One more vote against PVC. I know lots of people use it(some I know personally). Black pipe is cheap too, why risk it? What is the trunk line? The first vertical line running from the tank to the ceiling?
The trunk line is the main pipe that all of the drops come off of. Black pipe is ok except for the condensation/rust problems. The system really has to be right to collect the garbage and keep it out of the tools. .
Black pipe is preferred for compressed air systems. The steel pipe tends to stay cooler longer and therefore the moisture inside condenses out of the air where it can be eliminated at a dirt leg or removed by a drier. That is why the branches from the trunk line go up before they go to the wall. The moisture lays in the bottom of the trunk line and if you look at the drawing in my first post the trunk line is slopped toward the end of the run where the moisture falls into the dirt leg where it has a pet cock to eliminate it. It should be drained each day just like the air tank.
www.rapidairproducts.com is the awesome pipe Keaser sells. If you want the BEST solution, this is it... I don't know what your budget is, but it is the most easily expandable, changable, etc. out there. Very cool looking too if you're into a neat shop...
I've never used PEX tubing before and I'm not advocating anyone do so but recently a ZURN rep came to my office on a sales call for a project that we are using PEX tubing for all the plumbing domestic water lines 2" and smaller. It's becoming more common in commercial plumbing and a substantial savings over copper, so we wanted a little info for our client. (We're Contractors, not Plumbers). The rep brought all kinds of data and some samples. I was most impressed with the samples that were testing burst strenght, the 1/2 piping was rupturing at around 800psi. It's tensile failure was around 600lbs if I recall correctly. The commercial system is crimped with anealled copper rings, although you can get push-connect fittings like a typical residential grade but I'm not sure where those are rated. When I get back to the office I'll open the brochure and see if there is any information about air use, might even call the rep. It does break down with UV exposure so that's a big downside.
Im sticking with black pipe with hydralic line at the compressor .... tried and true .... and Cheap! But one thing I do thats nice I run a 220v 80 gal for big jobs and a little five gallon 110v for filling tires etc .... both mounted outside the shop but switched at my airstation .... and bleed them off after each use.
I just recently did my garage air system and I did my homework before hand. The Rapid air system looks good on paper but in person it loses some luster. First off, their dimensions are for tubing, not pipe; it's OD, not ID so the 1/2" supply line I wanted to run equated to the much more expensive 3/4" size of the Rapi Air/Maxline. Secondly, the Maxline tubing comes in coils, making it a whole lot of fun getting them run straight. Third, and the deal breaker for me was the Maxline is only rated for 175 psi operating pressure at a meager 70 degrees. That wouldn't leave me any safety margin considering the capabilities of my compressor. I decided against copper pipe because I'm not handy with a torch and copper is too easy to dent. PVC has already been well discussed. I'm not fond of shrapnel grenades in my garage. So, like many professional shops do, I ran black iron pipe. I have an 80 gallon compressor and my flow requirements are far less than what 1/2" pipe is capable of so I used 1/2". My local plumbing supply cut the pipe to all the lengths I needed and I cut the threads myself with a Harbor Freight pipe threading kit. (I don't recommend that by the way, shoulda just paid the few extra bucks to have them threaded) The key to black pipe is layout and proper maintenance. Somebody already posted a good layout that's very similar to mine. I based my layout on this: My setup is far less extensive but the design is the same: For the transition from compressor to wall pipe, I used a short length of rubber air hose from D&B Supply.
Okay, next issue - I need to put my compressor in a small out-building next to my shop. Unheated/a/c. How will temp differences affect the system when it runs through the wall into my heated/a/c shop?
I had that thought myself. It gets into 105* in summer here. I thought of a lattice type wall with a roof to keep rain out. Still need a flex line from compressor to wall. Also noise for the neighbor might be a problem.
Im bringing this one back.... I wanna gain some more shop space and want to put my compressor in a non-climate controlled lean-to. How about it??
If it's subjected to freezing temperatures, you might be well advised to add a crankcase heater to keep the oil at a serviceable temperature. And be careful how you plumb it, to prevent freeze-ups at low points in the air piping. Realize that the air entering your compressor will be "raw", so you will probably need a good refrigerated dryer for summer use to get the moisture out.
Tommy's spot on about all of this. I ran my lines uphill all the way so whatever water condensates in the lines, runs back into the compressor tank. That's the function of the black iron (besides strength) to cool the air passing through it. Ask anybody that has nothing but rubber hoses for lines how much water they get (the rubber insulates so the moisture never condensates coming out in the tools. Rule of thumb on line size was 3/4" up to a 75' run, 1/2" drops. I made my compressor manifold out of 1 1/2 coming out though the wall, elbowing up to a ball valve (to shut the shop off at night) and elbowing down with one airline fitting so that I have air when/if the line has to be shut off. it goes up to seven feet and tees/reduces into the 3/4 line. I also put ball valves about halfway down on ever drop so if I need to change the quick connect (if something blows, or if they leak which is more common that you think) or re-arrange the fittings they can be shut down quickly. I religously leak check all my connections to insure they are tight, and again, you'd be surprised how little wear a it will take a quick-connect to leak, and thats where the drop shutoffs come in. I don't get any moisture in my line mostly because my Eaton compressor's only turn 600 rpms so they don't produce much heat. Less heat= less moisture. Here's a good link to the TIP site that has a diagram of the proper way to pipe a shop... http://www.tptools.com/StaticText/airline-piping-diagram.pdf
I poured a small pad and bolted my compressor to it outside my shop them built a lean to roof same size as the pad, its been going strong for over 3 years now. Best thing is I dont have to hear it running and I gained alot of space, I ran 3/4 pvc on 3 walls with seveal drops to plug into, these drops point up so water dosent sit in them and a clean out pointing down at the end of each run with a ball valve. I run 180psi. I have a ball valve just as the main line enters the shop incase I need to work on the system or spring a leak. MrC.
OK, so this isn't going to be very helpful, but I saw a system on one of those Sunday car TV shows that looked really cool. They used plastic pipe and rubber compression fittings that tighten by hand. It looked real easy and provided for quick connections and modifications to the system.
pex is not okay to use, better than PVC which is a for sure dont use. Ever! there is a product the looks and feels like pvc but is call DURAPLUS it is rated for 185 psi at 73F and 86 psi at 140F. it cuts glues easily and lasts it is resistant to the oil that compressors put out. a dryer is a wonderful idea.
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