Replacing Copper Air Compressor supply with.....?

[jmlcolorado]

Hey folks!
I need to replace my semi flexible copper supply line on my field air compressor.....again!
I have a small oiled compressor for work in the field and i have had to replace the copper line from the compressor to the tank a few times. Problem is the compressor side has a flare connector and the vibration from the compressor running breaks the flare.
I'm wondering if anyone has used a more flexible hose to replace with. Maybe a hydraulic line, or Teflon line with stainless steel webbing?
Any advice would be much appreciated.

 

[Provincial]

jmlcolorado, what type of flare fitting is on the compressor now? A plumbing type 45 degree flare is the weakest flare design. Ingersoll Rand uses an inverted double-flare (like a big brake line fitting) on their industrial compressors and they seem to hold up well. Another good system is a JIC flare with a backup sleeve, which is basically and aircraft (AN) system from the WWII era. Both types of fittings are available from a good auto parts store or hydraulic supply.

Are you annealing the copper tubing before you flare it? Flaring work hardens the material and makes it more likely to crack. To anneal, just heat until dull red and let it cool. You could anneal both before and after if you are using "hard" copper tubing - the kind that is straight rather than in a roll.

If your compressor is limited to 125 psi or less, check with a parts supplier to heavy trucks. They use a flexible line from the compressor to the first tank that is made to resist heat and vibration. Use the same fittings as the flex line.

 

[jmlcolorado]

jmlcolorado, what type of flare fitting is on the compressor now? A plumbing type 45 degree flare is the weakest flare design. Ingersoll Rand uses an inverted double-flare (like a big brake line fitting) on their industrial compressors and they seem to hold up well. Another good system is a JIC flare with a backup sleeve, which is basically and aircraft (AN) system from the WWII era. Both types of fittings are available from a good auto parts store or hydraulic supply.

Are you annealing the copper tubing before you flare it? Flaring work hardens the material and makes it more likely to crack. To anneal, just heat until dull red and let it cool. You could anneal both before and after if you are using "hard" copper tubing - the kind that is straight rather than in a roll.

If your compressor is limited to 125 psi or less, check with a parts supplier to heavy trucks. They use a flexible line from the compressor to the first tank that is made to resist heat and vibration. Use the same fittings as the flex line.

It has a 45* flare on one end and a 3/8" compression fitting on the other.
I did not anneal the copper prior to flaring, and my experiance with flaring is not all that great to begin with, so im sure that plays a huge part in the failures.
Compressor valve is rated at 125 PSI.
Thanks for your input! Ill check out some local heavy truck places!

 

[Outlawmws]

You can probably get by with copper again, but put a full loop in it as a strain relief. This allows the vibrations to be spread over the full length instead of being concentrated at the connector.

 

[sberry]

Good tip on heating the line, I have some small steel tubing which gives me a fit on occasion, might try this.

 

[stonesfan68]

I would bring the fittings and tube to a local hose shop and have them fabricate a flexible stainless or copper tube for you.

 

[Canadian Cowboy]

Hey folks!
I need to replace my semi flexible copper supply line on my field air compressor.....again!
I have a small oiled compressor for work in the field and i have had to replace the copper line from the compressor to the tank a few times. Problem is the compressor side has a flare connector and the vibration from the compressor running breaks the flare.
I'm wondering if anyone has used a more flexible hose to replace with. Maybe a hydraulic line, or Teflon line with stainless steel webbing?
Any advice would be much appreciated.

You are using a short barrel nut switch to a long barrel tube nut which is used on natural gas lines it better when using a single flare also only tighten enough to make the copper seat on the brass male fitting over tigthening cause the copper tube to weaken.
That is already soft copper you have there if you heat it it will make it even softer and weaken it further.
Here is a picture of a long barrel nut.

CC

 

[ZRX61]

Another vote for a tube with a loop in it.

 

[Canadian Cowboy]

I agree as well, most compressors have the tubing coiled from the pump to the tank except for the the cheapies.

CC

 

[JASTECH]

Tube with loop will work. I think long term fix would be change the static fittings to upgraded ones and then have hydrolic line made to connect the 2 and be easily replaced. JMHO

 

[alan camby]

I also agree with what has already been said.

I would put the loop in and put a long nut on. The long nut is for extra support of the tube in vibration applications. http://www.ebay.com/itm/2-PC-Parker...A%2BFICS%2BUFI&otn=21&pmod=190525203599&ps=54

 

[alan camby]

Is the pump mounted on a metal frame or is it on some kind of rubber mounts?
If it is not mounted rigid to the tank I would go SS hose. Something like Mcmaster 5680k12.
http://www.mcmaster.com/#braided-stainless-steel-hose/=j1rhon

 

[EOC_Jason]

+1 put a loop in it... You could actually do more and it will help cool the air before it enters the tank...

You can get short lengths of hydraulic line from Northern Tool, TSC, and others. However those just have NPT ends so you would have to get some adapters to make it work.