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Can Pex be used for air lines?

jlansaw

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Nov 30, 2009
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Central Illinois
I find conflicting arguments regarding the use of PEX tubing for air lines. :headscrat
I know people are using it for air lines but what are the problems associated with its use. The cost of PEX for a compressed air system in my new shop would be considerably less than copper or black pipe not to mention easier to install. I plan to run lines in the attic and inside the walls so uv is not a concern. Your thoughts and experience appreciated!
 
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mrvalvoline

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Nov 13, 2009
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I installed pex tubing (truck air brake line) and the push connect fittings in my shop, and have freinds tha have used it for years. No problems. Easy to modify (I added additional outlets after I installed my lift) I ran mine on the shop wall, not in the wall.
 

spongerich

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Monroe, NY
PEX-AL-PEX is rated for compressed air use. It's a PEX-Aluminum-PEX sandwich.

I priced some a little while ago. It's cheaper than copper and a lot quicker to install.


I just used some PVC*















*NOT REALLY - NEVER USE PVC - FOR ANYTHING. IT'LL KILL YOU DEAD.




http://www.lowesforpros.com/get-to-know-pex
 
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oldtractors

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

srmofo

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SW ohio
I think I have heard some people say it doesnt pull the heat out of the air as well and therefore doesnt pull the moisture out. I honestly dont think that its that big of a deal or big of a problem. Then again, Im not painting cars.
 

Torque1st

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Plastic tubing is hard to get sloped right for moisture removal. Moisture tends to collect in the low spots and "burps" out. But then plastic lines don't cool the air very well in the first place so moisture will mostly find it's way out at the tool. Putting plastic lines inside a wall just adds insult to injury for moisture removal.

Follow the directions here:
http://www.tptools.com/
http://www.tptools.com/StaticText/airline-piping-diagram.pdf

Air lines are not rocket science but there is no need to reinvent the wheel either.
 

jduffle

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Jun 2, 2010
Messages
50
Confession time!

My and my dads garage has been plumbed with sched 40 PVC pipe for our air line for over 10 years now and doesn't leak a bit!

I know some may think we are crazy or stupid, but it works and has done so for 13 years now that i figured up how long its been since we renovated it.

Jim
 

danski0224

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Location
Near Naperville, IL
Confession time!

My and my dads garage has been plumbed with sched 40 PVC pipe for our air line for over 10 years now and doesn't leak a bit!

I know some may think we are crazy or stupid, but it works and has done so for 13 years now that i figured up how long its been since we renovated it.

Jim

You won't get any warning when it lets go.
 

scott37300

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

Here we go with the PVC debate!

If you use it and it works then good for you-till it explodes and sends millions of shattered pieces of plastic everywhere. Some things you can go cheap on, pvc air lines is not something I would ever chose to. I can use a block of wood under a car as a jack stand also. It would be great until the day it rolled or slipped and then the 30-40 bucks I saved not using the right material doesn't seem like such a savings.

To the OP, I'm not sure if just regular pex is rated for air lines or not. Or if it is a good idea or not. But I can tell you that you should have 30-40 FT of copper or black pipe right out of the compressor before any pex. This is to cool the air and take the condinsation out of it. Plastic will not cool the air like metal pipes will. Then AFTER the air is cool, not right next to the compressor you need a filter of some sort.

All of this has been discused in great depth, I'm sure if you do a search you will find many hours of reading on air lines.
 

collmorgen

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Deep East Texas
The chemical plant that I manage uses PEX for all instrument air. The white is not UV stable but the black is. Works fine for six years now.
 

Steevo

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If we put all of the PVC debate threads on GJ together end-to-end, we could wrap it around the world three times.

We need a sticky with them all in it, and then we can provide a single link to use as a default response to "why not PVC"?
 

mikeyr

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

Could you put me in your will so I can get your tools ?

My and my dads garage has been plumbed with sched 40 PVC pipe for our air line for over 10 years now and doesn't leak a bit!

