CVPC or PVC Air line?

[k4lmy]

Does anyone have an opinion on using PVC or CVPC as air line in a shop? Have recently seen it used and I know that some of the PVC from the big box store has a 400 or 600PSI rating.. I know that in commercial situations that black pipe is the way to go but the plastics are easier to assembly..

Henry

[Rob Stokes, N. Vancouver]

Don't do it. I've had one (PVC) blow up on me and was bloody lucky I still have eyes.

That rating is for liquid, not gas. They're very different ratings.

Use copper or steel - no compromises.

[goodbasil]

Brake shop here was using pvc pipe, running 3 to 4 tools at a time.
Worked for them.

[David G]

I've seen lots of cabinet shops, millwork shops, furniture outfits, etc. run pvc pipes. Used to be more common than now. I think people figured out that they can fail dramatically. One shop I knew had a shard of plastic stick into a fellow's arm. I know I wouldn't take the chance... though many have without incident.

[pipefitter]

We used 1" sched 80 pvc and adapted it to galvanized at the outlets that were subdued well, so that the pvc remains undisturbed when plugging fittings in. Same system for 6 years now at 165 psi working pressure. No leaks. Come in after the weekend with the compressor shut off and is still right about the pressure it was left with. It also allows you to get creative with moisture traps built into the line without the need for custom threading. No female adapters. All male adapters to galv fittings. We also used a flex hose from the compressor to the pvc manifold.

[Nicholas Carey]

Black iron or copper.

One fact in favor of copper: it fails safely (e.g., sans shrapnel).

I'd use PEX before [C]PVC due to its graceful failure mode and ease of repair/replacement. PEX is rated at 160psi @ 73.4F, 100psi @ 180F, 80psi @ 200F. At least one manufacturer -- Wirsbo (http://www.sheltertech.com/wirsbo_pex_tubing.htm) -- has a long term test running (151psi @ 203F). They claim to be at 26 years and counting.

Just remember: every horizontal run should be pitched so it drains. Every vertical drop should have a drain valve at its bottom or land on horizontal run that will drain it.

[gert]

ALL the professional shops (10) I have worked in used copper.

If it's a commercial operation your setting up your local Workers Compensation Board may have an "opinion"

[PaulT]

I had one fail several years ago and did a pretty fair amount of damage. FYI, I had 110 psi of air standing on it at the time. I've got iron pipe now. It's not that much more expensive and doesn't take but a few minutes more to install. I won't use it (plastic) again for air lines.

Sincerely:
Paul T

[Rob Stokes, N. Vancouver]

Brake shop here was using pvc pipe, running 3 to 4 tools at a time.
Worked for them.

Basil - I was working in a commercial radiator shop (in Sidney) and our PVC lines worked perfectly (for several years), right until they failed catastrophically.

The explosion that occurred was instant and complete, with an amazing amount of shrapnel flying around. It's not something I'd wish on anyone and for the sake of saving a few $$ or a bit of time on the install, PVC airlines just aren't worth the risk.

Not only will I never install PVC for airlines, I'll not even set foot in a shop that has them.

[k4lmy]

OK Fellows ... The vote is in.. and safty has it.. Black iron and a few minutes time.. off to the big box store..

Thanks for the replys and maybe it will help someone else..

[gert]

Doesn't the iron pipe rust on the inside because of the moisture and contaminate the air tools? Short of getting a commercial grade dryer wouldn't copper be the first choice; is the iron that much cheaper?

We just ran HD rubber hose around our home shop (fastened high up on the walls) because they were short runs from the compressor, and there's only 4 outlets.

We also used an old propane tank for reserve storage; though I'm not sure that's such a good idea because we didn't put a drain in it and sooner or later it will probably rust thru.

Put in a line drain also, at a low point in the system; if you have long runs.


Nothing wrong with using PVC for compressed air lines as long as you don't cap off the other end or restrict the flow too much.

How does that work? How would you maintain air preasure if the system is engeneered to leak? (or am I not understanding you statement?) You can't have the compressor running constantly. Besides, it's probably the fittings that are the weak link in a PVC system.

[Nicholas Carey]

We also used an old propane tank for reserve storage; though I'm not sure that's such a good idea because we didn't put a drain in it and sooner or later it will probably rust thru.
better than a propane tank is to go to a truck parts store and get a tractor-trailer air tank. They're standard sized and relatively cheap (~$50-75). Lots of options for how they're tapped for air lines.

http://shop.easternmarine.com/images/product/8494.jpg (http://shop.easternmarine.com/index.cfm?fuseaction=catalog.prodInfo&productID=8494&categoryID=470)

[oznabrag]

better than a propane tank is to go to a truck parts store and get a tractor-trailer air tank. They're standard sized and relatively cheap (~$50-75). Lots of options for how they're tapped for air lines.

http://shop.easternmarine.com/images/product/8494.jpg (http://shop.easternmarine.com/index.cfm?fuseaction=catalog.prodInfo&productID=8494&categoryID=470)

Or a truck junkyard!

I have outfitted my new (tiny) shop with salvaged tubing and fittings from an industrial conveyor system. Very high-quality stuff.

As to PVC: NO!!

