Black pipe or galvanized for shop air lines?

[8N Ren]

I work in a very strict industry, pharmaceutical manufacturing, everything mechanical in the plant is inspected by outside firms, as well as fda and health Canada, you can get shut down for infractions that cost millions sometimes. Because of this they don't want any water or rust in the air system, behind the scenes there are water traps and filters as well as in the manufacturing rooms. The only thing they install and use is 3/4" copper. Been there for 10 years and never seen one fail. I'm buddies with most of the millright mechanics and asked them one day if there's ever been a problem with the copper, they all said no. One of them did copper in his own little shop and loves it.

 

[kennyd]

In today's world, I would look into PEX as well. It is flexible unlike pvc making installation quick with fewer fitting to possibly leak. When I built my home I used Kitec which has a layer of aluminum sandwiched between the plastic that when bent, it stays. Copper is so expensive and inferior for water lines today.

Call any of the PEX manufactures and see if they approve their products for use with air/gasses under pressure.

 

[superpickle]

I used truck air brake lines in my pole barn. Can withstand temp extremes and super easy to work with. Plus I used push to connect fittings so I can change and put drops wherever I want. Drops all over the shop make it nice. And was plumbed in a short time.

 

[jenkinsph]

I can easily work with any of the materials mentioned so far and have all the tools to do this. Every thing considered I would go with copper tubing using L hard (in 20ft straight sticks). Having soldered joints instead of threaded or crimped connections will reduce the chance of annoying air leaks. I agree with others though about using the simple air hoses as needed, so I would not get carried away with a bunch of air line piping you may never utilize. Maybe a couple of well placed drops on a larger home shop.

 

[the old grind]

Copper doesn't eliminate water but allows it to be passed along, say to a filter that may not last forever. Fine for hospitals, labs, etc that are heated year-round, but pole bans & workshops aren't always so.

Water in an air system is increased by heavy use, by having a compressor's air intake in a humid vs well ventilated location, or by seasonal climate variations. There will always be some moisture in compressed air. Draining the tank regularly can reduce the size of the puddle at the bottom of it vs depending on traps & separators downstream.

What works for someone in Arizona might not be the best plan in Washington state or New England. YMMV, as always.

I agree with others though about using the simple air hoses as needed, so I would not get carried away with a bunch of air line piping you may never utilize. Maybe a couple of well placed drops on a larger home shop.

I second that! :thumbsup: Gotta know when 'more' isn't always 'better'...

 

[Clint S]

I used black pipe as well. Not so much to get air where I needed it, as a rubber hose on a reel does that, but to control moisture. I did no go crazy just ran it across the ceiling 24 feet and down to the regulator/water trap and my hose reel. After doing this my water issues went down to almost bill, I just drain the tank every month or so depending on use. Water trapped in the compressed heated air needs a chance to cool before it will come out and either get caught in the trap or run back into the tank.

 

[dgeesaman]

I used 3/4 pvc when I built shop 16 years ago.Run 175 lbs air pressure constantly as compressor is always on and have yet to low an airline.Air is used everyday without a problem.lots cheaper and easier to work with,

And extremely prone to shattering is subfreezing temps, IME.

I used black steel / iron pipe.

 

[bcp]

Use air hoses and tees, instead of pipe, but fastened around the walls, not lying across the floor to trip, snag, and tangle.

Bruce

 

[kennyd]

I used truck air brake lines in my pole barn. Can withstand temp extremes and super easy to work with. Plus I used push to connect fittings so I can change and put drops wherever I want. Drops all over the shop make it nice. And was plumbed in a short time.

That's a great idea :thumbsup:

 

[jejeosborne]

Call any of the PEX manufactures and see if they approve their products for use with air/gasses under pressure.

One quick example of what I described.

Industrial Compressed Air System | Compressed Air Piping System | Compressed Air System for Business

 

[boggen]

lots and lots of comments.... ya know, i can pick up 100' foot extension air hose fairly cheap. as long as i put in enough pipe hangers (prefer plastic hangers with smooth edges) and account some for stretching and bowing down of the line. for slop and getting water to goto a tank or drop leg.... what is the issue?

folks are talking PEX, but there is a good amount of other hoses out there, that are rated for higher pressures, and are rated to be exposed. and not needing a protection cover over it.
to not it CPVC and PVC (solid hard plastic is a NO NO) but the softer plastic hoses should be fine. only issue with plastic, is heat/UV light and causing things to wear quicker, may eventually start to leak if you have major vibration going down through the lines and there is a sharp point / spot were hose can wear down.

some issues i have with galvinized or black pipe. is the fittings to pipe. there is a "edge" were water can get trapped at. along with other crud. before the water has a chance to flow onto the next section of pipe.

copper fittings on the other hand. generally have a much smoother adjustment all the way through fitting and to the next section of copper pipe.

various plastic hose fittings. also have ugly internal connections. though some of the more expensive PEX connections have a better internal flow to them much like copper pipe.

 

[kennyd]

One quick example of what I described.

Industrial Compressed Air System | Compressed Air Piping System | Compressed Air System for Business

Yes, that is a purpose built product for compressed air systems, probably on par with copper when you price it out.

