SteveP
Active member
Looked on here for ideas to run air lines and saw suggestions for PEX. Contacted a PEX supplier and they said there are no lines rated for forced air systems. Thoughts?
PEX question
- Thread starter SteveP
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Nighttrain
Well-known member
Rapid-air.com I am looking at this instal as we speak.
ishiboo
Well-known member
RapidAir uses nylon tubing, not PEX. Different material, similar concept with plastic pipe.
Torque1st
MEMBER EMERITUS
If PEX was good for compressed air the manufacturer would love to sell you some. Checking with the manufacturer was a smart move. Just don't think real hard and talk yourself into believing the manufacturer must be full of sh**.
Steves32 is doing the job right.
If you can actually come up with something definitive, rather than just assumptions, against PEX, I'd love to hear it..
brianh
Well-known member
I have used it and will be using it in my new garage. I used to work in a wood furniture manufacturing shop most of our equipment was pneumatic and ran polyethylene air hoses.
I never had a hose failure from bursting, only at a faulty joint.
Msc supply or grainger sells all kinds of polyethylene air hose.
I hope this doesn't turn into a thread like welding on a compressor tank
I never had a hose failure from bursting, only at a faulty joint.
Msc supply or grainger sells all kinds of polyethylene air hose.
I hope this doesn't turn into a thread like welding on a compressor tank
MartyO
Well-known member
I have had more water failures with plastic tubing and not one with air delivery.
Go figure.
I will keep using the plastic. It is cheap and easy to work with. And it let's me make quick changes if a layout change is needded in the shop.
Just sayin'.
Go figure.
I will keep using the plastic. It is cheap and easy to work with. And it let's me make quick changes if a layout change is needded in the shop.
Just sayin'.
Torque1st
MEMBER EMERITUS
No assumption here at all. Have you ever worked in manufacturing? The manufacturers all know their products best. Do us all a favor and see if you can find a PEX manufacturer that recommends PEX for compressed air service.
Another little problem with plastic tubing of any sort is that it does not dissipate heat well. Heat dissipation or cooling capacity is one of the functions of air distribution systems having a direct impact on water separation.
I have also designed equipment that used miles of plastic air tubing. That tubing was far from the main air distribution system so water separation was not a factor in the design.
Home shops or garages rarely have any sort of chiller to remove water from the airstream. Many industrial plants have chillers and well designed distribution systems. It is not unusual to find plastic tubing being used on machines in those facilities. I have done it myself. I would not use it in my home garage/shop.
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Right. Metal is better for water seperation and durability/fire resistance. And PEX has some degree of weakness to UV rays. But you make it out to be PVC's shrapnel cousin or something..
Quoted from another forum:
I sent an email to a company that supplies PEX (pexconnection.com) here is what he said when I asked about using PEX for compressed air in a hobby woodworking shop
" Air is routinely used for pressure testing PEX plumbing systems, and we use it here to distribute the air for our air compressor, so I would say that it should not be a problem for you to do that."
Then I asked about exposure to fluorescent lights in my shop. And his reply was:
"For best results, you will most likely need to cover it. PEX should not be exposed to direct UV light for more than 30 days. I will say, however, that the PEX we are using (for water and air) is exposed to direct fluorescent light and indirect sunlight and is performing well. Still, the recommendation is that it not be exposed to UV light."
I used PEX for the first time to move a toilet supply in our basement. It is so much nicer to work with than copper.
http://www.sawmillcreek.org/showthread.php?46903-pex-tubing-for-compressed-air-lines
Maybe pex manufacturers haven't fully tested, approved and are ready to accept liability for it's use in compressed air applications? Due to some catch like long term high UV exposure instability, or its long term exposure to trace amounts of lubrication oils or something silly like that. Some degree of UV instability and a potential fire hazard are the only potential fathoms of a risk I can come up with..And I don't see how systems like Rapid Air are any different when it comes to fire..
Quoted from another forum:
I sent an email to a company that supplies PEX (pexconnection.com) here is what he said when I asked about using PEX for compressed air in a hobby woodworking shop
" Air is routinely used for pressure testing PEX plumbing systems, and we use it here to distribute the air for our air compressor, so I would say that it should not be a problem for you to do that."
Then I asked about exposure to fluorescent lights in my shop. And his reply was:
"For best results, you will most likely need to cover it. PEX should not be exposed to direct UV light for more than 30 days. I will say, however, that the PEX we are using (for water and air) is exposed to direct fluorescent light and indirect sunlight and is performing well. Still, the recommendation is that it not be exposed to UV light."
