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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EXAIR Standard Air Knife: Engineered For Performance

In 1983, EXAIR Corporation was founded with the goal of engineering & manufacturing quiet, safe, and efficient compressed air products for industry.  By 1988, the EXAIR-Knife (now known as the Standard Air Knife) was quickly becoming the preferred choice for replacing loud and inefficient drilled pipes, long nozzle manifolds…anywhere an even, high velocity curtain of air was required.

The EXAIR Standard Air Knife’s design takes advantage of a fascinating principle of fluidics to achieve quiet and efficient operation: the Coanda Effect, which is the tendency of a fluid jet to stay attached to a convex surface.  If you want to see it for yourself, hold the back of a spoon, handle up, under the kitchen faucet.  Those who haven’t seen it before may assume that gravity will take over and the water will fall from the bottom of the spoon’s ‘bowl’ – but it doesn’t:

Likewise, the air flow (which is just another example of a fluid jet) exiting the Standard Air Knife’s shim gap follows a convex surface (which we call the “Coanda profile”) causing it to entrain large amounts of air from the surrounding environment:

Compressed air flows through the inlet (1) to the Standard Air Knife, into the internal plenum. It then discharges through a thin gap (2), adhering to the Coanda profile (3) which directs it down the face of the Air Knife. The precision engineered & finished surfaces optimize entrainment of air (4) from the surrounding environment.

This entrainment does two things for us:

  • First, because we’ve engineered the design for maximum entrainment, it’s very efficient – creating a high flow rate, while minimizing air consumption.  In the case of the Standard Air Knife, the entrainment ratio is 30:1.
  • Secondly, this entrainment forms an attenuating boundary layer for the air flow, resulting in a high velocity, high volume airflow that is also incredibly quiet.

The EXAIR Standard Air Knife comes in lengths from 3″ to 48″, and in aluminum or 303SS construction.  All sizes, in both materials, are on the shelf and available for immediate shipment.  For most applications, we recommend the Kit, which includes a Shim Set (to make gross changes to flow & force,) an Automatic Drain Filter Separator (keeps the air clean & moisture free,) and a Pressure Regulator (to dial in the performance.)  Deluxe Kits add our Universal Air Knife Mounting System and EFC Electronic Flow Control.

(From left to right) Aluminum Standard Air Knife Kit, SS Standard Air Knife Kit, Deluxe Aluminum Standard Air Knife Kit, Deluxe SS Standard Air Knife Kit.

If you need a hard hitting curtain of air for blow off, drying, cleaning, cooling, environmental separation, etc., the EXAIR Standard Air Knife is an easy and economical solution.  If you’d like to discuss your application and/or product selection, give me a call.

Russ Bowman

Application Engineer
EXAIR Corporation
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Don’t Forget About Operating Cost: How To Calculate Return On Investment

If you have a stock portfolio, or even a retirement account, you’ve likely heard the term “return on investment.” It basically tells you how hard your money is working for you, and, the higher, the better.

The term is also used to determine the financial benefits associated with the use of more efficient products than you’re using right now:

  • The cost of operating industrial pumps, air compressors, and a variety of industrial rotating equipment, can be greatly reduced by using variable frequency drive systems that sense the demand and change the motor’s speed (and hence power consumption) accordingly.  These systems are not cheap, but the reduction in operating costs is often quite noticeable.
  • At home, installing energy efficient windows (spoiler alert: your builder probably used the cheapest ones he could find…mine sure did) or upgrading appliances & HVAC can cost a pretty penny, but you’ll also see your electric bill go down.

EXAIR Corporation has a worldwide reputation for providing highly efficient compressed air products for industry.  Our Engineering Department has a company-wide reputation for being data fanatics…which is key to allowing us to provide our customers with ample information to make the best choices to optimize your use of your compressed air.

