Compressed Air Piping
- Thread starter gzig5
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daves66valiant
68 Dart 340/727:66 Signet Vert 340/5spd: 68 D100
3/4” Rapidair. Easy peezy. Used my copper manifold from my old shop. Super clean, cool, dry air to all my drops. Proof was in the paint pudding. Very nice system. Finished install in a day easily.
You can buy the Rapid Air system at Northern Tool. If you don't have one close by, you can order it online. It's what I bought for my garage after mulling over copper. Copper was more expensive for how I wanted to lay out my lines, plus, I have no experience silver soldering pipes and it's hard to get my brother in law nailed down to do it. I never considered black iron because of rust, and didn't consider galvanized because a friend of mine used it and has always had to deal with the pipe flaking off little pieces of galvanize and clogging filters/regulators. Whatever type of pipe you use, turn your tees for your drops up, instead of down. Moisture flows in the bottom of your long runs, so if you slope it slightly down towards the far end, and turn the tees up, the moisture will travel to the end where you can purge it with a gate valve below your connection. I will admit that before my garage was built, and I worked in my basement, I had my Sears rattle around in the floor portable compressor over in the corner, and a short run of PVC ran along the floor joists above, and terminated by my work bench. I was VERY fortunate that it never 'sploded and killed me! If it had been hooked to a serious air compressor like my Quincy in the garage....KABOOMYOW!
I would have to see a picture of what you are talking about with the drops. My mind does not work that well. lol
Krooser
Building Chinese Free Engines since 1959...
I used black iron..3/4".
moparmat2000
Well-Known Member
At the bottom of your runs where the hose fittings come out you should drop the tube down about a foot below it, and put a drain petcock. This will allow a last place for water to collect before your air hose starts so you can drain it off. Even with a water air seperator this helps as a last defense.
I prefer the time bomb. I guess it's been 31-32 years now. No issues. Oh and I have a 7hp CompAir Kellog compressor.
JDMopar
Well-Known Member
Here's a pic of what I meant, but it's galvanized pipe. Can be done with any kind of pipe.
That's what I have on my small compressor inside the shop. I have a big one outside that's 220. I am wanting to run "some kind of" shop air around the shop from the big compressor.
Ok so the drop goes down to where? a drain? or to a quick connector for air hookup?
famous bob
mopar misfit
Laughing at this subject still going around about what people think is best. I aint saying mine is best , but I put 3/4'' shedule 80 pvc in about 2 compressors ago, no problems. Shedule 80 was designed for way more pressure than any of ur compressors will put out !
Easy to come up with and easy and fast to install , can be modified easier than about anything else, with exception of the new air poly systems. Make stationary, never in sunlight , vibration connection at compressor ,no problems------
even added a pex line "for speed" to the other side of garage. If I ever have to redo it , it will all be PEX.
JDMopar
Well-Known Member
It goes down to a quick connect for air hose. You can put a tee in at that location, with the connector off to the side, and a gate valve straight down so you can purge every now and then to drain water that might trickle down that way.
Ok. Thanks. I am looking at that 165 dollar kit at Northern Tool. It's probably all I would need. It may be a minute before I can get it though, so I hope I can depend on some guidance when I do. Thanks.
JDMopar
Well-Known Member
I've used schedule 80 pvc in the past too, and it's still in the rafters in my basement. PVC is rated for water pressure, which is a lot different than air pressure. I've been lucky, just like you have...but I'm at the age that pushing my luck just ain't worth it no more. I wouldn't be afraid of Pex pipe for air lines, but I would use the brass fittings. Shark Bite fittings cost out the ying yang!
famous bob
mopar misfit
Not worried about the schedule 80 in the slightest, not planning on changing it ever-----------agree sharkbite is outta sight, a lot of plumbers use it because its so easy and fast , especially if the customer is paying for it.
So how is water PSI different than air PSI? After 33 years as a firefighter, 19 years as a Driver Engineer, inquiring minds want to know.
Big_John
In my defense, I was left unsupervised.
Pneumatic pressure has more stored energy than hydraulic pressure. Think of a bursting water balloon versus a balloon filled with air. The water inside the balloon and the balloon itself will just fall. A bursting balloon with air will send the balloon pieces all over.
I've always understood that testing of pipe etc. shouldn't be done over 10bar or about 145psi. I think the link says that somewhere. As I also understand it, although I can never find anything to verify it, that you want to figure that a pneumatic rating will be about a third of a hydraulic rating.