You mentioned "PEX" and "Kitec" so I took that as you where suggesting the regular stuff made for water lines-hence my comment to see if they approve such use.

I did Google "Kitec" though as I had never heard of that brand, all I found was reference's to a major class-action lawsuit and settlement...

 

[jejeosborne]

Yes, that is a purpose built product for compressed air systems, probably on par with copper when you price it out.

You mentioned "PEX" and "Kitec" so I took that as you where suggesting the regular stuff made for water lines-hence my comment to see if they approve such use.

I did Google "Kitec" though as I had never heard of that brand, all I found was reference's to a major class-action lawsuit and settlement...

Yes the early fitting had corrosion issues in certain conditions. Mine has the newer style fittings. The pipe I showed I would consider a pex pipe.

 

[franklin2]

It all depends on your intended use. Some shops would get by fine with just a couple of hose connections. But other shops would not. If you have lots of different uses for air, it would be like having one 120v outlet for the whole shop, and running extension cords all over the place, and constantly having to go over and unplug one thing and plug in another. And the you end up walking/tripping over all the hoses, they get damaged by sparks and things falling on them, etc.

Long hoses also restrict air. Unless you get a really large one, if you have something that uses a lot of air like a spray gun or a grinder, their performance will not be very good with a long hose. A decent piping system will in itself act like a air tank, giving a little bit more capacity to a compressor that is marginal to begin with.

I guess this forum's theme is "do it yourself" and I include in that being able to readily buy it also at a reasonable price. Copper is nice but expensive. I think threaded pipe is pretty much the only thing you will find that has the id for good flow. Someone said something about PEX. If that would work it might be a option too.

 

[Cat_Driver]

from here
Best air compressor lines

PVC pipe not to be used in compressed air systems
The Department of Labor and Industries warned consumers and employers in May 1988 that plastic-polyvinyl- chloride (PVC) pipe cannot be used in compressed air piping systems without risk of explosion. By law, employers must protect their workers by avoiding the use of unapproved PVC pipe in such systems. Existing compressed air systems that use PVC piping must be completely enclosed, buried or adequately guarded according to specifications approved by a professional consulting engineer. Only Acrylonitrile-Butadiene-Styrene (ABS) piping was approved for use with compressed air, provided it was marked on the pipe as approved for compressed air supply.

In October 1989, the Plastics Pipe Institute (PPI) amended their original recommendations for thermoplastic piping in the transport of compressed air and other gases. WISHA's (Washington Industrial Safety and Health Act) Division of Consultation and Compliance Services now will accept thermoplastic compressed air piping that meets the following guidelines (recommendation B, to the PPI 1972 recommendation):

"The Plastics Pipe Institute recommends that thermoplastic piping intended for the transport of compressed air or other compressed gases be buried or encased in shatter-resistant materials, unless the piping has been manufactured from materials which shall resist shatter-type failures under the anticipated conditions. Specifically, above ground installations of thermoplastic piping should only be made using products which have been suitably evaluated and which are recommended by the manufacturer for the particular intended service.

"It is recognized that while adequacy of strength is an important element in the safety of a compressed gas piping system, consideration must also be given to the nature of failure should accidental failure occur, whatever its cause. Above-ground piping which fails by shattering can present a serious hazard to personnel by the resultant flying shards, or pipe fragments, which are rapidly propelled by the released energy of the suddenly decompressing gas. Because the inclination of a material to fail by shattering is determined not only by the nature of the material, but by pressure, pipe and fitting dimensions, and by the nature of the gas, the evaluation of shatter resistance should consider all these and any other pertinent factors."

If you have questions about the suitability of a material for air system piping, call the Department of Labor and Industries Regional Office for a free consultation.

 

[dfkrug]

Use air hoses and tees, instead of pipe, but fastened around the walls, not lying
across the floor to trip, snag, and tangle.

That's what I do, too. PVC or rubber air hoses are cheap and very easy to install on the walls and ceiling.
I am surprised more folks don't do it this way. Mine are "home-run" with no fittings, except at the 2 ends.

 

[Buckgnarly]

Careful of running any kind of flexible runs. Low spots gather moisture, another no go for painting.

 

[bcp]

Careful of running any kind of flexible runs. Low spots gather moisture, another no go for painting.

Lay the hose on a 1x2 nailed to the wall, with a slope (and no sags) just like you would with pipe.

Bruce

 

[murphy1244]

One quick example of what I described.

Industrial Compressed Air System | Compressed Air Piping System | Compressed Air System for Business

That's what I used in my new barn.

 

[mikehaugen]

This is sort of on topic, and possibly a consideration for the OP...

I work in an industrial environment, and have installed thousands of feet or black pipe for air lines. Just recently we have switched to using copper with crimp fittings for just about everything becuase it is so easy. Anyway, I have a theory about the water seperators and some agree with me and others not. Some people like to put in bigger separators (probably because they don't get emptied like they should), but I think you would lose performance that way. Looking at how they appear to work, they will do best with more air velocity going through them, so using one designed for say a 1" line on a 3/4" line would not be beneficial. Hopefully someone that knows them better will shed some light on this, and we can all benefit from the knowledge, since we are talking about moisture in lines.