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  #101  
Old 08-09-2010, 08:14 PM
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Lu47Dan Lu47Dan is offline
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Originally Posted by AdreamSoReal View Post
Been running 3/4" PVC sch 10 for 12 years now without any problems. My comp. is a eagle 3 cyl (18 1/2) cfm @ 100 PSI 130PSI max.
I have seen glue joints fail without warning on PVC waterlines, I know that there are a lot of people running PVC for air lines out there. Just because it has held up well for you does not mean that you could get it by an OSHA inspector or even your insurance company. PVC does became brittle with time, UV light is one culprit, but atmospheric chemicals are another one. Copper does not degrade as fast as other materials used as air lines and is immune to moisture in the air stream. Copper can fail as with any material, or man made system. Copper has the advantage of being light weight, highly corrosion resistant ( why do you think it is used as a roofing material ), easily installed with hand tools and no noxious chemicals.
PVC has it place in the shop but the one place it should not be used is as air lines. Until the day it is approved for use as air line in factories and industry I will stay with copper.
Dan
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  #102  
Old 08-09-2010, 08:57 PM
AdreamSoReal AdreamSoReal is offline
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Originally Posted by Lu47Dan View Post
I have seen glue joints fail without warning on PVC waterlines, I know that there are a lot of people running PVC for air lines out there. Just because it has held up well for you does not mean that you could get it by an OSHA inspector or even your insurance company. PVC does became brittle with time, UV light is one culprit, but atmospheric chemicals are another one. Copper does not degrade as fast as other materials used as air lines and is immune to moisture in the air stream. Copper can fail as with any material, or man made system. Copper has the advantage of being light weight, highly corrosion resistant ( why do you think it is used as a roofing material ), easily installed with hand tools and no noxious chemicals.
PVC has it place in the shop but the one place it should not be used is as air lines. Until the day it is approved for use as air line in factories and industry I will stay with copper.
Dan
Hmmm... The PVC has to be stronger then the rubber air hose we use, right? If i was going to do it again, i'd use the copper. I know what you're saying there.

But this has me thinking. How much PSI will it take to blow up a sch 10 PVC pipe???
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  #103  
Old 08-09-2010, 09:14 PM
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Dream, they're not talking about pressure or "stronger than rubber".
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  #104  
Old 08-14-2010, 04:24 AM
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http://www.easy2diy.com/cm/easy/diy_...ge_id=35749917

This would be of possible help for someone standing on the threshold of very basic and beginnings of working with/soldering copper pipe and fittings.
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  #105  
Old 08-14-2010, 07:56 AM
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That video is well thought out and realistic. If a person tried a few joints after seeing it I believe they would be doing a good job very quickly.
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  #106  
Old 08-14-2010, 09:05 AM
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Jef, yep that is a good introduction into sweating joints.
OM, the only thing I disagree with the video is the statement not to reuse fitting once they have been disassembled. All you have to do is learn the trick to it. Heat the socket until the solder stars to flow and clean out the solder with a fitting brush, the brush will drag out the solder and the fitting can be reused. It might take several cycles to save the fitting but can save a fitting from the scrap pile when you need it at 9pm after all the stores have closed.
Dan.
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  #107  
Old 08-14-2010, 04:06 PM
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A good number of years ago I used PVC for an air line but it always made me nervous knowing what would happen if it let go. The reason that I did use it was that I lived in a rental and knew that one day it would need to come down.

When I built my shop here I used copper and now I rest much easier. At the time I was plumbing the air in the shop I don't believe that copper was too all full expensive.

Even if I was plumbing it now I would spend the extra money and use copper.
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  #108  
Old 08-14-2010, 09:21 PM
kbs2244 kbs2244 is offline
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All I can say is that every industrial install I have seen has been 1 or 2 sizes oversized black iron pipe with a drain leg and valve at the bottom of every vertical.
Some of the valves even have a log on them.

And I have never seen a water plumbing type union used.
If that kind of joint is needed, they use a flange to flange connector with an “oh” ring.

I have seen 1/8 inch of dust on some of those pipes, so I guess they don’t cause much problem.
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  #109  
Old 08-15-2010, 08:21 AM
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With industrial projects usually there is a much greater volume of air, and the sizing would be cost prohibitive to use copper. Also, commercial dryers do a much better job of removing the water than what most home systems generally have.

As to unions, I don't recall seeing any used either now that you mention it.....
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  #110  
Old 08-15-2010, 09:08 AM
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Lu47Dan Lu47Dan is offline
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Charlie, I was at a friends home shop yesterday to inspect the damage from a broken PVC air line. His wife ran into an air chuck with his small tractor,she was parking it in a different spot than normal. The rear tire hit the chuck and snapped the pipe right above the tee, now she wants the whole PVC system replaced. He called me to help him figure out what materials he needed to do the job correctly. It took him a half hour of looking to find the air chuck and tee which hit his 70's Mustang project car, and ended up laying inside the top of his tool chest on the far wall.
I recommended copper, and he is going to order everything through where he works and get their discount on Monday, I cut off and piped in a new 1" copper feed line from the compressor into the shop, added a shut off valve and a two temporary air chucks above the valve so he could use his air tools today.
kbs, Unions are used to join new mains to older piping on industrial air lines. I have seen it and done it a couple of times but they are the 3000PSI forged type not the regular hardware store stuff. See Photo below.
Greywynd, most of the time socket weld fittings would be used to join the piping forming the drops, now if you can not get a "hot work permit" for a specific area then screw fittings would be used. Industry is more concerned with longevity of a system then initial cost to a point, so welded systems are the norm over screw pipe. I have seen three piece forged steel socket weld valves used on air to eliminate a threaded point in the system.
Industrial air drying systems can cost more then most peoples homes, but over the life of the system, it use will pay for the added expense a few times over with lower maintenance costs.
Just my observations over time. Dan
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