I know some may think we are crazy or stupid, but it works and has done so for 13 years now that i figured up how long its been since we renovated it.

Been living on borrowed time quite a long time, think its time to replace that stuff.


All joking aside, PVC will shatter and send out shrapnel, you most likely will not be injured because unless you spend your life in the garage, you wont be there or will be in the other end. Your odds of winning the lottery are better then the odds of getting hurt by PVC lines going boom, but why risk it.

Think of it like a garage and car guy, you will not be harmed but your cars new paint job will be destroyed...now are you willing to let that happen ?
 

mad57

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Jan 30, 2009
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i know a few people that have pvc lines running thru out there shops without issues.i'll be running it in mine soon.

dont do it...how are we gonna cruise carlise sea pirate ect ... If your dead or cant see from pieces of pvc in your eyes.
 

fflintstone

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MOFnowhere Mi.
We all want to be relatively safe when working in our garages. I myself will be having a young son of mine with me. There are hundreds of people on this site that talk about the dangers of PVC pipe for airlines, and hundreds of people that say they have been using it with no problems.
I myself would like to see PHOTOS of exploded airline and MULTIPLE documented cases of PVC failure. I just Googled “ PVC air explosion” and the top ten replies turned up this 22 year old document. When I have time I may look for more compelling proof but for the source to be quoted so often I would HOPE it is correct.


(This document was shortened to fit the 10,000-character limit)

Occupational Safety & Health Administration
OSHA Hazard Information Bulletins

The Use of Polyvinyl Chloride Pipe in Above Ground Installations.
OSHA Hazard Information Bulletins - Table of Contents by Year OSHA Hazard
Information Bulletins - Table of Contents by Year

* Information Date: 19880520
* Record Type: Hazard Information Bulletin
* Subject: The Use of Polyvinyl Chloride Pipe in Above Ground Installations.

May 20, 1988

MEMORANDUM FOR REGIONAL ADMINISTRATORS

THRU: LEO CAREY
Director
Office of Field Programs

FROM: EDWARD BAIER
Director
Directorate of Technical Support

SUBJECT: Safety Hazard Information Bulletin on
the Use of Polyvinyl Chloride (PVC) Pipe
in Above ground Installations

The Dallas Regional Office has brought to our attention a potential serious hazard
existing with the use of polyvinyl chloride (PVC) plastic pipes for transporting
compressed gases in above ground installations. An employee in a Texas plant was
injured recently by a rupture in a PVC compressed air line. Plastic projectiles from
the point of rupture caused lacerations of the employee's hand. This is noteworthy
because the Plastic Pipe Institute, in its Recommendation B dated January 19, 1972,
recommends against the use of thermoplastic pipe to transport compressed air or
other compressed gases in exposed plant piping. (See attachment.)

Furthermore, sections 842.32, 842.43 and 849.52(b) of the American National
Standards Institute/American Society of Mechanical Engineers (ANSI/ASME) B31.8-1986,
Gas Transmission and Distribution Piping Systems Standard, limit the operating
pressure of plastic piping distribution systems to 100 pounds per inch (psi) and
prohibit the installation of such systems above ground except where ". . . the above
ground portion of the plastic service line is completely enclosed in a conduit or
casing of sufficient strength to provide protection from external damage and
deterioration." (Excerpts attached.)

Additional consensus standards applicable to PVC compressed gas systems include
American Society for Testing Materials (ASTM) D1785-86, Standard Specification for
Polyvinyl Chloride Plastic Pipe, Schedules 40, 80, and 120, and ASTM D2513-86a,
Standard Specification for Thermoplastic Gas Pressure Piping Systems.

Please disseminate this bulletin to all Area Offices, State Plan States and
Consultation Projects.

