Air lines in a shop, what would you use?

[Alphacowboy]

ok, my dads shop is going to get air lines in the next month, but cant figure out what to do. Its a 80x60 area, and is a wood shop. My dad is convinced that the only way to go is galv. cast iron pipe. I tend to disagree. Yes, its pretty much indestructable... but $$$$ and a little over kill. If you were to do a shop what would you use? My dad is afraid of copper, because he is afraid that couplings could blow off and kill someone, but I told him that is soldered correctly, this wouldnt happen. He also doesnt like PVC, as that too he is afraid that it could burst to easily, but again I told him, if done correctly, it would be fine. The reason I say go with copper or PVC, is because of ease. His shop is not huge, and he is constanly changin things, when he gets new tools and such, so I think copper or PVC would be a lot easier to reconfigure when needed, and plus it seems like it would be alot of $$$ cheaper.



Anyway, what ya'll think?



1. )Copper

2. )PVC

3. )Cast Iron (galvanized)

 

[Paychk]

Don't use PVC; when it fractures (not if), it will explode violently and plastic is tough to remove from a body.

Read more here:

http://www.lascofittings.com/supportcenter/compressedair. asp

http://www.osha.gov/dts/hib/hib_data/hib19880520.html

If you want to use a plastic pipe, there are ABS products that are rated for use in compressed gas applications, these products won't fracture when they fail, instead they split, which means no projectiles flying around.

BTW if you use threaded pipe go with black pipe, over time the galvanizing flakes off inside the pipe and does a number on your air tools.

Cooper if soldered correctly is good to 200 psi or better.

http://www.copper.org/applications/plumbing/techref/cth/cth_2select_recom.htm

 

[nickleinonen]

i'd go with regular black iron pipe in sch 40 or 80 wall. . it is easy to work with [you can thread it and use threadded fittings, or get lap fittings and weld it]. most of the piping at work is black iron for the air and water and steam and most of it is 50 years old and there are very few leaks, and none are really from rusting through. you could go with galvinized, but i don't think it is needed. there is enough oil coming through the compressor to lube the inside of the pipes [depending on where you put your filter, dryer and oilers]



only the fittings are cast when working with the iron pipe [and you can get the machined steel fittings too]



copper can work well, but the thin wall if something smacks it, it will burst when you have the ±125psi in the pipe.



PVC is a big no no i think. sure it can hold the pressure, but if something goes wrong, you have plastic sharp pieces flying around.



when i get my own place and plumb it for air, i will use 1/2" and 3/4" black iron and just rent/borrow a threading machine. it is easy to use. the learning curve on the machine is like 30seconds. i did one test piece and that is all i needed to learn to use it. and with one set of dies, you can thread 1/2", 3/4", 1", 1-1/4", 1-1/2" iron pipe. 2" is where the thread pitch changes i believe.

 

[sarj]

1) copper- best choice by far, thick wall preferred. Corrosive resistant, easy to work with, bends & is less inclined to break if it gets hit.



2) easy, but not a good idea. Breaks on impact, plastic will fatigue, on failure, the material will explode sending projectiles. Probably isn't to code ( a gas rated plastic would be, but I hear it's pricey.



3) galvanized- not my choice, pricey, hard to work with



4) black pipe- a choice of many, but it may corrode on the inside.



Run the copper, install a few Tee's with stubs and caps for future expandability. Secure it well against vibration, and don't forget the dryer.

 

[Turbo Tim 1]

I would go with copper, alot of industrial applications of compressed air use copper these days in 125-150 psi applications. When I pipe up my garage it'll be copper. If you decide down the road you want a new fitting in a certain location you just cut the pipe and sweat in a new tee, no dismantling and cutting and threading. Iron pipe would be the BEST for longevity and durability and strength but it is overkill. My father basement and garage are piped with copper and the place I work at is piped in copper.

 

[TORQUE THIS]

If you are moving the air system around quite a bit, I would use instant tube fittings. Don't get the ones from Home Depot.



Look in www.mcmaster.com



These are also good for 150 psi, you can use the 1/2 for feed. The tubing I have used is clear, flexible, and holds up very well to impact. They even sell shut-off valves. Mount them in areas where damage may occur to minimize having to shut down the entire system. There are fittings also with pipe thread to thread into oilers, dryers, etc...

 

[Alphacowboy]

thanks guys... . I was really thinking Copper would be the best, but trying to convince dad might be hard. Good info on the galvanized pipe, didnt think about that, but I am sure the galvanizing flaking off and into nail guns and such is a bad deal. Copper is sounding the best... . I just dont see why my dad has a problem with it.

 

[Philip]

I use 3/4" copper on my shop air lines. My system has been in use for around 5 years now. Not one problem.



Here is a link with some good reading on copper. Look threw the tables they have listed for pressures and joint connection ratings.



http://www.copper.org/applications/plumbing/techref/cth/cth_3design_burst.htm

 

[CumminsAholic]

There's plastic lines in my cabinet shop. 5 years no problems. . They're almost all covered though. We put them in when it was built so they're in the walls and ceiling. Copper would probably be the best bang for the buck if it's exposed, if it gets hit it'll crack too, just no shrapnel. I wouldn't be afraid to use plastic though as long as they're up high enough where they won't get bashed with anything. . mainly vehicle bumpers. (I think it'd take a pretty good hit to break them). If you have the $ of course iron will be the strongest... overkill if you ask me.

