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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Efficiency Lab Leads To Big Savings

EXAIR Corporation manufactures quiet, safe, and efficient compressed air products for industry. We want our customers to get the most out of our products, and, in turn, their compressed air systems. To do that, we offer a unique service called the EXAIR Efficiency Lab. Here’s how it works:

  • An Application Engineer can arrange to have your existing compressed air device(s) sent in to our facility.
  • We’ll use our calibrated test equipment to measure the compressed air consumption, sound level, and force applied of those devices.
  • You’ll receive a detailed test report, along with our recommendations to implement an efficient, quiet, and safety compliant solution.
  • We’ll even send your tested device(s) back to you, at no charge, if you wish.

I recently had the pleasure of conducting just such a test on some air guns.  The caller was the Environmental Health & Safety Director for a plastics manufacturer.  The main concern was safety compliance…a recent audit had shown that some workstations were using handheld blowoff devices that did not comply with OSHA standard 1910.242(b), which limits dead end pressure of compressed air products used for cleaning to 30psi.

After discussing their typical uses for these (and other) air guns, they sent in a couple for testing.  Here’s what we found out:

“Thumb guns” are especially popular for blowoff because of their compact size, ergonomic design. and low price.

The air gun with the 7″ straight extension (top) is a “textbook” example of non-compliance with OSHA standard 1910.242(b).  Because it has an open-end discharge with no relief path, this one could cause an air embolism if it were inadvertently dead-ended into the operator’s skin – a potentially fatal condition.  It also uses a considerable amount of compressed air, and is quite loud.  At 80psig supply pressure:

  • Compressed air consumption is 40.7 SCFM
  • Noise level is 95.5dBA
  • Force applied, at a distance of 12″, is 13oz

For comparison’s sake, EXAIR Model 1210-6 Soft Grip Safety Air Gun is fitted with our Super Air Nozzle, on the end of a 6″ rigid extension:

  • Compressed air consumption is 14 SCFM
  • Sound level is 74dBA
  • Force applied, at a distance of 12″, is 13oz…same as theirs.
Model 1210 Soft Grip Safety Air is fitted with an EXAIR Super Air Nozzle. We can also supply it with a Rigid Extension and Chip Shield (right).

The other one is OSHA compliant (it can’t be dead-ended…the cross-drilled hole provides a relief path, but it was still pretty inefficient and loud.  At our standard test pressure of 80psig:

  • Compressed air consumption is 30.8 SCFM
  • Noise level is 94.8dBA
  • Force applied, at a distance of 12″, is 16.9oz

Although the force generated by the Model 1210 Soft Grip Safety Air Gun isn’t quite as high as theirs, it’s still our recommendation here.  Oftentimes, the flow and velocity generated by the engineered Super Air Nozzle is more than capable of meeting the needs of the typical blow off applications these types of air guns are used in.

EXAIR Efficiency Lab testing proves that replacing these air guns with our Soft Grip Safety Air Guns (or at least replacing the tips with EXAIR Super Air Nozzles…we also have adapters for that) will result in compressed air savings of 66% and 55%, respectively, and lower sound levels to within OSHA standard 1910.95(a) limits:

All EXAIR Soft Grip Safety Air Guns comply with these limits for 8 hour exposure.

If you’d like to know more about the efficiency & safety (or lack thereof) of your current air blow off devices, give me a call.

Russ Bowman, CCASS

Application Engineer
EXAIR Corporation
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Ion Air Cannon Keeps Paper Recycling Baler Working

One of the cruelest pranks I’ve ever been party to happened during my time in the United States Navy. All it took was:

  • A cigar box
  • A rubber band
  • The scrap “dots” from every 3-hole punch we could find

We cut the lid off the cigar box, filled it with the “dots,” used the lid and the rubber band to make a wind-up flapper that we stretched across the open top of the box, and carefully placed it in our Leading Petty Officer’s (LPO’s) desk drawer.  Then we waited for hilarity to ensue the next time he opened that drawer.

