Black pipe or galvanized for shop air lines?

[boggen]

some prespective of what i have here on the farm....

i generally have projects that there are no way to bring to the shed/shop. were i would like to use air tools. including broken down tractor /truck with flat rear tires, or shingling a cabin roof, or something. because of needing stuff else were on farm. i have a small 3200w generator (barely able to manhandle, on the uglier days), a small air compressor 120psi max 7 gallon tank on it, a portable 5 gallon air tank.

i modified the portable air tank, so i can hook it inline, with air comrpessor.. other words.... generator -> air compressor -> short hose -> portable tank -> hose -> what ever tool i need. the portable tank, allows me to run some impact wrenchs long enough before my PSI goes down. or to run air nozzle to clean out a radiator / oil coolers on tractors.

the small air compressor has been used with chisel hammers on home to deal with knocking a hole in basement concrete block wall. to other...

i do have a second older small air compressor as well. that i sometimes TEE together. (so 2 air compressors and portable tank all connected together) to raise my CFM of air and overall volume of stored air pressure. to help run through some projects that demand the extra air. the 2nd air compressor pretty much stays connected and never moves out of the shop/shed.

with my luck, so happen so today, the second older small air compressor, the belt decided to come apart on me :/ thankfully i was able to complete the task with other air compressor. and there been a couple years back, when another air compressor also went bad, and having the backup kept me going on the given project.

===============
budget still has not allowed it, to buy up a few hundred feet of air hose and more so fittings. to route air through the shed / shop area. and i dread the long 40 foot hose and the stinking mess it ends up getting into. "half time untangling it, vs using a given air tool" and because of that tend to have 3 to 4 short 5 to 10 feet hoses with swivel ends. half coil/spring type hoses, to half straight hoses. allowing me to mix and match. between dragging stuff to tractor / truck outside shed door "checking air pressure" to working air tools inside. impact wrenchs, air gun, sander, etc...

with above said, for my own shed/shop area. i would most likely be better served. with ceiling spools of air hose, that i can grab a hold of, and pull a few feet of air hose out as needed. so i am not tripping over the stuff constantly between air compressor and work site area. this also goes with electrical extension cords. other words my walls are cluttered with storage and storing of tools and my work space is in the center of it all.

 

[ultrarunner]

Same here... everything is brazed copper K and L pipe... without exception.

Sized from 1/2" to 4" copper... (Very little 4"... mostly 3/4 and 1")

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.

 

[TomSeller]

some prespective of what i have here on the farm......i generally have projects that there are no way to bring to the shed/shop.... because of needing stuff else were on farm. i have a small 3200w generator (barely able to manhandle, on the uglier days).... and i dread the long 40 foot hose and the stinking mess it ends up getting into. "half time untangling it, vs using a given air tool" .

Right, I do the same, here is my 6 HP diesel generator I haul from place to place to use power tools where I have no power. I hope this method of hauling is OSHA approved since I tied square knots in the strap. Sometimes I haul an air compressor too if I need air tools and power the compressor from the gen.

 

[dcomp]

I know it's already been said but I highly recommend pex plumbing pipe it's easy to work with and I've used it successfully in several shops now.

 

[dragoneggs]

I know it's already been said but I highly recommend pex plumbing pipe it's easy to work with and I've used it successfully in several shops now.

Even though I am a big fan of plastic, being in the composites industry, I personally would not use or recommend PVC, PEX, etc. for air lines. Water yes... and usually this is at lower pressures than air compressors will generate. The factor of safety is lower than that of metal piping, and if it ruptures, it is more dangerous. Cheaper yes and I know people that do use plastic but it is just not the right material for the application IMHO.

 

[grsthegreat]

I ran my shop in copper 3/4" over 12 years ago. Live in frigid climate in a usually unheated shop. Never had any issues.

I DO have a refrigerated air drier attached so i dont have water in the pipes.

In a COLD or frigid environment i would NEVER use plastic pipe....ive seen the results of exploded pipes.

As far as rigid galv vs black iron, id probably use black iron as its cheaper and being indoors you wont have issues with rust anyways.

 

[like2wheel]

The biggest problem with moisture is the heated air from the compressor. The compressor heats the air when it compresses it, so the air will have the ability to hold more moisture. As the air flows out into the system, the rest of the piping tends to be cooler, and the this makes the moisture "fall out" of the air. It's very hard to avoid this, thus why the piping system is designed to accomodate some moisture in the piping. That is all a air dryer is; A A/C unit that cools the air so the moisture will drop out. But even it can't get it all out, especially during high flow rates.