Some reading on the subject:
Pressure Tests of Piping systems-Hydrotest Vs Pneumatic Test – What is Piping
The one thing that's always overlooked when siting PVC pressure ratings is that PVC degrades at higher temperatures. Even as low as 110 degrees, PVC pipe pressure rating is about half of what it is at 73 degrees. At 140 degrees, it's 22%.
Schedule 80 PVC pressure ratings:
https://dpk3n3gg92jwt.cloudfront.net/domains/ryanherco/attachments/spears_Schedule80PVCTechInfo.pdf
Since you are a firefighter, you may appreciate this. I read (somewhere) of a small fire in a guy's garage. The heat was just enough for the PVC pipe with compressed air to rupture. Suddenly, there was a nice source of pressurized air blowing into the fire. It just escalated from there.
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gzig5
Well-Known Member
Schedule 40 or schedule 80 don't matter, you can BS yourself all you want. If that pipe loses any of it's original elasticity, which I assure you it does as time goes by, it becomes brittle and can't keep up with the pressure changes in the system. What people don't understand is that it isn't the max pressure that always kills the pipe, it is the pressure changes. The pressure in the pipe changes every time you use the blow gun or the grinder. Each of those pressure cycles are stress on the pipe. When the accumulated stress is too much, the pipe fails. It will happen to steel or copper too if it is in use long enough. That is how pressure vessels are tested for long term reliability. Water heaters get thousands of 5psi cycles, which replicates turning a faucet on and off. Eventually the vessel will fail at a contaminated spot in the steel, next to the weld if it is good, or separate the weld if it is poor.
famous bob
mopar misfit
Pressure is pressure , no diff. , but air will leak out of a place that water wont.
A very small water leak "as in seep" will occasionally stop itself from impurities in the water and corrosion , air wont do that .
famous bob
mopar misfit
pre
True some what, do u know the meaning of water hammer, air doesn't stop fast as a more solid substance creating a hammer effect ..
turn off a faucet with a 2 lever handle and compare it to a faucet that has a single lever , water wont cushion itself , air will , air will compress, water wont. Schedule 80, strapped down , but not excessively tight ,where it wont move , not in a bind, not in sunlight ever, no damaging blows to it , doesn`t concern me in the slightest. I have been using all kinds of plumbing lines for over 50ish yrs. I have a pretty good idea of what works and what don't work--------done w/ the subject.
True some what, do u know the meaning of water hammer, air doesn't stop fast as a more solid substance creating a hammer effect ..
turn off a faucet with a 2 lever handle and compare it to a faucet that has a single lever , water wont cushion itself , air will , air will compress, water wont. Schedule 80, strapped down , but not excessively tight ,where it wont move , not in a bind, not in sunlight ever, no damaging blows to it , doesn`t concern me in the slightest. I have been using all kinds of plumbing lines for over 50ish yrs. I have a pretty good idea of what works and what don't work--------done w/ the subject.
^^^^ Exactly, no better example than the air your engine compresses. When a engine cylinder fills with air it will compress, fill it with water? You know the answer. As a Driver engineer, I have witnessed the results of a water hammer. I too have been using heavy sch pipe for routing of air lines with no problem. Years ago they taught us about never attacking a LP tank fire from the ends of the tank. Why? Because in one instance the tank under heavy flame impingement ruptured at the end when it BLEVE ( Boiling Liquid Expanding Vapor Explosion). So it became gospel. Later we learned better. Anything can fail, you don't draw a absolute because of it.
A408Cuda
Well-Known Member
Ive had 1/2 SCH 80 PVC rigged up for 10 years now, not one failure, I think the operating range on that is somewhere around 500 psi. Anyway my compressor gets turned off when I'm not there and I only run 120 psi so i guess I'm not to worried.
famous bob
mopar misfit
If I remember right , mine was rated at 680 something ----
Works for me too.
Simplicity bolted to the wall.
20x30 shop 60 gal 220 compressor in corner hose reel within 3 feet.
50 footer easily covers entire shop and well out into the driveway.
Jesse Martin
Title Don't need no stinkin title!
Copper is great, Just set this up for painting to help with removing water, the cost is on the higher side but like others said heat dissipation is great with it, added valve to the bottoms to drain water build up.
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