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I want to plumb some compressed air lines to various sites in my house from my compressor in the shop (for filling bike tires and airbrushing). Can I use copper? Is there a specific gage copper required? If not copper, then what? Can I even do this legally?
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Steve:
Yes you can run compressed air in copper pipe with sweated fittings. You should probably use the thicker, type K? I am a glutton for punishment, so I have run air lines in both residential and commercial in galvanized iron pipe. Black pipe is also used in some installations. I would not use PVC, even though I have seen it in use also.
As far as legal, you will have to ask your local inspector's office if they have an opinion, as local codes vary greatly.
Do read up on how to plumb compressed air. You must slope the pipes for water drainage. You must also run enough pipe to cool the air to cause the water to fall out. You need petcocks to drain the water. Many people fail to do this and wonder why water is inside tires and balls or their air tools spray water out the exhaust. And you definately want clean dry air to paint with, even air brushing. Moisture and oil in paint will cause you no end of problems. I recomend a coalescing (sp) filter to remove the oil, and a water trap type air transformer at the point where the air brush will hook up. These can be pricey, but help eliminate problems.
For your indicated use, 1/2" pipe will be sufficient.
Frank
*Steve,
Joseph FuscoView Image
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I used a rubber hose product by Goodyear rated at 600psi. I don't know how the price compares to other stuff, but it sure installs quickly. Similiar to all the pex tubing discussions, it snakes over and around if/when necessary and has an easily installed fitting on each end only. I agree with Frank on the oil/water filters; my hoses are sloped back to the compressor with water drains at the low points. I also use an aftercooler to get rid of a lot of the water, but am using bigger spray guns, an airbrush probably consumes so little air that it has time to cool in the hose/pipe system.
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We used pvc air lines in a shop I once worked in.Used pvc because the air lines were used to circulate an acid bath at 132* temp.When I left the pvc was still working great,submerged in acid for at least 5 years.Thats when I decided it would probably hold up just fine in a house.
good Luck,Stephen
*I've looked at this issue a lot (having designed/installed about 80 environmental cleanup systems at toxic waste sites). We often use compressed air pumps to keep electricity away from flammable/explosive materials.I doubt you'll find a knowledgable plumbing inspector who would approve plastic piping, especially PVC, for compressed air. Two biggest concerns are failure mode and longevity. When rigid plstic piping fails, it shatters. Compressed air has tremendous energy in it and could send the pieces flying near bullet speed (BB. .177 or .22 only - they couldn't go supersonic). Whereas metal deforms, typically splitting open without shattering. (And water has so little energy in it, a crack or hole quickly relieves the pressure).Longevity is the other issue. Note that plastic piping is aways installed inside a wall or trench. PVC gets UV embrittled. Ever get some from the outside storge yard at the home center? It's harder to cut without shattering because a few months of sunlight have already made it more brittle. Painting it helps a lot. Paint it after it's all installed or you'll have to sand the paint off for every glued joint.That said, I would use PVC on the jobs described above (if the building department wasn't involved) and have used you it many times when it wasn't completely kosher. But I consider how long the piping will be used (sometimes only months), if there are people around to get injuried, and work to redure UV exposure. When there are clients, workers, or inspectors involved, that forces me to metal piping or rubber hoses.Joe - nice looking shop! If you've got a PVC air line that gets a lot of sunshine through a window, you might want to vent the system and try rapping it with a hammer to see if it's become brittle. If so, replace those runs and paint them.Legally: most everywhere lets homeowners work on their own homes if you follow the local codes. A nice run of copper air lines look really good in a shop and you don't have to worry about it getting whacked and breaking.
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Frank;
I used to be a building mechanic which included maintaining the air comp & running new supply lines. We NEVER used galvanized pipe. The zinc coating would flake & get into the lab equipment. We stayed with black iron.
Cheers; JE
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Ahh, finally a a thread that I can enjoy!
Do you think, that these types of installations should be included in the perfect small house, or maybe in planned communities? I think that no house should go without a well designed compressed air system!
I'm thinking about writing my congressman, oops, congressperson, and suggesting a new national law requiring a 1" copper system on all thaose interesting new small houses that retirees are building!
Screw the cherry wood paneling, berber carpeting, and corian tops...just get the air system right!
Why should oldsters, have to walk all the way out to the barn to air up their matresses, and bow up dolls? A mini nuclear compressing plant should be included in all tract, plnned communities, and fixed use towns or whatever is built from now on!
I'm going with the copper on mine!
Blue
*And if one does use galvanized pipe for air or natural gas, you ought to install a vertical, downward-pointing dead leg just before the appliance to check some of those flakes. Use a tee as your last fitting before the flex tubing. Bring gas in from above, dead leg below, go horizontally out to the appliance.
*If the market is the oldsters, why not have oxygen plumbed to every room? Like a whole-house vacuum system helps house cleaners, this would help all those ex-smokers with emphysema. No more toting around those little tanks. Just plop yourself down, plug in, and breath away.My brother once converted (rather casually) a former comestics factory to apartments. The huge lab area had 30 feet of granite countertop with natural gas and vacuum jets every 4 feet. Want to warm up a cup of coffee? There's always a bunsen burner nearby.
