Air line material recommedations?

[Wesley J]

Hi Guys,

Winter is here so I've been spending my weekends and evenings finally "finishing" my shop. I have a little 24x24 that I use for metal and woodworking. I've been upgrading my lighting and finishing the drywall mudding, taping and painting. Ucoatit will be happening soon too.

I currently have 1/2" and 3/8" copper air distribution. The 1/2 comes off the compressor and feeds my reg/dryer/"cooling loop" then I have a 1/2 high flow drop for the LVLP/impact. From here its 3/8 over to the 3/8" hose reel.

This brings me to my question. My plasma/tig/mig cart and welding table are in the opposite corner of the shop. As well, I need a drop over at the lathe/mill. Its not a really long run but copper is pricey here so I was looking at alternatives such as PEX. I've tried searching here but have not come up with any good threads detailing the +/- of the materials out there.

Advice for an inexpensive system?

Thanks in advance,

Wes

 

[FastEddieG]

I'd personally stick with copper to keep the system uniform. At the least, I'd stick with metal so that leaves copper or black pipe.

How much is a 10' 1/2" copper stick by you? And where are you? 3/4" 10' L was $13 here in Chicago when I did my garage this summer, and I believe 1/2" L was under $10.

-Ed

 

[krooser]

keep it copper...

 

[HoosierBuddy]

This is a common question on this forum, but it's almost impossible to find in a search due to the way the search engine treats 3-letter words.

Anyway...the whole thing boils down to this: You should use a piping material that is approved for use with air. While Pex might work, it isn't approved for air or any compressed gas for that matter. The materials of choice are rigid copper tubing (as you already have) or maleable black iron pipe (same as used in natural gas service).

Personally, I have easier access to threaders than I do to large volumes of cash so I went the black steel route. If money was no object, or if I already had the beginnings of a copper air system, I would definitely follow the previous responders' advice and stay with copper. It's easy to work with, it will last, it's approved for compressed gasses, it looks great.

If someone responds "use PVC" below...just ignore them, because they are obviously wrong.

Phil

 

[Costner]

Stick with copper. You will only do the job once... might as well do it right the first time.

 

[AZAV8]

Listen to HoosierBuddy. I've designed compressed gas systems for years in my engineering job, and copper is the only way to go. PVC will shatter under impact loads and pressure spikes with sharp shrapnel resulting. Black iron (steel) will corrode from the condensed moisture and leave you with rust flakes in your air stream. Yes, copper is pricey; BUT, you will have fewer problems and it will last forever.

Phil

 

[FastEddieG]

For a small garage system, I don't think L copper is as expensive compared to black pipe as it's being made out to be. Maybe 2-4 years ago, sure, but in 2009, not so much.

In the SW Chicago suburbs, Lowes has 10' 3/4" black iron for $10, and $13 for 10' 3/4" L copper. The fittings aren't THAT far off either when comparing 3/4" black pipe to 3/4" copper. This summer I ran 60' of L copper with 4 connections and valves for just over $100. Can't see using black pipe being that much cheaper. Especially for the OPs relatively short expansion run.

-Ed

 

[dankeenan]

Another inexpensive alternative is to run rubber air line. You can buy a 100' air hose pretty cheap and install it. I did this to get air over to my 2-post lift via the attic. I has been trouble free for 8 years, easy install - no danger.

 

[e-tek]

It's unbelievable that, for how often this topic comes up, one CANNOT search and find any of the $%%^# threads!!!

But just because the first 5 guys answering are for copper, doesn't make it the best choice. IMO & historically, black pipe is the best of all worlds - due to saftey, ease of install, ability to add and change, it being a better heat-sink and more. (NO FLAMING PLEASE - WE EACH HAVE OUR OPINIONS!)

So keep researching and then make your decision based on what's best for your set up!

 

[e-tek]

Stick with copper. You will only do the job once... might as well do it right the first time.

In a perfect world maybe!! Last week one of my line filters started to leak. Had I used copper I would have had to cut it out and sweat in several extra pieces. With black pipe you unscrew, replace and screw back on!

 

[sberry]

You can put unions in copper too.

 

[GeorgiaHybrid]

e-tek,

My copper lines have unions and all of the filters and ball valves are screw threads. To me, the copper was easier, to others, black pipe is easier. Either one will work well. The main thing is that we all have air...

 

[mustangmccance]

just to throw out something new you could use aluminum. such as air net or garage pak but that would be even higher than copper, the plus side is it is very easy to modify later.

 

[Torque1st]

just to throw out something new you could use aluminum. such as air net or garage pak but that would be even higher than copper, the plus side is it is very easy to modify later.