It’s not hard at all to calculate your potential savings from the use of an engineered compressed air product, assuming you know how much air your current device is using.  If not, we can tell you if you can send it in for Efficiency Lab testing (free and fast; call me to find out more.)  Here’s an example for a VERY typical situation: replacing an open copper tube blow off with an EXAIR Super Air Nozzle:

  • A 1/4″ copper tube uses 33 SCFM @80psig
  • A Model 1100 Super Air Nozzle uses 14 SCFM @80psig

33 SCFM X 60 min/hour X 8 hours/day X 5 days/week X 52 weeks/year = 4,118,400 SCF

14 SCFM X 60 min/hour X 8 hours/day X 5 days/week X 52 weeks/year = 1,747,200 SCF

4,118,400 – 1,747,200 = 2,371,200 Standard Cubic Feet of compressed air savings

If you know your facility’s cost of compressed air generation, you can calculate the monetary savings.  If not, we can get a good estimate via a thumbrule used by the U.S. Department of Energy that says it typically costs $0.25 to generate 1,000 SCF of compressed air:

2,371,200 SCF X $0.25 ÷ 1,000 SCF = $592.80 annual monetary savings

In 2019, the cost of a Model 1100 Zinc Aluminum Super Air Nozzle is $41.00.  Daily savings (not counting weekends) is:

$592.80 ÷ 260 days (5 days/week X 52 weeks/year) = $2.28 daily savings

Meaning the payoff time for the $41.00 investment in the Model 1100 is:

$41.00 ÷ $2.28 = 17.9 days

Or…just over three weeks.  Now that I’ve shown you the math, I’d like to introduce you to the EXAIR Cost Savings Calculator.  Just enter the data, and it’ll check your math (because I know you’re going to do the math anyway, just like I would.)  It even does the ROI for you too.

Engineered solutions (like EXAIR Intelligent Compressed Air Products) are the efficient, quiet, and safe choice. Does the one on the right look familiar?  It’s literally the example I used for the above calculations.

If you’d like to find out more about how – and how fast – EXAIR Intelligent Compressed Air Products can pay off for you, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Factors When Sizing a Cabinet Cooler System

Heat can cause real problems for electrical and electronic components, in a hurry…we all know that.  Fortunately, we can also specify the right Cabinet Cooler System for you in a hurry too.  And since we keep them all in stock, we can get it to you in a hurry as well.

You can access our Cabinet Cooler Sizing Guide online, here.  You can fill in the blanks and submit it, or you can call in your data.  We do it over the phone all the time, and it only takes a minute.  Here’s what we’re going to ask for, and why:

NEMA 4 Cabinet Cooler
  • Enclosure dimensions.  We need the length, width, and height of your enclosure to calculate the heat transfer surface, and the volume of the enclosure.
  • Current Internal Air Temperature.  How hot is it inside your enclosure?  This is the starting point for figuring out the internal heat load…how much heat the components inside the box is generating.  This needs to be the air temperature – don’t use a heat gun, or you’re going to give me the surface temperature of something that may or may not be close to what I need.  Just put a thermometer in there for a few minutes.
  • Current External Air Temperature.  How hot is it in the area where the enclosure is located?  We’re going to compare this to the internal air temperature…the difference between the two is actually proportional to the heat load.  Also, if there’s anything cooling the enclosure right now (like circulating fans; more on those in a minute,) this reading is key to figuring out how much heat they’re removing.
  • Maximum External Air Temperature.  How hot does it get in the area on, say, the hottest day of summer?  We’ll need this to calculate the external heat load…how much heat the enclosure picks up from its surroundings.
  • Maximum Internal Temperature Desired.  Most electrical and electronic component manufacturers publish a maximum operating temperature of 104F (40C) – it’s kind of an “industry standard.”  Based on this, a lot of us in the enclosure cooling business set our products’ thermostats to 95F (35C) – if we’re maintaining the air temperature a decent amount cooler than the components are allowed to get, history and practice has shown that we’re going to provide more than adequate protection.  If your enclosure houses something with more sensitive temperature limitations, though, we can work with that too…that’s the only time you’re going to want to put something other than 95F (35C) in this field.
  • Cabinet Rating.  This is all about the environment…we offer three levels of protection, per NEMA standards:
    •  NEMA 12 – oil tight, dust tight, indoor duty.
    • NEMA 4 – oil tight, dust tight, splash resistant, indoor/outdoor duty.
    • NEMA 4X – oil tight, dust tight, splash resistant, corrosion resistant, indoor outdoor duty.

