Ok guys I am going to buy a new compressor for the shop and was wondering what everyone recommends for airline. PVC ( has a bad rep. for exploding), Steal ( will fill up with rust over time), Aluminum with press fit fittings($$$$$$$), or Copper (i don't know anything about). I will be running various air tools, hoist, sandblaster,etc... I am thinking about a 1" diameter and probably going to need about 100 feet. What do ya think?
I have used PVC in my own shops and worked in a few others that had it. It does NOT explode. It can crack though, but I've only ever seen that happen at the connections. It's cheap enough you should try it for yourself without believing all the hype.
Having worked in several places plumed in PVC I have seen a few failures and in every case the failure came from one of two issues:
The pipe was run on an uninsulated outside wall and when it got nutty cold the line was so brittle that if you looked at it hard it went all 'splodey on you.
Or, the install either left the coupler mounted so that to hook it up people where putting mechanical pressure on it or the mounting of the run put stress on it and over time it failed.
My last shop and this one are all PVC and I have had ZERO problems.
I worked for about 4 years for a shop that repaired/ installed industrial air compessors. I know alot of people have used pvc and had no problems That said I've seen several places that had PVC pipe "explosions". Do you want to be standing at ground zeero when it happens? The larger the dia of PVC the weaker it gets. Cold definately has effects on it, and it does become very brittle very quickly even a modetete temps say 40-50 deg.
We used either iron pipe or copper. With the price of copper nowdays, I'd probably use iron. Copper is a little simpler to work with. Almost anyone can cut it and solder up the joints. Good prep is the key to good solder joints. Small bends can be made with a conduit bender, say jogs for a sill plate on block.
Steel pipe is even easier to screw together, but long pieces get awkward. Unions can simplify this. You don't even have to own a threader any more as HD and Lowes will tread it to the length you ask. Rust is seldom and issue if you do the following. Drain your comp. regularly. You can buy auto drains if you run the comp alot and set them to drain every 30 min - 1 hr. Don't run just off the comp. feed from a tank. Add a cooler, this can be as simple as some copperfinned tube with a fan. The idea is cooler air holds less moisture, so get rid of it where you want not where it wants. Oil lubed air, prevents rust and is great for tools but not a great idea if you want to use it for paint.
Be sure to solidly mount your disconnects. I like to use a length of iron pipe 8" long with straps and a 90 elbow for mounting disconects, even with copper unless my drop is 3/4" or larger. This gives you a solid section that the hose can pull on. A short flex line with a disconnect say 12"-24" will do the same thing but it costs more to make them. I you have a lot of conectors and want the flex option go to a haudrolic shop and have them crimp on the ends it will be cheaper than clamps. Connect the comp to the air piping with a flex hose to limit vibration and noise. Dont forget line drains for longer runs and pitch helps.
I run 3/4" for mains and 1/2" for most drops unless you have a really big comp and use a lot of air. then 1" to 2" and 3/4" drops. Example: big sand blasers. Bigger is not nesc. better. Yes you gain storage in the line but you can get a good size pressure drop as the line draws down and your comp tries to keep up. ie 1 1/2" OR 2" main with 3/4" drop on a small say 5 cfm machine. yes its an exageration.
My dinky "shop" is actually half of a 2 car garage. Hell, calling it a shop is a long shot. I just have a 50 foot hose reel mounted to the ceiling and it works great for me. One day, when my wife and kids stop spending all my money, maybe I'll move up to the big boy's league like you guys and build a REAL shop.
from that link:
An employee in a Texas plant was injured recently by a rupture in a PVC compressed air line. Plastic projectiles from the point of rupture caused lacerations of the employee's hand.
Last year, a section of PVC pipe being used for compressed air exploded 27 feet above a warehouse floor. A fragment of the pipe flew 60 feet and embedded itself in a roll of paper. Fortunately, nobody was in the area at the time.
A PVC pipe explosion in a new plant in Selah broke an employee's nose and cut his face.
PVC piping buried 3 feet underground at a Yakima manufacturing plant exploded, opening up a crater approximately 4 feet deep by 3 feet across.
When a PVC pipe or fitting fails when under stress from compressed gas it literally explodes like a bomb, sending shards of plastic flying several feet in all directions. Liquids, on the other hand, being compressed by only 1/10th of 1% contain very little stored energy. When pressurized systems with liquids fail, the energy is dissipated very quickly, thereby creating a much lower potential for hazard.
FYI As a not so trivial fact. Air at sealevel is 15 psi, thats how many pounds of air is above you. you "feel" nothing and your pressure gauge will read 0. In diving every time you decend 33ft you decrease the volume of air by 1/(pressure/15). In other words a 1 cu ft box filled with air at the surface when submerded to 33ft would be 1/2 full. This also works in reverse. The same 1 cu ft box filled with air at 33ft when brought to the surface would expand to fill a 2 cf balloon. This continues every 33 ft so at 66ft the air would fill a 3 cf balloon, and so on see list at bottom.
