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Using PVC as an Air Compressor Lines

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54K views 58 replies 48 participants last post by  Bluepine38  
#1 · (Edited by Moderator)
As many of you know I have recently put my Air Compressor up in the loft of my shop and ran Sch 40 PVC down to my bench. What I have found so far is a bit on the disappointing side. The pipe itself has not given me any issues. I have been having problems at a couple of points. The first and primary problems are at the threaded PVC couplers where I have to connect the brass to the PVC itself. These couplers keep wanting to split on me once under pressure and exposed to the heat in the loft. The other are at elbows, but I had only one of these crack.

I am using the white 3/4" Sch 40 PVC pipe and I am thinking that I am going to have to rip it all out and replace it with copper. This is not a fun prospect and if I make the call I will probably start by making a copper run to the front of the loft and hang a hose reel down until I have the time and $$ to put the copper into place down at the bench level.

Has anyone tried the pre-solder copper couplings yet?
 
#2 ·
I have my compressor in the garage and just cut a hole so I could run a hose into my basement shop. The hose is relatively cheap, flexible and comes in almost any length. Doesn't answer your exact question, but there's an alternative solution that's an easy fix.
 
#4 ·
Not sure about PVC but if you do end up swapping it out, just use galv. steel pipes. A lot cheaper than copper.

If you do go with copper you can forget about soldering by using compression fittings.
 
#5 ·
Hi sIKE;

Since my apprenticeship was served as a plumber, I can't bring myself to use those fittings. I guess I'm "Old School".

I have to imagine they work just fine, or they wouldn't be so readily available.

There, that's about 2 cents worth, I guess I'm done!

Good luck with it.

Lee
 
#7 ·
Rule of thumb around here is never use plastic plumbing pipe for compressed air (hence the splitting and such.)

Agreeing, copper will be expensive. Never used pre-soldered. Never needed it.

I would avoid compression fittings. Although I don't know the specs. on them, most house water pressure is in the 50 lb. range and I wouldn't feel comfortable using the comp fittings. I'm betting they really aren't designed for 100 lbs or more from air comp.

'Round here we use black pipe. I'm thinking alittle cheaper even than galv. When connecting hard line to the compressor, you might consider a flex line to isolate the hard pipe connection from vibration.
 
#11 ·
I'm thinking that flexable rubber hose is the way to go. I have a 50 ft run to make to my workbench and as an outside drop when needed there.
 
#13 ·
I have used PVC for several years the only problem ever encountered was when using som fittings that were old. As far as the threaded connections go try using a male threaded piece of PVC, teflon tape and pipe dope, then add the fitting. Don't torque the fitting too tight. Don't run more than 150 PSI in the lines.
 
#14 ·
Having witnessed a PVC failure first hand in a shop I worked in, I will not use it for air line. The shop I worked in had added some square footage and ran 2" Schd 40 PVC as a temp. air line. The line failed at a coupling, a fellow working at a bench received a laceration on the top of his of his skull about 6 inches long that went to the bone. Bled like a stuck hog - the rest of the pieces took out two eight foot light fixtures, not just knocking them down but breaking them beyond use. The only thing the investigation could come up with for the failure was an unseen weak spot in the pipe. This pipe did not "come apart" it exploded. All that damage from 100 PSI. I might use it in a pinch, but not for long and not as a main run.

I'm not trying to rain on any bodies parade, just trying to get the other side of the story out.
Later,
Doug in AZ.
 
#15 ·
I had the use of an old shop for while about 5 years ago and the deceased old guy who built it had 220V outlets in convenient locations as well as galvanized steel air lines running all around the perimeter of the shop with convenient places to tag into the air. Those lines probably been there for many years and will probably last many more….
 
#16 ·
ya pvc's not good for air. its not made to handle the pressure and it is an insulator so it doesn't let the air cool down because the air comes out of the compressor very hot. no experience with the copper fittings you're talking about but copper is the way to go. don't use steel because as the air cools there will be moisture and it will rust the steel but not the copper.
 
#17 ·
copper will rust too, depending on which schedule copper you use. I work for a company that manages apartment complexes, and when these place were built, usually 10 to 15 years ago, they used cheap copper. We now have to deal with the copper getting pin holes in them and because the leak is small it takes a while to find and sometimes floods buildings. Copper is exspensize and thinner compared to galvanized pipe. Galvanize is little tricker to work with because it's harder to cut, but it won't rust for years, 25 or more. most older houses built before 1980 have galvanized pipes and are still holding up pretty well.
 
#19 · (Edited by Moderator)
I only use regular airline hoses in my shop…

#1 They are made to handle the pressures , moisture , and temperature differences.

#2 I can put them where ever needed

#3 They are suspended from overhead until needed.

#4 I can take them with me where ever I need to go . If I need to use my air tools on my vehicles or blow up a tire or two , I just run the hoses outside and leave the compressor behind.

#5 I guess a lot of people don't realize just what PSI stands for and that's why they get hurt by using the wrong product for the job …. ( like plastic pipe )

#6 Maybe you should check with your local building inspector or insurance carrier to see what is recommended . Every business that I ever worked for had either galvanized or black steel pipe for the compressed air system . There are several grades of copper pipe / fittings , so beware if you choose to go that route . Best wishes : )
 
#20 ·
My compressor is in my garage and plumbed to the basement shop with standard airline hose. From there it goes to overhead retractable reels. I have three reels in my 1000 sq' shop. Pull them down, hook them up as you need them, store them overhead when you don't. I do the same thing with 110 electric cords. bbqKing
 
#21 ·
Don't forget about moisture in the line. The following PDF file gives some of the basics of plumbing for air.
I designed the air system in a 40,000 sq ft building, so I know it all applies.

Basically you want to have one ppint that will collect the water and put a fitting there.

http://www.box.net/shared/nfou0upc1u
 
#23 ·
By far the best choice would be galvanized steel piping. Without using a compressor that none but a lab can own (outrageously huge pressures that we (normal use wood/metal workers) would ever need) it will not break unless it isn't sealed, it will just leak. You can add lines all over it and it taps and accepts quick disconnect fittings really easily as well as being pretty much impervious to rusting. it is the best way to go and by far the absolute safest way to go.