Can Pex be used for air lines?

[Torque1st]

CPVC carries the same manufacturer warnings as PVC.

As an example from:

http://www.spearsmfg.com/prod_brochures/80C-2-0406_1108_web.pdf

NOT FOR USE WITH
COMPRESSED AIR OR GASES
Spears® Manufacturing Company DOES NOT
RECOMMEND the use of thermoplastic
piping products for systems to transport or
store compressed air or gases, or the testing of
thermoplastic piping systems with compressed
air or gases in above and below ground locations.
The use of our product in compressed air or
gas systems automatically voids any warranty
for such products, and its use against our
recommendation is entirely the responsibility
and liability of the installer.

WARNING: DO NOT USE COMPRESSED AIR OR GAS TO TEST ANY PVC OR CPVC THERMOPLASTIC PIPING PRODUCT OR SYSTEM, AND DO NOT USE DEVICES PROPELLED BY COMPRESSED AIR OR GAS TO CLEAR SYSTEMS. THESE PRACTICES MAY RESULT IN EXPLOSIVE FRAGMENTATION OF SYSTEM PIPING COMPONENTS CAUSING SERIOUS OR FATAL BODILY INJURY

When you look you will find that even LOW pressure testing is not recommended.

Just use the right stuff and don't take chances with the lives of those around you.

 

[Charles (in GA)]

So, I've never run air piping in my shop. At the present I have a regulator and water separator on the compressor and hose laying on the floor.

Problem is, I'm installing the Lanair waste/used oil heater in this thread.... here, and last night, I moved a bunch of "stuff" to put the heater where I planned to install it. It is only a few feet from the compressor. I even started to install conduit for the power to it. Finally stopped, jury rigged some power and tried the blower. I had put it on the opposite side of the shop from where I do 90% of my work. The blower only reaches about 30 ft (the building is 60x60) and so it barely reaches the point where I usually work on the car and truck, and probably would not reach the "shop" corner where the workbenches and drill press, etc. are located.

So this afternoon, I moved everything back into place the moved the heater across the building to the shop side. It won't be blowing on the workbenches, but in the general area I work and more toward a ceiling fan (which will be pushing the hot rising air back down).

I now need to get compressed air all the way across the shop. 2 CFM at 60 psi, so my original thinking was two 50 ft cheap air hoses strung across the roof trusses, tywrapped to braces, conduit, whatever. Then I got to thinking about PEX. But I don't know anything about it. My original plan was to have a regulator at the compressor to reduce to the 60 psi. I have the regulator, but it will not go above 60 and I'm thinking I'll install one set at about 100 psi at the compressor and the 60 psi one near the heater. The heater has its own regulator/separator to reduce it further to 15 psi or so.

Tell me more about PEX, what sizes does it come in?, how pricey is it? What about fittings?

Charles

 

[Torque1st]

Charles, just pipe it with galvanized pipe. -No worse than rigid conduit. Plastic is really no good for airlines.

 

[Charles (in GA)]

Charles, just pipe it with galvanized pipe. -No worse than rigid conduit. Plastic is really no good for airlines.

1) need to do this in a hurry.

2) don't need a huge galvanized air line to deliver 2 CFM to the heater.

3) don't want to spend a lot of money right now, the $5K for the heater was enough.

4) could care less about "moisture" issues, as I have a two stage compressor and the extreme heating of the air, and cooling in the tank, takes out virtually all the moisture in the tank itself, rarely does any get to the water separator.

5) heater has a mini-regulator/water separator

In short, I need a functional, quick and dirty solution. Its either PEX or cheapie air hose.

Charles

 

[Torque1st]

Just run the cheapie air hose or some nylon line then. The cheap hose has the advantage it could be used for something else later.

It sounds like your air receiver is built correctly also.

 

[mrailing]

From the sound of what you need, for $100 at Northern Tool you can buy the RapidAir kit, 100 ft of line, two drops and the manifold. I a, currently installing this in my garage, but I am putting in a full loop system of about 300 feet and 14 drops at various points.

It goes together quickly and easily and will supply the air you need for the heater.

