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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Steps to Find Compressed Air Leaks in your Facility

The Second Step to optimize your compressed air system is to Find and fix leaks in your compressed air system. The reason leaks are important to find and fix is because they can account for 20-30% of a compressors total output. A compressed air leak fixing process can save 10-20% of that lost volume.

6-steps-from-catalog

Unintentional leaks will result in increased maintenance issues and can be found in any part of a compressed air system. Leaks can be found at a poorly sealed fitting, quick disconnects and even right through old or poorly maintained supply piping. Good practice will be to develop an ongoing leak detection program.

The critical steps needed for an effective leak detection program are as follows:

  1. Get a foundation (baseline) for your compressed air use so you have something to compare once you begin eliminating leaks. This will allow you to quantify the savings.
  2. Estimate how much air you are currently losing to air leaks. This can be done by using one of two methods.
    • Load/Unload systems, where T= Time fully loaded and t=Time fully unloaded:
        • Leakage percent = T x 100
          ——
          (T + t)
    • Systems with other controls where V=cubic feet, P1 and P2=PSIG, and T=minutes
        • Leakage = V x (P1-P2) x 1.25
          ————–
          T x 14.7
  3. Know your cost of compressed air so you can provide effectiveness of the leak fixing process.
  4. Find, Document and Fix the leaks. Start by fixing the worst offenders, fix the largest leaks. Document both the leaks found and the leaks fixed which can help illustrate problem areas or repeat offenders, which could indicate other problems within the system.
  5. Compare the baseline to your final results.
  6. Repeat. We know you didn’t want to hear this but it will be necessary to continue an efficient compressed air system in your plant.

EXAIR has a tool to assist you in finding these leaks throughout your facility, the Ultrasonic Leak Detector. Check one of our other Blogs here, to see how it works!

Leak Detector

 

If you’d like to discuss how to get the most out of your compressed air system – or our products – give me a call.

Jordan Shouse
Application Engineer
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Leaks and Their Impact on Your Compressed Air System

Leaks are one of the major wastes of compressed air that could happen in a system. But what affect can leaks have on your system and how can these leaks be found? Total leaks in a compressed air line can account for wasting almost 20-30% of a compressors output. These leaks can commonly be found in areas were a pipe comes in contact with a joint, connections to devices that use the compressed air, and storage tanks.

There are four main affects that a leak in your compressed air system can have and they are as follows; 1) cause in pressure drop across the system, 2) shorten the life of almost all supply system equipment, 3) increased running time of the compressor, and 4) unnecessary compressor capacity.

  • A pressure drop across your compressed air system can lead to a decreased in efficiency of the end use equipment (i.e. an EXAIR Air Knife or Air Nozzle). This adversely effects production as it may take longer to blow off or cool a product or not blow off the product well enough to meet quality standards.
  • Leaks can shorten the life of almost all supply system components such as air compressors, this is because the compressor has to continuously run to make up for the air loss from the leak. By forcing the equipment to continuously run or cycle more frequently means that the moving parts in the compressor will wear down faster.
  • An increased run time due to leaks can also lead to more maintenance on supply equipment for the same reasons as to why the life of the compressor is shortened. The increase stress on the compressor due to unnecessary running of the compressor.
  • Leaks can also lead to adding unnecessary compressor size. The wasted air that is being expelled from the leak is an additional demand in your system. If leaks are not fixed it may require a larger compressor to make up for the loss of air in your system.
EXAIR’s Ultrasonic Leak Detector

All of these effects are an additional cost that is tacked onto the already existing utility cost of your compressed air. But luckily there are ways to find these leaks and patch them up before it can get to out of control. One of the ways to help find leaks in your system is the EXAIR’s affordable Ultrasonic Leak Detector. This leak detector uses ultrasonic waves to detect were costly leaks can be found so that they can be patched or fixed.

If you have questions about a Leak Prevention Program or any of the 16 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.    