Corey

 

[Alphacowboy]

There's plastic lines in my cabinet shop. 5 years no problems. . They're almost all covered though. We put them in when it was built so they're in the walls and ceiling. Copper would probably be the best bang for the buck if it's exposed, if it gets hit it'll crack too, just no shrapnel. I wouldn't be afraid to use plastic though as long as they're up high enough where they won't get bashed with anything. . mainly vehicle bumpers. (I think it'd take a pretty good hit to break them). If you have the $ of course iron will be the strongest... overkill if you ask me.

Corey

Hey, i see your in Minnesota as well, where is your shop, and what company? My Dads been building cabinets for over 18 years now, so we know alot of the shops in this area.

 

[CumminsAholic]

I'm in Willow River. Prachar Cabinets. I do work all over, a lot on the north shore, some even down your way. If you ever get up this way stop in. I think the only TDR member that's been there is Josh when he came to get his head.

Corey

 

[rivercat]

GO pex or black iron> If you go cheap and use pvc don't expect it to last more than 5 years and use a big piece of black iron to condense the water out befor it gets to the pvc and melts the glue at the joints

 

[sstefanini]

I've seen/ installed type K copper in some good sized industrial plants and labs. Its commonly used on clean air and industrial bulk gas service. Use 95/5 solder or silfoss(brazed) joints and it will last forever and install in half the time.

 

[Matt400]

I voted PVC but wait before you flame. .



You have to take precautions with it. Use at least schedule 40 rated to 600 psi and regulate the pressure down to 125 psi, secure it well so its not disturbed by pulling on it with hoses that are too short. Don't expose it to any area of possible flying debris. It doesn't condensate as bad IMO as metal and is low cost and easy to work with. I have used it successfully since 1987 in 3 different locations.



Now for an even better option might be this- http://www.nibco.com/cms.do?id=2&pId=14



I would go that route for a more safe system and will consider it next time around.

 

[rivercat]

All DAMP air is going to condensate, the metal pipe takes the mosture out to a drain before it hits your airtools. Just a fact of life when you compress damp air it makes it hot and then when it hits the cold steel it condenses the water right out early-a good thing.

 

[seemore]

Here is one option: http://www.garage-pak.com/index.cfm. I don't know how good or expensive it is, buts looks easy. I thing the link came from a DIY Show

 

[jwgary]

I agree with what Rivercat said. The air in the line is at 100% relative humidity because it condenses out any excess moisture. The metal line allows better heat transfer to the surrounding air to help lower the temperature and thus condense out more air (warmer air holds more moisture than colder air). You must have a drain in the line so that that water doesn't come through anyway, and it's a good idea to have the drain on a dedicated drop so that there is no chance of the moisture getting whipped up by the air flowing through the line and coming down also. There are even auto-drains that have a little float that will empty when there is enought water to raise the float. The problem I have is with black iron pipes. They don't mix with water very well and could get you into some problems with clogging the drains, or worse, your tools. My vote is copper. It's a great conductor, easy to work with and kinda looks cool too.

 

[Alphacowboy]

wow, this got dug up from a few months ago! :-laf



Dad still hasnt done anything yet, but looks like he is going to go copper! Our plumber we use is going to do it for him on trade for I believe cabinet doors and counter tops. Works out well for them both. sure pays to know the right people!

 

[DLausche]

On a small project I would probably go with black iron, but that shop is HUGE and that would cost a ton. Good you could convince him to go with the copper.



-Deon

 

[y-knot]

The great air line debate... ... ... sounds good



First, I have NEVER seen a PVC pipe explode when used as a raceway for compressed air. It has a burst rating of 450 psi, which is 2-3 times the average shop pressure.



I have piped several shops for air, and as it just so happens I am about to do another one. I did two with Galvanized Rigid 1" pipe. It works great, looks real fancy if done right and is a one time job. I plumbed all runs in 1" and then reduced to 1/2" where ever there was an connection fitting or a gauge. The down side is of-coarse the cost and extra time required to do the work. 1" rigid is about 15-20 bucks a 10' length, and the fittings required for all the bends, reductions and fastening add up very fast. A simple shop set-up would run somewhere between $3000 to 5000. Larger or more elaborate systems will of coarse add to the bill.

Copper is an alternative, but I have never used it. it's burst strength is not that high and again it is very expensive for what you get. 1" copper is almost as expensive as rigid, but the application goes much faster with copper. Just cut and solder it in, much faster then threading pipe. I do not see any reason that one could not use copper.

PVC. My favorite It is the most cost affective and the quickest to install. PVC looks nice and does not leak it installed correctly. The biggest problems are when you transition from slip joints to threaded joints. The threaded joints require alto of attention to insure they remain leak-free. It's just a case of plastic threads and tapered joints. I use Teflon tape and pipe joint compound on all threaded joints, and use it heavily. I just last winter did our new house and garage with PVC, and with-in the next couple of days will begin piping our new shop for electric, air and water. I will use PVC for all the air lines, copper for the water and EMT conduit for the electric, can't wait.

PVC isn't cheap, but it is about 1/3 the cost of copper and 1/6 the cost of rigid threaded pipe. You do not need any special tools for it's installation and it is basically immune from most household and light garage chemicals. It will not rust (inside mainly) like the rigid pipe will, and it is not conductive like both the copper and rigid pipes are.

We run 2-stage air compressors, with 5 HP motors and 80 gal tanks. I would not run the main lines in anything smaller then 1", and only reduce down as close to the connection as possible. Good luck with your dads shop and enjoy the time together while you still can.