compressed air system: copper,pvc,or steel?
#1
compressed air system: copper,pvc,or steel?
I am looking to install several drop points at various places around my shop. So, I was wondering would it be best to use copper pipe, steel pipe, or PVC pipe, to run my compressed air lines.
#2
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Copper ( with flared fitting connections, not compression or soft solder) or galvanized steel are OK. The plastic pipe manufacturers industry groups specifically state that use of plastic pipe in compressed gas systems is contraindicated. Too brittle, does not like possible surges, too many bad things happen if it breaks; many plastics like PVC not rated for the possible temp. of compressed air. I do not know if any building codes specifically allow or disallow; but it is not recommended.
#3
Use copper as this will be the easiest material to install.
Code wise, it will fall on "follow the maunfacturers installation...blah blah..." and as 594 stated, there is no plastic pipe manufacturer that has approved pipe material for compressed air.
One final note....there is a requirement under the fire code that requires directional arrows and tags be placed on compressed gas systems. Air falls under this requirement. I know, it's over kill for a small shop, but every 20 feet, or wall penetration, directional arrows and an ID tag should be in place. Now I can sleep tonight because I told you this....
Good luck with your project...
Code wise, it will fall on "follow the maunfacturers installation...blah blah..." and as 594 stated, there is no plastic pipe manufacturer that has approved pipe material for compressed air.
One final note....there is a requirement under the fire code that requires directional arrows and tags be placed on compressed gas systems. Air falls under this requirement. I know, it's over kill for a small shop, but every 20 feet, or wall penetration, directional arrows and an ID tag should be in place. Now I can sleep tonight because I told you this....
Good luck with your project...
#4
Member

I would not use copper and never have. I have never seen a shop that used anything but steel and I've been quite involved w/cars and racing for more than thirty years and been to hundreds of shops. The big issue w/steel is of course rust. Use galvanized and in reality you'll be OK.
Each vertical drop should have a water trap. Simply, place a T where you want to tap the hose from and then run another 8-12 inches of pipe downwards to a plugged fitting. Every once in a while depressurize the system and open the plugs and drain. There are automatic drains for this very purpose if you want to spend the $$. Of course you should be draining your compressor daily as well.
Also, if you really want things right, instead of connecting the hose or quick disconnect fitting right to the T, first connect a water speparator (filter) then the hose or disconnect. A regulator could be nice too... if you need it.
The small amount of rust that accumulates in the piping over the years is negligable and the filters will pick up loose scale. Air tools are rather forgiving about a little water and are less forgiving about not being oiled.
Each vertical drop should have a water trap. Simply, place a T where you want to tap the hose from and then run another 8-12 inches of pipe downwards to a plugged fitting. Every once in a while depressurize the system and open the plugs and drain. There are automatic drains for this very purpose if you want to spend the $$. Of course you should be draining your compressor daily as well.
Also, if you really want things right, instead of connecting the hose or quick disconnect fitting right to the T, first connect a water speparator (filter) then the hose or disconnect. A regulator could be nice too... if you need it.
The small amount of rust that accumulates in the piping over the years is negligable and the filters will pick up loose scale. Air tools are rather forgiving about a little water and are less forgiving about not being oiled.

#5
I work in a agricultural repair shop that used to have plastic pipe for a lines,osha required us to change to steel because of the chance of the plastic bursting and sending debri in the air.Like syakoban suggested the drops install a radiator drain valve or "petcock"as mechanics call them,then you can leave them open just a little bit to let your moisture expell when ever your air is on.I would strongly recommend a filter be put in before your air tool,its surprising over time how much rust you will get.
#6
Air lines
I assume that you want to do this yourself, the best system that I can think of is type L copper, use a hard solder they are rated far above the pressure that you will use, Steel means that you have to have the ability to theard pipe [Most DIYERS don't have this}, Pvc not rated for air will explode! Lots of luck.