Cody Biehle
Application Engineer
EXAIR Corporation
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EXAIR Provides you with the Necessary Tools for Training

I recently participated in a spicy wing eating competition here in Cincinnati. A last-man-standing format where contestants were tasked with finishing a single wing in 30 seconds per round. As the rounds increased, so too did the heat level of the sauce the wing was tossed in. The GRAND PRIZE for the daring winner was quite a haul, a $50 gift card to a local wing joint. Why put yourself through this for the chance at winning a $50 gift card I was repeatedly asked. Who knows, maybe I’m crazy. But, anyone who knows me knows I love a good competition and I wasn’t going to go into this one unprepared. Training for the competition was going to be necessary if I wanted to stand a chance.

peach reaper queen of the wing
Peach Reaper Peppers – The Breakfast of Champions

Several weeks of putting myself through a hellacious bout of pain, misery, and indigestion by way of Ghost Peppers, Trinidad Scorpion Peppers, and Peach Reaper peppers from my garden, I felt like I was ready to go. I started off the morning of the competition with some Peach Reapers in my breakfast burrito (the hottest I had on hand). Through the sweat, tears, and pain (along with a few eye rolls from my wife) I felt as prepared as I could possibly be. Unfortunately, all of my training didn’t quite get me the win. But, a respectable 2nd place finish wasn’t a bad showing. I suppose I’ll have to step my game up for next year…

queen of the wing
Do note the usage of proper PPE during the competition…

At EXAIR, we’re committed to providing our customers with the tools necessary to train themselves, their customers, and their employees on the proper ways to use compressed air. From right here on the EXAIR Blog, our YouTube Channel, and the Knowledge Base on our website there’s a ton of valuable information out there for your use. Best of all? It’s Free!

Within our Knowledge Base, you’ll find case studies that highlight examples of applications where we’ve helped customers improve their processes, save money by reducing compressed air consumption, and help improve on worker safety. There’s a list of FAQs categorized by product line, a library of calculators to help estimate the savings you’ll experience, and a list of application examples.

In addition, we also have a library of previously recorded webinars that are free to view at your convenience. With topics such as “Intelligent Compressed Air Solutions for OSHA Compliance”, “Intelligent Solutions for Electrical Enclosure Cooling”, “Optimize Your Compressed Air System in 6 Simple Steps”, “Simple Steps for Big Savings”, and “Understanding Static Electricity” all of the tools are readily accessible to make sure you’re fully prepared and equipped to handle your compressed air system.

Don’t let these free resources go to waste and take the time to train yourself on the available solutions to Intelligent Compressed Air usage. I promise it’ll be a lot less painful than a steady diet of super hot chili peppers!

Don’t feel like we’re leaving you to figure everything out on your own. In addition to all of the resources available to you within the Knowledge Base, EXAIR has a team of highly-trained Application Engineers with experience in a wide variety of industries and processes. There’s a good chance one of us has dealt with the very same application and we’ll be happy to help point you in the right direction. Don’t wait, give us a call!

Tyler Daniel
Application Engineer
E_mail: TylerDaniel@EXAIR.com
Twitter: @EXAIR_TD

 

What’s So Great About Air Entrainment?

Air entrainment is the phenomenon that occurs when air (or any gas) under pressure is released from a device in such a way that a low pressure is generated in the immediate area of the air (or gas) discharge.  Air (or gas) from the surrounding environment is then pulled (or entrained) into the discharged air stream, increasing its volumetric flow rate.  EXAIR Corporation has been engineering & manufacturing compressed air products to take maximum advantage of this phenomena since 1983…and we’ve gotten better & better at it over the past 36 years.

Obviously, the first thing that’s so great about air entrainment is…free air flow.  Every cubic foot that’s entrained means that’s a cubic foot that your compressor didn’t have to spend energy compressing.  Considering the EXAIR Super Air Knife’s entrainment ratio of 40:1, that makes for a VERY efficient use of your compressed air.

Another thing that’s so great about air entrainment is…it’s quiet.  As you can see from the graphic at the top of this blog, the Super Air Knife entrains air (the lighter, curved blue arrows) into the primary compressed air stream (the darker, straight blue arrows) from above and below.  The outer layers of the total developed flow are lower in velocity, and serve as a sound-attenuating boundary layer.  The sound level of a Super Air Knife (any length…here’s why) is only 69dBA.  That means if you’re talking with someone and a Super Air Knife is running right next to you, you can still use your “inside voice” and continue your conversation, unaffected by the sound of the air flow.