                     The NEMA rating does not affect the cooling capacity at all.

  • Other:  If the enclosure is mounted to the side of a machine, or a wall in the plant, you really don’t need to put anything here.  If it’s outside and exposed to direct sunlight, tell us what the surface finish (i.e., polished metal, painted grey, etc.) is so that we can account for solar loading too.  If anything else is unusual or peculiar about the application, let us know that too.
  • My Cabinet Is…Not Vented, Vented, Wall Mounted, Free Standing, Fan(s).  We’ll use what you tell us here to verify heat transfer surface (a wall mounted cabinet’s back surface isn’t a radiating surface, for example.)  Also, I mentioned fan cooling before, so without further ado…
  • Fan diameter or SCFM.  If there are fans circulating air into (and/or out of) the enclosure, they’re providing a finite amount of cooling right now.  Proper installation of a Cabinet Cooler System is going to require their removal.  Running a Cabinet Cooler System on a vented enclosure is just like running your air conditioner with the windows open.  So, if we know the size (or the SCFM…sometimes there’s a label on those fans, and we LOVE those folks who do that) then we can use that, and the temperatures you gave us above, to take the fan cooling into account.

Once we have all this information, it’s down to the math. Like I said, we do this all the time (especially during “Cabinet Cooler Season”) – give me a call.  Your heat problem isn’t waiting; why should you?

Jordan Shouse
Application Engineer
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Compressed Air Pressure Regulators Conserve And Protect

Imagine you’re enjoying a nice shower. A cascade of warm water is soothing your body – and spirit – then, someone starts the dishwasher. Or a load of laundry. Or flushes the toilet. Suddenly, the “soothe” turns to “scald” or “freeze,” depending on whether you’ve been robbed of hot, or cold water.  So, what happened?

What happened is, all of those “loads” on your house’s water supply that can ruin your shower experience are controlled by simple on/off valves…they open to permit a certain amount of water FLOW to pass.  When the dishwasher starts, or someone decides to wash a load of whites, the HOT water from your nice warm shower is diverted, leaving a stream of cold water.  When a toilet flushes, or it’s a load of colors, the COLD water is diverted…and that’s not just unpleasant, but downright painful.  Either way, (in my house anyway,) a teenager is getting read the riot act.

The same phenomenon can apply in a compressed air system, if simple flow control valves are used to throttle the appropriate supply of air to a pneumatic device.  If someone, for example, hooks up an air gun to blow off their tools or parts, the valves on EVERYTHING else will need to be opened up some to keep those devices working the same.  In the case of an air gun like this, it usually happens too quick to make the necessary adjustments (by hand) and you’re probably left with a machine tripped off-line, or a ruined part.

Pressure Regulators can prevent this by keeping (or regulating) their downstream pressure to a set value.  If a load elsewhere in the system is activated, the Pressure Regulator opens up, automatically, to keep its output constant.  When that load is secured, the Pressure Regulator closes back down accordingly.  Either way, no single load affects the operation of any others.

That’s only half the value of the use of Pressure Regulators, though.  The other half is, well…the value.  Just looking at a typical function of many EXAIR Intelligent Compressed Air Products – blow off – they’ll all pretty much accomplish the task if you run them, unrestricted, straight off your header.  That’ll give you a good, strong blast of air flow…and it may be more than what’s required, and a waste of good air.  Pressure Regulators will prevent this by allowing you to “dial in” the supply pressure to whatever it takes to get the job done, and no more.

