# CO2 regulator to CO2 tank connection washer



## TWood

I recently installed a refilled CO2 tank with a new washer. It had a slow leak at the regulator/tank connection that was stopped by -really- tightening the nut. The other day the CO2 ran empty way before its time. Knowing how tight I had it, I was surprised when the fitting came loose easily. The only way that could happen was if the new washer compressed and made some space to loosen the connection. Are there different types/grades of washers to correct this?

Thanks,

TW


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## QuantumCranker

CO2 will degrade normal rubber/plastic pretty quickly sometimes. I have been using Gas grade (always yellow instead of white) teflon tape around the threads for a couple years now with no washers with very good results. If you feel you must have a washer, make sure it's nylon,teflon, or fiber. Also, the metal "crush" type washers work very well.







They are round instead of flat and look like an o-ring but are metal....usually copper.


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## TWood

It was provided by the gas supplier, looks like black fiber of some sort. The original was white nylon I think. 

TW


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## MatPat

Hey Tom,

For what it is worth, I have seen it suggested to go back and re-tighten your regulator to tank connection a day or so after you initially put it on the tank. I forget the exact reason why but it had something to do with expansion/contraction of the tank as it heats up after refilling???

I don't know if this method works or not as I have not had any problems (yet) with my regulator/tank connection leaking. I use the fiber washers also!


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## TWood

Thanks Matt,

I did just that - re-tightened it a day or so after the initial installation. The tank itself wasn't a fresh refill, so temperature didn't play into it. I think there's a limited rebound in the structure of the cheaper washers.

TW


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## Salt

The washers that usually come with the regulators are #111 o-rings.

I swap my CO2 tanks out. I've also bought several regulators. The design of all of the regulators and all of the tanks I've used so far is identical. And in that design, setting one o-ring into the regulator does absolutely nothing. When you tighten the connection, bare metal will make contact against bare metal, and the o-ring will not make any contact:










Now this might work if there was a raised metal ridge on the tank's connector. But I have yet to get a tank where the connector isn't just flat.

I solved the problem by installing a _second_ #111 o-ring, like this:










Now, as a general rule, doubling o-rings is a bad idea. But in this case, there's two things at work that make this safe: one, there is a sturdy circular connection completely filling the inside of both o-rings; and two, once the metal makes contact, compression stops. So we've eliminated the two main dangers with o-ring doubling: displacement, and crush.

I've used the same o-rings this way for years now. No signs of stress or damage.

I also don't use the o-rings that come with the regulator. They are probably fine, but, I don't know what material they are made out of. I prefer to use Viton. You can get them from allorings.com.


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## TWood

That's not the standard CO2 fitting.

TW


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## thatguy

yeah, that looks like an asian or euro style co2 regulator..... i had one like that, i had to grind down the inner flange to fit US co2 tanks.


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## Laith

Don't think its European. The o-rings on my regulators fit in a groove where the smooth metal flange is in these pictures.


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## thatguy

most US regulators dont use o rings they use a washer. there is no flange at all on the regulator, it is completely flat as is the face of the co2 tank valve. Euro and asian regulators seem to have flanges and the co2 tank valves have a recessed hole for the inner flange.

thats why salt has to use 2 o rings, so that his regulator face can be set flat against the co2 tank valve and not have metal to metal contact.


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## thatguy

here is a pic of an asian style co2 tank. see the inner hole in the face of the tank valve. the o ring on the regualor above can fit the lip of that valve...and the inner flange will go inside that hole.


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## Salt

*All* of the regulators I get are like the ones I pictured. Over the years, I've bought from Marine Depot, Drs. Foster & Smith, Aquarium Landscapes, & Florida Driftwood.

The regulator in the pics is an M3 regulator that was purchased recently from Marine Depot.

These vendors must all be selling regulators that are made in Europe or Asia.

This might explain why some people get leaking and some don't.

For people with regulators without the raised center, where are you getting them?


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## thatguy

id post a photo of my regulator, but I dont want to take it off the tank now.. but i believe the jbj regulator is flat as well as my friend has that and ive seen it.


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## TWood

The M3 (Marine Monolith Monsters) regulator I bought several years ago has the flat face connection. Actually, the face looks a lot like the face of the tank connection - flat with a circle around the port machined into the metal. Another one I bought from a local gas supply company was labelled as a "beer regulator" and I think it's a Clippard.

TW


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