I used PEX for the first time to move a toilet supply in our basement. It is so much nicer to work with than copper.
http://www.sawmillcreek.org/showthread.php?46903-pex-tubing-for-compressed-air-lines
Maybe pex manufacturers haven't fully tested, approved and are ready to accept liability for it's use in compressed air applications? Due to some catch like long term high UV exposure instability, or its long term exposure to trace amounts of lubrication oils or something silly like that. Some degree of UV instability and a potential fire hazard are the only potential fathoms of a risk I can come up with..And I don't see how systems like Rapid Air are any different when it comes to fire..
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I did my whole house in pex, including radiant in the floors. I'm not sure if I would use it in the garage for air or not, but if you do I would plan to cover it so it isn't exposed to UV rays. They do state that as a weakness, so it would be worth a few bucks to get the sleeve material you can run over the pipe so it isn't exposed. The other ption would be running it only in the walls and using cooper stub-outs for wall penetrations. These are made for PEX applications.
Torque1st
MEMBER EMERITUS
That was never my intention and that assumption is yours. I have never said rapid-air systems are any good either.
A manufacturer and a distributor are two entirely different things. They have entirely different liability concerns. A person can find all kinds of "statements" on the web. Just because someone has done something and nothing bad happened does not make it safe or desirable to do so again:
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Torque1st
MEMBER EMERITUS
Putting a sleeve around the PEX or running it inside walls adds insult to injury for important air distribution system functions.I think you're missing the point of my post. Do I think PEX is the right choice for air lines? No. But if you're going to use it wouldn't it make sense to heed the basic manufacturers warning that it shouldn't be exposed to UV rays?
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59 wagon man
Well-known member
think of it this way somepeople play russian roulette not all of them die
Torque1st
MEMBER EMERITUS
It would be reasonable to heed the manufacturer's warnings. 
Unfortunately sleeving the tubing or running it inside walls makes it even less efficient separating water since that adds more insulation over the tube reducing heat dissipation. PEX also has 100 psi at 180°F pressure/temperature limitations that make it very questionable for compressed air applications since the outlet air from a compressor will go much higher. There are much better materials for air systems. Plastic materials just do not work well for compressed air regardless of ease of installation. PEX does work VERY well for regular hot/cold water systems, and radiant heat etc. which are the uses it is intended for.
Unfortunately sleeving the tubing or running it inside walls makes it even less efficient separating water since that adds more insulation over the tube reducing heat dissipation. PEX also has 100 psi at 180°F pressure/temperature limitations that make it very questionable for compressed air applications since the outlet air from a compressor will go much higher. There are much better materials for air systems. Plastic materials just do not work well for compressed air regardless of ease of installation. PEX does work VERY well for regular hot/cold water systems, and radiant heat etc. which are the uses it is intended for.e-tek
Well-known member
OMG.....
While I wouldn't use PEX in my shop because Ithink there are better alternatives (though lots of people have issues with black pipe too!), I do what I think is REASONABLE - and as such I wouldn't really have issues with using PEX for air..... if it wasn't for the long-term UV exposure problem!
BADSIX
Well-known member
what do you think about the eastwood tubing its nice but only rated at 150. i still like copper and steel pipe theres no worries
Torque1st
MEMBER EMERITUS
No on that Eastwood nylon plastic. Nylon 12 tubing frequently carries a 212°F temperature limitation. The listed pressure ratings are typically at 70°F.
Personally, I like galvanized steel pipe.
Yup, they sure do. granted this is for pex-al-pex. a close cousin to pex
here ya go although Im sure you still find something against it because of its ability to remove moisture,yada,yada,yada. Its no different than having an air hose attached directly to the tank like I do. Zero moisture problems other than draining the tank occasionally. If I was painting that would be another story all together and would want a drier regardless of the plumbing. You guys worry too much.
http://www.astm.org/Standards/F1282.htm
http://www.astm.org/Standards/F1281.htm
Looks like almost all pex is made in china. But here is one
http://amicopipe.en.ecplaza.net/10.asp
and another
http://www.nbpipe.com/Multilayer_Pipe_(_Tube_)_/PEX-AL-PEX-20611.htm
and yet another, just follow the link astm 1281 that I posted earlier
http://www.uponor-usa.com/Header/Service/For-Professionals/Tech-Documents/Codes-and-Standards.aspx
BTW looks like ipex is the supplier to ardi which I quoted earlier.