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

Compressed air isn’t free.  Heck, it isn’t even cheap.  Don’t use any more than you have to, and get the most out of what you do use.  Pressure Regulators are one important step in doing this.  If you’d like to talk about optimizing your use of your compressed air system, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Benefits of Atomized Liquid Nozzles vs. Liquid Nozzles

There are a great many applications that require a spray (as opposed to a stream) of liquid. Certain droplet sizes, and flow rates, are beneficial for certain applications. For example, if you’re fighting a fire, you want as high of a flow rate as possible – the more water you douse the fire with, the quicker it goes out.  You also want a fairly large droplet size, since a mist would tend to evaporate instead of extinguishing the flames.

Pressure washers also benefit from higher (though not near as high as fire hose) flow rates, and droplet sizes.  You want an appreciable flow rate, because that means high velocity, and good sized droplets combine that velocity with their relative mass to “blast” away dirt and detritus from the surface.

Medicine delivery devices, like asthma inhalers, are designed to produce mid-sized droplets, but pretty low (and controlled) flows.  The droplets need to be small enough to efficiently spread the medicine through the breathing passages, but large enough to where they won’t evaporate before they ‘plant’ on the nasal & bronchial membranes to get absorbed.

These are examples of “liquid-only” nozzles…no other media or means of force are used to effect the spraying action.  Most of the time, the droplet sizes in these applications are measured in hundreds of microns, which “liquid-only” nozzles are ideally suited to generate.  Other applications, however, call for much smaller droplet sizes…such as those only attainable through atomization.

EXAIR Atomizing Spray Nozzles use compressed air to create a fine mist of liquid, with droplet sizes as low as 22 microns.

A typical “liquid-only” nozzle is capable of producing droplet sizes of 300-4,000 microns. Atomizing Nozzles’ droplet sizes are consistently under 100 microns, and can be as small as 20 microns!

Small droplet size is key to cost effectiveness in many applications:

  • Think about expensive coatings…the smaller the droplet size, the better and more even the coverage, and the less you have to spray (and pay) out.
  • Or humidification…smaller droplet size means more stays airborne, for longer, and in a larger space.
  • Petroleum based lubricants, by their nature, only require a thin layer for best results.  Smaller droplets make as even and thin of a layer as possible.
  • Dust control is much more effective with smaller droplet sizes, since the longer the mist lingers in the air, the more dust particles the individual droplets will adhere to…and then drop with them to the surface.  This also prevents getting the surface of the material any wetter than it has to be.
142 distinct models. 8 different patterns. Liquid flow rates from 0.1 to 303 gallons per hour. If you’ve got a spraying application, EXAIR has an Atomizing Nozzle for you!

If you’d like to discuss a liquid spraying application, I’d love to hear from you.  Call me.

Russ Bowman
Application Engineer
EXAIR Corporation
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Adjustable Air Amplifiers Aren’t Just About Adjustability

Adjustability is a key feature for a great many devices:

  • An adjustable wrench – or as I like to call it, the trusty “all 16ths” – is my go-to for work around the house involving anything with a hex…fittings under the sink when I’m cleaning out a drain, nuts & bolts on furniture or household items needing some tightening (or loosening,) etc.  I don’t get out my combination-end wrenches for much except automobile maintenance.
  • Speaking of sinks, my kitchen faucet lets me adjust water flow (and temperature) which is important because I use different flow rates (and temperatures) if I’m getting a tablespoon of water, or if I’m rinsing my hands, or if I’m filling the sink to do dishes.
  • Speaking of tablespoons, I’ve even got an adjustable measuring spoon that lets me get a full tablespoon, a half a teaspoon, or anywhere in between, by moving a lever block back & forth in the spoon head.

Adjustability is a key feature for several EXAIR Intelligent Compressed Air Products too…like our Adjustable Air Amplifiers.  The ‘adjustable’ part has to do with setting the air flow:

Just loosen the locking ring, and you can thread the plug out of, or in to, the body to increase, or decrease the flow and force of the developed flow.  There’s a hole in the plug (opposite the “EXAIR.com” stamp) so you can use a spanner wrench (another adjustable tool!) to thread the plug in or out.