I always thought it would be helpful to have more than just a graphic with blue arrows to show the effect & magnitude of air entrainment.  A while back, I accidentally stumbled across a stunning visual depiction of just that, using a Super Air Knife.  I had the pleasure of talking with a caller about how effective a Super Air Knife might be in blowing light gauge paperboard pieces.  So I set one up in the EXAIR Demo Room, blowing straight upwards, and tossed paper plates into the air flow.  It worked just as expected, until one of the paper plates got a little closer to the Super Air Knife than I had planned:

As you can see, the tremendous amount of air flow being entrained…from both sides…was sufficient to pull in lightweight objects and ‘stick’ them to the surface that the entrained air was being drawn past.  While it doesn’t empirically prove the 40:1 ratio, it indisputably demonstrates that an awful lot of air is moving there.

If you’re looking for a quiet, efficient, and OSHA compliant solution for cleaning, blow off, drying, cooling…anything you need an even, consistent curtain of air flow for – look no further than the EXAIR Super Air Knife.  If you’d like to discuss a particular application and/or product selection, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Chip Shields, OSHA, And You

Safety is a key part of our culture at EXAIR Corporation.  We have regularly scheduled, all-hands required, safety training on a number of topics.  Our Order Entry team can likely tell you as much about our lockout/tagout procedures as our Machinists can.  Nobody even thinks about entering The Shop without safety glasses, and it’s not just because of the signs.

We pay attention to these…

…so we don’t ever have to use this.

OSHA 1910.242(b) states that “Compressed air shall not be used for cleaning purposes except where reduced to less than 30 p.s.i. and then only with effective chip guarding and personal protective equipment. (emphasis mine)  All EXAIR Intelligent Compressed Air Products are engineered to meet the requirements of the first part (30psi outlet pressure to prevent dead ending…we’ve written about that numerous times, including here, here, and here) and we can also provide pre-installed devices to satisfy the second part:  the EXAIR Chip Shield.

Any EXAIR VariBlast or Heavy Duty Safety Air Gun can come fitted with a Chip Shield, and any Soft Grip Safety Air Gun, except for those with Stay Set Hoses, can as well.  Safety Air Guns with Back Blow Nozzles automatically come with a Chip Shield. The principle is simple: a clear polycarbonate (so you can still see what you’re doing) round disc slips over a short (or long if you want) pipe extension between the gun & the nozzle.  It’s fitted with a rubber grommet so you can position it to where it’s most effective – sometimes that might be closer to the part being blown off; sometimes it may be back a little closer to the operator.

EXAIR Safety Air Guns are available, from stock, with Chip Shields.

If you already have an air gun that’s doing the job, you can easily add an EXAIR Chip Shield to it.  They’re made to fit a wide range of extension diameters, and can even come with the extension if you need it.  We also stock a number of adapter fittings; if you know what threads your air gun has (or if you can send us some photos) we can quickly & easily spec those out for you.

Convenient and inexpensive “thumb guns” with cross drilled nozzles (left) are compliant with the first part of OSHA 1910.242(b). Fitting one with an EXAIR Chip Shield (center) makes it compliant with the second part. A Model 1102 Mini Super Air Nozzle (right) makes it quiet & efficient.

We can provide a Chip Shield for most any device with a threaded fitting. I couldn’t find a way to re-use the non-OSHA-compliant nozzle that came with this gun (thank goodness.)

Another example of a larger air gun fitted with a more powerful cross drill nozzle (left) that can be made totally OSHA compliant with an EXAIR Chip Shield (center.) An EXAIR High Force Super Air Nozzle (right) keeps the power, while reducing noise level and compressed air consumption (right.)

Since 1983, EXAIR Corporation has been manufacturing quiet, safe, and efficient compressed air products for industry (emphasis mine.)  If you have concerns or questions about safety in regard to your compressed air use, call me.

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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