The Makeup of Earth’s Air

Most people know that oxygen, makes up about 20% of the earth’s atmosphere at sea level, and that almost all the rest is nitrogen. But did you know there’s an impressive list of other gases in the air we breathe

whats in air
Reference: CRC Handbook of Chemistry and Physics, edited by David R. Lide, 1997.

We can consider, for practical purposes, that air is made up of five gases: nitrogen, oxygen, argon, carbon dioxide, and water vapor. But because water vapor is a variable, this table omits it, water vapor generally makes up 1-3% of atmospheric air, by volume, and can be as high as 5%.  Which means that, even on a ‘dry’ day, it pushes argon out of third place!

There are numerous reasons why the volumetric concentrations of these gases are important.  If oxygen level drops in the air we’re breathing, human activity is impaired.  Exhaustion without physical exertion will occur at 12-15%.  Your lips turn blue at 10%.  Exposure to oxygen levels of 8% or below are fatal within minutes.

But here at EXAIR we care about how compressed air can be used efficiently to better your process! 

Any of our products are capable of discharging a fluid, but they’re specifically designed for use with compressed air – in basic grade school science terms, they convert the potential energy of air under compression into kinetic energy in such a way as to entrain a large amount of air from the surrounding environment.  This is important to consider for a couple of reasons:

  • Anything that’s in your compressed air supply is going to get on the part you’re blowing off with that Super Air Nozzle, the material you’re conveying with that Line Vac, or the electronics you’re cooling with that Cabinet Cooler System.  That includes water…which can condense from the water vapor at several points along the way from your compressor’s intake, through its filtration and drying systems, to the discharge from the product itself.
  • Sometimes, a user is interested in blowing a purge gas (commonly nitrogen or argon) –  but unless it’s in a isolated environment (like a closed chamber) purged with the same gas, most of the developed flow will simply be room air.

Another consideration of air make up involves EXAIR Gen4 Static Eliminators.  They work on the Corona discharge principle: a high voltage is applied to a sharp point, and any gas in the vicinity of that point is subject to ionization – loss or gain of electrons in their molecules’ outer valences, resulting in a charged particle.  The charge is positive if they lose an electron, and negative if they gain one.  Of the two gases that make up almost all of our air, oxygen has the lowest ionization energy in its outer valence, making it the easier to ionize than nitrogen.  You can certainly supply a Gen4 Static Eliminator with pure nitrogen if you wish, but the static dissipation rate may be lesser.

If you want to learn more about the compressed air or any of our point of use compressed air products, you can contact an Application Engineer.  We will be happy to help you.

Jordan Shouse
Application Engineer

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Air photo courtesy of Barney Moss Creative Commons License

Video Blog: Filter/Separator and Pressure Regulator Mounting and Coupling Kit Installation

Using EXAIR mounting and coupling kits you can assemble EXAIR Filters and Regulators into one plug and play assembly. Follow along with the video posted below to complete this task!

If you need a deeper understanding about how EXAIR’s products can be applied and help your process or product, feel free to contact us and we will do our best to give you a clear understanding of the benefits when using our engineered compressed air products. We can also explain proper implementation of accessory items such as compressed air filters and regulators.

Jordan Shouse
Application Engineer

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Save Compressed Air Energy with Pressure Regulators

Why should you consider a Pressure Regulator when designing your compressed air system? As many know, our products and those of other  product manufacturers have a certain set of specifications regarding performance at stated input pressures. But what if your application doesn’t require that “full, rated performance”? Maybe instead of needing two pounds of force, you only need one pound? Sometimes more force does not produce the desired result for an application. By that, I mean you cause damage to the target or other surrounding items in the application. Or, perhaps blowing too hard (or vacuuming too hard in the case of a Line Vac or E-vac) might cause the vessel or the material you are picking up to collapse or deform (due to too much power).

Regulators catalog
EXAIR offers a range of Pressure Regulators capable of handling air flow of up to 700 SCFM.

