Plumbing my garage for compressed air...

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jtolbert

jtolbert

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So, my lovely girlfriend bought an air compressor for me for the holidays. What a girl. :D It's just a Craftsman twenty-six-gallon, 150PSI, 3.8SCFM@90PSI, upright jobber, but it'll do what I need quite adequately for now, which will mostly be running air tools. I don't think I could paint a car using HVLP gear with it, but if I decide to do that...I'll rent/borrow a better compressor. :)

I've decided to run hard line around my garage. My garage is 20'x20' and barely fits a '67 Plymouth Valiant with all the sheetmetal on and the garage door down. :) My goal is to position the air compressor near the outside rear corner of the garage (to minimize noise inside the house) and to run air along both sides and the rear of the garage. The rear will get one drop for air and the sides will get two, one near the front and the other either in the middle or near the house door, depending on the wall we're dealing with.

Complicating things are some wire shelves that are mounted fairly high on the side walls. Not sure if I'm going to go over/through or under the shelves yet.

I'm going to use 1/2" Type L copper for the hard line throughout. Why copper?


  • PVC is an accident waiting to happen. PVC is downright nasty when it explodes.
  • Black pipe will corrode fairly quickly when exposed to moisture---which will happen in a compressed-air system---and requires special tools to thread the pipe.
  • Galvanized pipe is just as difficult to work with as black pipe, and even though the corrosion risk with galvanized pipe is a lot less, there's still a good chance of zinc flaking off the inside of the pipe and ending up downstream.
  • Copper is easier to work with; you don't need much besides a tubing cutter and a torch to work decently with copper.
  • Copper and sweat/solder joints can withstand the line pressure (probably regulated down to 120PSI or so) quite easily with no worries.
  • Copper is the best material for getting the compressed air's temp down as low as it can go quickly, which is key for getting water to condense out of the compressed air and drain away effectively.

The only real downside to copper is that it isn't quite as durable as steel pipe is...I can live with that.

I'm going to start with a metal isolation hose (to keep vibration from making its way into the rest of the copper) going up from the compressor into a tee, with the pipes from the tee going vertical. The downpipe will be a drain with a valve near the end and the vertical will tee at the top into the main run, which will go (mostly) horizontal, with a slope down from the main tee.

The equipment taps will be teed up from the main horizontal line, go up for six or eight inches, then into a ninety-degree elbow and another ninety-degree elbow down the wall, crossing over the main horizontal into yet another tee with a downpipe and a sidepipe for the air connection that leads into a 1/4" NPT to 1/4" industrial-type quick-connect. There will be a drain valve on the downpipe and possibly a shut-off valve above the tee. Not sure about that yet.

At both ends of the horizontal run will be the "main" drains, which will just be ninety-degree elbows going to a downpipe with a drain. valve.

I'm going to anchor all of this well to the walls; a blown-out pipe can whip around pretty badly under pressure.

For now I'm probably just going to set up one dryer/filter/regulator arrangement and move it from the couplings as necessary. Down the road I may fix some in place, but moving from spot to spot isn't a huge issue.

Thoughts? Suggestions? Anyone care to see updates as this comes together? I have about $230 in Lowe's gift cards from the holidays so this will hopefully get underway very soon. :)
 
Copper is expensive and thieves love it. It might not be to bad if it only needs a little ran in a small shop but when it needs to go 100ft to the other side of the shop it might start getting expensive quick.

My boss has sch 40 3/4 PVC which is good up to 480 psi ran in his shop. He told me its been there for over 30 yrs without any problems. His son has painted many a car with PVC pipe.

I have always wondered about the 1/2" copper versus the 3/4" PVC in far as volume. Seems like the 1/2" copper would not produce as much volume but I'm not a expert on these matters.

Oh... PVC won't show up on X-RAYS so the doctor can dig it out of your body. lol
 
Copper is fine. Pitch the pipes at least 1/4" per foot, probably away from the compressor, and put a couple of long traps in, with drain cocks at bottom.

Instead of soft solder, consider using what we called "silfoss" used in refrigeration. It's a braze rod used with oxy/ acetylene, acetylene only, or Mapp torches. Needs no flux and is a HELL of a lot stronger than soft solder, and won't corrode or deteriorate

In the summer, you can plumb the outfeed of the compressor to a big coil of copper in a garbage can full of water. This will realy help condense water out of the airflow, but of course you'll need a big trap there as well.
 
I have a buddy that did his garage with 3/4 sch 80 main line and 1/2 in drops never a problem,he now is devorced and no garage bummer

Moe
 
Sounds way overboard with all the drops. If it were just me I'd stub it in and just use a hose. The compressor won't run more than one tool at a time very well anyway.Then just get a good quality hose that stays flexible even in cooler weather. It will last for twenty years if you disconnect it when not in use. And PVC would work fine. I have watched them test different plastics at Amoco Labs and some of that stuff will take enough pressure to blow up like a balloon before it gives.It wouldn't surprise me if the piston or pistons? in your compressor are plastic. For more than one line I just put a simple tee together with a male and two females and there you have it. I will also use a small portable tank in-line if I need more than 100 feet, like up on the roof or something. Also you live where it is cold so use big wire if you put it outside because it may have start up issues.
 
mullinax95 said:
Copper is expensive and thieves love it. It might not be to bad if it only needs a little ran in a small shop but when it needs to go 100ft to the other side of the shop it might start getting expensive quick.