Also found that ipex had a big recall on their kitec line a few years ago
And nibco had a bad batch back in 09 that fugged up several peoples homes badly
Also found that ipex had a big recall on their kitec line a few years ago
And nibco had a bad batch back in 09 that fugged up several peoples homes badly
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Torque1st
MEMBER EMERITUS
Your pex/al/pex is not a close cousin to plain PEX. The standards do not imply suitability. In fact they state:
The aluminum layer does not improve the thermal conductivity over plain PEX. If a person only uses a little air occasionally they really do not need an air distribution system. The plain old hose off the receiver works fine.
The aluminum layer does not improve the thermal conductivity over plain PEX. If a person only uses a little air occasionally they really do not need an air distribution system. The plain old hose off the receiver works fine.
Limitations are still 145PSI & 200°F for the hot water/heating type B pipe,(type A is lower). This makes it unsuitable for compressed air distribution systems near the compressor. An alternative would be to use mechanical refrigeration or using a substantial length of ordinary steel or copper pipe right out of the compressor to cool the air before converting to P/A/P.
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brianh
Well-known member
I am sure the Wright brothers called all the manufactures of the parts that they made there plane out of if they were safe for aviation.
Its a piece of plastic pipe guys, stop being so OCD.
Its a piece of plastic pipe guys, stop being so OCD.
Torque1st
MEMBER EMERITUS
Nobody knew anything back then, now they do. And you ain't the Wright brothers.
brianh
Well-known member
And I will use pex for my air tubing thank you
Torque1st
MEMBER EMERITUS
To each their own. You can lead a horse to water but you can't make it drink.
nissan_crawler
Well-known member
It seems to me if somebody was dead set on "plastic", that air brake line would be the best choice, if such a diameter could be found.
you said show where a manufacturer says pex is suitable for compressed air, I showed where a manufacturer says pex-al-pex is suitable. Thats all I did. Im aware they are not the same, but they are formed the same way with the one of 3 same processes out of the same materials which in my mind makes them close to the same product. I never said the aluminum section would help pull the heat and moisture from the compressed air. I was also finding p/a/p ratings at [email protected] also read on this board that if you dont need need more than 100psi, its not efficient to pressurize that high. I cant remember who it was though. Now the burst pressures I keep finding are rated at 395psi @ 180F for 10 hours
Without any testing, I bet the temps would be low enough with a section of black pipe plumbed straight up then tee'd off onto pex-al-pex that it wouldnt make a bit of difference assuming your not running 5 blast cabinets and several sanders at the same time.
Im with ya on the issue of people not really needing an air distribution setup. I think a lot of people want it for the "wow" factor. Hell a 50' hose reaches anywhere in my 24x36. I thought I wanted a system like that until I really thought about how useless it really is without a 100'+ building. And if that was my case I would run a main line up and down the center of the building with all the leg drops being p/a/p.
Youd probably blow a gasket if you saw me stretch my 100' pvc air hose to the house, then attach another 50' of rubber hose plus a small 10' section of stretch coil hose. I dont even want to get into the horribly bad pressure loses I would see ,huh?
At the end of the day whats the worse case scenario if a section of that pex pipe fails?
1) compressors runs non stop, solved by shutting it off when not in use
2) fire breaks out when no one is around and the compressed air feeds the fire; no one was around to put it out anyway
3) it burst; you replace it with another section
I dunno, maybe you can think of another scenario that we cant. Please enlighten us instead of just saying "its bad"
Like you said, To each their own, I just cant think of any bad scenarios that come from using the wrong material in this case.
Torque1st
MEMBER EMERITUS
Air brake tubing is mainly heat and light stabilized seamless single wall extruded nylon tubing. Available in sizes 1/8 (-2), 5/32 (-2.5), 3/16 (-3), 1/4 (-4) and 5/16 (-5).
Temperature Range: -40°F to +200°F (-40°C to +93°C).
Maximum Working Pressure: 150 PSI.
Again it is plastic and not good for water separation. I have no idea what happens to the pressure rating at elevated temperatures for that particular product.
Torque1st
MEMBER EMERITUS
PEX is way different. You would not get very far on a pure rubber or nylon tire but a composite material tire may get you 50K miles.
I would use 2-3 sections of black pipe before I transitioned to plastic. But why use plastic when metal is much better? I have spoken many times about not setting your system pressure any higher than necessary.
A system like that would probably work OK with a good slope on the P/A/P lines to avoid moisture pooling. But the fire prevention problems still remain.
Youd probably blow a gasket if you saw me stretch my 100' pvc air hose to the house, then attach another 50' of rubber hose plus a small 10' section of stretch coil hose. I dont even want to get into the horribly bad pressure loses I would see ,huh?
