PEX For Shop Air Lines?

[bennygreensociety]

I just bought a 100-foot air line from Harbor Freight and snaked that throu gh the walls from the garage to the basement shop. I added a moisture trap and a regulator at the basement end. The compressor runs at 125 psi and I can cut down the pressure in the shop to anything I need for pin nailers, etc. This is really convenient and probably cost less and took less effort than any kind of plumbing. That being said, a friend used ordinary CPVC pipe which is rated at 200 psi .

[J. Clarke]

And he may luck out and move before it breaks, or he may luck out and there not be anybody near it when it breaks. You might find a couple of videos instructive:

Note that the second one is by a major manufacturer of PVC pipe--_they_ are telling you to _not_ buy their product for this purpose.

Yes, there are more likely ways to get hurt in the shop. That does not justify using something that is known to be a hazard when there are well established safe alternatives.

[DerbyDad03]

rough the walls from the garage to the basement shop. I added a moisture t rap and a regulator at the basement end. The compressor runs at 125 psi an d I can cut down the pressure in the shop to anything I need for pin nailer s, etc. This is really convenient and probably cost less and took less eff ort than any kind of plumbing.

How instructive is a video that shows that they couldn't get the PVC to shatter until they battered it numerous times with a weight of an unspecifi ed amount from a height of 12' and then *froze* the frigging thing?

For all we know, it would have shattered at 0 PSI after taking all that abuse and then being frozen. Heck, for all we know, it would have shattered the *first time* at 0 PSI once it was frozen. Bad example.

How instructive is a video of some guy who says nothing more than "Don't do it" without anything to back up his words other than some videos of PVC bursting after being subjected to...oh, wait...we have absolutely no idea what it was subjected to. Bad example.

[krw]

It may have shattered without pressure but it wouldn't have exploded, throwing shrapnel. No thanks.

No, not at all but you're welcome to experiment with your life.

[DerbyDad03]

through the walls from the garage to the basement shop. I added a moistur e trap and a regulator at the basement end. The compressor runs at 125 psi and I can cut down the pressure in the shop to anything I need for pin nai lers, etc. This is really convenient and probably cost less and took less effort than any kind of plumbing.

Nothing I said indicated that I plan to use PVC for high pressure air or th at I suggest anybody should.

There's a big difference between pointing out bad examples vs. disagreeing that with the main concept. Just because those videos do a terrible job of expla ining why you shouldn't use PVC with air doesn't mean that you should.

For example, if that second video had given any indication of what PSI caus ed the failures they would be perfect. Since they don't, we have no idea if the te st resembled real world conditions or were just done for effect.

In other words, they weren't very "instructive" other than to proof that yo u can indeed cause PVC to shatter while under pressure. Freezing the pipe apparently helps too .

[DerbyDad03]

...snip...

How about I post this video with the warning "Never, ever, ever fill your tires at a gas station!". I'll make sure I label it as "instructive".

I'm pretty sure that you, being the intelligent gent that you are, would be one of the first to point out that we know very little about the root cause of that explosion. Our *experience* tells us that the situation is out of the ordinary, therefore we wouldn't consider the video to be "instructive" as it relates to the "Never, ever, ever" warning given.

Regarding the PVC video linked to above, we don't know if they tested that PVC with 60 PSI or 600 PSI. To be considered "instructive" (and that *word* is the only thing that I'm talking about) the video needs to tell us something about the test conditions.

To be clear, I am *not* recommending or even suggesting that PVC be used for air under any conditions. My only point is whether or not those videos can be considered "instructive" in the context used.

[Joseph Gwinn]

On Dec 26, 2018, DerbyDad03 wrote (in article):

The standard approach is to slope the airline so the water will run down to a well-situated release valve at the bottom of a T with vertical stub.

The water won´t hurt PEX, which is used for water service.

If you intend to use the wire for a paint sprayer, a dryer is needed.

PEX probably won´t explode, unlike PVC pipe. Do not use PVC for compressed air. But I´d ask the PEX manufacturer which kind of PEX is suitable for compressed air, if any.

The traditional way to carry compressed air is iron pipe.

Joe Gwinn

[-MIKE-]

Just google it. There is PEX designed especially for compressed air.

