Air pressure line run

[David Ragan]

Am in the midst of moving a 60 Gal compressor to another room in the basement to save room in my small shop.

The compressor is a Husky (Campbell-Hausfield made) specs are 10.2 SCFM @ 90 PSI; 135 Max PSI.

220v.

I want to have my air hose reel (in the shop) anywhere from 30 to 50 feet from the compressor; Naturally, there will be a large drop if I run regular air hose that distance from the compressor over to the reel in the shop.

Can anyone tell me where to go on web, or how the math works to see the diameter of pvc pipe for the run?

And, how about some type of industrial larger diameter flexible air compressor hose, if one is made? So I wont have to run rigid pvc-which will be a major pain.

[Ole Anderson]

Check out this active thread a few lines down: http://www.sawmillcreek.org/showthre...ompressor-Line

Bottom line is one material you DON'T want to use is PVC. 1/2" should be plenty unless you are running a 1" impact gun.

[Rod Sheridan]

Dave, PVC isn't suitable for compressed air.

Use threaded steel or soldered copper pipe...3/4" would be suitable................Rod.

[Victor Stearns]

I would look for the D.O.T. push-to-connect fittings and line. These use simple, but $$, brass fittings that are reusable. The air line is a plastic reinforced that is designed for pneumatic applications. I purchased line and fittings from McMaster for my shop. Very pleased with the results. I also found this via a quick web search. http://www.eastwood.com/3-4-inch-pro...-line-kit.html
(This is the same line and fittings the heavy trucks today.)

[Steve Rozmiarek]

A word about the pressure drop. It's pretty insignificant. My farm shop has several hundred feet of runs, all 3/4", and no noticeable difference anywhere with any impacts. The key is use a big enough diameter to flow enough, 3/4" is safe for anything I can think of.

Fun fact, there used to be a air drive center irrigation pivot system produced. Worked using air cylinders. Huge compressor, 1/4 mile long system and the ones I've seen have been plumbed with 1/2" and 3/4" lines.

[Anthony Whitesell]

Most air hoses are 3/8". Even 1/2" copper has a larger ID (the important factor in this discussion) than the 3/8" air hose. If you are SERIOUSLY pressed on budget, 1/2" copper would be better than OK, but not as good as 3/4".

[roger wiegand]

So according to the calculator at http://www.engineeringtoolbox.com/pr...pes-d_852.html the pressure drop from 120 psi for 10 CFM at 100 ft in a 3/8 in pipe is 4.8 lbs (~4%), while a 3/4" pipe will have a drop of 0.15 lb. Less indeed, but is it even worth worrying about?

[Steve Peterson]

Dave, PVC isn't suitable for compressed air.

PVC has been mentioned twice as being unsuitable, but no reasons were given. The pipe may be rated for 600psi for water use. The typical usage is buried. The white PVC eventually becomes brittle after exposure to sunlight. Failures result in a burst seam and a water leak.

Failures in PVC air lines are much more dramatic. A split seam results in all the energy from the compressed air getting released through one focal point. It can explode and send PVC shrapnel everywhere. Using it for air is potentially lethal.

Many people talk about using it for 20 years without failure. This may be true, but I would really start to worry about an old installation where sunlight through a window could be slowly making portions of the pipe very brittle.

Steve

[Anthony Whitesell]

(A) 3/8" copper tubing has a larger ID than 3/8" air hose. So there would be more pressure loss.

(B) Pressure loss is only one factor, what about the ability to supply CFM?

Something doesn't feel right about the 4.8 psi loss at 100 ft. I used to have 3/8" poly line (rated for 140psi, but burst anyway) and after 60 feet could not use my 3/8" impact gun (CFM 4.5) for long before I didn't have the pressure to make it go. There had to be more than 5 psi loss in just 60ft of 3/8" tubing, or so much CFM loss that I could not maintain the pressure at the tool.

[David Ragan]

I got it hooked up- all 3/8"
50' straight to 25' on the reel. Most of the 50 is straight
good pressure-is fine for my needs, as the only pneumo tool is hobby pin nailer

[Ole Anderson]

I agree on the 4.8 psi loss at 10 cfm. Although I believe in tables and used to rely on them at work for pressure loss in water lines (usually 6"-16") I have the same problem with my rattle gun. All I have to do is watch the pressure gage in my garage just after my filter/regulator but before the hose reel which is about 10 feet away from the tank. Pull the trigger and the pressure drops on the gage at least 10 psi and immediately returns when I let off on the trigger. And when using my conversion gun with a small gage at the regulator at the gun, I can see a dramatic drop at the end of my 50 foot 3/8" air line. Not so much that I can't maintain the 20 psi the gun calls for. At times my "600 ft-lb" IR gun can't even remove a stubborn lug nut due to my compressor cycling 80-100 psi and the losses in the hose. Gotta get me one of those 175 psi big suckers and ditch my 30 year old 1 hp Craftsman compressor.

[Steve Rozmiarek]

I would look for the D.O.T. push-to-connect fittings and line. These use simple, but $$, brass fittings that are reusable. The air line is a plastic reinforced that is designed for pneumatic applications. I purchased line and fittings from McMaster for my shop. Very pleased with the results. I also found this via a quick web search. http://www.eastwood.com/3-4-inch-pro...-line-kit.html
(This is the same line and fittings the heavy trucks today.)

That is good stuff. Not self supporting, so takes a little more work to install a system in the shop, but well tested and effective. Pretty easy to source anywhere that sells truck parts too.

[Pete Duffy]

How about PEX, the stuff used in radiant floor heating? It is amazingly easy to work with, joints & fittings are minimal, and the stuff is tough. I saw a video once of a guy kinking the stuff and beating it with a hammer, smashing it all up. Then he applied some heat with a torch or heat gun, and it came back to shape with no trace of damage.

It won't shatter and holds a pretty high pressure. Way better than PVC, way cheaper and easier than either copper or black iron pipe.

Just my 2c.

[Ole Anderson]

and easier than either copper or black iron pipe.

Hey we are woodworkers, since when did easy come into the equation?

[Anthony Whitesell]

I looked into PEX at one point. The burst pressure appears to vary dramatically with temperature. Not an issue when used with water that is typically less than 80 psi. But where air compressor lines are 60-120 psi, maybe as high as 140-150 psi, crosses the boundary into the region where the temperature, pressure, and burst pressure may not work well together.