Compressed air piping.

MikeL_2

I've finally convinced a good friend that the 1" PVC piping in his woodshop is dangerous. I don't do much of this type of piping; what is most commonly used?

pecmsg

What pressure?

MikeL_2

120 psi

GroundUp

I typically cut and thread schedule 40 black or galvanized for compressed air. Some codes will call for type L copper- sometimes soft soldered, sometimes pressed, occasionally silver soldered, usually brazed to eliminate cracked joints from vibration. My shop at home is soft soldered for ease of install, and I would do it again.

EBEBRATT-Ed

copper tubing soldered would be the best way to go. I don't think pvc is allowed on compressed air

hot_rod

rapid air products.com has a few different plastic piping options

MikeL_2

Thank you, everyone!

Solid_Fuel_Man

I see a lot of DIY use PVC for compressed air. It seems to hold up for a few years and then deform. It's technically good with the pressure, but I believe the oil and heat from the compressor is what kills it.

I use soft soldered copper in my own shop. Heat water and oil wont hurt that!

FranklinD

I’ve used the RapidAir system in my garage shop with good results. It’s essentially just the same nylon tubing used in truck air brake systems, seems to hold up well - no issues in the last 3 years. I went with it for ease of install and ease of future modification/expansion. That said, my go-to has usually been threaded black pipe.

Gilmorrie

PVC for 120-psi compressed air? How are the joints made up, and what is their risk? Personally, I would use steel pipe and fittings.

hot_rod

The issue with PVC is it turns into sharp shrapnel like pieces when it let's go under pressure.

There are some composite piping systems I've seen in commercial shops, push type fittings. Look like Aquatherm piping.

Kaeser Smart Pipe is an aluminum tube system I have seen in trucking repair shops in my area.

Pex Al Pex is another option.

Voyager

Pex works well if you don’t mind ugly. I personally would not use it in my shop. I am looking at installing an air system also and will use copper as I can easily install it myself. Iron pipe is the most robust option, but internal rust is always an issue. The aluminum piping systems are nice, but pricey.

As Hot Rod said, the issue with PVC is the failure mode. If PEX or copper fails, it will just split in one place with no flying pieces. PVC just isn’t sufficiently ductile.

Zman

I did a buddies shop with steel threaded pipe. No issue 12 years later. Be sure to put a dryer on the compressor and drip legs with drains at low points.

Leonard

PVC is brittle and when it breaks it makes very sharp jagged shrapnel. In late fall cool NH weather I smashed some 2inch PVC with a sledgehammer........very sharp pieces.

Voyager

Zman said:

I did a buddies shop with steel threaded pipe. No issue 12 years later. Be sure to put a dryer on the compressor and drip legs with drains at low points.

I would also add a filter at each port to be sure. The issue isn’t so much moisture as it is flakes of rust after a few years that will begin to come off. Even a good drier doesn’t get the RH to 0 so light rust will form and eventually come off in small flakes that can cause issues with paint sprayers and such. Probably won’t cause much harm to larger air tools.

Steel is the most robust, but copper and aluminum are much cleaner if you are doing spray painting. For only air tools, steel is probably fine.

ChrisJ

> @hot_rod said:
> The issue with PVC is it turns into sharp shrapnel like pieces when it let's go under pressure.
>
> There are some composite piping systems I've seen in commercial shops, push type fittings. Look like Aquatherm piping.
>
> Kaeser Smart Pipe is an aluminum tube system I have seen in trucking repair shops in my area.
>
> Pex Al Pex is another option.

Why pex-al-pex and not normal pex?

Leonard

As a kid in dad's garage we wanted to extend the air line. I found a long steel pipe bent it up to fit in pickup truck bed. Hammered it straight and noticed inside had a LOT of rust . I just put a filter on the outlet. Used the air for body work tools and paint gun for shooting cars.

ChrisJ

> @Leonard said:
> As a kid in dad's garage we wanted to extend the air line. I found a long steel pipe bent it up to fit in pickup truck bed. Hammered it straight and noticed inside had a LOT of rust . I just put a filter on the outlet. Used the air for body work tools and paint gun for shooting cars.

Erm

rick in Alaska

Run it in galvanized and you won't have to worry about the rust issue. The galvanized that is out now does not have the flaking issues like before. Galvanized is all I am using on my gas piping as I can't stand rusty looking pipe, which around here takes about a couple of weeks.
Rick

Leonard

The old galvanized I found discarded in a hole ~ 50 years ago was only galvanized on the outside.

Leon82

There are extrusion setup where you tap it after you cut it an put an oring sealed end on.

Others are aluminum tube with a shark bite type fitting you screw on