You can get an amazing range of flow from a little twist*:

These are the performance values for a Model 6042 2″ Aluminum Adjustable Air Amplifier with a compressed air supply pressure of 80psig. Regulating the pressure can give you even lower…or higher…flows.                                              *0.002″ to 0.010″ is about 1/4 turn of the plug.

A gap of about 0.010″ is about the max for 80psig supply pressure.  Above that, the air flow overwhelms the Coanda profile, creating a turbulent ‘storm’ in the throat, hampering the efficiency and effectiveness.  The proper “adjustment” for that is to select the next larger Air Amplifier!

While the range of air flow is certainly impressive, their versatility is another major factor in their selection.  I reviewed our Application Database (registration required) for real-life details on Adjustable Air Amplifiers “in the field” and found a litany of other benefits that made them better suited to particular installations than a Super Air Amplifier:

  • A customer who builds automated equipment incorporates the Model 6031 1-1/4″ SS Adjustable Air Amplifier to blow open bags with a puff of air as they move into position on an automated filling machine. They use it because it’s available in stainless steel construction, and it’s still compact & lightweight.
  • A mattress manufacturer uses Model 6043 3″ Aluminum Adjustable Air Amplifiers to  cool mattress springs.  They’re lightweight, the perfect size to match the springs’ profile, and they can “dial them out” for high heat removal before putting springs on a rubber conveyor.
  • A tier 1 automotive supplier has Model 6234 4″ SS Adjustable Air Amplifier Kits installed on their robotic paint line to blow off moisture from parts to prevent water spotting between the wash cycle and the oven.  They use them because the stainless steel construction holds up to high heat due to the proximity to the ovens.
  • A food plant uses Model 6031 1-1/4″ SS Adjustable Air Amplifiers to improve the drying time of 3,000 liter mixers that must be washed between batches of different products.  The stainless steel construction holds up to the rigors of the frequent washdown in this area.
  • A bedding manufacturer replaced a regenerative blower with a Model 6041 1-1/4″ Aluminum Adjustable Air Amplifier for trim removal on stitched fabric at bedding manufacturer.  The blower was prone to failure from lint & dust; the Air Amplifier, with no moving parts, is not.  It’s also compact, lightweight, and virtually maintenance free.
  • A light bulb manufacturer installed Model 6030 3/4″ SS Adjustable Air Amplifiers on the ends of open pipes that were used to cool mercury lamp wicks.  This reduced noise levels significantly while providing the same cooling rate, and the stainless steel construction holds up to the heat of the operation.

Because of the simplicity of their design, Adjustable Air Amplifiers are also extremely adaptable to custom applications.  We’ve added threads or flanges to the inlets and outlets of several different sizes, to accommodate ease of mounting & installation:

Among other custom Air Amplifiers, we’ve put (left to right) threads on the outlet, ANSI flanges on the inlet/outlet, Sanitary flanges on the inlet/outlet, and Sanitary on the inlet/ANSI on the outlet. How are you installing your Air Amplifier?

Adjustable Air Amplifiers are available in both aluminum and 303SS construction, to meet most any environmental requirements…except extreme high heat.  In those cases, the Model 121021 High Temperature Air Amplifier is rated to 700°F (374°C) – significantly higher than the Aluminum – 275°F (135°C) or the Stainless Steel – 400°F (204°C).  They’re commonly used to circulate hot air inside furnaces, ovens, refractories, etc.

A Model 121021 1-1/4″ High Temp Air Amplifier directs hot air to a rotational mold cavity for uniform wall thickness of the plastic part.

Adjustability.  Versatility.  Durability.  If you’d like to know more about the Adjustable Air Amplifier, or any of EXAIR’s Intelligent Compressed Air Products, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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