Illustrating The Importance of Proper Compressed Air Supply Lines

“Proper compressed air supply lines” in this context means properly sized air hose, pipe, or tube and properly sized fittings which connect your compressed air supply into an EXAIR product. With under-sized compressed air supply lines and/or fittings a pressure loss through the product will occur. We spend a good amount of time speaking with customers about getting our products plumbed up properly so they may realize the best performance of our products, or any compressed air product.

One of the easiest places to find our recommendations for line sizes is in the Installation and Maintenance Guide included with the product you have purchased. All of the install guides have a chart specific to the EXAIR product which looks like the one below. You may also visit the .pdf library in our website’s Knowledge Base.


(CLICK images to ENLARGE)

Many customers pay close attention to their available pressure and assume if they have enough supply line pressure, then they are OK. And while pressure is necessary it will not make up for a lack of volume of compressed air. You need the right amount of volume of compressed air to maintain a specific pressure level. You cannot feed a fire hose with a garden hose, there is not enough volume of water through the garden hose to support water pressure inside of the fire hose. The water will just trickle out of the larger hose. Air Line sizes which are too small or fittings with small inside diameters will decrease air volume to an extent which lowers air pressure and performance of some products.

Here are a number of images (click on them to enlarge) to illustrate improper sized lines/fittings and a pressure loss.  The large pressure gauge shows the supply pressure and is always set at 80 PSIG. There is also a pressure gauge on the inlet to an EXAIR 12″ Super Air Knife which will fluctuate depending upon the size and type of air line and fitting. The first image shows a very common 1/4″ quick disconnect on a 3/8″ inside diameter hose; you will see the small gage on the knife reading 54 PSIG even though there is 80 PSIG from the inlet compressed air supply. It is the very small inside diameter of the quick disconnect which starves the knife of air.

The second image shows another common hose and fitting setup is to use a push to lock fitting. These fittings again have a small inside diameter which restricts the air flow and results in a pressure loss. And remember the tubing used is called out by referring to its outside diameter. For example a 3/8″ tube refers to the outside diameter of the tube which actually has only a 1/4″ inside diameter in most cases. A 1/4″ inside diameter is not large enough to maintain pressure through this knife and results in a 17 PSIG pressure loss.

And finally, the third image shows what we recommend for this particular setup. It is a 3/8″ inside diameter hose with a hose barb fitting pushed in to the hose and a 1/4 MNPT fitting to screw into the Super Air Knife. You can clearly see that there is no pressure loss through the compressed air supply lines.

If you are experiencing a product which does not seem to be performing very well, or you are getting a trickle of air out of a product which should produce a lot of force, the first thing we will recommend is to place a pipe tee with pressure gauge into the inlet of the product (just as shown in the images) so you may compare your known supply line pressure to the pressure you are getting through the product. This will allow for a good starting point of troubleshooting the application.

Properly sized compressed air lines will maintain peak performance of your EXAIR product by providing enough volume of compressed air  to keep up pressure  to help assure you of a successful application.

If you have any questions about compressed air applications or supply lines, please contact an EXAIR Application Engineer.

Kirk Edwards
EXAIR Corporation

Problem with OSHA Compliance and Air Nozzles?

While we are usually focused on helping customers solve their application problems by implementing use of EXAIR products, these are not the only kinds of problems we see in a given day.

Another type of situation that can occur is a review of compliance to OSHA regulations. This can either be conducted by an OSHA inspector or perhaps by the company’s safety team. Reviews of everything from lock-out tag-out procedures, to MSDS sheets, to compliance with dead end pressure requirements set forth in CFR1910.242(b) are covered.

Once the safety review has been conducted and violations have been discovered, we end up receiving the call from the person in charge of bringing the company back into compliance with the “dead end pressure” directive as we call it here.
Basically, the directive states that when compressed air is used for blowing or cleaning, the pressure measured cannot exceed 30 PSIG. It also states that effective chip guarding and personal protective equipment must be used.
 The concern is that if the nozzle tip were to ever come into contact with human skin, an embolism can occur. An embolism is a blockage in an artery that either slows or completely stops blood flow to a part of the body. Air bubbles present within a person’s blood stream, in this case, caused by the direct contact with the compressed air source can cause this condition. An embolism can make a person very sick or even cause death. This is why it is taken so seriously by the OSHA inspectors and industry in general.

When an OSHA inspector comes to visit your site and wants to check a nozzle, he will have a special pressure gauge that he will place up against the tip of the nozzle. If the nozzle outputs more than 30 PSIG, then it fails, if not, then it passes the inspection.

All EXAIR Nozzles and other air blowing equipment will pass such an OSHA inspection as we perform this same test in our design lab when we are producing any new design to make sure our equipment will do what we say it will.

If you find yourself in the position of needing help locating OSHA compliant nozzles, air knives or air amplifiers, please feel free to contact with one of our technical staff for some helpful recommendations.

Neal Raker
Application Engineer
nealraker@exair.com

2010 In Review

2010 In Review

Today is the last working day of the year here at EXAIR. And what a year it has been.

