Top Ten Preventive Maintenance Items For Compressed Air Systems

Anything that has moving parts is, sooner or later, going to need maintenance.  One popular school of thought is “If it ain’t broke, don’t fix it.”  One major problem with that is, when it DOES break, you HAVE to fix it before you can keep using it.  That’s where preventive maintenance comes in: you get to choose WHEN you work on it.  This allows you to do that work at planned times that are convenient, and that have the least impact on your operations.

Patrick Duff, a production equipment mechanic with the 76th Maintenance Group, takes meter readings of the oil pressure and temperature, cooling water temperature and the output temperature on one of two 1,750 horsepower compressors. Each compressor is capable of producing 4,500 cubic feet of air at 300 psi. The shop also has a 3,000 horsepower compressor that produces 9,000 cubic feet of air at 300 psi. By matching output to the load required, the shop is able to shut down compressors as needed, resulting in energy savings to the base. (Air Force photo by Ron Mullan)

Compressed air systems not only have moving parts, they have parts that air moves through.  Periodic preventive maintenance can not only keep your system running; it’ll keep it running efficiently, meaning it costs less to operate.  Different types of air compressors in different environments will have different specific requirements, but following is a decent general list of ten items it might make sense to stay on top of:

  1. Intake vents. The air your compressor pulls in is going to go through some pretty tight passages.  Particulate can do some damage in there, and some of it will end up in your system where it’ll wreak havoc on your air operated equipment too.  Take care to keep your air compressor’s intake vents clean.  Many manufacturers and service professionals recommend a weekly inspection, and cleaning as needed.
  2. Lubrication.  Don’t be fooled by the term “oil-less” in an air compressor’s description.  This often means that there’s no oil in the air end.  The drive end is going to have bearings & moving parts that are lubricated.  Again, the compressor manufacturer will likely include periodicity and procedure for this in the manual.  This should include period oil (and oil filter) changes or grease renewal.
  3. Motor bearings.  Many air compressors are either direct coupled or belt driven by an electric motor.  Checking the temperature with a contact thermometer, or monitoring for changes in the ultrasonic signature (EXAIR Model 9061 Ultrasonic Leak Detector is a quick & easy way to do this) can give you indication of pending bearing failure.
  4. Belts.  Drive belts have a finite life span.  Vibration can also affect their tension and alignment.  If you have a belt driven compressor, check these out on a regular basis to make proper adjustments to the motor slide base.
  5. Lubrication, part 2. A friend of mine had a car that leaked oil.  He carried a couple of quarts with him…it was so bad that he had to add some every few days.  He called this replenishment system “self-changing oil”.  It isn’t.  Finding and fixing oil leaks is critical from both operational and housekeeping perspectives.
  6. Dryer.  Most industrial air compressors have a system that removes moisture from the compressed air before discharging into the system.  Different types of dryers require different types of maintenance.  Desiccant and deliquescent dryers, for example, will require media changes from time to time.  Refrigerated and membrane dryers will have parts like condensers or cartridges that you have to keep clean.  Keep up with the manufacturer’s recommendations, and you’ll have one less thing to worry about.
  7. Air leaks.  Air is free.  It’s literally everywhere, in great abundance.  COMPRESSED air is expensive, which makes leaks costly.  Good news is, compressed air leaks, like failing motor bearings (see #3, above) generate an ultrasonic signature, so you can get even more use out of an EXAIR Model 9061 Ultrasonic Leak Detector.  Find & fix leaks, and start saving money today.