This is why divers can not hold thier breath and return to the surface, their lungs WILL literally explode. The US Navy has submarine personel enter a chamber under pressure at 100' and swim to the surface exhaling the entire time. You just keep exhaling as fast as the air expands and you will not have to inhale as your lungs will stay full of air.
150psi is equal to 333 ft of water or 11 times the amount of air at the surface. At 180 Psi it is 13 times as big. This is why air line explosions are so dangerous and powerfull. You've got 11 feet of Sh*t in a 1 ft box.
Are you guys really seeing a need for running air hose all the way around a shop? I mean - my shop is 30x40, and 50' hose reel reaches anywhere in the shop, and winds up nicely when I'm done. At most, I can see adding a second hose reel on the other side of the shop by the work benches, and maybe another one by the front door. But then again - I have a 50' coiled hose I can hook to the hose reel if I need more line
I'd personally find it annoying to go back to plugging in extension hoses to the various line drops, then having to deal with putting those away all the time.
I have been running my shop with one, 50', 3/8 hose reel, for the last 5 years. It was a quick thro-together when i moved in, but its just not quite enough. Its time to bite the bullet and do it right, and be done with it. My goal is to have 2 hose reels in the shop, one on each end. 1 drop to run my hoist and can crusher. And a 30' run to the back of my biulding where i do my outdoor sandblasting. I don't want to spend anymore than i have to, but don't ever want to have to redo it either. Learning from all that have posted, plastic explodes and steal will rust, so i am leaning towards copper at the moment.
There is also a company that does the blue aluminum (I think) systems designed specially for compressed air systems. I know it was featured on horsepower tv a while ago and I assume it can be found at Grainger.
FWIW some pex tubing is rated for air use, it may be a possible option in some cases. The fittings can get expensive but if you just wanted to get from one side of a shop to the other it might be a good alternative to pvc.
I was doing some reading here, and they claim copper should not be used because "soldered joints can come loose under pressure (Safety Hazard)".
I have zero experience, but I've read a ton, and have never seen anyone else say this. Have any of you ever seen it? Copper seems so much easier to work with that it's the way for me to go, unless it really is an unnecessary hazard.
The only problem that I see arising is if you have a soft solder joint subjected to high vibration, like connecting directly off the compressor with no means of vibration relief. I regularly deal with copper subjected to much higher pressures than you would see in a shop air system and I have yet to see a properly soldered or brazed joint fail due pressure. If copper is the easiest way for you I would do it without a second thought.
I used copper and sweated it together. The a/c industry has been using sweated copper forever and it withstands much higher pressure than compressed air.
I'm thinking a 50' hose to the front of my shed hooked up to a reel is the way to go. My shop is the rear half and we park in the front, so it wouldn't be used on a steady basis.
Line size is going to matter more to you than material type. Plumb some 1" line and forget about it. I'm going 1" or 1 1/4" galvi this summer since I'll be running too much of it to justify the cost of copper. Try to make your drops connect together to form a ring.
My family got into the tire business about 45 years ago. We have an Ingersoll rand compressor with a build date of 1960. There are hundreds of feet of steel pipe in the building, some black and some galvanized. The pipe coming from the compressor is 1 inch until it reaches the bay where 3 separate 3/4 pipes come off of it. The other half of the building is a mechanics shop where most of the pipe is 1 inch except where it goes to quick connect fitting where it is half inch. Some of the pipe has a bit of rust in it where water would sit due to low air demand. the only problem i can remember ever having with rusting is a quick connect at a tire changer managed to get a bit of shit inside of it and restrict it. We own an electric threader so whenever we need to modify something or make additions it is easy. If I didn't have access to the threader i would use copper.
Steel and copper can take some abuse under pressure, i don't think pvc will hold up very good. Just use copper ,steel, pex or something else that is approved for air. For the people saying "my shop has had pvc for years and I've never had a problem" I say you are lucky and cheap.
Let's look at the economics of hose reels. The cheapest I know of are H-F. They are currently on sale right now at $79.99 each with 50' of hose. Four would run almost $320. I can run one Hell of a lot of pipe, either copper or iron for that price and have to just to get it to the reel. A quick coupler is what, $5.00 worst case? Hose is cheap as well. I can put in four quick-connects for $20 and a chunk of hose for $25, total $45 versus $320. Seems like a simple solution to me.
I can spend a bunch of money on hose reels that are in parts of the shop that get less use than others, or I can put spigots everywhere and drag a hose with me when I need it there.
I just collected on a big job, maybe next weekend, I'll plumb my air system a little more correctly :flipoff2:
For me it's more of an organizational issue, the hose always has a place and just looks neater. Plus you don't have to coil the thing up when you're done using it.
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