 

[Dragster Racer]

I have in the past been critical of pex for air line due to the experience I have had with the push type fittings. Most of mine leak a little. I had one blow apart, and generally they have been a pain in the rear. This weekend Menards had a pex crimper on sale, so I bought it and some crimp connections. I could kick myself for not doing this before. What a fast and easy way to run air line! And it actually doesn't leak! I do have a dryer at the compressor, so air in the lines is minimal anyhow. I'm kind of excited about adding some branches now that I can get them not to leak!

 

[Norcal]

Old Thread Alert!

One problem w/ PEX besides not being rated for air is that the some makes of PEX pipe need UV protection, & skylights, windows, would be a problem IMO.

 

[Dragster Racer]

Old Thread Alert!

One problem w/ PEX besides not being rated for air is that the some makes of PEX pipe need UV protection, & skylights, windows, would be a problem IMO.

Another issue of course is that it won't cool the air as much as metals, and the air will carry more of the moisture with it through the tool as opposed to condensing the moisture so it can be drained. It is commonly used for air, and does not fail the way that PVC does. It splits instead. Scares ya but doesn't hurt ya. And sure, if you have skylights etc, you may have an issue.

 

[BigJimmyP]

So after a little research on PEX for my water lines, I can tell u that there are a few types of the stuff. My swiss cheese memory tells me this: PEX-A is white, will degrade and cack when exposed to any UV. So don't use it around flourescent lights or Windows. The other PEX is blue or red, sold at HD, and I think is good for a 20 day exposure. Think that was rated for 200psi. Some Pex can be found lined with aluminum. Yeah the sharkbite fittings are fast and easy but expensive. The crimps are cheap but the crimper is pricey.

Look up Videos about PEX. Lots to know, cool stuff. I will b running some air lines soon myself. I will be covering with something, though, to keep any UV from it. Otherwise it should work great!

 

[Albiemanmike]

Well I won't get into the PVC debate as I am in the camp that says don't use it and if the ASTM/OSHA advise against it that is good enough for me. To the OP just go buy some cheap 3/8" rubber air line and run it to your furnace and be done with it. No need for exotic or expensive piping to just run a small amount of air to your furnace/oil burner. Why not just get an electrical blower motor for the furnace?

Anyway to address the PVC ongoing constant debate I have challenged the Mythbuster guy's to take on this debate and put it to rest once and for all. Hopefully we will see an episode in the future of them blowing stuff up with PVC pipe compressed with air................

 

[CNGsaves]

Well I won't get into the PVC debate as I am in the camp that says don't use it and if the ASTM/OSHA advise against it that is good enough for me. To the OP just go buy some cheap 3/8" rubber air line and run it to your furnace and be done with it. No need for exotic or expensive piping to just run a small amount of air to your furnace/oil burner. Why not just get an electrical blower motor for the furnace?

Anyway to address the PVC ongoing constant debate I have challenged the Mythbuster guy's to take on this debate and put it to rest once and for all. Hopefully we will see an episode in the future of them blowing stuff up with PVC pipe compressed with air................

FACTS are that PVC used as airline is CRAZY, proven to get brittle and burst with great potential danger. Some crazy people still smoke when filling up their gas tank, they might get lucky for a while, but might come a day where they blow themselves up!!

Take the time and spend 10 minutes determining where you need air drops around the shop and install lifetime system from either black pipe steel or copper. Both are proper and won't burst.

 

[carcajou]

I run pex in my shop 9 years ago for air lines, no problems then or now. Shop get cold in the winter too.

 

[darkk]

I run pex in my shop 9 years ago for air lines, no problems then or now. Shop get cold in the winter too.

Anti pexers just wont believe pex works. We can tell them its been in the open with 150lbs in it for 10 years and they still wont admit it. You guys can spent all you want on black pipe,copper pipe whatever. I can do my entire shop less air fittings for under $60. I know for a fact it works well without failure...

 

[69lm69gp]

Anti pexers just wont believe pex works. We can tell them its been in the open with 150lbs in it for 10 years and they still wont admit it. You guys can spent all you want on black pipe,copper pipe whatever. I can do my entire shop less air fittings for under $60. I know for a fact it works well without failure...

I think you are confusing the comments against PVC with being anti PEX. But the fact is, PEX has limitations. For me, the lack of heat dissipation is enough to use something else. But a refrigerant air dryer at $1000+ might solve the water issue problem. As would living in the desert.

Of course the people who say they don't have a problem with PEX/water never seem to have their location in there profile.

