If your air compressor is intended to be hard-piped into the workshop or plant, how do you decide what to use to plumb an air compressor?
First, let’s look at the choices available to us for plumbing the air compressor.
- PVC hose
- rubber hose
- galvanized pipe
- black pipe
Plastic for compressed air
Be very careful when considering plastic for a compressor plumbing material. Not all plastic pipe (Schedule 40 or Schedule 80 PVC or CPVC for example) are able handle the pressure of a compressed air system. Make sure the plastic pipe is compressed air rated.
For plumbing the workshop or small shop, sure, use poly tube. It’s cheap, flexible, water resistant, uses a host of relatively low cost fittings, cuts with a knife or tube cutter and is readily available.
First, make sure the tube you get is rated for compressed air. Some may not be. Typically that means a pressure burst strength about twice what the compressor can deliver.
Another concern is that unless you are really careful, poly tube fittings leak pretty easily. If you have a small bleeder leak in a fitting, and you shut down your compressor after use and drain the tank, the leak will be inconsequential. If you are trying to leave air in the lines overnight or for an extended period, the leak will drain the compressor tank, and your compressor will cycle on and off when you least expect it. Big leaks will affect the air flow to the tool, and must be corrected.
Tube size might be an issue since it’s limited in diameter. Run the main line around the garage or shop up on the wall, using 1/2″ tube as an air main. Lines tee’d off that down to quick couplers attached to the wall at strategic points would be 1/2″ too or maybe or 3/8″ depending on what is being powered by the air flow. The line to the tool would be rubber hose, sized to suit.
Water will collect in the lines, so if you don’t want it blowing through your air tools, get some compressed air filters in there.
This is plastic PVC too, but is built to handle the pressures a typical compressor might deliver. It is easy to install, fairly inexpensive, and is a good choice to plumb air from the compressor to a small workshop or plant.
There may be some concerns about flow capacity if your equipment needs lots of compressed air supply.
Install the PVC hose in the same manner you would the Poly tube referred to above.
Great for air lines to tools, wear resistant, stays flexible when it’s cool or cold, a good choice for air to the tools.
Also a fine choice to run an air main around the garage or workshop.
More expensive than some other options and just a bit more complex to plumb, yet lots of fittings around to plumb any way you want. Water resistant, crud resistant.
Install the same way you would the poly tube referred to above.
Using galvanized pipe for a compressed air systems appears to be problematical.
Dozens of people have written in telling us about problems relating to the galvanized coating inside the pipe not being consistent, of it cracking, of particles being generated, about water from the now rusting the pipes etc.
Unless you are using some sort of quick connect system (which makes it a much more expensive option) galvanized pipe is difficult to install. Not a good choice.
While black pipe won’t have a coating delaminate and contaminate your air stream, it sure does rust, and that rust may be come a problem over time.
Black pipe requires skills and equipment to install that the average person may not wish to acquire.
It’s plus is that it’s fairly cheap and it comes in large diameters which makes this piping the choice of a lot of plants that require high volumes of air.
There are a number of companies now that manufacture quick-assembly aluminum compressed air plumbing systems. They are wonderful! It’s just that this humble writer cannot afford to use them. If you can, go for it. They are neat, easy to install, and look very, very cool.
Use your browser and search for aluminum air pipe or air line and you will find suppliers.
Sure, a properly sweated copper fitting is leak proof, water and air-borne debris in the compressed air will not affect the copper, copper does not rust, it is available at any plumbing store, and it looks good.
Yet copper it is expensive, and for folks not into soldering copper, it’s complex to install. That is, of course, unless you used a quick connect system, and that rockets the cost up substantially.
Yet if the budget allowed, copper is what we would use for plumbing our air system, for sure, even with the issues of sweating copper fittings.
What To Use To Plumb An Air Compressor?
As with many choices, the best solution may be the most expensive.
For lowest cost, plastic is the first choice. Just make sure that it’s got the flow capabilities your compressed air equipment requires.