Compression fitting for undersized OD copper pipe

[Bmw4life]

I purchased some 1/2 OD pipe from Amazon to install a cooler/radiator into my compressor, and turns out the pipe is a little undersized. Because of that, I cannot install the compression fitting.
The ferrule is a bit loose, so it doesn't get pressed properly, it always goes at an angle.
I can't seem to find a proper copper line, so I'm considering how to best make it work.

I'm thinking that maybe I can try to buy a flaring kit, but I have a feeling that it may not be able to hold the pipe tight enough.

I'm thinking it I could expand the pipe slightly, it's all that's needed to to able to use a compression fitting.
So I'm thinking this kit might do it?
Not sure if anyone has experienced this problem before.

 

[rlitman]

Those expanding swages are meant for brazed tubing. I wouldn't trust expanding a pipe under an olive like that.

Have you looked for brass insert support bushings? They're required on plastic tubing to keep the OD from collapsing under the squeezed olive, but they improve the reliability of copper compression connections as well. In your case, you might need to hammer the bushing in. If you have a flaring tool, you could hold the tube about an inch from the end with it's clamp, rest that on the jaws of a vise and use that to make it easier to force the bushing into an undersized tube.


But you might not even need to force it in. The olive compresses the tube quite a bit, and the bushing resists that compression, improving the ring tension on the olive. Without the nut squeezing the olive, the bushings usually just about fall in, but once the fitting is squeezed, they're as permanent as the olive.

 

[The Cobbler]

would it be possible to solder a pc of 1/2" ( 5/8 OD) copper to the undersized pipe & use 5/8 compression fittings?
have you determined the pipe is undersized by measuring? ... return it to amazon ?

 

[BillK]

I purchased some 1/2 OD pipe from Amazon

??? Tubing is normally sized by the id, not the od. What exactly did you buy and which compression fittings are you trying to use ? It sounds like you may have 3/8" tubing ?

 

[Bmw4life]

Those expanding swages are meant for brazed tubing. I wouldn't trust expanding a pipe under an olive like that.

Have you looked for brass insert support bushings? They're required on plastic tubing to keep the OD from collapsing under the squeezed olive, but they improve the reliability of copper compression connections as well. In your case, you might need to hammer the bushing in. If you have a flaring tool, you could hold the tube about an inch from the end with it's clamp, rest that on the jaws of a vise and use that to make it easier to force the bushing into an undersized tube.


But you might not even need to force it in. The olive compresses the tube quite a bit, and the bushing resists that compression, improving the ring tension on the olive. Without the nut squeezing the olive, the bushings usually just about fall in, but once the fitting is squeezed, they're as permanent as the olive.

Never seen these before but I'll look them up and try them!

 

[u2slow]

You probably got 12mm tubing from amazon, not true 1/2" - due to the country of origin.

I would do the flare (if considered "soft" copper), or look for local supply of true 1/2" tube.

 

[Bmw4life]

would it be possible to solder a pc of 1/2" ( 5/8 OD) copper to the undersized pipe & use 5/8 compression fittings?
have you determined the pipe is undersized by measuring? ... return it to amazon ?

I would return it but I don't know where to buy the right pipe unfortunately. All hardware stores either don't have them or it's even worse quality.
Soldering might be a good idea but I've never soldered pipes before and don't have any 5/8 pieces. Could be a good idea if I can't find another solution.

 

[Bmw4life]

??? Tubing is normally sized by the id, not the od. What exactly did you buy and which compression fittings are you trying to use ? It sounds like you may have 3/8" tubing ?

This is what I got

Quickun Copper Tube 3/16" ID × 1/4" OD (5-6.35mm) Seamless Round Pipe Tubing (9.84FT) https://www.amazon.ca/dp/B0B42BMLCH?tag=atomicindus04-20

 

[The Cobbler]

Tubing is normally sized by the id, not the od.

tube is measured OD, pipe is measured ID

 

[The Cobbler]

you probably got a metric "close to 1/2" tube

 

[The Cobbler]

this is probably properly sized https://www.amazon.ca/MECCANIXITY-R...nditioner/dp/B0D319PSFP/?tag=atomicindus04-20

 

[Jim greengo]

??? Tubing is normally sized by the id, not the od. What exactly did you buy and which compression fittings are you trying to use ? It sounds like you may have 3/8" tubing ?

