PVC air lines

[swvega]

I just finished plumbing my new shop with pvc. Had it in a past shop for 10 yrs no problems. A freind of mine said his has been in for almost 20. I used sec 40 pipe 3/4 in. marked on side 600 lbs pressure. Just be sure you have a flexable line from compressor to the pvc air line. And dont run into it. and attach well to wall.

 

[Stephenw]

It is simply unbelievable this topic comes up so many times on so many shop related forums.

OSHA SAYS NO TO PVC AIRLINES! THE PIPE MANUFACTURERS SAY NO TO PVC AIRLINES! IT'S UNSAFE!

 

[Charles (in GA)]

There is a small family owned tire shop that I use for all my tire business now, good people, neat shop (not spotless, just neat) same people working there every time I go in.............. but they have PVC air lines. Like everyone who uses the stuff, its not mounted real well, runs down the top of the tire storage racks, along the roof purlins (steel building) and everywhere else, kinda floppy.

I brought up the subject of PVC and the dangers of it and how if something happened, the state OSHA people (who actually do most of the enforcement of both state and federal rules at the small business level) would not be happy at all. They told me they've never had a problem, been there for 20 years, yet I'm standing there looking around and see new pieces spliced in here and there........... Hmmmmmmmmm!!!!!

Charles

 

[Mr.Nutcase]

use copper.....

 

[Ramblur]

I witnessed a PVC airline explosion in an automotive machine shop/parts
store I worked at about 25 yrs. ago. Bossman left the radiator torch running
and laid it on the side of the water tank instead of back in its holder while
he answered the phone. After the phone call we broke for lunch out front
and halfway through my sandwich was one hellacious explosion that knocked
40 years worth of dust outta the ceiling(and onto my sandwich)
Obviously the heat from the torch had softened the pipe but it was still
a few feet away. That 3/4" line musta been the size of a football before it
let go. Can you say shrapnel? The largest piece I found was about the size
of a dime. No PVC for me!

 

[Torque1st]

The PVC pipe manufacturers would LOVE to sell PVC pipe for shop air but they KNOW it is dangerous and having warnings stating such.

I guess someone like OSHA will need to push thru legislation to have the side stripe on PVC and regular ABS pipe say it must not be used for compressed gasses. Some people would probably still interpret that to mean not to use it with natural gas because they don't realize air is a gas. People can be unimaginably stupid about such things.

Stupidity is why we have warning stickers on lawn mowers about not sticking your hands under them and not using them as hedge trimmers. The same sort of people that would do that will use PVC for compressed air because there is a pressure rating on the side of the pipe. Even if they removed the pressure rating (I think it would be a good idea) some people would "remember" it used to be good for 500PSI or some such number and go ahead and use it anyway. Then they tell others it is safe to use PVC because they did. The PVC pipe manufacturer obviously does not know anything.

 

[e-tek]

I witnessed a PVC airline explosion in an automotive machine shop/parts
store I worked at about 25 yrs. ago. Bossman left the radiator torch running
and laid it on the side of the water tank instead of back in its holder while
he answered the phone. After the phone call we broke for lunch out front
and halfway through my sandwich was one hellacious explosion that knocked
40 years worth of dust outta the ceiling(and onto my sandwich)
Obviously the heat from the torch had softened the pipe but it was still
a few feet away. That 3/4" line musta been the size of a football before it
let go. Can you say shrapnel? The largest piece I found was about the size
of a dime. No PVC for me!

This same thing could conceivably occur with copper lines as well - too much heat near a soldered joint and kA-BOOOOM!

Just HAD to stick that in!

 

[burleymike]

Personally if I was going to use PEX it would be PEX-AL-PEX. I would also make sure it is all sleeved since UV exposure longer than 6 months will start to un-crosslink it. The other thing is making sure no compressor oil can get to the PEX.

 

[79firebird]

a local auto shop just moved and used pvc agane with no prob passed inspections but it was in a 2x6 wall i my self have it ran to my car shelter but its 1 foot under ground. A buddy of mine has it in his shop still no prob with it with a pice of rebar with 125psi in it only cracked 2 feet along and dident blow any thing out replaced 2 feet and its fine. i know its true as i was 10 feet away as it hapened. i have seen plastic pvc pipe blow yes. BUT the where exposed to the sun for months then hit and they will shatter

 

[Torque1st]

This same thing could conceivably occur with copper lines as well - too much heat near a soldered joint and kA-BOOOOM!