There is also the concern about using more energy than one really needs to in order to achieve the desired effect in an application. In other words, if you can achieve your goals with only 40 PSIG, then why would you ever use 80 PSIG to accomplish the goal? By reducing your compressed air from 80 down to 40 PSIG, you can easily reduce the air consumption of the “engineered” solution by another 40% or more.  Once you have installed engineered air nozzles to reduce compressed air on blow off applications, a pressure regulator can fine tune the pressure to save even more energy.

Regulator Internal
Regulator Internals

Then there is the issue of taking advantage of the pressure differential (from 80 down to 40 PSIG) that creates a little bit more air volume capacity. At 80 PSIG, your compressed air to free air volume ratio is 6.4:1. At 40 PSIG, it is only 3.7:1. The net effect is you effectively have an overall larger volume of air you can use for other applications in your facility. By reducing compressed air pressure of your demand applications, you may be able to reduce over all compressor discharge pressure. Reducing compressor discharge pressure by 2 PSIG also reduces required input power by 1 percent – so keep your pressure as low as possible!

Regulating pressure is definitely warranted given the benefits that compliment the operation of the core EXAIR products.

If you need a deeper understanding about how EXAIR’s products can help your application, feel free to contact us and we will do our best to give you a clear understanding of all the benefits that can be had by our products’ use as well as proper implementation of accessory items such as compressed air filters and regulators.

Jordan Shouse
Application Engineer

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Importance Of Proper Pneumatic Tube, Pipe, And Fittings

When it comes to engineered compressed products, the number one cause of less-than-optimal performance is improper supply line sizing.  This can mean one of two things:

  • The hose, pipe, or tubing running to the device is too small in diameter.
  • The hose, pipe or tubing is big enough in diameter, but too long.

The problem with either of these is line loss (follow that link if you want to do the math.)  Put simply, the air wants to move faster than it’s physically permitted to.  Any time fluid flows through a conduit of any sort, friction acts on it via contact with the inside surface of said conduit.

With smaller diameters, a larger percentage of the air flow is affected…no matter what diameter the line is, the air closest to the inner wall is affected by the friction generated.  When diameter increases, the thickness of this affected zone doesn’t increase proportionally, so larger diameters mean less of the air is affected by friction.  It also means there’s a lot more room (by a factor of the square of the radius, times pi…thanks, Archimedes!) for the air to flow through.

Likewise, with longer lengths, there’s more contact, which equals more friction.  Length, however, is often a non-negotiable.  You can’t just up and move a 100HP air compressor from one part of the plant to another.  So, when we’re talking about selecting proper supply lines, we’re going to start with the distance from the compressed air header to our device, and pick the diameter that will give us the flow we need through that length.  In fact, that’s exactly how to use the Recommended Infeed Pipe Size table in EXAIR’s Super Air Knife Installation & Maintenance Guide:

This table comes directly from the Installation & Operation Instructions for the Super Air Knife.

Once we have the correct line size (diameter,) let’s consider the fittings:

  • Tapered pipe threads (NPT or BSPT) are the best.  They offer no restriction in flow, and are readily commercially available.  If you’re using pipe, these are the standard threads for fittings.  If you want to use hose, a local hydraulic/pneumatic shop can usually make hoses with the fittings you need, at the service counter, while you wait.
  • If you need to frequently break and make the connection (e.g., a Chip Vac System that’s used throughout your facility,) quick connects are convenient and inexpensive.  Push-to-connect types are by far the most common, but a word of warning: they’re notoriously restrictive, as the inside diameter of the male end is markedly smaller than the line size.  If you use them, go up a size or two…a quick connect made for 1/2 NPT connections will work just fine for a 1/4″ line:
  • The nice thing about these quick connects is that you don’t have to depressurize the line to make or break the connection.  If you have the ability to depressurize the line, though, claw-type fittings (like the one shown on the right) provide the convenience of a quick connect, without the restriction in flow.

Proper air supply is key to performance of any compressed air product.  If you want to know, at a glance, if you’re supplying it properly, install a pressure gauge right at (or as close as practical) to the inlet.  Any difference in its reading and your header pressure indicates a restriction.  Here’s a video that clearly shows how this all works:

I want to make sure you get the most out of your compressed air system.  If you want that to, give me a call with any questions you might have.

Russ Bowman
Application Engineer
EXAIR Corporation
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