Depends ,refrigiration tubing is measured by o.d
Sounds like it would be easier to just get a roll of 1/2" i.d copper.

 

[Bmw4life]

this is probably properly sized https://www.amazon.ca/MECCANIXITY-R...nditioner/dp/B0D319PSFP/?tag=atomicindus04-20

Ordered thank you! Will find out tomorrow.

 

[fitter30]

Try the flare. Sealing is all done 45° surfaces might want to oversize the flare. The swagging tool will make the diameter to large for compression ferrule. Soft solder a piece of m or l copper on it or make a bushing going into a fitting.

 

[Bmw4life]

Try the flare. Sealing is all done 45° surfaces might want to oversize the flare. The swagging tool will make the diameter to large for compression ferrule. Soft solder a piece of m or l copper on it or make a bushing going into a fitting.

For the flaring I need to buy the flare tool and the flare fittings. Still no guarantee the tool will grip the undersized tube...
I think this tool can control the widening of the tube



But first I'll try different ferrules

 

[Bmw4life]

You probably got 12mm tubing from amazon, not true 1/2" - due to the country of origin.

I would do the flare (if considered "soft" copper), or look for local supply of true 1/2" tube.

I think you're right.
Actually before I try anything else, I'm gonna try 12mm ferrules intread of 1/2.

This way I don't need to return the copper tubing that I already bent and I don't need to buy more tubing.
I guess 12mm is 0.47 inches, so this might just work the easiest.

 

[rlitman]

...I think this tool can control the widening of the tube...

I wouldn't touch that thing with a 10' pole. It looks like a terrible PEX expander being resold for a job it isn't up to. Might work for making brazed coupling joints on 3rd world air conditioners, but yeah, that's hot garbage.

 

[Bmw4life]

Those expanding swages are meant for brazed tubing. I wouldn't trust expanding a pipe under an olive like that.

Have you looked for brass insert support bushings? They're required on plastic tubing to keep the OD from collapsing under the squeezed olive, but they improve the reliability of copper compression connections as well. In your case, you might need to hammer the bushing in. If you have a flaring tool, you could hold the tube about an inch from the end with it's clamp, rest that on the jaws of a vise and use that to make it easier to force the bushing into an undersized tube.


But you might not even need to force it in. The olive compresses the tube quite a bit, and the bushing resists that compression, improving the ring tension on the olive. Without the nut squeezing the olive, the bushings usually just about fall in, but once the fitting is squeezed, they're as permanent as the olive.

The brass insert, I tried looking them up. I would need them to be 12mm ID, and I don't see any for sale. They would need to be super thin walled as well.

 

[rlitman]

The brass insert, I tried looking them up. I would need them to be 12mm ID, and I don't see any for sale. They would need to be super thin walled as well.

The ones I've used all came with the compression fittings, and yes, they're damned near paper thin, but they do their job.

 

[Bmw4life]

The ones I've used all came with the compression fittings, and yes, they're damned near paper thin, but they do their job.

You probably had something like this, but with 12mm ID instead of 8mm as in this case. The sleeve needs to go over the Cooper tube, so ID has to be 12mm for it to slide over. Here it's only 8mm.


The other thought I had was to use a "quick connect" fitting. But will try smaller ferrules first.

 

[BrandonV]

Depends ,refrigition tubing is measured by o.d
Sounds like it would be easier to just get a roll of 1/2" i.d copper.

All tubing is OD IIRC. The only thing that is really ID measured is hose.

 

[tool_scrounge]

I think the listed 10-12mm OD in the title would give me pause. Maybe I missed it, but what is the actual measured diameter?

