View Full Version : air compressor line requirements
02-17-2005, 12:14 PM
I am interested in running some pvc or other line throughout my basement, so I dont have to drag my air compressor around everywhere. What type of line should I use. Would schedule 40 be sufficient? I have a "home duty" machine that limits pressure to ~120psi.
02-17-2005, 12:25 PM
Oh man, I'd stay away from PVC if you can help it. Go with "L" size copper pipe. I've seen too many examples of PVC getting hot at the corners and the glue letting loose. I don't know anybody that uses PVC for air. Plus the metal work as a way to get the condensate out of the air before it get's to the tool. Copper is the way to go if you see the need to make changes. Galv pipe can even be used. Most recommend black iron pipe as best but the stuff just rusts and ends up putting more contamination in the lines.
02-17-2005, 12:30 PM
If you click on the search link and type in "compressor line" you'll get a lot of hits on previous discussions that should answer all of your questions.
02-17-2005, 12:30 PM
DON'T use PVC for air lines. It tends to fail in a spectacular fashion with lots of flying shards. I live in Oregon and the building codes go so far as to say that any pvc line pressurized with gas has to be enclosed in a secondary shield.
If you want to use plastic, use nylon or polyethylene tubing and push lock fittings. These can split or crack if crushed, but don't eject fragments.
Personally I favor copper with swage lock fittings or black iron pipe for fixed runs as the plastic melts and burns in a fire and if pressurized will really fan the flames.
I suggest you have a read here:
02-17-2005, 12:55 PM
Its funny. I suggested PVC because I have seen it in many shops I have visited. Guess I will go with something else. So much for an easy and cheap weekend project. I will runa a serch as well. I did not search because I expected a quick "yes that would be fine" answer.
02-17-2005, 12:56 PM
Unless you're trying to make a pipe bomb, stay away from pvc. Black iron pipe & galvanized pipe both work well -- I've run over 150' in my shop -- and both work well. Here's a link with diagrams & good information:
I used polyethylene tubing. Easy to run, and cheap. For a really good, high-class installation, probably copper tubing would be the way to go.
But avoid the rigid plastic!
As stated above, avoid pvc piping. I ran 1" copper, each drop goes up first and includes a drain. For me it was worth the extra $100-$150 to know that the piping was not going to fail. I usually remember to turn off the compressor, but with my luck I would forget one day and that would be the time the piping would fail. Then the compressor would be running continously till someone came home.
[This message has been edited by JPR (edited 02-19-2005).]
02-17-2005, 03:36 PM
I have rubber air hose running overhead to a few outlets and a hose reel. Not as snazzy as rigid lines but it works.
Hoffman in Warner Robins Ga
02-17-2005, 06:13 PM
I've run both polyethylene and rubber hoses to distribute air and they work. The polyethylene with the push to lock fittings go in really fast and are quick and easy to alter down the road.
The time I ran hose I had one issue. When you run it pull it tight with no air pressure inside. When you pressurize it will get a little longer and hang down in broad sweeps between tie downs. To hang it I used tie wraps that come with a screw hole tab on the lock end of the wrap. I screwed them down with dry wall screws.
Since then I've replaced most of it with black iron. I've heard with galvanized that the zinc in the pipe corrodes with humidity and ends up carrying down the pipe as particles that gum up anything not protected with an air filter. Black iron develops rust, but it's not big chunks.
One other little item, if using copper pipe type "M" thinwall copper is not approved by code for compressed air service in North America.
02-17-2005, 07:10 PM
Over here in West Aus, you can purchase a "plastic" air line.
It is approx 1/2" diameter and blue in colour and is designed specifically for compressed air. Fittings and joints are push in connectors. This is not the blue "hosepipe" type material.
Also avialable is a black semi-flexible pipe that is used on my Range Rover air suspension. This can be obtained in the same internal diameter as the "standard" flexible air lines, so it can deliver plenty of air. It is much smaller in OD and it also uses push on connectors. These lines are VERY easy to use and install.
Obviously though they are NOT as tough as copper etc.
I am sure it must be available where you are http://bbs.homeshopmachinist.net//biggrin.gif
[This message has been edited by Peter Sanders (edited 02-17-2005).]
There is a rated plastic pipe available from Ryan Herco specifically for compressed air service, it isn't cheap.
My advice is to go with one inch copper tube, it's available everywhere, doesn't rust, makes making changes easy and in a reasonable size shop is relatively cheap.
This Old Shed (http://http:thisoldshed.tripod.com)
02-18-2005, 02:31 AM
And not only that..."Think rigid copper!"
02-18-2005, 11:48 AM
Is the copper pipe at Home Depot (Lowes, etc.) stores type "L".
02-18-2005, 01:38 PM
Over the years, I've "replumbed" air lines with gavanized, copper and PVC (never again PVC after reading the stories about failure a few years ago) and rubber hose. By far the easiest is simple air hose with barb connectors and worm clamps, and it serves well for so many years you might as well consider it permanent. The connections go fast and easy, the installation is remarkably stable, and you can redo your entire shop in an afternoon!
02-18-2005, 02:58 PM
I stopped by The Big Orange monster at lunch and the one here had both L & M type copper pipe.
02-18-2005, 04:18 PM
Last time I was at Home Depot they do carry L copper pipe. But some stores don't so it's sort hit or miss. Our local OSH handles L copper pipe too. Out in CA.
02-18-2005, 08:38 PM
Why 'L'? All the fittings available (unless you use brass) are 'M' Sweat fittings once were much heavier but today's version are not.
02-19-2005, 12:00 AM
Refrigeration copper,comes on a roll,put it together with compresson or flare fittings,no solder joints to sweat and no need to use fittings for 90* bends.In additon the long radius bends reduce restrictive loses in volume/pressure.
Restrictive loses may not seem improtant in the home shop,but the smaller pumps benifit the most from not using sharp 90* elbows and tees.
<font face="Verdana, Arial" size="2">Originally posted by Jpfalt:
[B]DON'T use PVC for air lines. It tends to fail in a spectacular fashion with lots of flying shards. B]</font>
My buddy ran 150 feet of PVC for his shop air. One day the whole works grenaded. Scared the hell out of everyone, but no one was hurt. He replaced it with steel.
02-19-2005, 08:49 AM
3/8 steel pipe.
02-19-2005, 09:52 AM
Wierdscience has a good point. The more you can do to reduce frictional losses, the more air volume is available for use. Especially important if you use air tools. Most people don't realize that the greatest loss of flow comes from using small ID flexible air line. My larger air tools (3 HP horizontal grinder & 3/4" impact) barely run on "normal size" coilhose.