Attachments


February 14, 1989

Mr. Jack Cannova Tempe
Industrial
412 W. Dryon Street
Tempe, Arizona 85283

Dear Mr. Cannova:

In response to your recent inquiry concerning our regulatory position on the use of
plastic pipe for compressed air systems, I trust this letter will clear up any
confusion over the issue.

It is our position that PVC pipe shall not be used as a means of transporting
compressed air. This position follows the manufacturer's own statements that PVC is
unsuitable for compressed air systems. We do allow the use of certain ABS materials
that are specifically designed for compressed air systems. One such product is
"Duraplus" air line piping system ABS pipe. However, as in any such system, the
manufacturer's specifications on acceptable pressure and temperature considerations
must be followed.

In closing, misapplication of a product, such as using PVC for compressed air
systems, may result in citations and penalties being issued dependent upon the
specific conditions.

I appreciate your concern and inquiry into this potential safety hazard.

Sincerely,

SAM A. ROGERS
Bureau Chief


October 5, 1988

Mr. Tim Arbogast
Arizona OSHA
800 W. Washington
Phoenix, Arizona 85007-2922

Dear Mr. Arbogast:

It has recently come to my attention that there is a severe safety regarding the
improper usage of plastic polyvinyl chloride (PVC) pipe. This pipe is designed for
the transmittal of liquids, and is dangerous when used for transmitting compressed
air or gas. Unfortunately, PVC has been frequently used with compressed air in
construction projects across the country.

The state of Washington has notified the public that PVC pipe is not to be used in
compressed air systems. I have also learned that the state of Nevada is in the
process of making a similar determination and announcement. Additionally
manufacturers of this product advise against its use with compressed air in their
catalogue publications.

I believe that it is in the best interests of the citizens of our state if your
office would expeditiously make such an announcement. A notice to users of the
hazards of PVC pipe - when used improperly - would have the effect of preventing
possible severe injury to people who work with or near this product.

By way of this letter, I am contacting the Department of Labor, OSHA, in Washington,
D.C. and asking their officials to report to me on actions taken on the Federal
level to restrict the use of this pipe and to notify users of the potential hazards
involved in improper use of PVC pipe.

Your timely consideration of this request is appreciated.

Sincerely,

DENNIS DeCONCINI
United States Senator


STATE OF WASHINGTON
Department of
Labor & Industries
Hazard Alert

For more information, call: 1-800-423-7233

FOR IMMEDIATE RELEASE May 26, 1988

PVC pipe not to be used in compressed air systems

OLYMPIA -- The Department of Labor and Industries warned today that plastic
polyvinyl chloride (PVC) pipe cannot be used in compressed air piping systems
without the risk of explosion.

When PVC piping explodes, plastic shrapnel pieces are thrown in all directions.

"We're seeing more incidents of explosive failure, and we're citing more employers
for using PVC air system piping," said Paul Merrill, senior safety inspector in
L&I's Spokane office.

"It's probably just a matter of time before someone gets seriously injured in one of
these explosions unless everyone pays more attention to the manufacturer's
warnings," Merrill said.

Last year, a section of PVC pipe being used for compressed air exploded 27 feet
above a warehouse floor. A fragment of the pipe flew 60 feet and embedded itself in
a roll of paper. Fortunately, nobody was in the area at the time.

A PVC pipe explosion in a new plant in Selah broke an employee's nose and cut his
face.

PVC piping buried 3 feet underground at a Yakima manufacturing plant exploded,
opening up a crater approximately 4 feet deep by 3 feet across.

Only one type of plastic pipe has been approved for use with compressed air. That
pipe, Acrylonitrile-Butadiene-Styrene (ABS), is marked on the pipe as approved for
compressed air supply.

By law, employers must protect their workers by avoiding the use of unapproved PVC
pipe in such systems. Existing compressed air systems which use PVC piping must be
completely enclosed, buried or adequately guarded according to specifications
approved by a professional consulting engineer.

NOTICE TO EMPLOYERS: If you have questions about the suitability of a material for
air system piping, call Labor and Industries at the number listed above for a free
consultation.