Just HAD to stick that in!

At least it would not throw shards of the pipe around... I suppose a couple of particles of solder may go flying.

 

[Torque1st]

a local auto shop just moved and used pvc agane with no prob passed inspections but it was in a 2x6 wall i my self have it ran to my car shelter but its 1 foot under ground. A buddy of mine has it in his shop still no prob with it with a pice of rebar with 125psi in it only cracked 2 feet along and dident blow any thing out replaced 2 feet and its fine. i know its true as i was 10 feet away as it hapened. i have seen plastic pvc pipe blow yes. BUT the where exposed to the sun for months then hit and they will shatter

Even NEW PVC will shatter while under pressure. It is the nature of the material. See the post about the test performed above. I am sure he did not use OLD UV degraded PVC test specimens.

DO NOT USE PVC FOR COMPRESSED AIR!!

 

[Identaltech]

just thought I would throw this out.
seems like some are worried about copper failing in a fire and spredding the fire
and if you dont use black pipe the firemen will not go in.
how about all the medical building that use copper for the medical gas?
one of them if 100% oxygen.
that would fan your fire way more than any of your compressor could ever thing of.
and as for in the garage would'nt the rubber hose on both ends of your piping system burst in a fire way before anything
IE pvc, copper or black pipe.
and for the record I would not use pvc

 

[Jeepguy]

I too would like to know why this is such a bad idea. Oh and by the way, thanks for the condescending response.

Look into Copro, or Probite fittings, they are for standard OD copper, stainless pex. similar to sharkbite fittings, but the copro and probite fittings are removable, reusable, and can be rebuilt it a seal goes bad. i think the website is www.quickfittings.com

 

[Torque1st]

just thought I would throw this out.
seems like some are worried about copper failing in a fire and spredding the fire
and if you dont use black pipe the firemen will not go in.
how about all the medical building that use copper for the medical gas?
one of them if 100% oxygen.
that would fan your fire way more than any of your compressor could ever thing of.
and as for in the garage would'nt the rubber hose on both ends of your piping system burst in a fire way before anything
IE pvc, copper or black pipe.
and for the record I would not use pvc

Most of the time firemen have no idea whether a home even has a compressed air system much less whether it has copper or iron pipe.

Firemen are well aware of medical oxygen systems and the associated hazards and safeguards. They also know which buildings have them.

Rubber will definitely burst. From the articles I have read the fire authorities seem to be worried about ANY soldered joint failing when exposed to localized heat at the start of a fire which would fan the flames. Anything that fans the flames decreases detection time and human escape time as well as reduces the time available for firemen to save the structure or contain the damage. Time is a big enemy in any fire.

 

[Identaltech]

SILVER SOLDER SOLDER MELTING TEMP PERCENTAGE SILVER
Hard 773 c 76%
Medium 747 c 70%
Easy 711 c 60%
Easy-Flo 681 c 50%
at 1258 fahrenheit mealting piont with 50 % silver I think you should have been out a long time ago.

info came from my med. gas book
I know the joint would let go at a lower temp but what is the max temp a human could survive.
cant help but think we are splitting hairs.

 

[Torque1st]

SILVER SOLDER SOLDER MELTING TEMP PERCENTAGE SILVER
Hard 773 c 76%
Medium 747 c 70%
Easy 711 c 60%
Easy-Flo 681 c 50%
at 1258 fahrenheit mealting piont with 50 % silver I think you should have been out a long time ago.

info came from my med. gas book
I know the joint would let go at a lower temp but what is the max temp a human could survive.
cant help but think we are splitting hairs.

There are other discussions here on air line materials other than PVC. Maybe you could post that information in them for future reference. It is good information to have.

As I recall the municipal codes disallowed copper in general but we have had discussions here on GJ re using the silver brazing materials vs soft plumbing solder. I think it may be the lack of being able to identify the material that was used to join the copper easily that may have led to copper in general being banned by those municipalities. I just read the resulting ordinances and was not privy to the decision making process.

If humans were in the room at the time the fire broke out there would be no problems because they could escape and give the alarm. Therefore the temperature at which they could survive has no bearing. It is a fire that breaks out in a garage while people are asleep in the home that gives the authorities problems. Fires in medical facilities and shops or factories full of combustibles are another matter.

