PEX for air - Reply from OSHA

[djjsr]

After reading several posts concerning using PEX for air line, I thought I'd contact OSHA to see whether or not they thought it was ok. I was hoping to get a straight yes or no answer but knowing how government agencies work, I had a feeling that would not happen.

My opinion is that if you have your own home garage or workshop, you can use an old garden hose for an air system if that's what you want. OSHA has no authority over what you do. But if you have a shop that's a business, with employees, you have to play by their rules. If something bad happens, you could have a serious problem.

So I sent an e-mail asking what I thought was a simple question ......

Topic: General Industry
Is there any "PEX" plastic pipe that is an approved safe material to use for piping a compressed air distribution system that is normally operated at approximately 140 psi. ? Submit Date: 19-MAY-15 08:43:28 AM

OSHA reply .........

Disclaimer - Responses to the Electronic Mail Forms are for informational purposes only, and do not constitute an official communication of the U.S. Department of Labor or OSHA. For an official response, please submit your inquiry in writing.

Thank you for your inquiry. I understand that you are interested in learning what the certification requirements are for a product that is to be sold in the United States. OSHA regulations require that certain categories of materials /
equipment are required to be approved by OSHA's Nationally Recognized Testing Laboratory (NRTL) per provisions of the General Industry Standard. The types of products that you are inquiring about do not fit into any of the categories covered by the NRTL program. A full list of the types of products requiring OSHA NRTL approval can be found at the following website https://www.osha.gov/dts/otpca/nrtl/prodcatg.html.

Please note that your product may need to comply with the requirements of other regulators including but not limited to the Food and Drug Administration (FDA), Federal Communications Commission (FCC) and the Consumer Product Safety Commission (CPSC). Each of these agencies may have unique requirements for your product.

If these references do not help you or if after reviewing this information you have questions about OSHA regulations and compliance with them, the most timely way to get an answer to your question is to contact OSHA.

-----------------------------------------------------

Well, I checked that NRTL link and found nothing related to compressed air systems. So I guess I don't know any more now than when I started. Or maybe I can use the old garden hose and it must be ok because it's not on the NRTL list?

But, as their last paragraph says, if I still have questions, the most timely way to get an answer is to contact OSHA.

Hmmmm ........... maybe I'll send them an e-mail?

 

[volleyball]

It seems you need to ask the question more directly. And explain you as an end user not a proposed mfg.

 

[mires]

I'm a plumber. We had a guy call last week trying to get on the schedule for us to replace his PEX air lines with copper. Said he was tired of blowouts First I had heard of anyone using PEX for air. We're so backed up that we couldn't even take the job though I wish we could have. Running copper lines for anything is by far my favorite part of the job.

 

[RECox286]

Government agencies and bureaus

I can think of several oxymora that may apply !

(But you didn't hear that from me...)

Uncle Bob

 

[joe_padavano]

Well, I checked that NRTL link and found nothing related to compressed air systems.

Possibly because of this:

The types of products that you are inquiring about do not fit into any of the categories covered by the NRTL program.

 

[finn]

Read the document they provided. I interpret it as a list of examples where certification is required, which does answer the op's question, as non flammable compressed air system piping is not on the list. Flammable and ammonia systems are on the list,

They would be irresponsible if they told you that a product i.e. pex is suitable for compressed air if the manufacturer does not market it as suitable for compressed air.

Remember, the vast majority of industry standards are NOT the result of government regulations or mandate, but rather products of various industry trade associations and technical groups, i.e. SAE, API, ASME, and probably a hundred others.

Accidents caused by applying materials or products outside of these guidelines may not result in violation of any federal or state regulations, but does not absolve one of civil liability.

Do you feel lucky? Is your insurance liability adequate to cover a negligence lawsuit?

 

[Scott r c]

I would just contact the manufacturer directly for approval, if they say its ok, then OSHA would be ok with it.

 

[j-guenth]

The Provost Air Products make some outstanding air lines and air line fittings.

I don't know what the cost would be but look them up.

 

[Dick in Wisconsin]

I would just contact the manufacturer directly for approval, if they say its ok, then OSHA would be ok with it.

This is a good idea. Let the manufacturer tell us if they have done the proper engineering and testing of its PEX tubing for compressed air. They might come back and say it is not "recommended" or "approved" for use in compressed air distribution systems ... or it "is" up to a continuous pressure of Xpsi and spikes of Ypsi.

I think the OP asked the question correctly. The response was disappointing.

I'm a plumber. We had a guy call last week trying to get on the schedule for us to replace his PEX air lines with copper. Said he was tired of blowouts First I had heard of anyone using PEX for air. We're so backed up that we couldn't even take the job though I wish we could have. Running copper lines for anything is by far my favorite part of the job.

This is interesting. I wish the guy who called the plumber would post his experience on the GJF.

Mr. Plumber ... couple of questions. If you were installing a compressed air distribution system in your own 1000sf garage shop, would you go with copper or black pipe? Reasons behind your preference?

Generally, presuming that a DIY guy can thread the black pipe properly and sweat copper joints correctly ... what is the cost difference between the two?

 

[djjsr]

I would just contact the manufacturer directly for approval, if they say its ok, then OSHA would be ok with it.

I did that a few years ago. They said it was not approved for compressed air because it was never tested for compressed air and it was never tested because that is not it's intended purpose.

Just to clarify, I have no intention of using PEX. I installed copper several years ago and I'm happy with it. The only reason I contacted OSHA was because I've read about guys on this forum using it and I was trying to find out if it was safe.

 

[Playwme]

I think you were lucky to get the reply you did. Do you understand how much it would cost a government department to have that question answered how you wanted?

Have you googled it? There are many commercial plastic options available, tested and approved. They're not PVC or PEX specifically, usually just another variation of PE.