NOTICE TO EMPLOYEES: If you suspect that a pressurized PVC piping hazard exists,
bring it to the attention of your employer. If you do not obtain satisfactory
results, you may file a confidential complaint with the Department of Labor and
Industries. Complaints are investigated promptly.

THE INDUSTRIAL COMMISSION OF ARIZONA
DIVISION OF OCCUPATIONAL SAFETY & HEALTH
P.O. BOX 19070
PHOENIX, ARIZONA 80005-9070

HAZARD ALERT

We have recently been made aware of a potentially serious hazard involving the
prohibited use of unprotected plastic (PVC( piping to transport compressed air and
other compressed gases in above ground installations.

While in Arizona we are not aware of any incidents of ruptured or exploding plastic
pipes, States such as Washington and Texas have experienced incidents and injuries.
Despite the lack of incidents in Arizona, we full recognize the potential for
similar occurrences in this State and thereby request that you review your
facilities and replace any such unsafe installations.

The Arizona Division of Occupational Safety and Health will be providing a program
of awareness, assistance, and enforcement. This notice will be going to
representatives of industry associations, labor organizations, print and electronic
media.

Through our consultation and training program we will be providing assistance based
upon requests received from employers. Through our compliance programs, we will be
conducting unannounced inspections to ensure compliance with manufacturers'
specifications and American National Standards Institute and American Society of
Mechanical Engineers' Standard B 31.8-1986, which limits the operating pressure of
212-370-7341
RECOMMENDATION B
THERMOPLASTIC PIPING
FOR THE TRANSPORT OF COMPRESSED AIR
OR OTHER COMPRESSED GASES
 
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Torque1st

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Messages
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We all want to be relatively safe when working in our garages. I myself will be having a young son of mine with me. There are hundreds of people on this site that talk about the dangers of PVC pipe for airlines, and hundreds of people that say they have been using it with no problems.
I myself would like to see PHOTOS of exploded airline and MULTIPLE documented cases of PVC failure. I just Googled “ PVC air explosion” and the top ten replies turned up this 22 year old document. When I have time I may look for more compelling proof but for the source to be quoted so often I would HOPE it is correct.

There are a number of GJ members that have seen PVC pipe explosions, including myself. There are a number of posts here from those members, some with photographs. I doubt the "hundreds" you stated either way. That document you found is easy to find because it is often quoted. There are many others. Keep looking and you will find them.

All of the PVC pipe manufacturers have statements on their websites and product literature about not using PVC for compressed gasses/air. I would think they would know the product best. I would also suspect they would love to market PVC for compressed air systems for the increased sales if it was safe. PVC manufacturer's literature also state the pressure ratings are for liquids only.

EVERY time the subject of PVC for air lines comes up someone will smugly say they are using it with no problems. I guess they want to talk someone else into being cheap and using it so they can feel better about being cheap and unsafe. After all, they are not around your shop but you, your friends, neighbors, wife, and children are. Lawyers LOVE PVC.
 

shotgunfatcat

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Joined
May 19, 2010
Messages
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Location
I am the Wanderer
The only Pex tubing I have found is only rated for 160 PSI, I guess my tanks goes to 150, but a buffer zone (outside the safety factor) is kind of nice.

Is there Pex tubing with a higher rating?
 

shotgunfatcat

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Joined
May 19, 2010
Messages
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Location
I am the Wanderer
I understand that, I was wondering what the PSI rating was, from what I find it is only 160 max psi. My tank can run higher than that although I keep it at 150 psi.
 

oldtractors

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Nov 19, 2007
Messages
374
Location
Iowa
It is too bad every time someone asks about PEX, it turns into a PVC debate.
Then someone says, "search the site, there are multiple threads on this." Unfortunately you have to use Google to search since PEX is only 3 letters and then you have to read through 10 pages of PVC posts to find the one guy that says "Yes, PEX will work fine for airlines, but is not rated for it."
 

