plumbing an air compressor manifold Qs

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moparmat2000

moparmat2000

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hi all

had a new shop built in my back yard last year. it is 27' L x 31'W x 12' tall. i was originally working out of a hangar at my regional airport. i got friends is all i can say LOL. now that i got everything under one roof in my backyard, i want to plumb an air manifold for air hose connections from my air compressor and remotely mount the compressor behind the building.

at my work we used schedule 40 PVC pipe and it seems to work just fine, but i am not a big fan of pvc. i was thinking more along the lines of using sweat fit copper pipe with a short 3 foot piece of air compressor rubber hose to connect it to the compressor tank.

what kind of pressure can the copper pipe take. i know pvc is used as a replacement for copper in water applications, i also know it can get brittle in freezing temps. i plan on pressurizing the air manifold to 110 to 120 PSI and having 4 air hose quick connect fittings run off of it one in each corner of the shop. i think the sweat fit copper would look a lot nicer, plus i think its easier to work on than the pvc.

any thoughts?? anyone do this kind of thing i am wanting to attempt??

thanks
matt
 
At the last factory I worked at we had copper pipes (3") air manifolds for our 200 HP compressor. It was a ring that ran over head, and used 30 degree elbows at the corners to make the air flow smoother. We ran 125 psi with no problems.
 
OSHA DOES NOT ALLOW pvc for air systems. That's because when air under pressure bursts the pipe (I've seen it) it can cause a massive explosion of plastic shards of pipe. There have been documented injuries.

(NOW you are gonna get 50 answers "I've used it and it works just fine."

Use either black iron or copper. use tee's pointing UP. Come out of the tee, with elbow, use second tee, with a "drip leg" and a radiator style drain at the bottom.

PITCH (slant) the piping at least 1/4" per foot for drainage, really does not matter toward or away from the compressor, but put a drip leg/ drain at the far end.

Some info on copper:

http://www.engineeringtoolbox.com/astm-copper-tubes-d_779.html

Standard "every day" water type should be fine, but if you want to guarantee longevity, go to an A/C supply outfit and get "type K" used for refrigeration. BE AWARE that domestic (Lowes/ etc) water plumbing copper is called out in "nominal" INSIDE DIAMETER sizes just like black iron/ galvanized pipe. BUT TYPE K refrigeration is normally called out in OD OUTSIDE diameter sizes. This can lead to confusion when calling fittings sizes.
 
well its been known that the oil from the compressor may attack the pvc glue and cause leaks or worse, if you are worried about water in the system , install an auto tank drain this will get rid of alot of condesation befor it makes it to the pipework , and yes please use the small piece of rubber hose before the copper or black pipe this acts as an vibration issolator otherwise your prone to broken or leaking pipes , i myself would not even worry about the 1/4 pitch , we dont even do that on large systems in the field , see ya ed
 
i knew about the vibration causing a work hardening of the copper making it brittle over time. i learned this in aviation maintenance school years ago. aircraft a long time ago (think pre WWll) used to use copper pipe for fluid lines, and it periodically had to be removed from the airframe, and heated up to anneal the copper to make it soft again.

thank god someone came out with aluminum tubing, as well as stainless steel and titanium tubing as the fluid systems in aircraft today are more complex than ever.

this being said i planned on pumbing all this with 1/2" tubing and having a tee come off each pipe run as it came down the wall for my air fittings. i was going to run the pipe straight down below each air fitting tee for about 1' and install a drain petcock for each of these. as on long runs the moisture in the compressed air will condensate as it cools so this is the last stop for it before it would end up going thru my air tools.

i periodically drain my compressor tank. it is a 60 gallon upright mounted to a 1/2" thick aluminum plate on craftsman tool box castors. trust me when the castors are locked this thing doesnt walk around the shop. anyway i removed the stock drain petcock, ran brass threaded tubing straight down , added an elbow, another piece of brass tubing with a ball valve, barbed hose nipple and some clear plastic hose. this setup allows water condensate to collect in the brass tubing below the tank helping to prevent rust inside the tank

i periodically stick the hose out under the shop door, and open the ball valve up, all i get is clear water, no rust. works well. i also have a water seperator / pressure regulator setup works pretty well too.

thanks for all the ideas, and thoughts on this project. as soon as i can i plan on starting on it. thinking of running a hose quick connect out of the wall next to the personnel door too. sweat fit copper pipe it is.

thanks everybody
matt
 
I used air line for semi truck trailer brakes and so have all are mechanics in their garages for years without problems but if I ever have any problems I'm going this route...............

http://garage-toys.com/racoairpisy.html

Or .....

http://www.rapidairproducts.com/

http://www.garage-pak.com/

Hmmm can't get the last one to work they may have went out of biz.....

This is a great garage forum.... I've spent way to many hours over there and got way to many ideas too.......... Doh!

http://www.garagejournal.com/forum/
 
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