# Reccomendations for Compressed Air lines



## SteveKorz (Mar 25, 2008)

Hey All-

I am going to install new air lines throughout my shop when I do the interior remodel of it, and I was curious what types of air lines that you all have installed in your shops. I presently have copper line, but I would like to get away from that. The line, over time, has proven to be leaky. Plus, for the amount of line I'm going to run (almost 100') with lots of fittings, I don't think it would be very cost effective. I would also like to stay away from compressed or crimp fittings, except for any hoses.

I was thinking about using PVC since it was a little more cost effective and really simple to use. Does anyone know what kind of pressure these lines can hold without rupture? I would love to have a cost effective line that I could run to all my work stations, and through the ceiling rafters for easy access to air all thru the shop without tripping on a line.

Will the diameter of the line make a difference? The line I have now is really small, but the line in a buddy's shop is much larger. Will this affect pressure or volume?

I'm looking at a MAX pressure of around 130 psi. It's just for my shop with just me… I won't have multiple people using it.

As always, thanks in advance…

Steve.


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## ajosephg (Aug 25, 2008)

Most of your answers are in this thread.

Diameter is important. Air pipe diameter is analogus to water pipe or electrical wire diameter. The greater the demand is, the larger the pipe.

Most likely 3/4 inch black pipe would be the way to go. If your air volume needs are low, and if your shop is small 1/2 inch might be ok, but the cost difference between 1/2 inch and 3/4 inch probably isn't big - so go larger.


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## ClayandNancy (Feb 22, 2010)

My shop is plumbed with iron pipe. Plastic won't cut it, I have seen it burst and throw plastic shards like a grenade. Volume is the key so run 3/4" inch as a main line and then branch off 1/2" to quick couplers. The size of the hose is also important, as a mechanic using 3/8" hose, impact guns ran better. But for a woodshop, air nailers and such, you can use 1/4".


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## manumurf (Mar 4, 2010)

I have read that you need schedule 80 if you want to run plastic.

Copper would be the easiest to put together and customize, just practice your soldering. Make sure the joints are clean and tight. You should be able to get it done with no leaks.


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## Abbott (May 10, 2009)

I know guys that have used PVC for airlines and haven't had any problems with it for over 10 years. They used the schedule 40 pipe. I have also seen it used in some commercial shops. In my shop I used a heavy red rubber hose that I had left over from running nail guns on job sites. I have run three drops in a 28'X36' shop. The hose doesn't do anything for cooling but my 5hp 60 gallon compressor doesn't operate or push hard enough to where heat/moisture has ever been a problem at my tools. I just drain the tank now and then to empty the moisture.

I usually run at about 110 pounds.


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## woodsmithshop (Sep 10, 2008)

your insurance will not cover pvc, also pvc can be very dangerous, when it blows it sends shards of pvc in all directions, according to an engineer I talked to, he said the reason it can be so dangerous is that air can be compressed, so there is greater pressure behind it when it blows, more so than with water. so I think black pipe is the way to go.


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## Chipncut (Aug 18, 2006)

Black iron pipe is recommended.

My shop at work, a state agency had black pipe.

It was all 1/2", some of the lines were 50', & all of the tools worked fine.

Some guys run a larger size pipe for more storage capacity, if your compressor has a small tank.

You need a Tee, & drip leg, about one foot, with a drain cock at every outlet, in order to get rid of the water.


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## mnguy (Feb 4, 2009)

My 2 cents

PVC is only suitable for a buried air line - too much risk of shattering if it gets banged by a board, etc.

Black pipe is an excellent choice, but will be expensive and you need a pipe cutter and a threader to install it, or you end up using a ton of couplings and short sections - expensive, a pain, and more potential for leaks.

I agree with posters recommending copper, with a little more attention to good soldering (I've done a lot of soldering, and I'm not 100% either  ) will give you the best bang for your buck.

As for pipe size, I agree that bigger is better, but if you are only running nailers and blowing off your bench, 3/4" is complete overkill. If you are running rotating air tools, 3/4" mains will benefit you.


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## bigjoe4265 (May 16, 2010)

Has anyone mentioned PEX? Not sure if it can be used for compressed air, but it has a higher maximum water pressure than copper.

Bigjoe


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## bigjoe4265 (May 16, 2010)

Don't know anything about this system, but it looks compelling.

http://www.rapidairproducts.com/index.asp

Bigjoe


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## Ger21 (Oct 29, 2009)

There is an ABS pipe made for airlines, called Duraplus. It's not cheap, though, but it won't kill you if you drop a hammer on it.


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## TheWoodsman (Jun 21, 2010)

I use the aluminum pipe from Kaeser Compressors. It's the same as the Transair - - - > http://www.transairaluminumpipe.com/

It's not cheap but it sure is nice, leak free, and easily reconfigured.


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## FJPetruso (Mar 29, 2008)

Most of the automotive & truck shops that I have worked in have twin two stage compressors & use black iron or copper pipe. High CFM tools like 3/4" or 1" impacts or running multiple tools would require 3/4" pipe to the point of use. The easiest to work with & the most efficient was the copper pipe. Main lines like your 100 foot section would be run out of 3/4" *HARD COPPER*. Drops & water traps with petcocks would be 1/2" *HARD COPPER*. All joints (except threaded joints) should be *SILVER SOLDERED*. Leaks would be all but eliminated. A flexible, large diameter section of reinforced rubber hose should be installed between any compressor & the piping to isolate the pipe, no matter which type of pipe you use, from vibration.

My 500 square foot woodshop has only a pancake compressor & a couple of brad nailers at this time so I placed a hose reel that reaches over 40 feet close to where I will need the air the most & am running just a 15 or 20 foot section of 1/2" rubber hose to the hose reel. My garage is completely at the other end of my Ranch style house so it was cheaper & easier to buy a pancake compressor than to run a line all the way to the other end of my house from my 3HP 30 gallon compressor.


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## wseand (Jan 27, 2010)

You can get 1/2 Black iron pipe for about ten bucks for 10 feet at any Lowes or BORG, They come all different sizes so you don't have to cut and thread. If worse comes to worse just buy regular air line and attach that to the wall.


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## Howie (May 25, 2010)

Definitely NO PVC. It's dangerous for compressed air,even at sch 80.
When I worked for Lowes I had a kid and his buddy come in that was going to run air in their shop. The one guy had been there before and was ok. His buddy was a know it all (about 20 y/o) The guy that was going to buy it was talking to me and I suggested copper or black pipe and was telling him how to put dirt legs in it etc. Well his buddy chimes in and says this pvc is a lot cheaper and it says right here it's good for 180psi. I tried to tell him that was based on 70 degree ambient temp. and as the temp went up so did the psi and the pipe would not take it.All you had to do was run it in front of a window and you had a bomb. He informed me that I was just trying to sell the more expensive stuff (I could care less,no commission)
I got p.o.'d at that. I told him I had spent 32 years as a pipefitter and 7 years as a high pressure piping inspector for the state so I probably knew a little more than he did. At that I just walked away you can't reason with an idiot. His buddy came back latter without the other guy and I designed his system for him and figured out all the parts and pieces(black pipe) He was very happy.
FLP has the right idea other than using silver solder. True silver solder(not silfos) is over kill and very expensive. Most people cannot use silversolder as it does not apply like regular solder.Compression fittings like swagelok or parkers when properly installed will hold as much or more than a soldered joint. Most of these fittings(not the el cheapos) are rated higher than the bursting strength of the pipe.


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## TheWoodNerd (Aug 30, 2009)

I've used compressed air hoses for many years with complete success. Very flexible, extremely easy to install/modify/expand, and pretty inexpensive. However, remember to leave 10-15% slack when installing because the hose expands slightly under pressure and consequently gets a little bit shorter.


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## TheWoodNerd (Aug 30, 2009)

bigjoe4265: As I understand it, PEX is for concealed use only. It will break down under exposure to UV light. I like my lines exposed since I'm always changing things around


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## BertFlores58 (May 26, 2010)

Thanks for all information you mentioned. I am misled and puzzled. Some are correct and regulated and some are not. But here is the most important of all. I work on a ship as chief engineer and with this I can help you much safer. 110 psi is nearly 8 bars. Here are the requirements and some pointers.

1. Relief valve and safety valves must be fitted on the lines much lower to the breakage point of the pipe used. In this case a 9 bars pressure relief valve will be okay if the pipe can hold a pressure of 10 bars and above. That means you have an allowance of 1 bar before the pipe breaks.

2. I dont limit myself with any tubing or pipes, what brand or any other… what is important is the pressure rating which is normally marked with the pipe or supplier details. Hose can also withstand, how much more if it a BI, steel, aluminum, etc. You have to ensure that the pressure rating of the pipe is higher than your working pressure.

3. Volume and consumption requirement are quite explained above… however please note that in every elbow joint you make, a corresponding decrease of pressure. More elbows will decrease the flow while in use and that is the reason of reducing the pressure.

4. The last one… NO MATTER HOW STRONG ARE YOUR MATERIALS, the bottom line is HOW IT WAS FITTED. The joints must be tested. Threaded, Welded, solvents, and glued deteriorate as time goes by. A regular testing should be done on this system prior work. With all valves closed and stayaway from the lines, run the compressor at full pressure until both relief valves and safety valves opens and the pipes are still intact.


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## BertFlores58 (May 26, 2010)

Howie,
You are also right about the temperature, compressor should have a cooling system to reduce the temperature of air being compressed. Take the maximum temperature that the material can withstand.


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## BTKS (Nov 30, 2008)

Bigjoe hit on it. I installed RapidAir this winter and I love it. I just rearranged most of the system without buying anything new. It's easy to work with and a quality product with a lot of flexibility. Hope this helps, BTKS


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## docholladay (Jan 9, 2010)

I used to install automotive shop machines such as lifts and tire changers., etc. Some of the machines would be plumbed for air using a variety of flexible plastic lines that were then secured using conduit type straps. The connections were actually made up using push type fittings. These actually worked pretty well and were pretty reliable, even the environment of an auto shop (mechanics are not gentle on equipment - they baby their tools, because they buy those themselve, but not the machines). Whenever I had to replace any of this stuff, I purchased the tubing at a hydraulic shop. The tubing was cheap. Unfortunately, I can't say that for the connectors. Those things must be made of gold because they ain't cheap.


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## Bearpie (Feb 19, 2010)

My boss, after I closed up shop and moved to Fl, ran pvc pipe in his shop against my recommendation was glad to save a bunch of money by using pvc. A few months down the road the pvc kept breaking all over the place and he spent more money by going pvc in the long run than he would have if he had used black pipe. Thats my recommendation as well! Spend a little now or pay a lot later. Spend a lot now and save a lot later.

Erwin, Jacksonville, FL


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## TheWoodsman (Jun 21, 2010)

Black pipe really is the industrial standard though it has it's share of problems, with rusting being the worst of them.


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## Chipncut (Aug 18, 2006)

The removal of condensation in the lines is important. Check this link.


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## JJohnston (May 22, 2009)

Everybody should read that link ^^. Rule #9 was especially surprising to me, but it makes perfect sense.


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## BertFlores58 (May 26, 2010)

The rule #9 is intended for industrial working tools and other pneumatic devices that need lubrication such as wrenches, rotary machines. hammers, etc. however those that are used for instrumentation purposes and require dry air, lubrication oil is detrimental. Please note that you will not use any oil lubrication in paint or any similar varnish, lacquer spray and instead you will need to use filter driers. This should be localized branches of connections. For every rule, please take note that there are exceptions.


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## JJohnston (May 22, 2009)

The way I read rule 9 is if you have an oilless compressor, your condensate will be more aggressive in its corrosive action, because it won't have "incidental" oil from the compressor mixed into it.


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## BertFlores58 (May 26, 2010)

Agree with you on the advantage of oil carry over being a source of corrosive control, I was a bit ahead in thinking of the necessity of type of compressor oiled or non-oiled. I normally used oiless compressors for sprays and using pvc plexible hoses and stainless fittings however the pressure is controlled to 2 bars only. In the office, I have oiled compressors and added some driers for our instrumentation too. Thanks for clarifying the issue. Regret for being so advance on the subject about the good and bad use of oil in the air system.


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## MarkwithaK (Sep 12, 2009)

Any leaks you may be getting from copper pipe can usually be attributed to improper installation, no offense. Soft soldering is a bad choice as it really doesn't hold up well to higher pressures over time. Copper lines, even soft copper tubing, with *brazed *fittings can withstand more pressure than your compressor can deliver. Case in point, look at the refrigeration lines for your homes A/C system, typically that is all soft copper with brazed fittings/joints and with the newer 410 systems they will see pressures upwards of 400 PSI.


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## JimDaddyO (Dec 20, 2009)

Just a tip that I saw before about running air lines. If you can, elevate the compressor. The first pipe out drops almost to the floor and a water seperator is installed there. The pipe then goes out from the seperator and raises to your nominal working height. This puts the water seperator at the lowest point, where the water wants to go. If you want really dry air for a special reason (like spray painting), get a big bucket that will sit on the floor so the water seperator is inside the bucket, fill the bucket with ice. This will encourage any water vapour in the lines to condense in the water seperator.

Oh ya, in-line lubricators are handy too. Just don't put one on the air line for your paint gun, you don't want oil in that feed.


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## bigjoe4265 (May 16, 2010)

BTKS,

Glad to hear the rapidair system works so well. I think I'm going to go down the same road you did when I finally get my shop to that point.

Bigjoe


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## Powerdiamond (Jun 14, 2009)

I will try and find it for you but there is now flexible piping for compressed air. The company will sell it in kits set to the length and drops that you plan to run. I wish I had seen it before I did my runs in copper. BTW, what are you using that requires 130 psi?


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## Powerdiamond (Jun 14, 2009)

One thing I've learned (and this applies a lot to medicine) is that just because something makes sense it does not make it true. It can be needless and a huge waste of money. Always look for proof first. This is what has really screwed up health care. Rant over, sorry. "Makes sense" can be a real money pit. I've been victimized myself in woodworking as well.


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## docholladay (Jan 9, 2010)

I knew a guy once that made his own air line dryer once. He used components from an old freezer. It worked great. He never had any moisture in his lines. The same guy also installed a sort of oil injector that would keep a small amount of oil present in the system. He never actually had to put any oil in his tools. He claimed that his tools lasted longer than in any shop he had ever worked. BTW, this was an auto shop that had numerous impact wrenches, tire changers, lifts etc. All of which used lots and lots of compressed air. It was a pretty cools setup. All home made, but well done. Probably not practical for a non production environment, but still cool.


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## iamwelty (Nov 14, 2009)

This says it all…

http://www.tptools.com/StaticText/airline-piping-diagram.pdf


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## Chipncut (Aug 18, 2006)

*I totally agree with the last comment.*


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## BertFlores58 (May 26, 2010)

I have only one point with the position of the pressure relieve valve Y… Normally, tanks are fitted with safety relief valves. We need to protect the pipes along the way with relief valves. Reguators breaks or leaks due to diaphram breakage and there should be a protection after the regulators… Dont save on this, they save lives…


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