Compression fittings on copper air lines

pattenp · Apr 27, 2009

Quote:
Originally Posted by pattenp
Has anyone used copper with compression fittings (No sweating joints) for air lines? I was thinking about putting in copper airline and using the compression type connectors. I know the sweat connectors are cheaper but I too hate sweating connections. Was wondering what the downside may be of using compression fittings.

Oh and I apologize, I should has started another post instead of hijacking this one.

Quote:
Originally Posted by back2class
This is the WORST idea I have herd all day! Definately NOT!

I wanted to take this to a new thread because I originally posted in the PVC Air Line post and got the above response. So why would this be a bad idea. The Garage-Pak product uses a mechanical connection with an O-ring. I would think using compression fittings on copper would be just as good as the type of fitting as used in the Garage-Pak product. Has anyone done this? Of course seeing the response I got, you may not want to admit to it.

ulev1st · Apr 27, 2009

We use them at my work all the time with no problems. They are pretty much fool proof. HOWEVER if the line is subject to a LOT of vibration they will over time fail and leak. If you have them isolated from vibration they are great.

akdiesel · Apr 27, 2009

I use them as well at work but on stainless. The thickness of the tubing wall can result in a failure of the compressed fitting if not done correctly as is any type of compression fitting but more so on the thinner wall.
I used Swagelok compression fittings on my air system through out my shop with .035 ss tubing.
I did use some pipe dope to help with the seals of the compression. The system has been is use for about 4 months now with no leaks.
This type of compression fitting is stronger than any sweated fitting and will last longer with no rust issues than iron pipe.

Torque1st · Apr 27, 2009

I use compression fittings on the compressor itself. Keeping soft copper tube straight and sloping the right way for a distribution system might be tough since it comes in a roll. Any low spot in the tube will collect moisture.

Personally learning to use hard copper is not that hard. Find someone to teach you. Do not use regular solder for air lines.

Jared · Apr 27, 2009

compression fitting will work fine, my old sears compresor came with them on the copper line from the pump to the tank.

Identaltech · Apr 28, 2009

we use compression fittings for conecting the main hose from the tank to the cooper line is offices all the time.
no failures.
quick and easy.
all other conections are sweated.
learn how to sweat pipe from someone.
I had a guy teach me. once you learn to heat it up right and a few pointer you will have it.

malibu101 · Apr 28, 2009

As Jared said- the only way I've ever seen the compressor output attached to the tank is by copper with compression fittings.
I have heard that copper is not the best choice for high vibration applications, I'd believe that compression fittings would not be the best choice either for heavy vibration.
BUT
with so many compressors built this way with no failures-Can it be that bad???

porschedude996TT · Apr 28, 2009

My Craftsman Air Compressor has a copper compression on Aluminimum tubing from the compressor to the tank. Had it for 28 years and it has never been a problem and it vibrates like crazy. I bought this compressor because I had a friend that made a ton of money prep'ing cars for custom paint and abused his on a daily basis. He never changed the oil, ran it until it almost glowed RED HOT, and had to hold the circuit breaker in with a c-clamp. At the time I figured this unit design was bullet proof. He never had a air leak at the compression fitting. Long story short, I think you will be fine with the compression fitting. If you are realy worried about the vibration, then apply some "Vibra-Tite" to the threads and that will prevent the movement from vibration. You can get it at Mcmaster.com for under $19 and the P/N is 75145A69. :beer:

Ramblur · Apr 28, 2009

My coppers been up for a few years now and soldering the joints wasn't
a big deal. I certainly had little to no experience before I started. I read
some "how to's"here and was sweating joints like a champ in no time. I
built mine in sections(as large as I could handle) to minimize sweating
in place on the wall. Wasn't hard at all,so I just don't see the need for
the extra expense.

JCByrd24 · Apr 28, 2009

It will definitely work, especially if you isolate from the compressor with a hose. If you go with an industrial compression fittings (like Swagelok) it'll work even better(longer) than if you use compression fittings from HD. Swageloks actually deform the pipe a surprising amount due to the amount of bite they take on the pipe, an impressive connection for sure. They are approved for use on various US defense programs.

The ability to sweat copper is up there with welding though, just makes you feel good knowing you can do it. A MAPP gas Bernzomatic will pay for itself in one project. A good how to I think is referenced somewhere on this site, search for "copper tube handbook".

Bull · May 24, 2012

Two questions, after finding this old thread in a search.

1. Are there new types of compression fittings for copper in 2012 that would make the answer different? I have heard of "Sharkbite" fittings on this site before.

2. If someone does a crappy job soldering, is the risk merely of a leak, or of a catastrophic explosion of a joint at 150 psi?

pattenp · May 24, 2012

I ended up putting in a Transair system with the slip-on o-ring style fittings. The Sharkbite fittings for copper work close to the same way. I just don't know if the Sharkbites are rated to 150lbs. Lowes carries Gatorbites.

Edit: Sharkbites are certified to 200 psi.

Compression fittings on copper air lines

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