 

[Wrench97]

I've found that flares on air compressors crack and break from the vibrations.

 

[no704]

Just a one time thing?

 

[T444e]

Tube is typically specified by the OD. However, like many things there are exceptions. Copper for refrigeration is called out by the OD while copper for plumbing and hydronic heating and cooling is called out by the nominal ID.

 

[chinboys]

I think Amazon or the seller on it mistakenly labeled the tubing. Others here have mentioned refrigeration tubing being referenced by its outside diameter.
This type of tubing is is called ACR... Air Conditioning Refrigeration.
Do yourself a favor and go to Home Depot to buy their type M or L copper 3/8 tubing that will fit your 1/2 compression fittings.

 

[The Cobbler]

Do yourself a favor and go to Home Depot to buy their type M or L copper tubing that will fit your compression fittings.

doubtful , as he has 1/2"OD ferrules . he will get 5/8 OD if he buys M or L

 

[Jim greengo]

All tubing is OD IIRC. The only thing that is really ID measured is hose.

But some people confuse tubing measurements and plumbing pipe measurements .

 

[jkuro]

Refrigeration copper is measured OD.
Plumbing copper is measured ID.

 

[Aileron]

need to be careful with tubing measurments these days. Some of the foriegn made mini splits are a mm tubing. Had a couple guys putting a system in and could not get a hot work permit in the building so no brazing inside at the site. The tubing was a old ball size and had to take the indoor evap unit back off the wall and off site to a nearby commuter parking lot to braze a small piece of coppper on to it. A zoomlock or the new quick connects from parker would not hold becuase of the od diameter of the tubing.

 

[firebirdparts]

Refrigeration copper is measured OD.
Plumbing copper is measured ID.

Ones tubing and ones not.

 

[andyvh1959]

tube is measured OD, pipe is measured

Yes, tubing is measured OD. Pipe though, is "nominal" size not ID size. 1/2" pipe SCHD 40 measures 0.622 ID and 0.840 OD.

 

[joel63]

Tube is typically specified by the OD. However, like many things there are exceptions. Copper for refrigeration is called out by the OD while copper for plumbing and hydronic heating and cooling is called out by the nominal ID.

Only thing is I don't know where metric tube sizes fit into this grand scheme.

 

[T444e]

Ones tubing and ones not.

Both refrigeration and plumbing copper is tube, as jkuro said, the difference is OD vs ID measurement being referenced. I've never seen seen copper pipe, only tube. However many people refer to copper as pipe, but it is tube. The OD of 5/8" ACR tube is the same as the OD of 1/2" type K, L, or M copper (5/8" OD).

Only thing is I don't know where metric tube sizes fit into this grand scheme.

Short answer, Europe. I'm not very familiar with metric copper, just know it is out there and seen it once. My only experience with metric copper is on hydronic heating and cooling panels from a German manufacturer. They use metric tubing in their panels and we had to sweat on metric x NPT adapters.

With the OP saying he got it from Amazon, the first thing that came to my mind is that he received metric tube. Now if he said it came from Grainger or McMaster-Carr it would be a head scratcher.

 

[Bmw4life]

I purchased 12mm ferrules. 12mm ferrules fit on tight on that copper line.
Then the 1/2 ferrule fits on top of 12mm ferrule and provides a tight fit. I think this was the cheapest and easiest solution.

 

[Bmw4life]

Also used push it fittings with a bit of electrical tape. Seems to be working fine as well.

 

[The Cobbler]

did you use the electrical tape to build up the OD of the tube?
I don't think I would trust that, I'm sure the tape will slip over time and allow it to pop off .

 

[Bmw4life]

Yeah used it to make it a bit tighter. I guess it might slide off at some point, but maybe it won't. If it does, I'll rearrange the connection

 

[PCustoms]

Sorry, stacking ferrules and adding tape?

....

 

[jkuro]

Why not just get a piece of the right sized copper.