Custom Discharge Tube

[StangStang]

Hey All,

I am having a hard time finding the info I need so I apologize in advance if this was already covered.

I made the mistake of running braided line from my compressor head to my aftercooler. Eventually I noticed that the compressor was running longer and longer. The rubber inside the line hardened and cracked, leaking air (lasted 10 months).

So, I want to replace with a copper tube / pipe.

Question: I need 1/2" outer diameter copper tube / pipe. What should I use? I have read soft and hard, type M and L. I need to know what exactly I need to buy in regards to copper. "Plumber" at Home Depot said you can't bend copper pipe so I am a bit confused. I see that I can buy a roll of tube or purchase a pipe, does it matter what I use?

Thanks all!

Stang

 

[The Cobbler]

you want 1/2od flexible copper tube (on roll). type m is not bendable, type L is somewhat but it's considered rigid .

 

[StangStang]

I thought Type L was harder than Type M?

 

[The Cobbler]

L is thicker walled than m
M will king and ripple if you try to bend it.
L would be a pain to bend for what you need . go with soft copper 1/2" od

 

[rlitman]

I thought Type L was harder than Type M?

Hardness and thickness are two different things.

Drawn tubing will be pretty hard unless annealed. If it's sold in sticks, it will be hard. If sold in rolls, it will be soft.

M is thin, followed by L which is thicker. K is the thickest. I've only seen K sold by the roll, but you could try and find it by the foot (still off a roll) at a plumbing supply.

L is usually found in sticks, and is not all that flexible. Though you can anneal it with a torch if you wanted to. Even if annealed, vibration (as you'll get off a compressor pump) will work harden it, and it will eventually crack if the aftercooler is not secured firmly to the tank.

There are high temperature braided lines that might be better. You'll want to look at something sold for AC compressor outputs.

 

[engineer2]

Type K is bendable with a proper tubing bender. You can buy coils of it in 1/2" OD anywhere. (Amazon, MSC)
An alternative would be having a hydraulic hose company bend you up a line in steel. More durable than copper.

 

[StangStang]

So what should I buy from the store/amazon? I assume that I have to purchase either type L or M roll, right? My aftercooler is mounted to a wall next to the compressor.

I have -8an male fittings coming off the compressor head and the aftercooler. Could I get a high temp braided line to work?

 

[Lelandwelds]

It is all bendable. Some is easier. There are mechanical benders. If all else fails, you can freeze water or pack sand. Crimp the ends.

You anneal copper by heating it up and dropping it into water. You could use aluminum or SS tubing. Compression fittings are easy.

 

[StangStang]

I just quoted $200 to make an a/c line..

I have 1/2" compression fittings to 8an coming so I would like to use copper. It's 150psi tank and needs to handle up to 400 degrees of temp. There isn't a minimum of copper I should aim for?? I'll buy a bender I don't care, I just need my compressor to run again.

 

[engineer2]

So what should I buy from the store/amazon?

Amazon 1/2" x 10 ft. This is just an example, no other specs, check actual OD and wall thickness, make sure it is what you need. You'll want annealed so you can bend it. Make sure it is actually 1/2" OD, not 5/8" OD. Type K 3/8" is often 1/2"OD

See https://www.engineeringtoolbox.com/astm-copper-tubes-d_779.html

 

[Lelandwelds]

I just quoted $200 to make an a/c line..

I have 1/2" compression fittings to 8an coming so I would like to use copper. It's 150psi tank and needs to handle up to 400 degrees of temp. There isn't a minimum of copper I should aim for?? I'll buy a bender I don't care, I just need my compressor to run again.

HVAC is the thinnest of all and is smaller than claimed nominal so the fittings are different. It's good for 600 psi and over 400 degrees.

I think you should confirm all Internet info with Google.

 

[The Tool Tyrant]

I've always used soft copper and either use compression fittings or flare it. The copper will dissipate heat better than your braided line also, so it's a 'win-win'.

 

[samss]

Find an HVACR supply house. Most of them will sell copper tubing by the foot if you don't need a 50' roll. They will also have flare nuts and flaring tools if you need them.

 

[StangStang]

Would this work then?

https://www.amazon.com/gp/product/B001AHAK20/?tag=atomicindus08-20

Can't tell if the material can handle the PSI or the temp...

 

[StangStang]

So I am seeing:
Type ACR: 1/2" OD, .375" ID, .032" wall, 720 psi, 400 degree max.
Type L: 1/2" OD, .375" ID, .035" wall, 779 psi, 400 degree max.

I can buy either one, what do you guys recommend? Can I use a tube bender?

https://www.amazon.com/dp/B002P8UUD2/?tag=atomicindus08-20

 

[samss]

ACR is straight, hard tubing. Get soft drawn, coiled tubing. Type L

 

[StangStang]

Ok great!

Last question. After I bend the tube to form it to my setup, do I need to heat the bends??

 

[rlitman]

Ok great!

Last question. After I bend the tube to form it to my setup, do I need to heat the bends??

Well, each time you bend copper, it work hardens a little. Like I pointed out before, a work hardened piece of copper is more likely to crack due to vibration. So, you may get a little more life out of it if you anneal it after bending. Though the best solution would be to clamp it securely so that it doesn't have the chance to vibrate as the pump runs.

 

[StangStang]

Well, each time you bend copper, it work hardens a little. Like I pointed out before, a work hardened piece of copper is more likely to crack due to vibration. So, you may get a little more life out of it if you anneal it after bending. Though the best solution would be to clamp it securely so that it doesn't have the chance to vibrate as the pump runs.

Yea, unfortunately my aftercooler is mounted to the wall next to the compressor. So, the aftercooler is good for vibration but the new line might have some issues. I can wrap some adel clamps around the tube and run a support to the compressor to help dampen the pipe. Might just work.

 

[engineer2]

The rubber might stink at 400 deg.
I've seen some compressors run a factory copper tube, so vibrational fatigue must not be a big issue.

 

[StangStang]

The rubber might stink at 400 deg.
I've seen some compressors run a factory copper tube, so vibrational fatigue must not be a big issue.

I found some high temp Adele clamps (700+ degrees).

Very true about the factory copper line. Mine did have one originally. But I need a longer line which may cause a change in harmonics causing earlier fatigue and failure?

Anyway, I appreciate all the help! I found some 10’ 1/2” OD type L tubing at Home Depot and purchased a 1/2” OD tube bender tool. Should work!