 

[darkk]

I think you are confusing the comments against PVC with being anti PEX. But the fact is, PEX has limitations. For me, the lack of heat dissipation is enough to use something else. But a refrigerant air dryer at $1000+ might solve the water issue problem. As would living in the desert.

Of course the people who say they don't have a problem with PEX/water never seem to have their location in there profile.

My location is visible..Willimantic Ct. And trust me when I say it gets cold and damp here. As stated, I know for a fact pex works well, if you use crimp collars you won't have any leaks. 99% of the pex used for air lines will never see enough uv to hurt it. My son on law has been using pex for many years without any water issues or any failures. He used pex because being a heating and plumbing contractor, that's what he just happened to have plenty of available...not saying it's better than anything else. It's cheap and it works.

 

[kjohnson1]

I plumbed 1/2" Pex in my garage for the air compressor. Less than six months....one of the lines blew yesterday. Upon inspection I would call it a tear

 

[SBs garage]

I'm interested in using PEX for my air distribution directly from my compressor. I have a sufficient sized reservoir to adequately cool the air prior to distribution.
My main concern is static electric discharge. I want to have the air circuit go between the two floors of my garage as well as to outdoor air fittings. I can't locate any information that I may need to ground my distribution main and all of the associated piping connections. If you have used PEX for these purposes please let me know if this is something you discovered or if this is a non-issue.
There are people reporting a few burst/"tears" in their PEX lines. I wonder if a low point drain and a filter/drier assembly in the air stream would account for any remaining oil/moisture in the air stream after compression. Perhaps the failures were a result of "dieseling".

Thanks for your input.

S.

 

[alberto]

I plumbed 1/2" Pex in my garage for the air compressor. Less than six months....one of the lines blew yesterday. Upon inspection I would call it a tear

Can you post a picture of the tear? What pressure are you running? Do you keep the compressor on 24/7 or do you shut it off every day (or close the valve feeding the lines)?

 

[Clik]

I haven't seen any mention of the plastic air-lines with push fittings that big truck manufacturers use for air-brake systems.

Certainly they are within our pressure rating needs; certainly UV stabilized; certainly resistant to oil; certainly resistant to heat; certainly resistant to cold, vibration, abrassion, salts, chemicals, etcetera.

Is it too expensive? Hard to get in long lengths?

I'm runnng line from my 80 gallon air-comp/tank to a second 60 gallon tank at the opposite end of my 80' shop, so, cooling and moisture shouldn't be a problem.

 

[Joe69]

Pex supposedly expands rather than breaks when frozen. What would that mean for pressure drop. Hmmmm.

Joe

 

[oldtractors]

I just plumbed my shop with Pex. I used 250' of 3/4 and about 50' of 1/2 in the install. Works great.

3 1/2 years later, it still works fine. Yes, I see moisture in the lines occasionally. I had the same condition with copper. I did have to replace the rubber hose running from the compressor to the pex after it failed twice. It is now hydraulic hose.

 

[hoho98925]

I am planning on using pex on my build. I will come off the compressor with a 2" galvanized iron pipe main running about 60 ft, sloped back towards a drain near the compressor. I plan on T ing off the main with pex run in the ceiling and dropping down in the walls. My theory is the iron pipe will help cool the air, helping with any moisture, I will also have a good quality dryer and filter off the compressor.

 

[skoronesa]

I want to hear more about this push together brake line for large trucks. It's not the push together part that interests me but the chemical resistance and durability.

If we know what this stuff is made of we can find it sold for something else but probably for cheaper. It's not like there are many options. Pex is either polyethylene or polypropylene. Pvc and abs aren't up to the task. Nylon seems like a plausible answer. I would like to say it could be polyethylene but it wouldn't have the heat resistance.

 

[LOU DISCOUNT CABINET CORN]

I just finished layingout the air suppl materials for our new shop. 4400 sf. with a small spray booth. 10 hp ingersoll rand 3 ph compressor.