Torque1st

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Messages
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Working pressure is a fraction of burst pressure and varies with size. Pipe and tubing is derated depending on the material and a number of failure modes or installation circumstances. Pipe and tubing also must be derated for various fluids they contain. Usually the manufacturer's literature will list compatible fluids and conditions. The terminology used in spec sheets can be confusing. If in doubt, call the manufacturer and talk to an application engineer. They may even be able to give you some tips or point you towards another material or product.

Pay no attention to RbrtAWhyt. He is another one of those guys that uses PVC and wants company so he can feel better about using it himself. Misery loves company.
 

fflintstone

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Joined
Jul 18, 2010
Messages
2,722
Location
MOFnowhere Mi.
I have figured a way to settle this PVC- iron pipe air lines debate! we will put “torque1st” in a room with “rbrtawhyt” and give each of them a 5 foot length of there preferred shop air pipe and see which one fairs better. HAHAHA!!:lol_hitti:deadhorse

All kidding aside, I did do more research and did not find definitive info on the OP’s pex question, PEX-AL-PEX or any other alternative to black pipe or copper. The only reason to use anything else would be ease of assembly and cost. :headscrat
I also did an image search for PVC air explosion, And found lots of wicked air powered spud guns. The only “exploded” PVC pipe I found was where someone had put 150 psi in a pipe and shot it with a .22.:gunfire:

I also found that the arguments for PVC vs. black pipe vs. copper vs. aluminum tube, are virtually the same on machinist, woodworking, welding and every other forum.

I have not made a decision on my own shop as that is a good 6 months or much more away. I would like to use copper but I will do some tests to see how hard it is to braze copper pipe. If I go black pipe I will be looking at the pipe/fittings at plumbing supply places. I refuse to try to make an airtight seal with the Chinese stuff they sell at box stores.
 

Steve_P

Well-known member
Joined
Sep 15, 2010
Messages
5,185
I believe that typical PEX is not rated for compressed air because the possibility that oil in the air (from the compressor) will break down / weaken the tubing over time.

mfgs of a product that's designed for a specific purpose, ie, transporting water, are not going to say, "yeah, use it for compressed air at 150+ psi"; that's just inviting lawsuits. So, you will get the people that say "it works for me..." like with PVC and compressed air.

As said, do it with copper tubing, do it right, and once, it'll last forever.
 

arb905

Active member
Joined
Dec 25, 2010
Messages
40
I'm not going to say PVC is safe to use for air lines. fflinstone used a report that made note of industrial use for air lines. I've worked on industrial compressors. They run at 175+psi. Also the one in Texas was run above ground. Plastic in Texas will not survive in the sun, I've lived there and know. The other problem was the report is 22 years old. There have been great advancements in chemicalas and production since then. Check the charts for max operating pressures. Also CPVC is different than PVC adnI have seen CPVC used for shop air under 150psi. I would assume the problem will come when you realize the medium used in the lines, water will not compress like air will. That gives air a much more damaging force.

Six to one, half dozen to the other. Good luck.
 

contactme_11

Well-known member
Joined
Dec 27, 2010
Messages
106
We all want to be relatively safe when working in our garages. I myself will be having a young son of mine with me. There are hundreds of people on this site that talk about the dangers of PVC pipe for airlines, and hundreds of people that say they have been using it with no problems.
I myself would like to see PHOTOS of exploded airline and MULTIPLE documented cases of PVC failure. I just Googled “ PVC air explosion” and the top ten replies turned up this 22 year old document. When I have time I may look for more compelling proof but for the source to be quoted so often I would HOPE it is correct.

http://www.tractorbynet.com/forums/...air-lines-garage-533672-pvc-pipe-blowup-3.jpg
 