The year began with our collective hopes for an economic recovery in 2010. As the year progressed, that recovery has changed from a wish to reality for many but not all. In a curious development, this time manufacturing companies are leading the recovery rather than being cited as examples of failure to adapt to the world economy. It seems that the reports of the demise of manufacturing in the U.S. were somewhat premature.

Here at EXAIR, we continued to do the things that made us #1 in the first place. Over the course of 2010, we became the first company (and only, in many cases) to achieve CE compliance for nearly every major product line.  If you want the confidence of third-party verification and the CE mark on your air knife, air nozzle, vortex tube or industrial vacuum – EXAIR has you covered.  EXAIR also continued to develop award-winning new products to help our customers solve problems. We were chosen as a finalist for the Plant Engineering “Product of the Year” award for the twelfth time (also our ninth consecutive year).  This year EXAIR also maintained our position as a sustainability leader with the introduction of UPS Carbon Neutral shipping to go along with our extensive line of energy-saving products.  What else would our customers expect from us?

2010 was another great year for EXAIR.  We extended our industry leadership in standards compliance, innovation and sustainability.  And 2011 will start with a bang.  Next week we will launch our brand new Catalog 24 – our biggest and best ever – along with a brand new family of products by mid-January.

As I have said time and time again in this blog, any company can make outlandish claims about their company, their products and their people.  Only real leaders have the proof to back it up.

EXAIR has the best team in the world and our success is directly attributable to our people and our culture.  We accept nothing less than the best from ourselves.

Claims are easy, proof is hard.

Bryan Peters
President
bryanpeters@exair.com

Smoother Than a Baby’s Bottom – Measuring Surface Finish

So just how smooth is a baby’s bottom? A verbal description would only be subjective. In machining though, a more definitive rule of measure is a mandate. In the United States, surface finish is usually specified using the ASME Y14.36M standard. The other common standard is International Organization for Standardization (ISO) 1302.

Surface texture is measured by three components:

  • Lay – where the machining marks are parallel typical of grinding and sanding operations.
  • Surface Roughness – where surface irregularities and finely spaced. They can be radial, cross hatched, or random.
  • Waviness – is the measure of irregularities with a spacing greater than surface roughness. This can be caused by tool chatter or warping.

The most common method to measure surface roughness is to use a diamond stylus Profilometer. For those of us old enough to remember the days of vinyl recordings, it uses the same concept as a record player. As the stylus is dragged across the surface it produces a frequency. This is deciphered by the instruments electronics producing a digital readout. The disadvantage of a Profilometer is that it is not accurate when the size of the features of the surface are close to the same size as the stylus.

Non-contact surface measurements are more accurate but more complicated. Here are some links if you want to read up on them:  interferometry, confocal microscopy, focus variation, structured light, electrical capacitance, electron microscopy, and photogrametry. For most manufacturing operations contact measurement are the norm.

A third “quick and dirty”  method is to use a surface finish scale. This is a flat piece of plastic with various micro finishes. Measurement is by a tactual comparison. You run your finger over the piece you are inspecting and then find the finish on the board that feels the same.

 Back in my machining days this was a source of many heated debates. My callused fingers could not detect with the same resolution as a female inspector with soft supple hands.

I hope you found this article informative. If  you need assistance with your application where you think compressed air products would be of benefit, feel welcomed to give me a call.

Joe Panfalone
Application Engineer

Phone (513) 671-3322
Fax   (513) 671-3363
Web: www.exair.com 
Twitter: www.twitter.com/exair_jp
Facebook: http://www.facebook.com/exair

Open Pipes vs. EXAIR Nozzles

Every once in a while I will receive an inquiry that concerns the comparison of our Air Nozzles to that of an open blowing pipe for an application.

The person making the inquiry usually makes the assumption that we market our air nozzles to have an equivalent force to an open blowing pipe. Nothing could be further from the truth and I would like to dedicate this blog to explaining why.

First, there is not any good way to measure and show such data about open pipes that is reasonable and applicable to all situations. Second, we are not interested in promoting the use of open pipes for a variety of reasons including safety, noise and general wastefulness. You may then reply by asking, “Aren’t you comparing your performance to an open pipe?”  I have to say no, we are generally not trying to compare our nozzle performance to an open pipe in terms of force generated on a target. This is simply what we will see in applications where a pipe or copper tube with a squashed end might be used as a “nozzle”. 
We are not trying to duplicate the force values of open pipe with our air nozzles. It is physically impossible to do. The extreme difference in the amount of compressed air volume used when comparing our nozzles to open blowing pipe is so large, it really is not a true apples to apples comparison. For example, if you compare the air consumption of an open ¼ steel pipe to our model 1100 (1/4 NPT nozzle), the nozzle uses only 10% of the air volume of the open pipe; two, totally different values all together. If the customer needs all of the force generated by the open pipe, simply move up to the next larger air nozzle in the range to get desired force.

Generally, it is our experience that the customer does not need all the force generated by the wasteful open pipe anyway. We find that this practice is usually started by someone who is a novice in compressed air systems and are in the habit of over-compensating when it comes to blowing applications.