 

[e-tek]

just thought I would throw this out.
seems like some are worried about copper failing in a fire and spredding the fire
and if you dont use black pipe the firemen will not go in.
how about all the medical building that use copper for the medical gas?
one of them if 100% oxygen.
that would fan your fire way more than any of your compressor could ever thing of.
and as for in the garage would'nt the rubber hose on both ends of your piping system burst in a fire way before anything
IE pvc, copper or black pipe.
and for the record I would not use pvc

All the hospitals I've worked in use SS lines for compressed gasses......

 

[Identaltech]

hospital yes but medical building they use copper and silver solder all the joints and charge with dry nitrogen to check for leaks.
the systems we install run at 55 psi with 100psi pressure relifs
O2 is run in 1/2 and N20 is 3/8 and the wag gases in 3/4
compressed air in 3/4

 

[Torque1st]

All the hospitals I've worked in use SS lines for compressed gasses......

But you must realize Canadians are SMART!

 

[Identaltech]

But you must realize Canadians are SMART!

I would agree

 

[thdewey]

I went to HD last week to get my galv steel pipes for my air lines. When I got to the plumbing dept I told the guy what I wanted to do. He said that he knew just what to use. Half way down the aisle, I said "you are going to suggest PVC are you?" He said "Uh, yeah it's rated for the pressure." I proceeded to tell him everything I learned from this site. I got the pipe I needed and left. When are they going to start hiring old contractors again. Geesh.

 

[buening]

Galvanized pipe has worked very well for my. Some worry about the galvanizing flaking off inside the pipe, but if you have a good filter at each outlet then there is nothing to worry about. I think my filter is either 1 or 5 micron and is a combination filter/regulator made by Norgren. If you keep an eye out on ebay, you can find new quality brand filter regulators cheaper than the chinese junk from HF. I paid $50 for 8 of the filter/regulators on ebay....to give you an idea of price.

 

[HoosierBuddy]

PVC shouldn't be used for compressed air and anyone that not only does it themselves but recommends it to others in an open forum (like this) when it is against code and against the manufacturer's direct instructions should reconsider their position and RETRACT their advice immediately.

As far as the "home depot" salesman that recommended PVC for air...it brings to mind a problem I had at the gas company, where I work. We were shutting off meters in a particular town on a regular basis because we were finding PVC being used for natural gas on the customers' side of the meter.

I finally went to this little town's little hardware store and told them "this ****'s gotta stop." You know...we haven't run into a single instance of PVC being used for gas since. It's amazing how many people one misinformed person at a hardware store can convince to do something dangerous.

BTW...when we shut these people off and tell them they won't have service until they replace the PVC they all say the same thing...Well...It's never caused a problem....

Yeah? Well when it does cause a problem it's going to be a BIG problem. And natural gas runs at about 0.25 PSI after the meter. I don't give a darn if the PVC says 600 psi...that's 600 psi water. It's not rated for ANY gas. None. Nada. Zip.

I recently ran my shop air. I used threaded black pipe. It looks good, works good, and wasn't all that expensive. You do have to be able to cut and thread pipe. It's slower to install than copper, but it will last forever and is a bit less expensive. I used 3/4" pipe. I installed a 50' retractible hose real for a drop at my lift. It's awesome.

Phil

 

[wantedabiggergarage]

PVC shouldn't be used for compressed air and anyone that not only does it themselves but recommends it to others in an open forum (like this) when it is against code and against the manufacturer's direct instructions should reconsider their position and RETRACT their advice immediately.


I finally went to this little town's little hardware store and told them "this ****'s gotta stop." You know...we haven't run into a single instance of PVC being used for gas since. It's amazing how many people one misinformed person at a hardware store can convince to do something dangerous.



Phil

It really surprises me that people don't learn to read what is in front of their faces. I worked at a hardware store for a very short bit. But I have always been one, to wonder why something is as it is, and how to read the markings (electrical cable, pipe, etc). Metal fittings for metal pipe (at least some brands) used to always say, WOG for water or gas. Never seen that on pvc.

 

[Dan in Pasadena]

...BTW...when we shut these people off and tell them they won't have service until they replace the PVC they all say the same thing...Well...It's never caused a problem....

