Leaky Flare nuts on mini-split refrigerant line.

[heater99]

I was wandering why mini splits use flare connections. I find them to be less reliable than soldered connections. Has anyone ever soldered the entire flare connection and nut assembly together?

[STANCILHVAC]

I was wandering why mini splits use flare connections. I find them to be less reliable than soldered connections. Has anyone ever soldered the entire flare connection and nut assembly together?

I have put some of those mini splits in and had no problems at all with the connections---used to have some problems with the older units that used the quick connect fittings but not the new mini splits---if i could not get it to stop leaking ,i would cut the connects out all together and braze the lines like that--i would not try to braze the entire nut?But to each his own if it works---but no i myself have never even seen that---thanks

[jpsmith1cm]

I've seen all three. Flare, QC and solder.

I prefer solder, followed by flare.

A well made flare will not leak, even after years of service.

Even so, why any manufacturer would use flares today is beyond me, but I'm not a manufacturer, I'm just a dumb tech.. :D

I would not solder the entire connection together, even if it is possible. Think about what happens if anyone needs to disconnect it later. They will swear at you.

As I said, flares can be a very reliable way to join lines. I've seen flare connections over 20 years old, in service daily that didn't leak.

Are you making the flare right? Deburr the tube? Oil the fitting? Did you overtorque and crack a flarenut?

If you are insistent upon soldering something, cut the connectors away and solder straight pipe in.

[ball a/c]

We have been told by one manufacturer that the flare fittings are different than what we normally use. It even takes a different flaring tool. Saying that, we have still always use the nornal flare tools and haven't had leaks. I 've always liked the flare fittings, if they are made properly.

[beenthere]

A flare fitting done right, won't leak. They're very reliable.

Use oil when making your flare, and tightening the fitting.
Helps to prevent splitting.

[cmajerus]

Notice on the flare nuts that are on the equipment from the factory are heavier than the ones that are on the linesets. They tell you to reflare both ends of the lineset and use the nuts that come with the equipment, or you may have leak problems.

[DeltaT]

The original mini splits made long ago were typically made in Asian countries and used there. And that is still true today. Dailin was one of the first over 20 years ago.

They are terrified of fire because of all the raw flamable building materials they use in building. Plus they just don't have the fire suppression systems we have.

So they pretty much built these put together systems where no open flame had to be used.

[agit8er]

Ever wonder why split systems that are still out there 30-35 years still run?
Old Carrier, flare connections. Old Trane,GE, pre-charged line sets.
Point is..... Keep the torch away and the components are quite happy. I talked to a service rep for Mitsubishi and asked this exact question. Obviously, flare connections make for easy unit service however Mitsubishi claims a very low return on failed components. Burned up txv, torched service valves and contamination in ref lines caused by not using nitrogen can't happen with a properly formed flare.

[hvacdoctor]

Ever wonder why split systems that are still out there 30-35 years still run?
Old Carrier, flare connections. Old Trane,GE, pre-charged line sets.
Point is..... Keep the torch away and the components are quite happy. I talked to a service rep for Mitsubishi and asked this exact question. Obviously, flare connections make for easy unit service however Mitsubishi claims a very low return on failed components. Burned up txv, torched service valves and contamination in ref lines caused by not using nitrogen can't happen with a properly formed flare.

agree 100% Lg REP told me no brazing because likely hood of contamination increase with r410 systems. Oil is very absorbant so less is better. IF you use a special 410 system flare tool you should never leak. if so cut it back and re flare. :rolleyes:

[riderman]

IF you use a special 410 system flare tool you should never leak. if so cut it back and re flare. :rolleyes:

hvacdoctor, can you explain this special 410 system flare tool? I own several flare tools, I never heard of this 410 flare tool. What is the difference from a regular good quality flare tool and a 410?

[riderman]

hvacdoctor, can you explain this special 410 system flare tool? I own several flare tools, I never heard of this 410 flare tool. What is the difference from a regular good quality flare tool and a 410?

Anybody have an answer?

[beenthere]

I think the angle is 60° istead of 45°.

[clokwork76]

yeah just be sure to put a little oil on that fitting... installed a few of these only had a problem with the fist one i ever did and thats cuz i overthightened and cracked the flare nut... i my experience it's been a good joint...

[hivacer]

No, the flare is 37.5 degrees instead of 45, and I would rather underflare a little than overflare it, because too big of flare you have to ripple it back down to get it to not leak, anyway a 410A FLARE is 37.5 degree and requires a special flaring tool. www.yellowjacket.com/HVACRProducts.asp?t=HVACR&l=9&c=84&p=188

[barty]

My understanding is that the big *Japanese manufacturers are about to go away from flares and to brazed connections.

However as it stands we often cut off the indoor flares to reduce potential leaks plus where the pipes pass along the bottom of the indoor case to reduce the bulk or out the back through the wall (our walls tend to be 2 brick + cavity) so the 'flare' would be in the hole as it were

Cheers

Richard

*I heard it about Daikin but they never act alone