Micro Matic Nitrogen Regulator Question

[Aqualab]

Hi,
I have an older Micro Matic nitrogen regulator that I probably haven't used in maybe 10 years or so, switched over to CO2. I am now setting up a kegerator for Guinness and want to use the nitrogen regulator again. It's well made and I never had any issues with it. But it looks like the o-ring that goes on the stem to the bottle is missing. I can't remember for the life of me if there was one on it before, I imagine there had to be one? Micro Matic is asking all kinds of questions age, etc.) and want me to buy a new regulator. Not sure if the fitting is CGA580 or not. If not, can I replace the stem only and would any major brand stem piece fit? Any help would be much appreciated.

Thank You

 

[day_trippr]

Your Micro Matic regulator has a CGA 320 stem. And it is indeed missing the O-ring at the tip. It normally would be "trapped" by the hex screw at the tip. I have a Taprite CO2 reg with a CGA 320 stem that also uses an O-ring like that, but you can (and I have) get by in a pinch using a standard nylon or fiber washer. In any case I expect the part you need is this: https://www.micromatic.com/en-us/ptfe-inlet-seal/p-kfqTWN8cNk6et23nP_jQpQ

I have a Micro Matic primary reg for my beer gas cylinder with an actual CGA 580 stem, and it has a different style O-ring: https://www.micromatic.com/en-us/o-ring-for-nitrogen-inlet-stem/p-6y2ezZvuJUiWqDPw68jPCQ

Cheers!

 

[day_trippr]

re: replacing your CGA 320 stem with a CGA 580 stem

Micro Matic "nitrogen inlet stem" uses a Left Hand Thread (not atypical of high-pressure side plumbing, I think Taprite does the same).
Their part can be found here: https://www.micromatic.com/en-us/ke...rogen-inlet-stem-lht/p-nMrCicJPHESDT2qUxFehZw

You'll also need their "nitrogen regulator tank nut": https://www.micromatic.com/en-us/inlet-nut/p-2Xk7aNPp_EyQKKSxXL6Dsg

Don't know if the captive O-ring is included in all that, so best to buy a couple: https://www.micromatic.com/en-us/keg-beer-o-ring-for-nitrogen-inlet-stem/p-Cxv93TxwZU-cv7hZlz2rrw

Note you could use any 1/4" LHT CGA 580 coupler...

Cheers!

 

[Aqualab]

Thank you day_tripper, I appreciate the information and clarification! I was starting to go nutty wondering what I had. Do you know if I can just replace the stem/coupling to a CGA 520? It is probably the simplest way to correct my situation since it's missing the O-ring anyway. So were the old nitrogen bottles fitted with male CGA 320 fittings? When did they change the standard? Thanks again!

 

[Aqualab]

Our last messages crossed, thanks for the links!

 

[day_trippr]

Apparently it is not illegal to fill a CGA 320 valved cylinder with nitrogen gas, or a beer gas blend. So it's not uncommon to find CGA 320 stemmed regulators being used for beer gas, although I'd be surprised if my local AirGas outlet would go along with all that these days...

Cheers!

 

[Aqualab]

I just ordered the stem, nut and 2 O-rings from Micro Matic. Should be all set now. I'm thirsty after all this! Thanks again!

Bill

 

[whoaru99]

I just ordered the stem, nut and 2 O-rings from Micro Matic. Should be all set now. I'm thirsty after all this! Thanks again!

Bill

Don't know where you live, but around here auto parts stores, fleet/farm type stores, ag/implement dealers, etc., all have oring assortments where odds are good there'll be one that works.

 

[Aqualab]

Thanks whoaru99 for the suggestion. I went ahead and ordered a new stem, nut and associated O-ring from MicroMatic since the fitting on my regulator is a CGA-320 which is probably no longer fillable and the nitrogen tanks are all CGA-520. Easy fix.
Bill

 

[whoaru99]

I'd read you ordered a different CGA nipple. My comment was more of a FWIW/FYI type of deal if someone is looking for orings.