260 lf pipe
3- ceiling hose reels
7- 2 outlet wall 'drops' dual ball valve

popular brand aluminum 1" tubing system---1800.00
type L copper 3/4 and 1/2" ----1400.00
pex and galvanized mix---1000
pvc and galv mix---1000

were a 2.5 m in sales company with 10 employees (small)

for the minimal savings of 400.00 its just not worth it.
yes the install is much harder, but ill never have a problem
and as we get larger, NO OSHA OR WORKERS COMP PROBLEMS.

yes the economy *****, and 400.00 and an extra day is worth something, but
NEVER USE PVC IN A COMMERCIAL ENVIRONMENT
DONT BE CHEAP OR LAZY, UNLESS ITS TEMPORARY.- just my opinion

 

[tlowery04]

I was looking for information on using pex for air lines and came across this thread.

For what it's worth, I have seen PVC schedule 80 explode and shred things in a shop. Luckily everyone was away on vacation. The issue didn't arise from general use, but rather from the pressure switch on the compressor failing. It kept building pressure until it popped like a baloon.

My dads shop had schedule 40 for 15 years or more, never had an issue.

Given the dangers of PVC lines and the relative ease in avoiding them, I think I'll do it the right way first and not worry about it ever again. Right now I'm set on copper unless the P-A-P stuff looks good. I hadn't heard of that roduct.

 

[StingRay]

Rated for a pressure liquid and rated for a pressure gas are two different worlds. Liquids don't have explosive decompression. Fluids are non compressible. That's why hydraulics work like they do. When any kind of liquid or hydraulic line fails it just blurbs out. Consider that when an airliner loses it's envelope just a handful of psi pressure differential escaping can take the whole plane apart. Same thing with a brittle material used for an air line. Changes in air pressure causing fatigue, environmental conditions, UV, petroleum products in the air and external wear and tear all take their toll on materials NOT designed for this use. When was the last time you saw a PVC or ABS air plane? You could build it and it would probably fly. NOBODY in their right mind would fly in it. Just because you can doesn't mean you should!

If I were to pick a lesser of evils PEX would worry me less but over time in the wrong conditions I'd bet it could break down and shatter much the same way. If you value your safety and those around you use materials rated for gases.

 

[Firebrick43]

Pex does not nor never will(unless dipped in liquid nitrogen) shatter. If it breaks down it just tears.

 

[rlitman]

Pex does not nor never will(unless dipped in liquid nitrogen) shatter. If it breaks down it just tears.

Correct.

The glass transition temperature of PVC is 87C.
The glass transition temperature of polyethylene is -125C.

 

[StingRay]

Really? I've seen polyethylene and polypropylene materials both degrade from UV and fracture. It takes a helluva long time but I've seen them chalk up, become brittle and fracture. Is PEX pipe fully UV stabilized? In desert locales the sun eats up everything that is any kind of plastic eventually. I was just looking at the lid to my 585 gallon water tank yesterday. It's polyethylene, it's black and its got a crack in it after 12 years of sitting outside and I don't live in a desert either.From a quick scan of the net PEX pipe has a very a limited time frame for UV resistance. I get that in normal new condition that it's really tough but that's not at all what I'm talking about. What about where it runs on a wall with direct exposure to sunlight through a window. I've been in my garage 12 years. Certainly long enough for sunlight to cause damage to anything susceptible with the right exposure.

Copper typically fails in a split too but never breaks down in the sun. If PEX were the cheap and easy solution to gas plumbing it would be an off the shelf recommendation...........and it's not. Why is that? They could sell tons of it. I'd love to have a market I could toss my product into and own with no liability. Natural gas service is run in poly pipe. Very particular pipe installed in very specific ways.

I work in the RV industry and we plumb our vehicles with PEX. I understand it well. I've also seen everything that can be made from any kind of plastic/polymer that was installed on the outside of an RV sooner or later come back in pieces if it lived it's life in the sun.

 

[rlitman]

... Is PEX pipe fully UV stabilized?...

It is not even slightly UV stabilized, unless you're talking Pex-Al-Pex.

Still, while UV degradation of PEX may lead to cracking (and what some would describe incorrectly as brittleness), it will not cause a failure that results in shards being ejected.

 

[Angelfire]

The Pex-Al-Pex products are rated for air....regular pex as far as I know, is not although many have used it and it's worked for them. Pex-al-pex has some UV protection but the manufacturer's I've seen all recommend keeping it protected from sunlight...hence why I'm putting mine in my ceiling. I live in the desert and there's not much I trust to put up with the UV we get here (which is why I'm sticking it in the trusses/walls and covered up).
Cheers.