My last (huge) shop came pre-plumbed with 1" PVC air lines. When the one branch let go, it shot a six-foot-long, javelin-pointed piece of pipe at me, which slammed into the bandsaw I was working with at the time, shattering the pipe.

PVC? No way.

[Robert L.]

By Feezer,
Nothing wrong with using PVC for compressed air lines as long as you don't cap off the other end or restrict the flow too much. In fact the PVC will probably last longer than the compressor in this configuration. Safety first.

Sounds pretty safe to me ;=)


by gert,
How does that work? How would you maintain air preasure if the system is engeneered to leak? (or am I not understanding you statement?) You can't have the compressor running constantly. Besides, it's probably the fittings that are the weak link in a PVC system.

I don't believe he mentioned anything about functionality, just safety, although there might be some long term sound level issues.


by Boylesboats

That is crazy, man.....

Not sure there is much danger of sudden jolts to the system as long as
you don't cap off the other end or restrict the flow too much.

Not sure but I think the man was making a joke. Now I could be wrong, but...

[pipefitter]

I question PVC installations that rupture or break because many people don't take much care fitting or installing it, will grab old pipe that has been sitting outdoors in the sun, don't know when the joints are primed well enough etc and then nearly split female fittings with metal ones. I have seen steel pipe installations where "plumbers" covered the entire threads with teflon tape well outside the depth of the fitting to where it caused the threads to rot from the outside in. You don't need teflon tape with steel pipe. Rectorseal is all you will ever need if the threader knew what they were doing or if one doesn't cheap out buying crummy import pipe with badly cut threads thinking that steel is steel.

We used "new" Sched '80' (working pressure of 378lbs, burst pressure of 2020lbs psi)PVC and it is installed within the face break of a wall girt. In the photo you can see the electrical conduit on the face of the girt but what you can't see is the 1" air line as it is concealed behind/under it. It's not going to throw shrapnel much of anywhere.

http://i99.photobucket.com/albums/l309/tigmaster/P1010058.jpg

Like this.

http://i99.photobucket.com/albums/l309/tigmaster/z-purlinspipe.jpg

I have seen shops with steel air lines and yet all of the hoses and the compressor, fittings and tools are Chinese harbor freight/home depot quality at the user end.

On these forums, when people ask these types of questions, you can pretty much figure that the budget is the main consideration. Our purpose is because we don't own the building. We don't want to leave behind an elaborate steel manifold system or to have to break it down and adapt it yet again, which is probably the case with most shops you see using PVC lines. There is safe ways to use it with a little foresight and creative engineering and consideration.

[James River Rat]

Harbor freight has a complete kit with push lock fasteners and unions..

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=66747

[BBSebens]

Black Iron will rust. and it will get in your tools. If you still want to go that way, make sure your outlets point up and your runs go down and have drain points. use lots of moisture traps. Also, instead of couplers, use tee's with plugs pointed up. this gives you flexibility later on.

That Pex is awesome stuff. not hard to work with either.

[Robert L.]

Long time ago I worked at a television station that used a bunch of the old 2 inch quad video tape recorders. Big monstrous things that used air bearings for the scanning heads. Really Big air compressor downstairs, plumbed with copper. PVC may be OK for some, but it seems a little scary to me. How do I know how much UV exposure the piece I am buying has had? Bought some once that just sort of crumbled. I don't have the threading tools or the inclination to work with iron and no experience with Pex. I like copper it is easy to work with and shiny. I like shiny. Anyway as I revamp my shop in the spring and the run air line it will probably be copper although the Harbor Freight kit that JRR references above does look interesting.

[ssor]

Copper is immune to uv damage and it doesn't get brittle with age. Black pipe with some proper air filters will last longer than any of us.

[Rob Stokes, N. Vancouver]

Nothing wrong with using PVC for compressed air lines as long as you don't cap off the other end or restrict the flow too much. In fact the PVC will probably last longer than the compressor in this configuration. Safety first.

Unbelievable. I tell you that I've been involved in a PVC air line explosion, and yet you tell me PVC is safe to use as air lines. I'm not sure how that works.

But if you don't believe me, have a read:
http://www.osha.gov/dts/hib/hib_data/hib19880520.html

[gert]

It would appear from that link to actually be "illegal" in some states to use PVC for compressed gas (air).

If it is illegal in your state and you do have an accident you may want to read the fine print on your health insurence policy...

Assuming you have coverage ;)

In Canada "stupidity" is covered :D T.G.

[David G]

Feazer,

There's something about this medium that makes attempts at humor less than clear. Making them understood as humor takes some practice. I assumed your post was an attempt at humor, didn't take offense, but thought the joke was obscure, opaque, and a bit of a stretch.

So... rather than get offended (and gratuitously snotty) that someone didn't get your joke... just take it as feedback about your internet humor skills. I'm sure you're quite witty in person, and I'm sure if we'd heard your tone of voice or seen your facial expressions we'd have gotten it... but it's harder/different on line.

Cheers,

[k4lmy]

As the original poster.. I can report that 3/8ths black iron was the choice .. Bought a tri pak from Northern tool with two filters, oiler, regulator, etc. assembled most of it today and need to pick up a couple additional bits and pieces tomorrow from the big box store..

Thanks fellows for the insight .. it's good to know that there are still folks that will share their knowledge..

Henry