Unbeknownst to us, he was going to a pretty important meeting that morning, so he was wearing his Service Dress Blues (also known as “crackerjacks” – the dark wool one; not the white one on the popular snack mix box).  When he opened his desk drawer, the rubber band-powered flapper flung those little white paper dots all over him.  It was wintertime, in an office space with electric baseboard heat, so the static cling was heinous.  It took several of us with makeshift lint brushes fashioned from duct tape to get his uniform “shipshape” and presentable for the meeting.

I was reminded of this incident recently when I had the pleasure of helping a caller from a paper recycling plant, who was having a static problem in a baler, with, basically, large confetti-like pieces of shredded paper.  These shreds are pneumatically conveyed through a long 8-inch duct, where they picked up enough static to cling to the inside of the baler chute, and built up to a point where they covered the sensors that opened the chute.  This caused the chute doors to cycle without the chute being full, which triggered the baler to activate with nothing there.  The result from the operators was a lot of slamming, frustration, and cursing…which further reminded me of my LPO’s reaction to getting covered in paper dots.

While lint brushes (and duct tape, in a pinch) work just fine for removing statically charged debris from one’s clothing, the baler required a different solution…in the form of a pair of EXAIR Gen4 Ion Air Cannons.  These were installed to blow into the baler, from opposite walls just above the chute, and aimed slightly down towards the sensors.  This keeps the sensors clear until paper shred actually DOES fill the chute, allowing it to dump a whole bale’s worth of scrap, keeping the baler (and the operators) happy.

Whatever you needs, EXAIR has a Gen4 Static Eliminator product to solve your static problem.

Many industrial static charge problems have similarities to “real world” experiences that most of us are familiar with.  If you want to talk about static control, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Static Eliminators Essential To Packaging Operations

I had a headache the other day. Of all the things that can make me grumpy, nothing makes me grumpier than a headache. Luckily, there are over the counter medications that work quite well, and quickly, to boot.  And I had a brand new bottle of them in the cabinet.

When I opened the package and removed the tamper-resistant plastic band on the cap, it stuck to my hand when I went to drop it in the trash can.  This raised my grumpiness just a touch.  I shook my hand to try and get it off, and it fell behind the trash can.  My grumpiness elevated a bit further.  I hit my head (you know, the one I was trying to cure the pain in?) on the counter while bending over to retrieve it.  That activated my grumpiness alarm, which sounds just like mild profanity.  My wife silenced that alarm pretty quickly.

The plastic band stuck to my hand, of course, because it’s made of a non-conductive material, and peeling it from the bottle cap, which is also a non-conductive material, generated a static charge.  As a subject matter expert on the topic of static elimination, I am quite familiar with the phenomenon, the problems it causes, and, more importantly, the numerous ways to apply solutions to those problems:

  • One such solution was related to my problem with the tamper-resistant seal.  A mouthwash manufacturer was actually having trouble getting those seals ONTO the bottles on their packaging line.  The bottle caps themselves had so much static charge on them that they repelled the seal as the machine tried to drop it in place before heat shrinking it.  An Ion Air Jet solved the problem:
Gen4 Ion Air Jet ensures bottle caps & necks are static free for application of tamper resistant seals.
  • Speaking of plastic bottles, the finishing process after extrusion can leave small bits of plastic particulate behind, and static charge can keep them on the bottle.  This was a great fit for an Ion Air Cannon:
Gen4 Ion Air Cannon eliminates static & dust prior to filling bottles.
  • Sometimes, air flow isn’t necessary, like in the case of a film that is eventually made into single-use condiment packages, with a static charge that was high enough to fry the print heads that apply the label text.  An Ionizing Bar protects those print heads:
Initial static charge of almost 17kV (left) is almost completely dissipated by the Ionizing Bar (center) to just 0.04kV (right)

EXAIR Corporation’s Gen4 Static Eliminator product line offers a wide variety of options for total static control.  If you need to get rid of nuisance shocks, clinging dust, tearing, jamming or curling of material, misfeeding sheets or rolls, or any of the numerous other problems that static charge can cause, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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