Plumbing Compressed Air

Plumbing Compressed Air; continued.

The first page of information on this topic, found here talks about the plumbing of a home shop portable compressor.

Now we'll talk about the fixed installation compressor.


Fixed Installation

While the concepts for both heavy duty industrial and home shop are the same, the level of expense will vary.

You'll want to do for your home shop what the experts do for the industrial installation, without spending the amount of money.

You see, it really depends on the level of dryness you want, but I get ahead of myself.

First off, you'll want a general purpose filter installed at the discharge of the compressor. If you want more information on compressed air filters, you'll find it here.

There's generally no need to install a regulator at the discharge from the tank, as you'll want to be able to adjust the air pressure to the differing applications in the shop or plant, and that will mean installing one at each point of use.

The drawing below shows the air filter at the egress from the main tank, air passing through a compressed air cooler (some sort of which you'll likely need if your plant is consuming a lot of compressed air, and a drop leg as the air line heads up to the ceiling in the plant or shop.







If you're plumbing compressed air for a plant, you'll want to plumb it similar to what's shown above.

If it's a home shop, and you'll be using air a lot, then you'll plumb it the same way. It's your call.

There's more on fixed installation a little further along. Right now I want to talk about what you use to plumb your air.


What Pipe?

Historically, industrial compressed air was plumbed using black metal pipe. Many folks still use it as it's relatively cheap when lots of pipe is needed for a plant installation.

Whether at home or in the plant, I wouldn/t select black pipe unless I absolutely had to.

Despite your best efforts at drying the compressed air, some moisture will still condense in those pipes, and rusting will occur. In time, the rust scales will migrate to the end applications, and become, along with the compressor oil, and air borne dust, another source of contaminant to foul up tools, valves and cylinders.







Of course, it's your money that has to be spent on plumbing, and maybe you'd rather spend less on the initial piping and more on air treatment? It's your call.

For my home shop or small plant, I'd first consider polyethylene tube. It's cheap, it's rated for industrial compressed air pressures, it's easy to install, and it doesn't react with moisture in the compressed air. It has scads of fittings to enable easy plumbing.

The problem with tube is that if you need large volumes of air, you can't get a tube large enough with sufficient pressure rating to do the job.

My next best plumbing material for the home or shop is copper pipe. Yup, the same copper that's used to plumb the water lines. It used to be fairly inexpensive (I know it's not anymore), it's easy to work with, has lots of fittings to convert from sweated (soldered) copper to threaded for installation into components, and it too, doesn't rust. If soldered properly, it will probably never leak which is a significant money saving consideration for plants using lots of air. To do a bang up job you'll want to be able to solder a copper joint, of course.

Next, consider using rubber hose, along with barbed fittings, to plumb your air. It's not pretty, doesn't end up looking as neat as a copper job, but it works, it's relatively low cost, and the rubber hose doesn't react to water. It will be a bit more problematical to install, and care must be taken to ensure that there aren't leaks.

There are some companies that build a composite plastic piping system for compressed air. I know that this product is not approved for use in every state, province, or country, so check carefully.

I'm not high on using plastic for plumbing compressed air. Should it fail, I believe rather than springing a leak, the plastic will shatter, sending shards in every direction.

I'm not saying don't use it, but due diligence is in order.

And now, of course, if you haven't got an unlimited budget to purchase 3" or 4" copper for the air mains, you're likely going to be forced into using black pipe at the ceiling ring. Oh well, more point of use equipment will be needed to deal with the by product of that.


When you get to the ceiling

You've now plumbed properly from the compressor, through the air filter to a "Tee", and now you want to make the connection from the riser to the ceiling main. Please see below.







As you can see, the line that goes to the ceiling, whether supplying air up to the main, or bringing air from the main down to an application, loops over the pipe, and connects on the top.

Any water that's in the riser line will tend to stay in the riser, and any water that's in the main, will tend to stay in the main, rather than following the air down to the application. The water will be on the bottom of the pipe.

Do you do this at home? Entirely up to yourself and the amount of air you expect to be using. If your air use is measured in hours rather than minutes, probably a good idea to install your air supply lines properly.

More on plumbing compressed air here.







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