Yeah? Well when it does cause a problem it's going to be a BIG problem. Phil

Does my heart good to read this. I am in the heavy civili construction business. Construction management, specifically Construction Quality. I can't tell you the number of times we get told, "...it's never been a problem..." or "I've been doing this for 30 years and I've never done it that way..."

Well, guess what? NOTHING isa problem until it becomes a problem. The codes and standards are written to save the collective "us" FROM us!

Oh, and buddy, "you've been doing it WRONG for 30 years. You've been lucky a long time, your luck is due to change."

 

[akdiesel]

You will still get risk takers because it is cheaper or easier or what ever the excuse.
The info has and probably will be posted again and again.
OSHA rules were writen in blood and for mainly buiseness purposes so the info does not really get out to the public and it should be communicated.

 

[Torque1st]

I went to HD last week to get my galv steel pipes for my air lines. When I got to the plumbing dept I told the guy what I wanted to do. He said that he knew just what to use. Half way down the aisle, I said "you are going to suggest PVC are you?" He said "Uh, yeah it's rated for the pressure." I proceeded to tell him everything I learned from this site. I got the pipe I needed and left. When are they going to start hiring old contractors again. Geesh.

Did you walk by the customer service desk on the way out and inform the manager that suggesting PVC to customers could get HD a nice lawsuit? Maybe a letter to corporate with the store #, date, etc would help also. Maybe that info would get corporate to put up signs in the stores.

HD in my neighborhood was happily advising customers to use regular nails and deck screws with ACQ lumber for decks. Customers were coming in with 2 year old decks falling apart because the original contractor had been just as ignorant. Stores have deep pockets and the lawyers always go for the deep pockets.

When installing black or galvanized pipe a person does NOT need to be able to cut and thread pipe. It can be done very well if you buy an assortment of threaded pipe of different lengths. It may not be quite as "professional" looking as a cut and fit job but if you have a little latitude about where you place your drops it is very acceptable. If there is a certain spot where nothing works quite right get a piece cut and threaded at the store. When you are done with the job just take the extra fittings back to the store. I have done several black pipe jobs for gas this way and a water pipe job. So far I have never had to have a pipe cut and threaded at the store for a job.

 

[rustbucket49]

WOW, what perfect timing!!! I just went to Home Depot at lunch and picked up the PVC pipe and fittings to redo my air system. I looked at the copper - knowing full well that it was the correct choice - but picked up the PVC since it was WAY cheaper!!!..

I am fixing to pick up my keys to go back and get my $$ back for the PVC and do it right. Thanks a bunch for helping me see the error of my ways !!!!!

 

[SteveU]

WOW, what perfect timing!!! I just went to Home Depot at lunch and picked up the PVC pipe and fittings to redo my air system. I looked at the copper - knowing full well that it was the correct choice - but picked up the PVC since it was WAY cheaper!!!..

I am fixing to pick up my keys to go back and get my $$ back for the PVC and do it right. Thanks a bunch for helping me see the error of my ways !!!!!

PVC works well for water but I wouldn't use it for air. I have seen it get brittle & break easily once exposed to UV for any length of time. I used black pipe but galvanized or copper would have worked as well. The rust angle is overblown, I get maybe 1/4 t of rust in my filter in 6-8 months which isn't bad considering I do most of my work during the warm months when it is most humid. Wanted to go copper but at the time I did mine it was 5.00/ft in 1" & 14.00/ft in 2" and I was planning on putting in at least 40' to take the water out of the air.

 

[rustbucket49]

I returned all the PVC and bought copper. I looked at the black pipe, but the copper was actually CHEAPER than the black pipe. Like $6.50 for 10 feet of 1/2" - the pipe was around $11-12 for a SHORTER length. The threaded copper couplings are expensive but I only needed a couple. Bought 50 feet of copper, all the ells, tees, ball valves, etc., and grand total was about $70.... Took me about 4 hours to sweat all the joints on the main line, water trap and drops - would have finished quicker, but my torch gave up on me.... I lack 1 coupling being done. Just hope it don't leak - what are the odds of that....

 

[Torque1st]

Leaks are much easier to fix on copper filled with air. Copper filled with water can be a PITA. Threaded pipe can be a PITA. Good luck and enjoy!

 

[rustbucket49]

Leaks are much easier to fix on copper filled with air. Copper filled with water can be a PITA. Threaded pipe can be a PITA. Good luck and enjoy!

So fixing a leak is simply adding more solder to the joint, 10-4???