My boss has sch 40 3/4 PVC which is good up to 480 psi ran in his shop. He told me its been there for over 30 yrs without any problems. His son has painted many a car with PVC pipe.

I have always wondered about the 1/2" copper versus the 3/4" PVC in far as volume. Seems like the 1/2" copper would not produce as much volume but I'm not a expert on these matters.

Oh... PVC won't show up on X-RAYS so the doctor can dig it out of your body. lol
Click to expand...

I have never ever seen any problems out of SCH 40... X2 why would any one us more then 180 lbs any way or even 200. Every Body shop I have been in I see 3/4 schedule 40 PVC.. :coffee2:
 
Pitch them all back torward the compressor . This way the horizontals lines will drain back to the tank . Less build up in the verticals. I used galvanized wish I would have use copper on the long runs. I already see brown water at the drains on the drops. Put a automatic drain on the tank. Everytime my compressor stops it drains the water off itself. They are cheap @ Harbor Freight
 
I just ran harbor freight rubber lines with quick disconnect splitters.

Easy and flexible and the job was done in an hour.
 
My dad made a pvc cannon once, well that wasn't his intention luckily no one was hurt.

It isn't the pipe that is the problem with pvc it is the joints and caps and fittings.

My dad's explosion was with sch 40 pipe, but on of the end caps apparently could not handle the pressure and blew. If you use PVC make sure you use quality fittings and clean prime and glue them very well.
 
Yes you must assemble PVC correctly. If you do the fittings correctly they fuse or weld if you like to the pipe and at that stage could be considered one. So instead of a cap just sort of blowing off it would suffer a more catastrophic failure.
 
trapster said:
My dad made a pvc cannon once, well that wasn't his intention luckily no one was hurt.

It isn't the pipe that is the problem with pvc it is the joints and caps and fittings.

My dad's explosion was with sch 40 pipe, but on of the end caps apparently could not handle the pressure and blew. If you use PVC make sure you use quality fittings and clean prime and glue them very well.
Click to expand...
X2!! Clean with purple primer and never just push them together, always give them a small twist and hold together for a 15 count... A must do for sure. :coffee2:
 
I ran a grey 1 inch sch 80 pvc overhead where its out of harms way. From the compumper up and all the drops are 1/2 galv.
To understand why I've used 1 inch and 1/2 inch when the hose connection to the air tools is only 1/4 inch you have to understand line restriction and the difference between volume ( cfm ) and pressure.
My pump is a horizontal unit on wheels. The first connection is actually a rubber hose with quick connect. There have been a couple of times over the years that I ran the pump on 220 to full charge and rolled it out to a truck and went to a disabled vehicle.
Enough stored pressure to whip a front drive axle job at least.
I roll it outdoors twice per year to drain the condensation from the tank too.
Everyones setup is different and I wont insist mine is the best but I haven't found anything I couldn't do yet.
 
We have had copper line in our garage for almost 20 years now, not one problem with it. Literally thousands of cars have been painted using this compressor.

For our two car garage we just ran the pipe around the back to the middle of the back wall. Then we run a rubber hose off of it. The yellow goodyear hose works very nicely for the price BTW, very flexible.
 
Hose reels are such a pain in the *** to deal with, at least as far as running air through a hose on a reel goes. My dad has one in his garage and I hate using it. I also hate that he's got a ton of water in his air cause he doesn't drain his tank or run any pipe to let water condense/drain out.

Yes, I know it's overkill, but I doubt I'll ever regret it.

Now that I'm thinking about it, I'll probably just go along the back wall with a tap/drain in the corner opposite the compressor and up the outside wall. It'll save me quite a bit of annoyance getting around the door to the house.

So, besides the "it'll cost more" and "thieves like it" issues, I can see no real reason to not go with copper.
 
I have used schedule 40 pvc for 15 years in my garage with no issues.
Use what ever you feel comfortable with.
I do have my compressor on the outside of the garage, so I don't have to listen to the noise. It is in a simple little plywood building to keep it dry.
One thing I would do and that is run a rubber line from the compressor to your hard line for vibration and use a water seperator at the end of each drop.
 
The cost of copper offsets the cost, time and trouble of threading black pipe, buying or renting a threader. I'm too damn old and crippled, anymore, to screw with manually threading anything larger than 1/2 pipe.

DO NOT ******* USE PVC. It is WELL documented what problems it causes, IE DANGEROUS if anything comes apart.
 
Mine is done with Copper and it is behind the Drywall. This was all done during construction. Some guys use a water separator right at the compressor outlet into the wall, I dont. I have 8 quick connectors in my shop and I use the bottom of the compressor bleed to get rid of any condensation. I pull the plug and let it out a couple times per year, not a super heavy user of the compressor but it makes jobs easier when I do need it. I use it to blow off the shop floor and it works great.
 
Any issue with using pex tubing and it's fittings, perhaps even sharkbites from home depot? I hate sweating pipes....
 
Most if not all PVC pipe manufactureres do not recommend PVC for compressed air and OSHA does not recommend PVC pipe for comressed air. The issue is that if you have a failure it can shatter like glass. I have seen a 6" PVC line that was buried and tested with air blow a hole out of the ground. There are plastic systems like AirPro and others that are used for compressed air because in the event of a failure they will have a small tear in the pipe called a ductile failure but no fragemts or shards that can injure someone. If you check out manufacturers like Charlotte Plastics, Spears, Nibco, LASCO etc... who manufacture PVC industrial pipe systems they all have a disclaimer "not to be used for compressed air".
 
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