    In addition to compressed air leaks, there are many industrial maintenance applications for Ultrasonic Leak Detectors. Contact an EXAIR Application Engineer for details.
  8. Filtration. Almost all pneumatically operated products work best with clean, moisture free air.  The compressor’s intake vents (see #1 above) and dryer (see #6 above) are there, primarily, to protect the compressor and the distribution system, respectively.  Good engineering practice dictates the need for point-of-use filtration.  EXAIR Automatic Drain Filter Separators have 5-micron particulate elements, and a centrifugal element to ‘spin’ out moisture.  Our Oil Removal Filters have coalescing elements to catch any trace of oil, and provide additional particulate filtration to 0.03 microns.  As filter elements capture debris, they start to clog, which reduces downstream pressure.  You should change these elements when the pressure drop across a filter reaches 5psi.
  9. Condensate drains.  Even the best dryers allow trace amounts of moisture into the compressed air system…even more so if the humidity in the area is high.  Properly designed compressed air distribution systems will have strategically placed drain traps to collect this moisture and rid the system of it.  They can be automatic, timed, or manual.  Inspect them periodically for proper operation
  10. Compressed air operated products.  Last but not least, make sure you keep up the maintenance on the tools and equipment that your compressed air system is there for in the first place.  Worn or damaged parts can increase consumption…and present very real safety risks.

EXAIR Corporation manufactures quiet, safe, and efficient compressed air products to help you get the most out of your compressed air system.  If you’d like to find out more, give me a call.

Russ Bowman, CCASS

Application Engineer
EXAIR Corporation
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Ultraviolet Curing and Vortex Tube Cooling

Recently EXAIR worked on a project to cool down parts that were using Ultraviolet (UV) light to cure a surface coating. Ultraviolet curing is a photochemical process that uses UV light to cure/dry certain inks, coatings, and adhesives. Due to the fact that UV light produces a good amount of heat the product would heat up during the curing process and create issues for them down the line which slowed down production in order let them cool. The simple solution to this was the use of the vortex tube to blow on the product to cool it down during the process. By doing so they were able cool the product down to a suitable temperature for the process to speed up.

EXAIR’s Small, Medium, and Large Vortex Tubes


EXAIR’s Vortex Tubes are great for cooling down surfaces to temperatures below ambient thanks to the cold air stream that is produced from the vortex tube. Vortex tubes use a source of compressed air to create both a hot and cold stream of air simultaneously which allows the unit to be used for cooling but also heating applications. The amount of air flow coming out of either end of the Vortex Tube can be controlled; by doing so one can adjust the temperature of the air streams coming out.

There are numerous methods to distribute the cold air flow from a lone, or a series of, Vortex Tubes.

Although the main application for the Vortex Tube is to be used for cooling, it is occasionally used to heat as well. Heating applications are uncommon, but they are still possible. Since a vortex tube creates a cold and hot stream of air; by controlling what the fraction of air is flowing out of the cold end you can create a temperature rise (a rise from the starting air temp) of up to 195F! Now that is hot.

If you have any questions about compressed air systems or want more information on any of EXAIR’s products, give us a call, we have a team of Application Engineers ready to answer your questions and recommend a solution for your applications.

Cody Biehle
Application Engineer
EXAIR Corporation
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Additional Benefits To The Adjustable E-Vac Vacuum Generators

The EXAIR Adjustable E-Vacs are available in 4 different sizes to fit whatever your pick and place, vacuum holding, degassing, or vacuum evacuation process may call for. These units have been used in a multitude of applications and the Adjustable factor makes them versatile enough to fit a production line with changing needs.

These are all examples of how an E-Vac pick-and-place system is just a solenoid valve away from automation.

The Adjustable E-Vacs have a few benefits that may go unnoticed if one is not keen to exactly how they are constructed and function. This sets them apart from many vacuum generators. When dealing with vacuum generator applications such as pick and place, having a part that is always the same is easiest. This is not always the case. Sometimes it is not just the dimensions of the part that changes, sometimes the material changes or even the surface finish of the part. This is where the ability to change from a porous to non-porous vacuum generator is extremely helpful. Generally this means the material of the parts getting picked up will allow air flow through them (paper, cardboard, wood) or not (plastic, glass). A porous vacuum generator will pull more flow through the part material to hold the vacuum, a non-porous vacuum generator will pull less flow and achieve higher vacuum levels.

To better understand the difference between porous and non-porous, we’ve written about that. Check out Tyler Daniel’s blog on the difference between the two here. The beauty of the Adjustable E-Vac is that it can easily convert from porous to non-porous with a simple adjustment. This is a great feature for a job shop that may change materials they are cutting or engraving on their machines and need to adapt in a moments notice for the job at hand. This could also reduce the number of vacuum generator variances a store room may need to keep on hand for a series of production lines and help to reduce the chance an incorrect model is installed on a machine due to fewer variants.

