Why don't we have a Compressed Air Pipeline?

A reader of this blog asked "Why do we not have a Compressed Air Pipeline like the Natural Gas Pipeline?"

Natural Gas is supplied by a finite number of wells geographically located where natural gas is plentiful. In order to deliver it to power plants and homes, a nationwide network of pipes was created.

Compressed Air, on the other hand, can be created anywhere. All you need is a compressor and electricity and you have compressed air. Therefore there is no need for an expensive pipeline.

What do you think?

No more Sonic Booms

Imagine flying at the speed of sound without the annoying sonic boom. You'll recall the passenger jet Concorde that could take passengers from New York to Paris in two hours? The Concorde was not allowed to fly over land due to the sonic boom. I recall as a kid, windows and glassware rattling in my house from the jets at nearby Hanscome AFB in Bedford, MA. But, since then, no aircraft are allowed to travel over land in the States at supersonic speeds. Sonic booms are created by compressed air infront and behind the aircraft.

That might be changing, though, due to an old design from German Engineer Adolf Busemann. He envisioned a biplane connected at the tips as a way to cancel out the noise. Recently, engineers from MIT and Stanford have simulated a design that just might work. Read here for more info.

Can I use PVC for my Compressed Air System?

PVC Pipe In a word - NO - Let me repeat just in case you didn't hear - NO!!

PVC is easy to use and connect, seal and is lightweight so why not use it for compressed air? First OSHA does not allow it. In a report that they posted, they warn that PVC pipe can explode and send shrapnel in all directions. In their report: "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."

PVC is subject to creep and fatigue over time. Also compressed air pipes can be subject to vibration. The compressible nature of compressed air means that when a rupture occurs, it occurs catastrophically. Compare that to a breach in a water line. Water is non-compressible. Once a rupture occurs all the pressure is quickly dissipated and an explosive tear is avoided.

Note that there are some forms of ABS (Acrylonitrile Butadiene Styrene) that are safe for use in compressed air systems. Please check with the manufacturer of the pipe to confirm that it is safe for use in your particular application.

President Obama is Amazed at the Power of Compressed Air

 This picture is courtesy of NBC. The young man in the photo  is Joe Hudy. Joe created the compressed air cannon that can shoot marshmellows 176 feet. He was at the White House as part of a group of young people from around the country. Check out his story at http://makerfaire.com/pub/e/6667

An email from a reader about his compressed air system.

A reader of this blog sent me the following email:

Message: Hi, I'm in the process of building a house. It will have a detached 24'x40' shop in which I'll be restoring cars. I've been using a small rolling compressor for years. It will run my impact wrench, but not  my sanders or pain gun. I'd like to build an air system into the garage that can handle all my tools and supply a paint gun. I've been looking at 2-stage 80 Gallon 7.5HP 230V single phase vertical compressors like this one. Am I in the right ball park for my purpose? What I'm really in the dark about is air-drying and lubrication. Are the in-line desiccant dryers enough or do I need a refrigeration unit? Any advice you can offer would be greatly appreciated!

Thanks, Jordan

And here is my response:

Hi Jordan, thanks for the email. In general, the IR brand of compressors is well built. It is industrial grade and should perform well. You may want to check with your local Ingersoll Rand distributor to see if they can supply the product. They would also be able to service it for you and help you make decisions like you ask below.

In general, to build a compressed air system into your large garage, I'd recommend creating a loop feed line. I blog about that here:
The loop assures that the air can be delivered uniformly. Also, be sure that you connect your equipment with a drip leg:

Instead of a dryer for the entire system, I'd put coalescing filters at the point of use. These filters will remove any rust and pipe scale as well as oil and liquid water from the compressed air line. If you equipment requires oiling, install an oiler after the coalescers. You can read about our Balston coalecsers here.

Most shop equipment does not need super dry compressed air. If you notice that you are getting too much water for the filters to handle, you may look at one of our membrane air dryers that lower the  dewpoint to +35F, which should handle most situations. In line desiccant dryers become saturated within a day. You are better off with a membrane dryer as it self regenerates.  Information about our dryers can be found here.

A dryer is recommended if you are doing any spray painting, especially powder coating. Here's an article to read. 

Another application for membrane dryers is bead blasting, we have an article about that here.