature slowly rising.

Thoughts for me to consider?

 

[IslandLizard]

Ok, I'm back at it this morning. I had fully shut off the CO2 tank last night, so before I gave the pressure regulator a 2nd chance today,

Did you happen to read the low pressure dial?
That's part of the (6-24 hour) leak test. Measuring losing pressure in a small "closed" system (no kegs attached or so) under pressure (say 12 psi) with the tank closed.

 

[Belgian Samurai]

Did you happen to read the low pressure dial?
That's part of the (6-24 hour) leak test. Measuring losing pressure in a small "closed" system (no kegs attached or so) under pressure (say 12 psi) with the tank closed.

Yes, it is the low pressure that I am referencing (the guage on top in the picture from my original post), but I did google it to make sure I had the nomenclature correct.

 

[Belgian Samurai]

Now the low pressure guage reads zero, which is 90-minutes later. FWIW

CO2 tank if still fully in the closed position. Also, the room is warmer.

 

[bracconiere]

if you have a shut off for the out line i'd open up the tank, shut off the out line, shut off the tank...give a night and if either of gauges dropped at all. call it a loss and drop the $60 on a new reg......was this used? in my experience regulators only last about 5 years for me, but i haven't learned how to rebuild and just replace the whole thing.....

 

[LarMoeCur]

if you have a shut off for the out line i'd open up the tank, shut off the out line, shut off the tank...give a night and if either of gauges dropped at all. call it a loss and drop the $60 on a new reg......was this used? in my experience regulators only last about 5 years for me, but i haven't learned how to rebuild and just replace the whole thing.....

A well maintained regulator will last 50 plus years. I've got welding regulator that were my grand-fathers and they are well over 50 years old and work just fine. There's only 3 or 4 places a regulator will leak. The gauges. They are threaded so some Teflon tape and a wrench will fix the leak in no time. The pressure relief valve. Again, treaded so, Teflon and a wrench. I have seen one go bad. They're about 4 bucks at a welding supply store. The shut off valve again, treaded so, Teflon tape and wrench. Next would be the "O" ring that connects the big nut to the bottle. When those go bad you will know it as soon as you crack the valve open. You will hear that leak for sure. "O" ring is about 5 cents.

The absolute worst case is when the diaphragm goes bad this will not cause a leak. The regulator will just act wonky and pressure will be all over the place. A replacement kit is about 14 bucks. Takes about 10 minutes to change it out with a wrench and a screw driver.

 

[bracconiere]

"O" ring is about 5 cents.

tank washers are free for me when i swap a tank....i learned not to trust the stupid tap-rite "O" ring. and so you have regulators older then me? i'm impressed! i'd figure they'd design flaws to keep you buying more!

 

[whoaru99]

If you have pressurized the system and there are no bubble with soapy water then I'd expect it's either just a bit of quirkyness of the gauge or regulator or some thermal effects as previously opined.

If your test is just the tiny bit of gas in the regulator and plugged fitting it doesn't take much change in anything to change the pressure.

 

[Belgian Samurai]

If you have pressurized the system and there are no bubble with soapy water then I'd expect it's either just a bit of quirkyness of the gauge or regulator or some thermal effects as previously opined.

Roger that! I'm now running a second test. So far, the guage is remaining right on 12# like it should. Looks like we are good to go.

I'll report back if anything drastically changes.

Thanks, everyone!

 

[hotbeer]

If this is just a one or two creeps of the adjustment soon after opening the valves and letting things pressurize....

Remember when you open that valve and do the initial pressurization that things in the regulator take a big hit with thermal dynamics of expanding gas. So it'll take a while. If you wanted to change the ambient temp to accommodate that, then you should have put everything in a freezer. But that has it's own issues.

Whenever you have a chance to pressurize something else, keep a hand on your regulator and note how cold it gets when gas is rapidly flowing through it.