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View Full Version : To flare or not to flare?



worthington
19-01-2002, 12:52 AM
has anyone any comments on the latest "fad",ie using sweated components instead of flares?
i can see from a manufacturing point of view why this would be done(cheapness,ozone friendlyness etc) but from a service point of view its a bloody nuisance.
in my experience there are few flare failures that cannot be attributed to poor standards or just sheer lazyness.the usual reasons are
1.an incorrectly formed flare in the first place
2.an overtightened flare nut
3.poor standards by the engineer replacing a component,who doesnt remake the flare.so it work hardens and fails.
4.unsecured or poorly secured pipework . so that the flare fails ,again due to work hardening.
5.failure to apply any lubricant to the flared end,thus causing abrasive wear and eventual failure
all of the above are due basically to poor standards.
am i the only one concerned about the abysmal standards of the majority of service staff?
before anyone thinks that im some chair bound desk wallah,i am and have been for many years a service guy at the sharp end!!

Prof Sporlan
19-01-2002, 02:33 AM
The Prof doubts Hamlet would have pondered this question... :)

No doubt the ubiquitous 45 SAE flare connection is destined for obsolescence. Very few OEMs are purchasing refrigeration components with connections other than solder type, with the exception of residential a/c and heat pump systems. Here, the short tube restrictor usually employs a threaded connection.

Other mechanical connections have been used with refrigeration components in the past, e.g., Swagelok, Rotolock, solder and threaded pipe flanges, 37 SAE flare, and various face seal threaded fittings. It's a problem where mechanical fittings that are more effective and foolproof tend to be much more expensive that solder connections.

subzero*psia
19-01-2002, 04:41 AM
Personally, I would rather use a sweat connection. If I sweat the connection I know I have greatly reduced the chance of a leak. I also think that sweat connects are much faster than flare connects not to mention the added costs associated with storing different size fittings and types of flare fittings for each application one could come across.

Just my opinion though... not saying it isn't just as good or even better in some instances. I use flares only where I have to though.

Abe
19-01-2002, 08:01 AM
I prefer sweat or solder fittings any day over flare type
I know the join is leak tight.
Flare is old hat
You try and get an engineer in the "field" who has a tea break and cigarette on his mind, whilst he is working in the wind chill to sit down and methodically redo flare, lubricate, etc, etc
No ways

Dan
19-01-2002, 06:39 PM
The fewer mechanical fittings you have, the better. The larger the refrigerant charge the more costly mechanical fittings become.

I do supermarkets. 15 years ago, a typical supermarket would have upwards of 500 flare fittings. Refrigerant was not only non-political, but also inexpensive.

Today, there is social responsibility as well as significant cost of refrigerant to deal with.

Today, you will see valves with fewer pilot lines, for example, simply because it reduces a fitting.

Any time one uses a wrench to remove something from a refrigeration system, he or she should use a torch to put in its replacement.

I feel rather strongly about this after years of being stubborn.:)

Dan

Rick Harris
05-05-2002, 07:10 PM
It seems funny talking about flares when most of the apprentices I see today could not form one to save their lives.Where I work hot works permits are like hens teeth so we have to flare,or more commonly use the Lock-ring system which although is a mechanical joint is the best thing I have ever seen outside weldingHas anyone else used this system?

freezetech
05-02-2010, 11:29 PM
yes we use this system why use anything else been using it for a while now oand not one falure absolutly brilliant

Colin G
05-02-2010, 11:33 PM
i hate doing flares, i dont mind using manufactured ones you get with split systems but when it comes to expansion valves and the like i would rather take the extra effort to do a brazed joint. I feel a manual flared joint is a weak link and im sure some people out there would go as far as to ban them from certain installs.

coolhibby1875
06-02-2010, 11:58 AM
i like to use flares at the drier, for ease of changing it on ppm's, but on everything else soldered joints are a must!

El Padre
06-02-2010, 04:37 PM
i like to use flares at the drier, for ease of changing it on ppm's, but on everything else soldered joints are a must!


Could'nt agree more, we used to change driers on a major service visit.

Cheers

monkey spanners
06-02-2010, 05:25 PM
I've changed to fitting brazed in components now after resisting the change for a while. Having a decent brazing torch helps, now i've got an oxy kit with a pepper pot burner on it :cool:

I used to like those t flow drier and sightglass combinations as you could braze them in and the drier just screwed on below with an o ring to seal.

It needs some enterprizing manufacturer to make a rotalock drier, surely it wouldn't cost much more to machine than a flare one. Just the pipe fittings to buy and install.

djbe
08-02-2010, 12:51 AM
I've changed to fitting brazed in components now after resisting the change for a while. Having a decent brazing torch helps, now i've got an oxy kit with a pepper pot burner on it :cool:

I used to like those t flow drier and sightglass combinations as you could braze them in and the drier just screwed on below with an o ring to seal.

It needs some enterprizing manufacturer to make a rotalock drier, surely it wouldn't cost much more to machine than a flare one. Just the pipe fittings to buy and install.

But O ring driers are already available. Us transport guys have been fitting them for years. Most transport equipment now uses O ring or sweat. Flare is dark ages, to be honest the only bit that worries me when I have to do my C&G 2079 is doing a decent flare when I wouldn't bother in the real world.

monkey spanners
08-02-2010, 01:20 AM
But O ring driers are already available. Us transport guys have been fitting them for years. Most transport equipment now uses O ring or sweat. Flare is dark ages, to be honest the only bit that worries me when I have to do my C&G 2079 is doing a decent flare when I wouldn't bother in the real world.


KMP stopped making or possibly importing their t flow driers into the uk, what make are you using and where are you getting them from?

I think valcon also made them but again none of the wholsalers near me stocks them :confused:

Come on Sporlan or Danfoss, fingers out of a*ses time :p

djbe
09-02-2010, 09:44 PM
Yeah you are right about KMP they stopped making the 'T' flow.

Valcon are available, but it depends on your supplier. We get them O.k.

Both Carrier and Thermoking use 'O' ring type driers now, these are not T flow but "straight through" and dimensionally the same as their previous flare type. i.e 303 'O' ring is the same size as 303 flare.

I believe they are made by Danfoss and have seen some made by Emerson, but they are seemingly impossible to get over the counter at somewhere like Dean & Wood.

Bones74
16-02-2010, 02:07 PM
I don't care how long it takes. I prefer sweat because of the contraction issues and they will always leak. I tell my guys the same thing. There may be a few different opinions here is your refrigerant costs $1600.00 for 8 ounces.

frosty74
13-03-2010, 08:36 PM
i prefer sweated driers i only fit flared if i really have to also sight glasses etc.