 

[Richard Givan]

So fixing a leak is simply adding more solder to the joint, 10-4???

Sometimes it's that simple. Heat 'er up and stick the solder to the thin part of the joint. On the other hand (my experience, mind), sometimes you have to heat it up, take it apart, and start over.

I just finished running about 70 of copper airline to extend my current basement shop to my garage. It was, of course, at the far end of the house, almost far as possible from the compressor. Also, I had to stick it up in the floor joists so it wouldn't be in the way of the drop ceiling. I was a bit tentative throwing the heat on joints a few inches away from raw wood, and probably because of that, had one leaker in a coupling that I had to go back and resolder. The reheat deal worked fine, and took all of a minute to do.

The only other problem was where I ran it through the wall from the basement to the garage and turned up to the regulator. One joint on the very end of the run where the threaded fitting coupled wasn't tight enough. I must have been distracted and turned it hand tight, but failed to get a wrench on it. That forced me to cut the three-foot section just before it so I could tighten it properly and then rejoin it with a coupler, a five-minute job. Now it's working perfectly and will easily outlast me.

So, for about $60-$70 and a couple of hours I now have good air in my garage--and no compressor noise.

Enjoy your system.

 

[rustbucket49]

Got mine finished up today. I bought a DeVilbiss QC3 Dessicant filter / dryer unit that I installed at the end of my line drop. I also have a water trap half way down the line upstream of the dessicant. So the QC3 has a little site glass that turns colors when the filter wears out. It starts out blue, then goes pink then white when it's worn out. I bought the unit brand new and it was shipped to me on Wednesday. When I got it, the site glass was the blue color. I installed the unit, turned the air to it, and next thing I know the freaking paper in the site glass is white !!!???? I know it's not worn out already - anybody know what gives with that???? I didn't do anything other than turn the air on to the blasted thing.

 

[Uncle Buck]

Say no to PVC air lines.

 

[Ray-CA]

Maybe there was a lot of moisture in the lines after the install? Take the filter off, turn on the air and blow the lines clear. If it's a desiccant type filter can't you dry the media out in a low heat oven?

Ray

 

[Torque1st]

Sometimes it's that simple. Heat 'er up and stick the solder to the thin part of the joint. On the other hand (my experience, mind), sometimes you have to heat it up, take it apart, and start over.

Correct, It pays to add some flux also when reheating.

I was a bit tentative throwing the heat on joints a few inches away from raw wood, and probably because of that, had one leaker in a coupling that I had to go back and resolder. The reheat deal worked fine, and took all of a minute to do.

Place an old asbestos shingle if you have one between the pipe and the wood. Otherwise scraps of that Hardi-backer board seem to work well but they are thicker.

Keep a spray bottle full of water handy.

 

[rustbucket49]

As I suspected, the leak was in a joint that I had to sweat upside down. Amazing how much coverage you get w/ flux and solder though... Even upside down my original joint had complete coverage except for one small spot in the back that I missed the first time. I still have a very small leak somewhere making it lose pressure slowly - time for the soapy water.

The dessicant dryer is almost stabilized. I had to open it up to install it and I guess the humidity here in Texas screwed up the paper. It's about back to where it was when I bought it.

 

[RbrtAWhyt]

I returned all the PVC and bought copper. I looked at the black pipe, but the copper was actually CHEAPER than the black pipe. Like $6.50 for 10 feet of 1/2" - the pipe was around $11-12 for a SHORTER length. The threaded copper couplings are expensive but I only needed a couple. Bought 50 feet of copper, all the ells, tees, ball valves, etc., and grand total was about $70.... Took me about 4 hours to sweat all the joints on the main line, water trap and drops - would have finished quicker, but my torch gave up on me.... I lack 1 coupling being done. Just hope it don't leak - what are the odds of that....

 

[rpsurfr]

Stuart
I have a pal who is an engineer- does work in building trades. Specailty is pipe and plumbing. He is a good source
I read your post and he is off the opinion that you are correct when it comes to PVC but the CPVC which is used for acid and rates to 220 psi would be ideal to use. It seem the issue from his view is the oil from most compressors splashes up and is pumped thru the lines and this is the issue that weakens them to the burst level
Pressure is not an issue nor is water which is their purpose.
I am ready to do my shop- I wondered if you had any expertise in piping to offer an opposing view?
Thanks good stuff on the forum