[DerbyDad03]

You are a month plus behind the times. ;-)

The PEX is installed and works fine for my needs. There was never a concern about the water hurting the PEX; I have PEX for water in my house. In fact, the PEX I use for water is actually run at a higher pressure than the air hose, but still way below the PEX ratings.

20+ years with no water leaks so I'm not concerned about the PEX used for t he air line.

[Clare Snyder]

Oregon OSHA states

Plastic pipe used for compressed air service must be designed for such service by the manufacturer. Examples of such pipe include high-density polyethylene (HDPE) and Acrylonitrile Butadiene Styrene (ABS). Compressed air piping systems that use plastic pipe must also be ?project specific? ? i.e., suited for a particular application or project ? and installed by a competent person. Polyvinyl chloride (PVC) pipe must not be used in compressed air systems unless it is buried or encased. PVC pipes are unsafe when they?re used for compressed air service because they can shatter or explode under pressure or from an external force. Sunlight (the UV component) can also reduce the impact resistance of PVC pipe.

[russellseaton1]

through the walls from the garage to the basement shop. I added a moistur e trap and a regulator at the basement end. The compressor runs at 125 psi and I can cut down the pressure in the shop to anything I need for pin nai lers, etc. This is really convenient and probably cost less and took less effort than any kind of plumbing.

ed for a particular

I tend to think of ABS and PVC pipe as being the same. My usage of either pipe is with plumbing. Hard to believe ABS is compressed air compliant but PVC is not. Seems to me both would not be compliant.

[DerbyDad03]

through the walls from the garage to the basement shop. I added a moistur e trap and a regulator at the basement end. The compressor runs at 125 psi and I can cut down the pressure in the shop to anything I need for pin nai lers, etc. This is really convenient and probably cost less and took less effort than any kind of plumbing.

ed for a particular

All true, and had *any* of that been included in the videos, then they coul d have been considered "instructive".

You do understand that my only issue is with the use of the "instructive" descriptor, right? Neither of those videos are "instructive" in my opinion.

Sensational? Sure. Condescending? The second one, yep. Instructive? Not so much.

[Joseph Gwinn]

On Feb 11, 2019, DerbyDad03 wrote (in article):

OK. I lost the bead on who said what.

This part is not on target. The problem with compressed air is that it stores a lot of energy, unlike pressurized water (which is incompressible). With water, if there is a crack, a little water leaks out, dropping the pressure instantly. With compressed air, the energy stored within causes the crack to grow explosively, tearing the pipe apart and spraying the area with shattered plastic. (FYI, Boiler explosions are even worse - superheated liquid water flashes into steam when the pressure is released.)

Anyway, I wanted to warn people away from using uncertified plastic pipe for compressed air, which has led to fatal accidents.

Joe Gwinn

[krw]

That *was* the subject.

Except that I don't want to be anywhere around it when it does. That's good enough for me. You welcome to risk your life foolishly.

[J. Clarke]

The chemistries of ABS and PVC are rather different. Among other things ABS is sufficiently impact resistant than at one time it was used for motorcycle and racing helmets.

[Clare Snyder]

ABS fails in a less spectacular fashion - less fragmentation.

PVC is also a lot nastierto glue as well, as it requires primer AND cement, where ABS only needs cement.

[DerbyDad03]

e:

hat through the walls from the garage to the basement shop. I added a mois ture trap and a regulator at the basement end. The compressor runs at 125 psi and I can cut down the pressure in the shop to anything I need for pin nailers, etc. This is really convenient and probably cost less and took le ss effort than any kind of plumbing.

test resembled

you can indeed cause

What is it that prevents you from understanding what I am saying?

[Spalted Walt]

Is this PVC pipe?

... asking for a friend.

[russellseaton1]

OK. I think of ABS as plumbing waste pipes. Black sewer pipe. And PVC as plumbing water pipes. The white/yellow/tan water lines. Pretty sure I have used both in plumbing. Both seem too hard and brittle for airlines.

[Scott Lurndal]

As with everything, the details matter. PVC pipe in a pipe chase or protected by an enclosure is perfectly fine for compressed air so long as the PSI limitations of the pipe are honored.

PVC pipe in a location where it is subject to abuse, bad idea.