 

[akdiesel]

djjsr

First - let me say, thank you for trying get some clarification on this matter.
Second - I have heard PEX - Al - PEX (aluminum jacketed PEX, the same as Rapid Air) is rated for air but I can not find this info now on the PEX website.
And Third - From what I know about OSHA is they really only make laws after the fact of a death or injury. So if this the case and there are no deaths or injuries related to PEX then we need a scape goat / test subject.

 

[Dick in Wisconsin]

If the PEX manufacturers were comfortable with the product liability of using PEX for compressed air, they would do the tests and label as such. I suspect there is a very good reason why it isn't labeled as for that type of usage.

 

[Scott r c]

If the PEX manufacturers were comfortable with the product liability of using PEX for compressed air, they would do the tests and label as such. I suspect there is a very good reason why it isn't labeled as for that type of usage.

I wondering if it has something to do with a lot of air lines being mounted exposed in shops, and the UV effect on PEX piping?

 

[nadogail]

Ryan - Herco sells, or did, a plastic pipe and fittings for compressed air plumbing.

I personally prefer metal pipe.

 

[mires]

Mr. Plumber ... couple of questions. If you were installing a compressed air distribution system in your own 1000sf garage shop, would you go with copper or black pipe? Reasons behind your preference?

Generally, presuming that a DIY guy can thread the black pipe properly and sweat copper joints correctly ... what is the cost difference between the two?

I guess it would all depend on exactly how much piping/fitting you had to use. I personally hate cutting and threading pipe but it would come out cheaper material wise for sure IF you already had the proper tools to do it with. I still would do copper though in my own personal shop if for nothing else besides I prefer the way it looks. I find it fun to work with, easier to repair and just looks pretty awesome in my opinion.

 

[RivennHewn]

I have had a few occasions to ask such questions, and I have found if you go direct to an inspector they will give you an answer.

Going to any government agency's main web page is going to get you nowhere.

 

[dynahoe]

I have no proof of this but... I read a post somewhere stating that the pex manufacturing plant uses pex for the airlines in their facility. Some guy wrote a letter to them asking about it's uses and he posted the reply. I use it and have no issues. but also no sunlight

 

[volleyball]

What country are the plants in?
I am not against using it. May try it when I expand inside. I will keep all outdoor plumbing iron pipe.

 

[TommyK]

PEX-AL-PEX is rated for compressed air.

 

[Trey T]

I believe the PEX tubings that's commonly use for water (hot or cold) is a safer material to be used on compressed air than PVC. PEX is a LOT more ductile (less brittle) than PVC. If you google up "PEX pipe burst" you'll see that the material is quite resilient. However, I'm NOT trying to convince people that the PEX is a safe material for compressed air but I know somebody out there will try to convince themselves otherwise.

 

[MoonRise]

Right from the 'trade group' for plastic pipes/piping:

http://plasticpipe.org/pdf/recommendation-b_transport_compressed_gas.pdf

where they seem to say it might be OK to use PEX for with compressed air, with caveats about protecting it from UV, physical damage, and securing/protecting it from 'whip' in case of failure (bury it or put it in conduit, pretty much).

But, I went the extra step and went to a manufacturer's website (NIBCO) and checked some of the info there. Looked, and looked, and looked some more.

Finally found an actual definitive statement regarding using PEX for compressed air.

The answer is "No".

NIBCO PEX Installation Manual, page 15

Frequently Asked Questions
Q: What if my tubing gets kinked?
A: Cut out the kink.
Q: Can I use NIBCO® PEX as an electical ground?
A: PEX does not conduct electricty and can NOT be used as a ground.
Q: Can I use NIBCO® PEX outside?
A: NIBCO PEX has UV stabilizers which allow for some limited exposure to sunlight during the installation process. But like all PEX,
it is not intended for outdoor installation and should be protected, to the greatest feasible extent, from exposure to UV light at all times.
Q: Can I use NIBCO® PEX for compressed air or natural gas?
A: These are not intended or approved uses of the product.
Q: How are NIBCO®poly PEX fittings used?
A: NIBCO’s poly PEX fittings (made of PPSU) can be used in all the same potable water applications as brass fittings. They are naturally lead
free and are time tested. They are subject to degradation when exposed to PVC and CPVC primers and glues - so avoid this condition!
Q: Can NIBCO® PEX be used for cold water service lines?
A: Yes. Although the enhanced temperature resistance of PEX makes it particularly suitable for hot- and cold-water interior plumbing
applications, it also makes excellent underground water service piping.

http://www.nibco.com/Literature/PEX/

go to the Product Data Sheets section, PEX Installation Manual, IM-PEX-1011

http://www.nibco.com/WorkArea/DownloadAsset.aspx?id=1365

 

[dynahoe]

I am 1 year in on pex-al-pex 1 inch id and no leaks or problems.

 

[maxpower_hd]

We have PVC in our shop at work and I can tell you it blows....and not in a good way. We are planning on replacing it with poly that IS air rated. We already have the line. I don't know which brand it is but it is similar to the on in this link. I would just buy one that is rated for air. The one in the link is rated for up to 200 psi.

http://www.polyconn.com/duratec-pipe-system-bendable-pipe-c-3-l-en.html

 

[Dick in Wisconsin]

I still would do copper though in my own personal shop if for nothing else besides I prefer the way it looks. I find it fun to work with, easier to repair and just looks pretty awesome in my opinion.

Do you polish the copper or leave it natural?

 

[dkroth]

Do you polish the copper or leave it natural?

I polished the exposed parts of my copper air line installation. It looked good for about a year but turned brown quickly after that.

 

[djjsr]

If you want to keep the copper looking good, clean it up with some scotchbrite then spray it with some rattlecan clear. I did some about 8 years ago and it still looks new.