Nah, I did the same thing running a PVC airline across the street to help a neighbor when an air bubble just would not do the trick. It was slow to get that truck tire inflated. But it was only about 120' of hose. I have an air bubble set up to use at the end of a long line so I can get a brief high pressure and volume blast for an air impact. It can make a huge difference out in the middle of a boneyard.
I have listed why plastic is bad many times. It really does not do anything right for an air distribution system. Must I repeat it every time for people that don't use the search function? Maybe I should just write it all out again and keep it in a file so I can just paste it in every week for the newbies.
Just use the correct material if you need an air distribution system. Why try to reinvent the wheel and try to out think years of industry experience?
The fire problem comes with accelerating the fire and reducing the time that people have to escape. Fire codes address that problem in a variety of ways and try to maximize the escape window. Firemen also have to deal with it when a smoky fire suddenly blows up on them.
Some cities won't even allow hard copper probably because people solder the connections instead of brazing them.
Remember, Murphy will strike on that night when you forget to turn off the air system. He seems to enjoy biting us in the ***. He can also strike when your back is turned or you are under that vehicle and your way out is blocked by a raging fire that was accelerated by compressed air. It is always a hazard in our shops so why make it worse?
When you place burns down and the fire marshal determines you used some experimental or illegal materials they might just charge you with a crime (probably not) but, the insurance company will certainly deny your damage claim.
I could sit here for hours and try to explain why life is cruel but I have work to do.
Just use the right stuff the first time. I am as cheap as anybody, and I may grumble and whine about having to use the right stuff, but in the end I just do it. I just spent $450 on parts for a new electrical panel. The damn wire was $105 alone. I did save ~$50 because I was able to show the inspector calculations and use some #2 wire that I had for my neutral conductor.
Daddy_Rabbit
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Do us all a favor and see if you can find a documented case where an insurance company denied a damage claim based on a fire due to the use of PVC or PEX in an air distribution system.
Thanks.
Thanks.
akdiesel
Well-known member
Torque1st has simply brought up very good suggestions in this catigory to help people build their set up in a safe manor.
Black pipe, if not used correctly, like anything else, can also create an unsafe condition.
I did a brief search on line for pex products and I could not find any info regarding usage for air. That is not to say it is not out there. But history has shown the results of rigid plastic pipe for air no matter how it was installed.
Daddy_Rabbit
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but PEX isn' considered a rigid plastic pipe like PVC, right?
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akdiesel
Well-known member
I was regarding PVC.
brianh
Well-known member
Has he ever used pex for air? I have, my old shop that I use has about 30' of it I think I put it in around 1995 I did not realize how I was risking my life.
The last company I worked in I installed black pipe setup with our 2 screw compressors and air dryer setup I am not a novice on air and pneumatic design, my point still is has he ever used it.
Black pipe gets rust and even the galvanized will over time that said I think it works fine.
As for water issues I have a solenoid timer valve on my compressor tank and a water trap 20' downstream I spray furniture with the setup and have never had water issues.
It great to have opinions and with the Internet you can look stuff up and sound good without actually doing a thing.
Some stay in the box some step out.
dude, I posted several links from manufacturers stating that it is acceptable for use with gases compatible with composite pipe. Im not sure If I have ever seen a gas move through a line without being compressed. That being said maybe they are referring to gases that are already compressed into a tank with the heat dissipated already.
Just about every supplier says its also okay. They are only selling a product and I never trust a salesman on his word.
Torque- I guess my biggest issue Im having is Im relating it to my garage and my setup. Its a small shop compared to some here and I just cant see any negatives in it besides an air distribution system being completely useless. To me it would be like running a rubber air hose off the regulater up and through the trusses then back down and leaving it there, whats the harm in that?
You probably should find your post about the reasons for plastics being bad and just copy it in a folder. Im not gonna do it because I just dont care that much and Im feeling lazy with my hangover. I was feeling spunky last night and took your challenge. Im still not sure if I won that or not
. Either way it was good talking at yaTorque1st
MEMBER EMERITUS
Sorry but I do not have access to insurance company records. I am sure some person around here does. All I know about insurance companies is they are always looking for any reason to deny a claim. Illegal wiring, insufficient structure, plumbing, or other materials are always big red flags. We have all read the news reports about faulty wiring etc. Unfortunately with our modern media and privacy laws we never hear the rest of the story.
As far as actually USING PEX for airlines. Why in God's name would I want too???? I have used steel and stainless but plastic? -F**k NO. Only people that did not know any better would use something like that. Most people never realized they have entertained risks because they never think. All they are interested in is if, when hooked up, it "works" or at least does not blow up in their face. That is why we have websites like "There I fixed it" and People of Walmart, etc. We laugh about them and deride anyone that would do that. Some are pretty clever in a redneck sort of way. But safe or desirable? -NO way.
