how to repair damaged flare tubing threads?????

[tsounos]

Hi guys i need your help.
Iwas doing an instalation on 18000 btus split system .aind i had everything done ,exept toconect the tubing on the out side unit. With flare nuts.
And when i tried to conect the 1/4 inch flare fiting i damaged the threads (on the male conector)
is there any way that ican repair the threads.
By the way i have bing doing instalations for over 15 years, inever had any problems....
Thanks for yor time
iam waiting for replis...

[glenn1340]

I`m not sure if you can get a die nut for these threads, failing that a thread file (match the tpi on the file to the tread on the fitting) should clean it up enough the fit the nut. I`d use the flare nut on its own to check all`s ok that way there would be no stress from the pipe that might pull it the nut out of square again

[Grizzly]

Hi tsounos.

I don't know how damaged the thread is.
But an old engineering trick is to use a nut. In this case a flare nut cut it across the nut at 90 degrees to the thread.
If you place the 2 halves of the nut on the thread, clamp them tightly with a mole type wrench.
Then as you rotate the nut the leading edge of each half of the nut "Chases the thread"
Or just cut once clamp the nut so that you are closing up the gap and chase the thread that way.
For a sharper cutting edge try a Steel JIC nut (Purchased from any good hydraulic hose supplier).

A 1/4 flare is 5/16 JIC not sure of 3/8 but take a sample with you and you should be OK.

Sorry to be so long winded but it's the only way I can explain what you could do.
Good luck Grizzly

[install monkey]

as a last resort u could get a new valve- i had it on a 5kw mitsi, cost £12 for a 1/4 valve

[icemanpaj]

+1 for a new valve. they are cheap and very easy to replace. I've had it on Daikins a couple of times.

[Grizzly]

Spoilsports, Iceman and Icemanpaj.

Let the man play!
Grizzly

[monkey spanners]

CPS make a thread chaser for 1/4" combined with a shreader valve tool and a shreader thread chaser, got one from HRP.

[Tesla]

hi Grizzly,
That is one of the best answers I have seen - to repair not replace. An old fitter showed me the same on a one inch thread where he spun a nut to the damaged area and tapped the nut with a hammer and like magic the thread was perfect again.

[Tayters]

Hi tsounos.

I don't know how damaged the thread is.
But an old engineering trick is to use a nut. In this case a flare nut cut it across the nut at 90 degrees to the thread.
If you place the 2 halves of the nut on the thread, clamp them tightly with a mole type wrench.
Then as you rotate the nut the leading edge of each half of the nut "Chases the thread"
Or just cut once clamp the nut so that you are closing up the gap and chase the thread that way.
For a sharper cutting edge try a Steel JIC nut (Purchased from any good hydraulic hose supplier).

A 1/4 flare is 5/16 JIC not sure of 3/8 but take a sample with you and you should be OK.

Sorry to be so long winded but it's the only way I can explain what you could do.
Good luck Grizzly

To add to that you could try cutting a couple of grooves opposite each other at 90 degress to the thread without cutting the nut in half - cut from the inside. This would mean getting the saw blade through the hole where the pipe goes in so not sure if it would fit on a 1/4 nut. Then line the nut up square on the thread and try and re-cut the damaged thread.

Likewise you can do this on a male thread to recut the female thread.
Used to do this on spark plugs to clean up the threads in the head.

If you are desperate then simply file the damaged threads flat on the male part but bear in mind no going back then and less threads to bear the load on.

Cheers,
Andy.

[Grizzly]

Tesla.
Thanks.
Kind words much appreciated.

The guys have a good point changing may well be the end result.
If the refrigerant is R410a ... No contest change it.
I just took the opportunity to pass on a very useful trick.
It certainly has got me out of a mess in the past. Particularly on the more aged / obscure kit.

Your scenario of the hammer and nut.
I have seen similar where a dockyard fitter took a seemingly ceased nut and bolt and proceeded to undo it by tapping the nut against a steel channel.
Turning the nut a little (by Hand) tapping and turning again and again.

Most amazing he undid the nut and bolt in front of me and laughed, asking me "Had I never seen that done before?"
No I had not! But I have never forgotten it either!

Oh and it does work.
Grizzly

[glenn1340]

I have seen similar where a dockyard fitter took a seemingly ceased nut and bolt and proceeded to undo it by tapping the nut against a steel channel.
Turning the nut a little (by Hand) tapping and turning again and again.

Most amazing he undid the nut and bolt in front of me and laughed, asking me "Had I never seen that done before?"
No I had not! But I have never forgotten it either!

An old trick that one Grizly. Another is when tightening a Jubilee clip give a few taps with a hammer and you`ll get another turn or two on it. And another is those rock hard gaskets that just won`t scrape off, use a ball peign hammer and the old gasket will break off it bits. Just look out for your eyes

[Hobair]

Hi, just another option i thought i would mention, I have seen the flare nuts completely removed on an installation and the pipework directly silver soldered onto face of the male fitting of the service valve, it looked like quite a large flare was left on the pipework. Dont see it being a problem as long as the valves are wrapped in lots of wet rag. When I asked about it on site was told it was because the client had stated no mechanical fitting on the pipework.

Paul.

[tsounos]

Thanks you all for taking the time and gave me all those good advices.. I will try them...