OP
J

jlansaw

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Joined
Nov 30, 2009
Messages
48
Location
Central Illinois
fflinstone is correct, the reasons I am considering PEX is ease of install and price. I had no intentions of using PVC nor did I want to spark the debate. Everyone jumping on that is kind of dissapointing. As for searching for prior PEX thread questions, I tried but didn't find what I thought I should see. Maybe I wasn't using search feature correctly or wasn't looking in right spot. Everyone is at different stages with all their projects and everyones experiences is what draws me to this sight, however if asking a question that has already been debated in a thread 3 years ago is a problem then maybe I shouldn't participate here.
 

mad57

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Joined
Jan 30, 2009
Messages
1,698
(however if asking a question that has already been debated in a thread 3 years ago is a problem then maybe I shouldn't participate here. )

There is no problem ask away thats what this site is all about, i have gained a ton of info from here while building my shop and continue to do so please dont let a few comments about the dreaded pvc get you down, my 2 cents i think pex would be fine... i personally went with a hybrid my compressor is out side about 30 ft away so i ran flex line braided hydrolic hose about 3 ft then 3/4 galvanized pipe under ground then i started to use 3/4 black iron but found it to inconstant it was oval and wouldnt thread for sh*t bought new cutting oil new cutters nothing worked so i returned it all to hd and just bought 3/4 copper and am happy with it..... i currently have a small leak guess where in the damn galvanized pipe which just developed so i can never leave the compressor (on) when im not out there, a full tank will last about week and a half so its a slow leaker..anyway good luck .
 

darkk

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Dec 24, 2009
Messages
3,361
Location
Willimantic, Ct.
Pex tubing is perfect for shop airline as long as you don't run the pressure over 130lbs at over 120deg according to the manufacturer. Trust me, pex is a lot stronger than that. I had to pressure test my home water piping for the town building inspector. I just pumped it to 125lbs and left it for a couple weeks til he showed up....
 
OP
J

jlansaw

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Messages
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Location
Central Illinois
As for now I think I'm going to run a couple lengths of 3/4" black pipe right off the compressor and up into the attic then switch to 3/4" pex for my main line and use 1/2" pex for my drops inside the walls. I think this will make the install relatively easy. I don't want mess with cutting and threading a complete black pipe system. I'm gonna make my own aluminum outlet blocks for surface mounting sorta like the rapidair outlet. Maybe I'll throw up some pics when I get to it and give everyone something to talk about.
 

axel

Member
Joined
Oct 23, 2010
Messages
9
there is a material similiar to pvc. Rated to 300 psi. It is glued together like pvc with elbows and unions. My friend used it in his shop. Had a couple drops for connections and a couple for water drains.
 

Torque1st

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there is a material similiar to pvc. Rated to 300 psi. It is glued together like pvc with elbows and unions. My friend used it in his shop. Had a couple drops for connections and a couple for water drains.
There was an ABS material that was rated for air pressure. AFAIK it is not available anymore.
 

mad57

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Jan 30, 2009
Messages
1,698
As for now I think I'm going to run a couple lengths of 3/4" black pipe right off the compressor and up into the attic then switch to 3/4" pex for my main line and use 1/2" pex for my drops inside the walls. I think this will make the install relatively easy. I don't want mess with cutting and threading a complete black pipe system. I'm gonna make my own aluminum outlet blocks for surface mounting sorta like the rapidair outlet. Maybe I'll throw up some pics when I get to it and give everyone something to talk about.

Why not just keep it out side the wall if you ever need to fix it its easy... how about just a short drop from attic to a hose reel or seperator than hose reel heres what i did. see hose reels on wall behind the 57.
 

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arb905

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Dec 25, 2010
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AXEL,
its CPVC. its rated for higher water pressures and for hot water. PVC is not pressure rated for high temps. CPVC is tan uses a yellow ABS glue. You can also buy the new metal or plastic Gator fittings for a quick fit system that can be taken apart. Those fittings can be used on PEX as long as you use the ferrel.
 
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