Flaring

[cikku]

I've read that oil can be applied on the flare part prior tighten the nuts for any refrigerant leakage. My question is, the oil applied to the flare part will be any given oil or one compatible with the refrigerant in the system?

[chillin out]

I've read that oil can be applied on the flare part prior tighten the nuts for any refrigerant leakage.
Putting oil on the flare will not prevent it leaking, what it will do is act as a lubbricant to stop the pipe turning when you tighten the nut. Thus stoping the pipe twisting.


Chillin:) :)

[chillin out]

My question is, the oil applied to the flare part will be any given oil or one compatible with the refrigerant in the system?
Any old oil will do.

Your not actually putting oil inside the pipe, but on the back side of the flare.


Chillin:) :)

[Peter_1]

Putting oil on the flare will not prevent it leaking, what it will do is act as a lubbricant to stop the pipe turning when you tighten the nut. Thus stoping the pipe twisting.
Chillin:) :)

Wow Chillin Out, that's new for me.
So you put oil in the inside of the flare and it stops twisting then :confused:

The better contact there is between flare and connection, the more difficult it will be that the flare will rotate together with the nut (or twisting the tube)
If you lube it, then there will be less contact and it will twist much easier should I think.

We all know the phenomena when we have soldered the tube very close to the flare and we tighten the flare afterwards: the tube starts twisting.

How do you prevent this? Adding oil on the inside of the flare doesn't prevent this. Try it once.

[US Iceman]

Putting oil on flare nuts is new one for me too. I have never used oil on these connections.

If the tubing is twisting I see two problems:

1) The flare joint is leaking, so someone tries to tighten it to seal the joint, and the tubing twists.

2) The flare joint is not properly made and leaks.

There is a proper sequence for flaring. It looks simple when you see someone do it, but it does take practice to make a good flare joint leak tight.

If anything, you can use Leak Loc (the blue stuff) on the threaded portion of the flare fitting to hold it tight. They do sometimes tend to loosen up from continuous expansion and contraction (heating and cooling) and vibration.

These are essentially compression joints. If they are tightened too much, you can stretch the copper flare joint and twist the flare off of the tubing end. Excessive tightening also makes the joint prone to premature breaking at the flare joint.

If the flare fitting is in good condition (no nicks or cuts on the male flare joint), the copper flare should be as simple as hand-tight, and then snugged up with a flare wrench.

You can tell how much force is necessary by hand.

[chillin out]

Wow Chillin Out, that's new for me.
So you put oil in the inside of the flare and it stops twisting then
You can put oil between the nut and the flare.

Not between the joint.

Hence why I said this...

Your not actually putting oil inside the pipe, but on the back side of the flare.

Chillin:) :)