I have thrown a hose up in the trusses and down again for a temporary hookup but to actually run a hose that way for a permanent solution... -Nope. Running PEX etc would imply a "permanent" solution. Otherwise just run a hose for a temporary solution.
Unfortunately, as this thread proves, there are many out there that think they know that something is OK or "works" just because they have had no problem. Just make sure you get nice pictures of your 'solutions" and post them so we can upload them to those "fixed it" websites and laugh.
If someone actually NEEDS an air distribution system please read up on what the functions of an air distribution system are. Then look for the actual tried and tested solutions. Just because some product is advertised for something does not mean it is any good or desirable.
PEX, or PEX/AL/PEX may be a great "solution" for those that can't or won't learn how to fit pipe or braze. But as far as being a good air distribution system it fails miserably.
If you don't need an air distribution system a hose from the tank works OK. Industrial and manufacturing facilities usually realize the trip hazards involved in hoses running across the floor or the lost time in snaking hoses around. So they invest in an air distribution system.
Below is a short discussion on airline systems. It leaves out a lot of technical info but it is mostly reasonable information. If someone wants more technical information there are reference books and standards available for $$$. A person could always join $$$ one of the professional organizations and debate other experts on why PEX is good stuff for air.
This company also sells air products so use the proverbial grain of salt.
http://www.tptools.com/StaticText/airline-piping-diagram.pdf
http://www.tptools.com/
As far as actually USING PEX for airlines. Why in God's name would I want too???? I have used steel and stainless but plastic? -F**k NO. Only people that did not know any better would use something like that. Most people never realized they have entertained risks because they never think. All they are interested in is if, when hooked up, it "works" or at least does not blow up in their face. That is why we have websites like "There I fixed it" and People of Walmart, etc. We laugh about them and deride anyone that would do that. Some are pretty clever in a redneck sort of way. But safe or desirable? -NO way.
I have thrown a hose up in the trusses and down again for a temporary hookup but to actually run a hose that way for a permanent solution... -Nope. Running PEX etc would imply a "permanent" solution. Otherwise just run a hose for a temporary solution.
Unfortunately, as this thread proves, there are many out there that think they know that something is OK or "works" just because they have had no problem. Just make sure you get nice pictures of your 'solutions" and post them so we can upload them to those "fixed it" websites and laugh.
If someone actually NEEDS an air distribution system please read up on what the functions of an air distribution system are. Then look for the actual tried and tested solutions. Just because some product is advertised for something does not mean it is any good or desirable.
PEX, or PEX/AL/PEX may be a great "solution" for those that can't or won't learn how to fit pipe or braze. But as far as being a good air distribution system it fails miserably.
If you don't need an air distribution system a hose from the tank works OK. Industrial and manufacturing facilities usually realize the trip hazards involved in hoses running across the floor or the lost time in snaking hoses around. So they invest in an air distribution system.
Below is a short discussion on airline systems. It leaves out a lot of technical info but it is mostly reasonable information. If someone wants more technical information there are reference books and standards available for $$$. A person could always join $$$ one of the professional organizations and debate other experts on why PEX is good stuff for air.
This company also sells air products so use the proverbial grain of salt.
http://www.tptools.com/StaticText/airline-piping-diagram.pdf
http://www.tptools.com/
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Daddy_Rabbit
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You dismiss claims by others when they have nothing to back up said claims yet you ask others to take your claims based on nothing other than your word?
That's not entirely fair.
As far as I can tell, NO ONE asked you to use PEX, yet you claim it is unsafe and even go as far as to insinuate that anyone that chooses to use this sort of system is less intelligent than you. Ok, let's try this ... you claim PEX is unsafe, yes? Can you show documentation to back this up? Can you show catastrophic failure of a PEX air distribution system that resulted in personal injury, death or loss of property?
ok.
Again, can you provide proof, documentation or pictures of PEX systems that have failed resulting in injury, death or loss of property? You ask others to prove their claim so do you not think it's fair that we ask you to held to the same standard?
No, but there is this little legality called product liability that prevents companies from advertising their products for applications that are unsafe.
Prove it.
I agree.
So you saying the only way to see evidence that PEX is unsafe for an air system is to pay for it?
ok.
I'm seriously not trying to stir the pot, start a ******* match or cause unneeded drama and I totally understand why PVC & CPVC should not be used for a pressurized air system, I just want to be shown hard evidence & logical documentation (not just hearsay based on personal opinion) on why PEX is not safe for an air distribution system.
Thanks.