*The only plastic pipe (a formulation of an ABS) that is rated for compressed air that I know of is a product from Chem-Aire. I used it when we replaced our compressed air supply system in our shop. We replaced the PVC because it was shattering, not with any help, but only because of constant use. The shrapnel from exploding sch.40, 1 1/2" pipe is a whole lot of no fun, especially when you are using the table saw. It is more expensive than black pipe, but when the work is 40 feet in the air it easily was the best choice.
*Blue,I am concerned about possible health issues involved with using lead soldered copper pipes.We wouldn't want to adversley affect the life of our air tools would we?Also do we need to consider proper venting and insulation of this system?Good Luck,Stephen
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Not only is PVC brittle, but it will melt in a fire. A fire starts, the air line melts, shooting out a jet of air, which fuels the fire. This is not just theory, it has actually happened. I would not use PVC for air lines. Iron pipe or copper is the way to go.
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Impact type air tools (hammers, wrneches, etc.) will quickly destroy PVC piped air systems.
-Rob
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A good story about compressed air. The place where I work was cleaning out an underground storage tank that had anti-freeze in it (1000 gal). Over a weekend they let compressed air force the anti-freeze into another tank.
Monday morning a computer repairman is cleaning the air filters and circuit boards on my lab computer. He hooked up an air hose to a vertical drop on the air line and cleaned the computer with anti-freeze.
It seems there was a power outage over the weekend. When the power went off the tank pressure forced some anti-freeze back into the system lines. It filled several vertical drops.
We now have many water separators in the system.
.....Dave
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Oh my gosh Stephen! i hadn't thought about that!
WHAT'S WRONG WITH YOU PEOPLE???!!! WHY WASN'T THE HEALTH HAZARD DULY NOTED AT THE TOP OF THE THREAD?!!! I AM COMPELLED TO INFORM SEAN ABOUT YOUR RECKLASS, YES LAWLESS BEHAVIOR!
Many thanks to you Mr. Hazlett for that life saving warning!
Blue
*So will my 16# sledge if I can land a good blow on the stuff!Blue
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I was chatting up a plumbing contractor at Home Depot on shop air (he was debating over compressors). He take is similar to others in the thread.
He said that you don't want PVC because of all those nasty fragments when it explodes. (UV embrittlement?) He noted that they do make a plastic line rated for shop air, but it is expensive and special order and why bother.
Copper or black iron. Copper is somewhat ductile and a bit more forgiving if something happens.
ToolBear
*Whew!You folks saved me! I was just about to go with the Type K copper when your timely alert got me worried about the toxic bicycle tire problem. And hey! What good are sickly volleyballs?Thanks to everyone on this thread...I really had no idea the depth of intuitive thought you guys apply to these mundane questions.With deep respect,Steve K.
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Blue:
I'm with you on requiring compressed air for houses. Housewives just have not been shown the bennifits to cleaning with compressed air. Now you can blow the dust bunnies out from underneath the furniture where the vacuum can pick them up easier.
And energy bennifits. With compessed air you can burn that oil you drained out of your work truck for house heat. And even more environmentally friedly, you can get all your neighbors used oil to burn also.
And think of the new games your kids will come up with using air hoses and nozzles!
My new house will have a 5hp installed. No need to go out to the shed for volleyball inflation. Overkill? No, I just had an extra compressor....
Frank
*Frank, I think your being a little chintzy with that 5 hp! 8 minimum! And crank up the psi to 140. It's great for blowing plates clean; no more wasteing water for that chore.Blue
*Yes, all my drops have dead legs on the bottom of the tees to trap dirt and water. I also put petcocks or ball valves at the bottom of the dead legs to drain the water. Here in Virginia you can mistake an air line for a water line in the summer....Frank
*Blue:Great idea on a new style dishwasher. Compressor is a two stage type, tank outlet pressure about 180 psi. I'll just skip the need for a regulator! ;-)Frank
*Not only will PVC melt in a fire, it will also burn. And release hydrochloric acid fumes. Do not burn PVC in the open or in a stove. Your eyes will hurt and your tools will rust. We still refer to the "Great PVC Fire of 1991" while cursing the rust on table saw and drill press.
*Has anyone seen an air driven hand mixer or food processor? I'm really getting intrigued about the concept of using shop air to reduce electrical loads in the kitchen and bath. This would also solve the problem of differing voltages and cycles in different countries. If the compressor air temperature can be maintained, it would also facilitate a hair dryer.
*Barry,I am sure there are plenty of Amish who have already perfected your idea.They convert lots of stuff to air or hydraulic use.(course you won't be able to contact many of them on your computer!)Good Luck,Stephen
*Barry: I've used a cordless drill on gourmet backpacking trips to prepare whipped cream or to whip up the egg whites. No reason you couldn't put a beater or juicer or whatever in the chuck of an air drill. Solves the voltage problem but we'd have to decide which air connector to standardize on. High temperature air is tricky. The expansion of air cools it. But 200 mph air would still be a good blow dryer.Stephen: There are and and or gates (transitors), accumulators (memory), adders, etc available as air circuits. Put about 13 million of them together and make your own air-powered Pentium. Then the Amish kids could finally have Nintendo.What goes, "Clip, clop, clip, clop, clip, clop, bang!, bang!, bang!, clip, clop, clip, clop"? An Amish diveby shooting.
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I want to plumb some compressed air lines to various sites in my house from my compressor in the shop (for filling bike tires and airbrushing). Can I use copper? Is there a specific gage copper required? If not copper, then what? Can I even do this legally?