Modification "later" may not be easy since those "easy plumb" products are a non-standard material and companies seem to go out of business or stop producing specialty items. Copper and iron will be available for decades. Specialty products may not be available next week...

Rubber hose may work for a specific piece of equipment with low demand but it is very poor for an air distribution system.

 

[Poncho Villa]

just to throw out something new you could use aluminum. such as air net or garage pak but that would be even higher than copper, the plus side is it is very easy to modify later.

I don't know if it's a problem to mix materials, but mustangmccance's air plumbing looks good and cost-effective:
http://www.garagejournal.com/forum/showthread.php?t=43635

 

[JUSTA50]

I would redo it with Prevost piping.

 

[Kevin54]

Pvc, pvc, pvc

 

[Falcon67]

Pvc, pvc, pvc

Firestarter!

You know perfectly well that 4" cast iron drain pipe delivers the best volume. The joints are a tad hard to seal though.

 

[JUSTA50]

PVC is not a good air line for the long haul. It will degrade over time with the passing of oil/moisture from the compressor. I'm getting ready to do my 30x30 with Prevost. No couplings to make, just screw the ends together. If you want to add or redo anything just unscrew. You can ever tap the lines and reseal if needed. Check it out.
http://www.prevostusa.com/categories.php?cat=29

 

[pcmeiners]

"You know perfectly well that 4" cast iron drain pipe delivers the best volume."

Damn, I nearly screwed up by using 1" copper. Did a pressure loss workup with 4" cast below.... wow, an amazing pressure Loss (psi) of only 0.002 for 100 feet of pipe.

Have to admit the sealing is a might tricky. The 80+ lb 4" cast sections have a tendency of going through shop walls, and anything else within 300 feet if not done just right. Just in case, I revised my shop build plans to use solid concrete block which should shorten that distance quite a bit.


Nominal Pipe Size: 4
Pipe Schedule: ?
Flow Rate: 23 SCFM
Viscosity (cP): 0.018
Inlet Pressure (PSIG): 90
Temperature (F): 70
Pipe Roughness (ft): ?
Actual Pipe ID (in.): 4.026
Fluid Velocity (ft/sec): 0.62
Flow Region: Turbulent
Friction Factor: 0.0322
Pressure Loss (psi): 0.002

 

[Torque1st]

Don't use those non-standard air line "kits" guys. Use copper or steel.

On the other hand there is cast iron gasket pipe available that would be easy to seal and would flow great. I have seen anywhere from 6" to 30" available. It even comes with concrete liners to avoid corrosion.

Just think of the impression you can make with the flow from air outlets like fire hydrants!!!!

Then there are the PVC people...

 

[pcmeiners]

"30" available"
Sounds interesting, do they make a 30" to 3/8" reducer, to lazy to drill/tap

 

[Torque1st]

"30" available"
Sounds interesting, do they make a 30" to 3/8" reducer, to lazy to drill/tap

They make those adapters for the fire hydrants. So it is kind of a two stage reduction process...

 

[pcmeiners]

"Just think of the impression you can make with the flow from air outlets like fire hydrants!!!!"

When I get to that stage, I want to be locked up and the key destroyed, same to the people who are impressed...at that point the shop build virus is beyond control

 

[Torque1st]

There are some in lockup now, -take a look in the gallery...

 

[GeorgiaHybrid]

There are some in lockup now, -take a look in the gallery...

The doctor tells me if I keep improving and reduce my meds, they will let me go to a halfway house in another year or two....

I wonder if the halfway house has a garage??? Do you think they would let me add on to it???

 

[Torque1st]

That would be great!!! They keep increasing my meds...

They won't even let me see the halfway house.

 

[HoosierBuddy]

They make those adapters for the fire hydrants. So it is kind of a two stage reduction process...

That's GENIUS!

I want an air hydrant!

You've got me thinking, I don't have any extra cast iron, but I do have some spare 4" bell and spigot joint, clay tile. It's older pipe, probably cast about the 1930's...but it's been underground where it's been protected from the sun...so I think it just might work for air!

Phil

 

[Torque1st]

That's GENIUS!

I want an air hydrant!

You've got me thinking, I don't have any extra cast iron, but I do have some spare 4" bell and spigot joint, clay tile. It's older pipe, probably cast about the 1930's...but it's been underground where it's been protected from the sun...so I think it just might work for air!

Phil

After being underground for so long you would have to protect it from the light. Wrapping it with duct tape should do the trick!

 

[2fast4u2]

i dont have any pics but i am using hard nylon fuel line works great and i get it all for free lol

 

[Vinko]

I have black pipe but would love to have the aluminum branded by Keiser and others.