To further clarify, the premise on which we are working when discussing air nozzles with customers is that our nozzles allow the air to be used much more effectively. There are a couple of reasons.
First, the biggest difference is going to be that our nozzles to not allow a significant pressure drop to occur across the supply pipe as is the case with an open pipe. Because we are restricting the flow all the way out to the very end of the pipe, the full system pressure is available at the nozzle tip. This is not the case with an open pipe. The diameter of an open blowing pipe is too large for it it to maintain working pressure all along its length and so a pressure drop occurs which makes the open pipe blowing even less efficient.

Take the following example with a simple garden hose. The hose running without a nozzle uses a lot of water but is actually ineffective at most cleaning operations (example, when you wash your car or the side walk). See following photo. The water comes out in great volumes but has no real energy to do the necessary work.

 
When you put a nozzle on the end of the pipe / hose, you restrict the flow and have higher velocity fluid flow much like the following photo.

  
You can achieve the high velocity power simply by adding the nozzle to the end of the open pipe. This allows the full, system pressure to be available at the point of use (for greater power to do more work in the application) and reduces the fluid flow.   

Getting back to the open pipe comparison, again I want to stress we are not trying to make our nozzles comparable to the kind of force you get from an open pipe but then again, that open pipe is hugely inefficient anyway in terms of compressed air waste. In fact, we challenge the customer who thinks they need all of that wasted power generated by an open pipe. It is our experience that they mostly do not need as much force as is being generated. Precision blowing that is well matched to the application is the name of the game. Using engineered air nozzles made for the express purpose of generating force in an application with a regulated air supply at the point of use is the recommended method of addressing such a need.

If the customer does have a rather challenging application in which a lot of force is truly needed, we have  larger Super Air Nozzles which can provide the necessary force. Models are available up to 1-1/4 pipe size and flow rates up to 460 SCFM @ 80 PSIG to develop up to 23 lbs (10.4 kgs.) of force.  95% of people do not need that much force, but if they do, we have the solution. Simply up-size to the nozzle that gives the force wanted / needed for the application. You can still save  air volume with the more efficient, safe and low sound operation of the nozzle vs. open pipe. 

Neal Raker
International Sales
nealraker@exair.com

Happy Holidays from EXAIR

Today was my second favorite day of the year. My favorite was last Saturday when we held our annual holiday party for our team members and their families.

Today was our annual holiday lunch at EXAIR. It’s a different sort of day. Special.

Years ago, we used to all go over to a local restaurant for lunch. But about three years ago we decided to just have lunch catered in to our building so that nobody had to go anywhere. It takes more work than the restaurant, but everyone agrees that it’s a better overall experience. Everyone gets to each lunch together in the same room, side by side, elbow to elbow, alongside people you might not normally see on any given day.

The feast doesn’t begin at lunchtime by any means. Not today. By 8 AM, word had already spread about cookies, candy and other treats all over the building. It’s great that so many people want to share with their coworkers.

In the end, of course, it’s not about the food.

The food is great, but that’s not the best part of the day. The fellowship and camaraderie are the best part of the day. Lunch only lasts for about an hour, but it’s a great hour. Today I had lunch next to Kirk, Chris, Ed and Gary. Those guys are from four different departments and don’t really work alongside each other on a normal day. But today we all just had our lunch and talked.

It was a great hour.

I want to say thank you to everyone that put together such a great lunch and to everyone that took part. It’s not that often that we all get to spend that sort of quality time together.

Today reminds me what a great group of people that we have at EXAIR. From all of us at EXAIR, Merry Christmas and Happy Holidays.

Bryan Peters
President
bryanpeters@exair.com

Knowledge [Base] is Power

I have recently placed a post on our Facebook page about our Knowledge Base and I am asking for comments about it. Please take some time to look into the Knowledge Base and its valuable information. After looking at it leave us a comment on Facebook (you will need to LIKE our page) or this blog. Let us know if you would like to see something which is not there, or if you have a question about the information, what would you add?

Right now You will see Air Data; a collection of pressure, force, flow and heat conversions. It also explains how to calculate air consumption at different inlet pressures which is helpful when you only have air data at 80 PSIG but your line pressure is 60 PSIG. Air Data also explains the best practices for air system piping and charts pressure loss through lengths of pipe.

You will see our calculators to determine potential air savings of switching to EXAIR products. You can link to this blog or read our FAQ’s. You can learn about our Efficiency Lab Service, view our product videos, and browse our wiki. There is also a link to our Twitter feeds.

If you choose to register you can gain these valuable resources: An Application Database with over 800 examples of how our products have solved a problem. Our CAD library offers 3D models and 2D drawings for download , all of our products are represented in multiple formats. You can also download the entire catalog or individual sections in .pdf form, we even have a section optimized for use with the iPad. And you can also view or present our slide shows to learn or teach about the products.

So help us gain knowledge, what did you see that we are missing? What do you think we should add or do differently? Leave a comment at our Facebook page (don’t forget to LIKE it) or on this blog.

Thank you,
Kirk Edwards
Application Engineer
kirkedwards@EXAIR.com

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