.

This is another big reason not to use plastic for the main line from the compressor. Plastic is a poor conductor of heat, & you need the air to cool as much as possible before any water trap or filter. Copper does this best, but iron does it well too. I would not use black iron though, I have seen some 3/8" black pipe almost swollen shut with rust after long term use for compressed air.

 

[MechE1]

Great topic and a lot of good information. I must confess, I ran my small shop with PVC. I realized the dangers and did an extensive amount of research. It’s a temporary shop (couple years) and I when I move the shop it will be copper or pipe, but most likely copper. From what I remember with my research the two main dangers with PVC are rupturing of the pipe and failure at the glued fittings. The rupturing is pretty self explanatory. Higher pressures and colder temperatures will be more dangerous. With the fittings, if I recall correctly, the problems were cycling and that the glues were not designed to work with a majority of compressor oils, aka, they would/could degrade after some time. I’m not sure how true that is, but it seems to make a bit of sense. The cycling issue makes sense too. The pipe/fittings will expand and contract with temperature and pressure changes in the lines. This will eventually lead to failure most likely at a glued fitting.

 

[BHD]

as all ready stated I ran galvanized for air, part of the reason, was avaibility of the galvanized, but also I have some gas line in the building and it is in black pipe, and it should help avoid any mix up of pipe if future changes are done,

 

[chopped]

I do the same for hauling .I used a pair of vice grips to keep a chain from sliding on the forks. Im surprised there isnt a clamp already thought of that would quick clamp to the forks .Im thinking maybe ill take some chain and wrap it around and then weld up some type of clamp for it. I have seen where some forks have the hole cut in them for a ball hitch..hmmmQUOTE=TomSeller;3854941]Right, I do the same, here is my 6 HP diesel generator I haul from place to place to use power tools where I have no power. I hope this method of hauling is OSHA approved since I tied square knots in the strap. Sometimes I haul an air compressor too if I need air tools and power the compressor from the gen.[/QUOTE]

 

[franklin2]

Great topic and a lot of good information. I must confess, I ran my small shop with PVC. I realized the dangers and did an extensive amount of research. It’s a temporary shop (couple years) and I when I move the shop it will be copper or pipe, but most likely copper. From what I remember with my research the two main dangers with PVC are rupturing of the pipe and failure at the glued fittings. The rupturing is pretty self explanatory. Higher pressures and colder temperatures will be more dangerous. With the fittings, if I recall correctly, the problems were cycling and that the glues were not designed to work with a majority of compressor oils, aka, they would/could degrade after some time. I’m not sure how true that is, but it seems to make a bit of sense. The cycling issue makes sense too. The pipe/fittings will expand and contract with temperature and pressure changes in the lines. This will eventually lead to failure most likely at a glued fitting.

What people with PCV pipe have to realize, things happen. We all agree it's bad if PVC breaks while under pressure. In reality most of these PCV systems will sit in those shops for years giving trouble free service. We are the problem. We get in there cutting 2x4's, angle iron, lifting engines and other equipment with some sort of crazy setup we have invented, and sometimes things happen we do not have control over. Just by leaning a piece of angle you have just cut against the wall, is a setup for disaster in a shop with PVC. All it has to do is fall over and strike the pipe, and it's more than likely going to bust the pipe. I do not know about you guys, but I keep my system leak free and pressurized at all times. So it would be a disaster waiting to happen 24/7.

 

[franklin2]

Duplicate post.

 

[like2wheel]

I do the same for hauling .I used a pair of vice grips to keep a chain from sliding on the forks. Im surprised there isnt a clamp already thought of that would quick clamp to the forks .Im thinking maybe ill take some chain and wrap it around and then weld up some type of clamp for it. I have seen where some forks have the hole cut in them for a ball hitch..hmmmQUOTE=TomSeller;3854941]Right, I do the same, here is my 6 HP diesel generator I haul from place to place to use power tools where I have no power. I hope this method of hauling is OSHA approved since I tied square knots in the strap. Sometimes I haul an air compressor too if I need air tools and power the compressor from the gen.

[/QUOTE]

I didn't realize that happy hour started @ 9:00am in New England

 

[TomSeller]

I didn't realize that happy hour started @ 9:00am in New England

It is always happy hour somewhere.

