After 6 or so years of no issues, I finally have a gas leak somewhere in my system. I think I have it pinned down to the high pressure portion of my regulator, but I’m wondering if you guys can let me know if my thought process is correct.
What I did was turn the gas on so that the high pressure gauge read about 500 and the low pressure gauge read about 14. I then closed the valve that leads from the regulator to the gas manifold and turned off the gas. When I checked it a few hours later, the high pressure gauge read 0, but the low pressure gauge still read 14, and there was still pressure that could be released through the pressure release valve (which then brought the reading on the low pressure gauge to 0). I repeated this process twice and obtained the same result.
My thinking is that this means the leak is in the high pressure portion of the regulator, so it’s either the connection between the reg stem and tank, the connection between the reg stem and body of the reg, or the connection between the high pressure gauge and body of the reg.
I believe my experiment shows that the low pressure part of the reg (pressure relief valve, low pressure gauge connection, pressure control knob, and valve leading to the manifold) are not leaking.
Does that seem logical? I’ll try to verify the source tonight using soapy water.
I’ve tested all the other parts of the system, and this seems to be the only one that won’t hold pressure overnight once the gas has been turned off.
It seems to me that you could have have a leak anywhere at or upstream of the valve between the regulator and the gas manifold. My experience with my regulator is that the high pressure gauge will read 0 when it couldn’t possibly be less than the psi reading of my low pressure gauge.
The one time I had a leak it was along the stem of the tank valve. I tightened the nut at the top handle and the leak stopped.
There is a poppet between the tank high pressure and the diaphragm regulator. If the high went to 0 with the tank off, the leak is on the high pressure side. Make sure the regulator to the tank valve fitting is tight and the washer is good. Once I had to tighten the high pressure gage on a regulator to stop a leak.
It is my understanding that some regulators don’t require the washer to seal to the tank.
Maybe I’m all goofed up, but I’m pretty sure I read this somewhere.
I have one regulator where it leaks if you use a washer and does not if you don’t. There is a small rubber washer built into the regulator stem that screws to the tank.
Some of them are definitely built differently. Mine has a “Built in CO2 resistant, long lasting solid Nylon inlet seal” - which is part #14 in the diagram on the replacement parts tab of webpage below.
The slightly less expensive version that Micromatic sells has a “Quad-Ring inlet seal at tank connection” - which is part #14 in the diagram on the replacement parts tab of webpage below.
I tried the test on a different, brand new regulator and the same thing happens (high pressure gauge slowly goes down to zero when the gas is turned off and the output valve between the reg and the gas manifold is also shut).
Now I’m not sure if this is indicative of a leak or if it’s normal regulator behavior.
Would someone mind trying this out on their system and letting me know if they get the same result? I’m going to lose my sanity.
The obvious culprit would be the reg not sealing properly at the connection to the tank, but it would be odd for that to happen on two different regs and on two different CO2 tanks when I’ve never had an issue with it in the previous six years.
I think that may be flawed logic. There is a tiny amount of gas in the high-pressure part of the regulator. If there is a leak in the low-pressure side that draws the pressure just below 14psi, the regulator will allow gas to flow from the high pressure to the low pressure side to maintain pressure. That will quickly deplete the gas on the high pressure side. Assuming its a slow leak the pressure could still be close to 14 on the low side.
Does your regulator have a valve on the output? I’d repeat and turn that off so see if the problem is in the regulator or elsewhere.
Cool, thanks again. I hope I can return the favor sometime.
You are right, and I thought about that, but I let it stand for a full day, and the low pressure side was still pressurized. I did have the output valve closed.