 

[Crazyjake8493]

i know a few people that have PVC lines running thru out there shops without issues.i'll be running it in mine soon.

We knew a neighbor that always worked under his truck with just a jack, no jack stands. One day, the jack let go and we had to go to his closed casket funeral.

Just because something works doesn't mean it's safe, or that you should be doing it.



Anyways, I would imagine PEX would split like copper if there was a failure, rather the rupture. I would consider plumbing my shop with PEX, but I don't do much work with air tools.

 

[L5wolvesf]

The Pex-Al-Pex products are rated for air....regular pex as far as I know, is not although many have used it and it's worked for them. Pex-al-pex has some UV protection but the manufacturer's I've seen all recommend keeping it protected from sunlight...hence why I'm putting mine in my ceiling. I live in the desert and there's not much I trust to put up with the UV we get here (which is why I'm sticking it in the trusses/walls and covered up).
Cheers.

Where can a guy get Pex-Al-Pex? HomeD or? Are there brand names I can search online?

Thanks

 

[Z2V]

I found this with a 5 second search

http://www.supplyhouse.com/Rifeng-PEX-AL-PEX-Tubing-12212000

 

[tonycastec]

Google RAPIDAIR for pex al pex

 

[Angelfire]

Where can a guy get Pex-Al-Pex? HomeD or? Are there brand names I can search online?

Thanks

I bought mine through.....wait for it.....Amazon! Badger Pipe sells there and they were the cheapest across all the sites I looked at.

That all being said, I'm having a helluva time finding the fittings. I am not investing in a press system where fittings are pretty common and am trying to use compression fittings but as I said, they are hard to find. Apparently, the PAP is really only being used in hydronic systems (ie. radiant heating) so manuf. have copped on that only certain fittings are needed and have discontinued many (such as reducting Tees, etc...). So do your homework first to see if you can locate the fittings you need before purchasing the tubing. I didn't even think ahead to fittings and am now regretting it a bit. You can get pretty much what you need from Rapidair but they are quite pricey
Cheers.

 

[L5wolvesf]

I bought mine through.....wait for it.....Amazon! Badger Pipe sells there and they were the cheapest across all the sites I looked at.

That all being said, I'm having a helluva time finding the fittings. I am not investing in a press system where fittings are pretty common and am trying to use compression fittings but as I said, they are hard to find. Apparently, the PAP is really only being used in hydronic systems (ie. radiant heating) so manuf. have copped on that only certain fittings are needed and have discontinued many (such as reducting Tees, etc...). So do your homework first to see if you can locate the fittings you need before purchasing the tubing. I didn't even think ahead to fittings and am now regretting it a bit. You can get pretty much what you need from Rapidair but they are quite pricey
Cheers.

Thank you

 

[L5wolvesf]

Google RAPIDAIR for pex al pex

Thank you

 

[Tim C]

We knew a neighbor that always worked under his truck with just a jack, no jack stands. One day, the jack let go and we had to go to his closed casket funeral.

Just because something works doesn't mean it's safe, or that you should be doing it.



Anyways, I would imagine PEX would split like copper if there was a failure, rather the rupture. I would consider plumbing my shop with PEX, but I don't do much work with air tools.

The pex splitting like copper has been my experience. The shop where I work was built in 1998. The Ingersoll Rand compressor charges all the pex lines to 175 max six days a week since then. It is shut off and the tank drained each night. All the lines are zip tied to the steel ceiling beams where the air hose reels hang except for three drops, one to a work bench in the middle of the shop, and two drops to two of the lifts which have air release safety locks. After 18 years in constant use the drops to both lifts failed this year months apart.

Both lines made a loud pop and split about 4-5" long. Each line or drop coming off the main line has a shut off so we were able to shut the lines off until repair could be made with minimal down time to the rest of the shop. Both the splits happened where the pex ran within 6-8" of the fluorescent lighting. When we cut out the broken pieces they felt brittle as described above a foot or so on each side of the split but the rest of the lines felt like normal pex.

We spliced in a new two foot section of pex with a rubber heater hose slipped over it to protect from uv off the fluorescent lights. Even with the pex crumbling and brittle it literally split like a copper pipe does when it freezes with no shrapnel.

After seeing this system in use daily I ran my personal garage with pex as well with no worries.

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