Adjustable E-Vac

Another benefit which can be helpful in a production environment that has an E-Vac picking up dirty or debris ridden material is that the Adjustable E-Vacs can be disassembled and cleaned. Picking steel sheets off a laser cutter in order to remove the scrap that has a volume of spatter / dust can cause an accumulation of debris on the internals of any vacuum generator. By unscrewing the plug from the body the Adjustable E-Vac can be easily cleaned and all passageways maintained at a level to offer continual performance.

No matter what, the adjustability coupled with minimum components and fastener free disassembly of the unit are two great features that can help minimize machine downtime, lower number of parts kept on hand for machines, and ensure optimal performance no matter what the requirement is for the vacuum generator. If you would like to discuss further, please contact us.

Brian Farno
Application Engineer
@EXAIR_BF
BrianFarno@EXAIR.com

Improve Noise Exposure with EXAIR Flat Super Air Nozzles

EXAIR manufactures a variety of nozzles that are OSHA safe, high quality, and very efficient.  They are engineered to entrain the “free” ambient air into the air stream to create a powerful force while reducing compressed air usage.  Thus, saving you money.  With a multitude of blow-off applications like clearing small holes to quickly cleaning gantries on CNC tables, EXAIR has the nozzles for you.  In this blog, I will discuss the features and benefits of the EXAIR Flat Super Air Nozzles.    

The EXAIR Flat Super Air Nozzles are manufactured to blow a wide forceful stream of air.  Their patented design creates a high velocity, laminar air stream with minimal air consumption and low noise.  They come in two widths; 1” (25mm) and 2” (51mm).  EXAIR offers a standard Flat Super Air Nozzle and a High Power Flat Super Air Nozzle in two different materials, zinc-aluminum alloy and 316 stainless steel.  And with a metal construction, breakage is not a concern and performance are not sacrificed even in the harshest of environments. 

The unique patented shims used with the EXAIR Flat Super Air Nozzles will give you three improvements to the design and function.  First, they come in different thickness to create a wide range of forces.  In conjunction with a regulator, you can “dial” in the correct amount of force from a breeze to a blast without overusing your air compressor.  The patented shim also allows an even flow across the entire width of the air nozzle.  Unlike the plastic flat nozzles that use holes which generates a fluctuation of forces across the width.  Lastly, they help to entrain the free ambient air; so that less compressed air is required.  The high efficiency design will save you money.  The EXAIR Flat Super Air Nozzles are effective in uniform blowing with safety and efficiency in mind. 

To expand more on safety, I will direct you to Noise.  With “open” holes in nozzles, the compressed air is turbulent and loud.  The National Institute for Occupational Safety and Health, NIOSH, states that 70% to 80% of all hearing loss within a manufacturing plant is caused by compressed air.  OSHA created a chart to show the maximum allowable noise exposure.  This chart shows the time and noise limits before requiring hearing protection.  The EXAIR Flat Super Air Nozzles are designed to have laminar flow which is very quiet.  As an example, the model 1122 2” Flat Super Air Nozzle has a sound level of only 77 dBA at 80 PSIG (5.5 bar); well under the noise exposure limit for 8 hours.   

With the EXAIR Flat Super Air Nozzles, you can take advantage of the durability, safety, and efficiency for your blow-off devices.  With automated systems, or machine builders, you may want to look at the EXAIR brand for your blow-off, cooling, and coating applications.  The overall cost of your system as compared to the cost of the nozzles should not warrant the use of poor-quality plastic nozzles to save a couple of dollars.  Because in the long run, it will actually cost you more with loss of production, compressed air waste, very loud noises, and unsafe work environments. 

EXAIR stocks these nozzles for quick delivery.  If you are within the U.S. or Canada, they come with a 30-day unconditional guarantee to try them out.  If you need any help with our Flat Super Air Nozzles or how to build an optimum blow-off system, you can speak to an Application Engineer at EXAIR.  We will be happy to assist you. 

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb