air line plumbing

[Dan_Shade]

What's best/meets code for air line plumbing?

copper, galvanized, or black iron?

[Al_Smith]

Generally speaking schedual 40 black iron  up to 150 psi .Over that schedual 80 with steel fittings rather than malable  iron up to 300 psi .

On your verticals always install a drip loop or blow down which is nothing more than a short piece of pipe with a cap or valve so you can release the condensate from the lines  which you will get no matter if you have an air drier or not .

In other words if you transition to a horizontal from a vertical it's a good idea to do as I suggested else eventually the lines will become water born or rust up .You use a tee rather than an ell fittings with the nipple below .Galvanized generally is not used because just like on gas lines the galvanize can flake off and clog air tools etc .

Now I've heard of people using CPVC piping but I personally wouldn't trust it  .On that though sure as God made little green apples someone will be along toot sweet who loves the stuff . ;D

[Brad_bb]

I've always used black iron.  It's funny because I had to buy a new separator today(20 year old one sprung a leak), and when looking at the milton website for setting up an air system, they were recommending galvanized.  I guess they just want more corrosion resistance.  It's overkill if you asked me.  Most people I know use black iron.  I've heard of some people using Pex or a pex like airline system that is supposedly faster and easier to set up.  But I'd have to look at the car forums for detail on that.

You can paint black iron pipe, but when I recently replaced my compressor and replace a section of black iron, the new stuff had this thick tar like coating on it.  It would not have been fun to try to remove that coating for painting.  I think I got those new pieces at Lowe's.  Consider the coating if you plan on painting.

[redbeard]

Galvinised pipe is not a good choice the dipping process can dislodge flakes and cause alot of damage to air tools. Black iron is a good low cost system but you need a good filter and water seperator and checked and clean regularly. Type L copper is the best but very exspensive these days. Pex I don't know haven't used it for air yet. Schedule 40 and 80 pvc dosent last it will get brittle a few years down the road. Just my plumbing 2 cents.

[Holmes]

  Schedule 40 CPVC pipe has a maximum operating pressure around 500 psi for 1/2 and 3/4 " pipes at 70 degrees. It derates 20% at its lowest operating temp of -200F. Most systems are run around 125 psi , you should not have any problems with CPVC pipe. Do not use more than 2 wraps of teflon tape on male fitting screwed into cpvc adapters to much tape will crack the fittings. CPVC is not the same as pvc, flow guard is 1 of the brands. You will need more hangers and supports [ every 32"] .  Holmes

[sawguy21]

   Do not use more than 2 wraps of teflon tape on male fitting screwed into cpvc adapters to much tape will crack the fittings.

I learned that one the hard way assembling fuel hose with aluminum fittings.

[bill m]

Use a piece of rubber hose between the compressor and cpvc air lines to take out the hammer effect when you are using air tools. I installed my system about 15 years ago and have not had any problems yet. Also use 3/4 dia. or larger pipe depending on how long the runs are so you get enough volume to run tools like impact wrenches.

[sawguy21]

Bill makes an important point. The flexible line off the tank will allow movement without stressing the pipes

[Don_Papenburg]

I used blac kpipe in the machine shed . that was a pain to cut thread and assemble .  Used 1'' copper in the shop with 3/4"drops.  I put Tees in the line where the drops were so that the air comes out the top of the main line . the main line also slopes to the air tank. All of this is supposed to help keep the H2O out of the tools.  The drops also have a ball valve above the 3/8 and 1/2" quick connectors and a short pipe below them with another ball valve to drain any condensate.

[DR Buck]

You can use PEX up to 160 PSI.      ;D    Easy to install and cheap.

[scsmith42]

Over the years I've used black pipe, PVC, copper, galvanized pipe and PEX.  My preferred choices today are black pipe and PEX.  Pex sure is easy, and it will flow more because you can bend it through curves instead of having to use fittings with black pipe.  Plus, it won't rust.

Black pipe can be painted though, which can provide a cleaner appearance in a shop.

1/2" and 3/4" pex is fairly economical, 1" is pretty expensive.

[Banjo picker]

I use PEX on my water lines ...if I were doing air, I would probably give it a try on that also.....I am thankful that the copper folks got so greedy or I would have never found it...Tim

[Al_Smith]

I have a piece of 3000 psi hydraulic hose between the compresser and the steel lines .Being somewhat of a collector of junk I just happened to have some actually a lot .

I too have ball valves on the drip loops . The seperator gets most of the moisture out of the air but not all of it .

[Faron]

Guys, do a little research before using cpvc for airlines.  I'm not an expert on hydraulics and air, but I don't think it is safe.  Remember, air compresses under pressure, while liquids do not.  If it fails, it produces very dangerous shards that will injure anyone in range.

[DR Buck]

Guys, do a little research before using cpvc for airlines.  I'm not an expert on hydraulics and air, but I don't think it is safe.  Remember, air compresses under pressure, while liquids do not.  If it fails, it produces very dangerous shards that will injure anyone in range.

One of the benefits of PEX is the cross-linked molecular structure.   If pressure is too high, it will just bulge and split, no shards or shrapnel.

[Dan_Shade]

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

[Al_Smith]

Steel piping is not a big deal to install --if you have a power threader .Righty tighty .Tight is tight,too tight is broke .

[Brad_bb]

I also use a flexible rubber line(reinforced hydraulic type) between my compressor and my black iron pipe system.  I had used a regular hydraulic line, but when I recently replaced it, I went to Motion Industries (cause they can make hyd lines) and they suggested instead of hyd hoses, which have steel fittings that can rust, to use these brass barbed fittings, both swivel and fixed and a rubber hyd line that you cut to length yourself and push onto the fittings and works great.  You can always cut the line and reinstall if you need to.  The fittings are reusable.  The barbed fittings work like a Chinese finger cuff.  I also went with the brass barbed fitting because they don't neck down like the steel hyd fittings do.  I didn't want the restriction there in the line.

[DR Buck]

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

Cheaper from Rockler   

http://www.rockler.com/product.cfm?page=30321&filter=air%20line

[b dukes]

I work for Ingersoll Rand  , we have something like the link in  DR_Buck post except it uses aluminum tube that is good for around 300psi. It is called Simple Air. Easy to install , use a tubing cutter to cut the tube and the fittings are a pushlock/compression fitting ,  they are pushlock but with an extra backing nut. The price isnt all that bad.

http://www.ingersollrandproducts.com/air/catalogs/Simplair%20EL%20Brochure_US.pdf