Nitrogen bleed in production brazing

[icemeister]

It's been quite a while since I've had an opportunity to visit a refrigeration production facility, but one thing that sticks with me is that I never observed any provisions for nitrogen flow while brazing. Like, what's the point in taking all that care in piping up a system if all the coils and units are full of black cornflakes?

I went through the operation at Phoenix in Conyers, Ga maybe 15 yrs ago and they were using some kind of new inert gas shielded brazing deal. Is that common today? I dunno and I'm a little out of touch.

I'd just like to know that the stuff we buy is put together as carefully as when we here in the field go to install it.

[frozensolid]

Good question ice.

I have seen quite a few Hill houses, that come prepiped to the floor penetration. When they are cut open to attach the risers. The end cuts look like little copper oxide ash trays.

[refer dude 2479]

When I worked for Hussmann in the early 80's they were still manufactureing in San Jose. Never once saw a nitrogen purge when they were building up the header packages for the TD. I do not think that the other manufactures do either. Tyler equipment that I installed was the same as frozen mentioned. Flake in the stubs at the drop out of the sheds. Only ones that get nailed are the installing contractors in the field.

[refer dude 2479]

Another brain fart.

I do mainly HVAC now. Just got through installing some big air handlers that were set up as split system refrigeration. Manufacture mainly does chilled water coil air handlers. Coils looked like chilled water coils, complete with purge plugs at the top of the headers. Yep you guessed right....

when we cut the lines to connect the refrigerant lines to the cond unit we got water. Had a lot of fun drying that system out before chargeing.

Factory said..."Yeh we hydrostatic test every coil we make to ensure that they are tight....."

Wow experiance something new every day....

[icemeister]

These are the types of responses I kinda expected.......then I really wasn't dreaming about this.

We should protest. In the market biz, the chains purchase all of this equipment direct from the manufacturers like Hussmann, Hill-Phoenix, Tyler, etc and don't require them to hold to the same specs as in the field.

Of course in reality, any contractor who would refuse to tie into a rack system full of crud like that probably wouldn't be doing markets much longer.

[frozensolid]

True ice. I always brought it to the attention of the market people. Then I would note it and move on.

Having gone through the trouble of flowing nitro everywhere, to provide a clean system. It just hurts a little, when you tie into stuff like that.

[cynic]

Called Baltimore Air Coil about an evap condensor being full of crud,,, their response was you should change the driers after its run awhile.

[icemeister]

Originally posted by cynic
Called Baltimore Air Coil about an evap condensor being full of crud,,, their response was you should change the driers after its run awhile.

There you go. That's what we're dealing with out there with all of this stuff.

NO N2.....FU!

[hvacmd2002]

I know of two large chains here in NH that refuse to run nitrogen when piping a market. They just change the suction filters and LL driers a few times after start-up.

[clydemule]

A coil mfg in Los Angeles that I buy stuff from uses natural gas while they braze the return bends.

They say it is a great backup gas and is way cheaper. There is a little yellow flame like a bunsen burner on the coil while the guy brazes.

The outfit I used to work for kind of purges. Every assembler has a nitrogen setup where he blows out an assembley before brazing, but it is not a constant flow or capped so it probably doesn't do much. The only adavantage is that it is better than blowing it out with compressed air after brazing and before capping.

Our evaporator assemblies (big tube bundles dropped in a stainless water tank) were always hydro tested and then baked in a big old oven to dehydrate them. That isn't done anymore.

Clyde

[refer dude 2479]

Originally posted by icemeister

Originally posted by cynic
Called Baltimore Air Coil about an evap condensor being full of crud,,, their response was you should change the driers after its run awhile.

There you go. That's what we're dealing with out there with all of this stuff.

NO N2.....FU!

yeh i like that.... we just make this crap. you have to install and make it work.... not our problem.... oh by the way we are working on your customers to get them to spec out stuff....

[freon500]

Still,...how about the smaller units with cap tubes? Would you skip the nitro,...? Might be bad luck!

[R12rules]

I my old friend Nate Fergusen were still living, he'd tell of stories piping markets where they got micro leaks from the N2 bleeds.
Now this was just on the runs, not necessarily the raks or machione set ups themselves.
Back in some of his stories, they had two compressors. One for hi and one for lo temp work. Those were some crazy markets he used to say.


But with all their creativity, they still got leaks once in awhile due to N2 bleeds while brazing the lines.



I liked his stories about sulfur dioxide too. Nate was pretty old .... But I dont think he ever worked in your area Dice, otherwise you'd have mentioned knowing him.... right? ;