nitrogen while brazing?

[navyguy1]

So I finally got on board with running nitrogen through the lines while brazing but im wondering about all the R410A systems Ive installed over the last few years that I didn't do that. So far I haven't had any problems after a good 5 years. Will this eventually come back to haunt me? If not then why is running nitrogen while brazing necessary? I always install a filter drier in my new systems even when a lot of installers Ive seen do not. Is the drier keeping the carbon particles out of the system?

Thanks

[Spitz]

With 4 to 6 joints on a resi system and 2 of them after the drier you probably wont have a problem. POE oil acts as a solvent and cleans the oxidation way more than MO. So purging a system with POE is more important. If you haven't seen issues in the first weeks or months of systems running you are most likely in the clear. That's just my opinion.

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[Saturatedpsi]

If not then why is running nitrogen while brazing necessary?

Thanks

There's no telling how many systems were and are, brazed up without nitrogen purges; and as you noted from past experience, it isn't necessarily an absolute "must do".

But we know for certain, without an inert gas environment, there will be some oxidation of the copper that could create a problem...at best it's producing some crap that will remain in the system forever.

It's not unlike pulling a true 500 micron vacuum with a micron gauge, versus pulling a 30 minute, 29.9" vacuum with a manifold during the lunch break, or measuring superheat by "beer-can-cold"...

It's simply a matter of following "best practices"...we know the best way, the right way to do stuff. Doing anything less, is less than professional. I would venture to guess, you'd rather your customers consider you the consummate professional.

And sooner or later, you'll be rated against the last tech or the next tech. The impression you want to leave with the HO is, you were the best. No telling how many service calls I've been on where the HO was watching and said, "That other guy didn't do all that stuff."

[Bazooka Joe]

Maybe one reason those Installers do not install field driers ( on new installs ) is because some brands already install them inside the condensing units at the factory, ( talking residential split ducted units mainly )

[71CHOPS]

There's no telling how many systems were and are, brazed up without nitrogen purges; and as you noted from past experience, it isn't necessarily an absolute "must do".

But we know for certain, without an inert gas environment, there will be some oxidation of the copper that could create a problem...at best it's producing some crap that will remain in the system forever.

It's not unlike pulling a true 500 micron vacuum with a micron gauge, versus pulling a 30 minute, 29.9" vacuum with a manifold during the lunch break, or measuring superheat by "beer-can-cold"...

It's simply a matter of following "best practices"...we know the best way, the right way to do stuff. Doing anything less, is less than professional. I would venture to guess, you'd rather your customers consider you the consummate professional.

And sooner or later, you'll be rated against the last tech or the next tech. The impression you want to leave with the HO is, you were the best. No telling how many service calls I've been on where the HO was watching and said, "That other guy didn't do all that stuff."

Very well said!

Any oxidation you see on the outside of the pipe, that wipes off with a rag.....is also on the inside of the pipe.

Depending on the amount of oxidation and size of the filter drier, you can begin to partially restrict a brand new drier.

[knave]

Off gassing refrigerant works almost as good as nitrogen.... and you get a side of phosgene to boot...

[itsiceman]

Uh-oh

[knave]

Uh-oh

lol

[BBeerme]

.

[knave]

Howdy D.R. Beer

[knave]

There ya go, now I’m gonna leave it

[Core_d]

I think tricking nitro while brazing also helps with the evacuation so its really a win win.


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[BBeerme]

Hey hey hey now, who told you that you could address me like that? We don't know each other.

It's either Dr. BBeeme, or Dick Rookie BBeerme.

After we drink a beer together, you may address me how ever you want.

Howdy D.R. Beer

[knave]

Hey hey hey now, who told you that you could address me like that? We don't know each other.

It's either Dr. BBeeme, or Dick Rookie BBeerme.

After we drink a beer together, you may address me how ever you want.

Haha, we’ve met before, I’m just not a frequent poster... but ok then lol

[Mike19]

Off gassing refrigerant works almost as good as nitrogen.... and you get a side of phosgene to boot...

ethm

[BBeerme]

I remember your avatar and username, just not any interaction. Must be the beer. Speaking of which, I need another.

Haha, we’ve met before, I’m just not a frequent poster... but ok then lol

[BBeerme]

Glad you picked on the humor. Sometimes others don't, and take offense where none was given.

[VTP99]

He correct about the out gas on service work. Been there done that many times.
Just gotta leave a path of exit.

[Rainman3400]

I've heard stories from some of the other techs I work with about TXV getting messed up because of no inert gas brazing being done during install. I figure since I pressure test for leaks anyways, why not just having the nitrogen trickle while brazing.