# Where is my CO2 leaking? And oh check valve?



## LTPGuy (Aug 8, 2012)

Here's a photo of the regulator...










Noted that I replaced the safety release valve with a stop valve. The safety release starts to engage at around 25 psi.

Short of dunking my setup in the bathtub, I cannot find any leak with soapy water. I've sprayed, soaked, dripped soapy water in every conceivable cracks and crevices, and I could not detect any leak.

With all of the valves closed, high/low pressure gauge show 950/20 psi respectively. After a few hours, both gauges indicate zero. I am trying to determine how long for the gauge to go down to zero.

Is this normal, or is there a leak in the regulator/valves setup?

Check valves. I didn't want to spend $25 on a Dennerle valve so I used a regulator air valve. It appears to work, but with the co2 shutoff, the water start to very very slowly creep up the tube toward the valve and eventually pass the valve.

My thought is that the CO2 in the line is slowly dissolving in the water, and the water is being sypphon up the tube as the co2 dissolves.

Anyone observes similar behavior with their cheap/high end valves? I am asking because I wonder if a co2 check valve is useful or necessary?

Thanks in advance.


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## Bigdaddyo (Jan 23, 2010)

Here's my opinion. Doesn't sound like you have a solenoid. If you turn your gas flow off at the valve on the tanks the pressure will slowly dissipate in your system (throught the water). You then have a vacuum and water will syphon back through your C02 lines. Get a check valve.


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## Darkblade48 (Jan 28, 2008)

LTPGuy said:


> Noted that I replaced the safety release valve with a stop valve. The safety release starts to engage at around 25 psi.


You replaced the pressure release valve with a plug?

I just want to be sure. This is not exactly the best idea, as the pressure release valve is designed to be a safety feature in case the pressure gets too high (and you have effectively removed it).



LTPGuy said:


> With all of the valves closed, high/low pressure gauge show 950/20 psi respectively. After a few hours, both gauges indicate zero. I am trying to determine how long for the gauge to go down to zero.
> 
> Is this normal, or is there a leak in the regulator/valves setup?


I suppose that you are opening (and then closing) the main CO2 cylinder valve (since both gauges drop to 0 PSI after a few hours).

I suppose you removed the flow valve that was originally attached to the regulator as well (and have attached a post body kit or at least plugged it?) That could be a potential point of leaking if it was not done.

Another possibility is that your plug for the safety release valve is not tight (not enough teflon tape, not tightened enough, etc).



LTPGuy said:


> My thought is that the CO2 in the line is slowly dissolving in the water, and the water is being sypphon up the tube as the co2 dissolves.
> 
> Anyone observes similar behavior with their cheap/high end valves? I am asking because I wonder if a co2 check valve is useful or necessary?


The creep that you describe is due to the reasons you mentioned. I find that cheap plastic check valves will allow water back through, slightly more expensive ones are better, but will eventually let water through (around 6 months). There are some cheap brass ones that are OK for about a year.

If you don't mind replacing the check valves on a regular basis, then you can get the cheap ones (which is what I do).

Check valves are important to prevent water from flowing back into your needle valve/solenoid.


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## LTPGuy (Aug 8, 2012)

Yes Darkblade, I replaced the SAFETY pressure release a with effectively a plug. This is not to be mistaken for the burst valve at the tank side. 

The safety release is on the low pressure side, and the only failure mode I see is that the diaphragm failed somehow, and thus bypassing gas from the high pressure straight through.

As the low pressure side is not connected to any pressurized container, gas will simply be released into the atmostphere or burst the airline at worst.

I'll replace the safety valve when connecting my tank to a pressurized setup on the low side - ie a kegerator!



I assume by flow valve you mean the valve with the red handle in the photo. That valve is still attached.

On our comment, I rechecked all of the joint paying more attention to the flow valve. Sure enough, there was a super small leak where the valve is mounted to the regulator body.

The valve came attached, and apparently it was lock-tite or sealing compound was used. 

It was a pain to loosen, but when taken off, the nylon gasket was missing. The gasket was not missing on the safety release side.

I was told by the guy who refill my CO2 that you should not use teflon tape as it can get lodge in the regulator and damage it. It is also not a very good seal, and that a gasket much like one used between the valve and the CGA nut.

I am going to see if I can pick up a gasket from hd or somewhere local. Else I'll have to order one online.

I hope this is the only source of the leak.

Thanks for making some suggestions.

BigDaddy, I am using a check valve, it's just not very good. I was hoping to hear if anyone else observe this creep up the airline toward the check valve and pass it on the more expensive valve.


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## Darkblade48 (Jan 28, 2008)

LTPGuy said:


> Yes Darkblade, I replaced the SAFETY pressure release a with effectively a plug. This is not to be mistaken for the burst valve at the tank side.
> 
> The safety release is on the low pressure side, and the only failure mode I see is that the diaphragm failed somehow, and thus bypassing gas from the high pressure straight through.


Well, safety devices are there for a reason. I would not recommend that you replace the safety pressure release valve (on the regulator) with a plug, but...



LTPGuy said:


> As the low pressure side is not connected to any pressurized container, gas will simply be released into the atmostphere or burst the airline at worst.


If your diffuser gets clogged, a dangerous situation could arise.



LTPGuy said:


> I assume by flow valve you mean the valve with the red handle in the photo. That valve is still attached.


You can remove that if you want.



LTPGuy said:


> The valve came attached, and apparently it was lock-tite or sealing compound was used.


A good pipe wrench along with a bench vise (optional) will do short work of taking it off.

The flow valve is not really needed, and as you can see, can cause headaches when trying to troubleshoot.



LTPGuy said:


> It was a pain to loosen, but when taken off, the nylon gasket was missing. The gasket was not missing on the safety release side.


This is normal. I have never seen a flow valve that has a nylon gasket/washer between it and the regulator.

The safety release valve is slightly different for each regulator; I have seen some with a gasket, and some without.



LTPGuy said:


> I was told by the guy who refill my CO2 that you should not use teflon tape as it can get lodge in the regulator and damage it. It is also not a very good seal, and that a gasket much like one used between the valve and the CGA nut.


I am not sure what the technician is telling you. Teflon tape cannot be used on the cylinder to CGA320 nut connection. Only a nylon washer can be used here.

Everywhere else, teflon tape or pipe compound can be used, with the exception of the high pressure port (the port that the CGA320 nipple screws into) - this connection must use teflon tape.

The only way teflon tape will get into the regulator and damage it is from the high pressure inlet. All other points have gas flowing past them (away from the regulator).


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## LTPGuy (Aug 8, 2012)

OK Darkblade, the safety release is back on the low side.

I bought a teflon washer from CT (in the plumbing section) for the flow valve, and the high pressure gauge hasn't budge for a day and a half! No tape or goop.

BTW, the flow valve has a check valve built it! I guess it makes sense for Kegerator equipment.

Thanks for help troubleshooting.


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