CO2 regulator leak

If you have soap tested every possible leak source, has the temperature of the bottle/regulator decreased substantially? (did you put it inside your kegerator? ...if so, that is normal.

 

Just looping in @billandsuz because he often has useful advice in these kinds of situations.

 

What do you mean by a leak "of about 10-15 PSI?"

 

800+ PSI? I feel like we need to restart this conversation.

 

The high pressure gauge doesn't tell you anything about how much CO2 is in the tank. At a constant temperature, it will read a constant pressure, until just before it's empty. With varying temperature (like your ambient air temp), the pressure will vary along with the temperature.

Congrats. You don't have a leak!

ETA: Well, you might have a leak, but the high pressure gauge isn't an indicator of that.

 

Not really. The thing to remember about a CO2 cylinder is that it's not full of gaseous CO2. It's mostly liquid (by weight). If you had a slow leak, the gas in the headspace above the liquid would be continuously replaced to maintain the vapor pressure of CO2 at the given temperature.

ETA: If I were to build my own regulator, I probably wouldn't even include a high pressure gauge. They're practically useless.

 

Just to be sure...you're seeing bubbles being continuously made, right? (i.e. not just soap bubbles made by spraying soapy water.)

If so, yes, that's what I'd try in this situation.

 

Check valves don't close unless there is more pressure (liquid) downstream...you must mean the shutoff valve, right?

 

I'm pretty sure he does mean the shutoff valve, which probably has a check valve inside its body.

 

Sometimes the regulator itself has one built into it also. If not using 2 wrenches to tighten and loosen connections it's not hard to get a leak where one didn't exist before. Soap will tell.

 

The gauges have teflon tape because those are NPT connections -- the tapered threads/tape actually create the seal. Other connections in the system may use flared fittings or a fiber/nylon washer like the one that connects the primary regulator to the CO2 tank. In those cases, the threads simply hold the sealing surfaces tightly together. Thus, teflon tape on the threads serves no purpose. It's not likely to hurt, but it also won't help. The biggest downside is that people who know how these things work will snicker behind your back when they see it.

 

Like propane, you need to go by weight and tanks are usually only filled 80% due to expansion. My stupid guage reads low even after filling.

 

Assuming you're talking about Co2...low compared to what?

 

This is what's going on inside your CO2 tank. Most homebrew regs have cheap gauges, the width of a high pressure needle and parallax far exceeds 10psi. PV=nRT is based on absolute temperature (Kelvin), if trying to compute the number of gaseous molecules you'll be in the 290°-ish range. More talk about stuff like this in Home Bar.