 

[kubotakid USA]

Just my thoughts,..
If I have the extra needed funds to spend on a galvanized air run,.. Iam going galviniseed,.All the way... Iam not a purist,.I'll dip and dive if needed ,. but I'll not,. Sacrifice my air supply.

 

[5030tinkerer]

One quick example of what I described.

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

I am looking at this very system. It's relatively pricey, but cheaper than copper (you can get a 100' run of the piping in 3/4" with fittings for three drops for $185 (Maxline M7500 Master Kit, 3/4-Inch x 100-Feet - Air Compressor Accessories - Amazon.com), which seems to be about what you'd pay for just 90' of 3/4" type L copper without fittings. The integrated aluminum should satisfy the bursting concerns, it's direct-bury approved (not that I'd do that, but it's good to know that it can handle it), and seemingly pretty simple to work with. There's a 1/2" diameter kit available as well that runs $166 (Maxline M3800 Master Kit, 1/2-Inch x 100-Feet - Air Compressor Accessories - Amazon.com) , but for the $19, I'd gladly go for the 3/4" kit.

We'll see when the kit shows up, but I am thinking I wouldn't even need the short section of hydraulic hose to my ceiling drops (though that is a way sweet idea) - I could just directly connect to the female 1/2" NPT fitting with a 3/4" line to 1/2" NPT adapter on the reel and go.

The big thing, it would seem, would be to plumb in water catch drains, slope horizontal runs just like what you would do in a black pipe install, and install water separators at every drop, as in the attached from the current tptools.com catalog. Also attached is their description of why you want to use black pipe (they sell the RapidAir kit as well, ironically on the preceding page of the catalog), but the more I read here, the more I am convinced that giving the compressed air (which is going to contain at least *some* moisture regardless of how hard you try) a place to interact with iron to form rust is to be avoided.

Around here, type L 3/4" copper pipe is essentially $2/lf. Type M runs $1.35/lf.

In both copper cases, by the time you add fittings, you'll be at a higher cost with more work.
With black pipe you've got rust concerns, even though it's cheaper.
With PVC, you've got bursting concerns.
With PEX, you *potentially* have bursting concerns, though I think you'd be just fine with the way more forgiving type A PEX such as what Wirsbo and others have.

That's my $0.02, derived largely from reading through eight pages of this thread!

 

[Raspy]

That kit looks very nice if it fits your shop and placement for the drops. You could always get more PEX if you wanted to go farther.

I kinda like the PEX idea, but is is close to it's limit on pressure and may be over it if temperature is involved or a two stage compressor is used. The air can be quite hot at the compressor outlet and that severely reduces the pressure limit.

The aluminum inner layer is there for oxygen permeation in radiant heating applications. It's radiant heat piping.

Be sure to keep it out of the sun as PEX does not have much UV protection and becomes weak and brittle if exposed.

 

[BethelHntr]

I installed a black iron pipe air system for my dad many years ago, He has a 30x50 shop that he does wrenching in so dragging hose around got old real quick. I had been working for a hvac company and brought home the rigid pipe machine and installed everything over head with 3/8" pex drops.
This is a two bay shop with a 10ft door, a 14ft and a 10x30 office/hardware area with workbenches and nut/bolt/parts storage. The total system has 10 access points to grab air where needed, One in the office for bench work, Two in each bay fore and aft, One for the sand blaster, One for the carburetor agitator, One for blowing parts off by the solvent tank, One for the tire machine and one more outside in between the two bay's for outside work. There are drains at the compressor and one at the end of the line, don't overlook installing drip legs wherever possible to catch sediment and or particles that have moved into the system, It's cheap insurance.
Overall It was relatively inexpensive and it provides my dad with a trouble free reliable air system that can be accessed anywhere in his work place.

 

[dragoneggs]

I would just away from plastic for this application. I assume you are looking for a long lasting robust safe system. Not worth saving a few bucks here IMHO. I know I have already chimed in on this earlier but I feel kinda strongly about doing it right.

 

[LAWALLSTRACTOR]

No way I would run PVC, hack at best. If you really want to do it right the first time and forever, go with copper. I would really be worried about rust if you plan on this for mainly painting, especially flaking.

My business is my livelyhood and believe me I don't need any down time. In 1984 when I put up the building, the air lines installed were PVC, and they have serviced me well for 30 years, with 0 failures. They have carried about 165 psi 6 days a week for 30 years.