The Importance Of Air Compressor System Maintenance

 

It should go without saying, but proper operation of anything that has moving parts will depend on how well it’s maintained.  Compressed air systems are certainly no exception; in fact; they’re a critical example of the importance of proper maintenance, for two big reasons:

*Cost: compressed air, “the fourth utility,” is expensive to generate.  And it’s more expensive if it’s generated by a system that’s not operating as efficiently as it could.

*Reliability: Many industrial processes rely on clean or clean & dry air, at the right pressure, being readily available:

  • When a CNC machine trips offline in the middle of making a part because it loses air pressure, it has to be reset.  That means time that tight schedules may not afford, and maybe a wasted part.
  • The speed of pneumatic cylinders and tools are proportional to supply pressure.  Lower pressure means processes take longer.  Loss of pressure means they stop.
  • Dirt & debris in the supply lines will clog tight passages in air operated products.  It’ll foul and scratch cylinder bores.  And if you’re blowing off products to clean them, anything in your air flow is going to get on your products too.

Good news is, the preventive maintenance necessary to ensure optimal performance isn’t all that hard to perform.  If you drive a car, you’re already familiar with most of the basics:

*Filtration: air compressors don’t “make” compressed air, they compress air that already exists…this is called the atmosphere, and, technically, your air compressor is drawing from the very bottom of the “ocean” of air that blankets the planet.  Scientifically speaking, it’s filthy down here.  That’s why your compressor has an inlet/intake filter, and this is your first line of defense. If it’s dirty, your compressor is running harder, and costs you more to operate it.  If it’s damaged, you’re not only letting dirt into your system; you’re letting it foul & damage your compressor.  Just like a car’s intake air filter (which I replace every other time I change the oil,) you need to clean or replace your compressor’s intake air filter on a regular basis as well.

*Moisture removal: another common “impurity” here on the floor of the atmospheric “ocean” is water vapor, or humidity.  This causes rust in iron pipe supply lines (which is why we preach the importance of point-of-use filtration) and will also impact the operation of your compressed air tools & products.

  • Most industrial compressed air systems have a dryer to address this…refrigerated and desiccant are the two most popular types.  Refrigerant systems have coils & filters that need to be kept clean, and leaks are bad news not only for the dryer’s operation, but for the environment.  Desiccant systems almost always have some sort of regeneration cycle, but it’ll have to be replaced sooner or later.  Follow the manufacturer’s recommendations on these.
  • Drain traps in your system collect trace amounts of moisture that even the best dryer systems miss.  These are typically float-operated, and work just fine until one sticks open (which…good news…you can usually hear quite well) or sticks closed (which…bad news…won’t make a sound.)  Check these regularly and, in conjunction with your dryers, will keep your air supply dry.

*Lubrication: the number one cause of rotating equipment failure is loss of lubrication.  Don’t let this happen to you:

  • A lot of today’s electric motors have sealed bearings.  If yours has grease fittings, though, use them per the manufacturer’s directions.  Either way, the first symptom of impending bearing failure is heat.  This is a GREAT way to use an infrared heat gun.  You’re still going to have to fix it, but if you know it’s coming, you at least get to say when.
  • Oil-free compressors have been around for years, and are very popular in industries where oil contamination is an unacceptable risk (paint makers, I’m looking at you.)  In oiled compressors, though, the oil not only lubricates the moving parts; it also serves as a seal, and heat removal medium for the compression cycle.  Change the oil as directed, with the exact type of oil the manufacturer calls out.  This is not only key to proper operation, but the validity of your warranty as well.

*Cooling:  the larger the system, the more likely there’s a cooler installed.  For systems with water-cooled heat exchangers, the water quality…and chemistry…is critical.  pH and TDS (Total Dissolved Solids) should be checked regularly to determine if chemical additives, or flushing, are necessary.

*Belts & couplings: these transmit the power of the motor to the compressor, and you will not have compressed air without them, period.  Check their alignment, condition, and tension (belts only) as specified by the manufacturer.  Keeping spares on hand isn’t a bad idea either.

Optimal performance of your compressed air products literally starts with your compressor system.  Proper preventive maintenance is key to maximizing it.  Sooner or later, you’re going to have to shut down any system to replace a moving (or wear) part.  With a sound preventive maintenance plan in place, you have a good chance of getting to say when.

If you’d like to talk about other ways to optimize the performance of your compressed air system,  give me a call.

Russ Bowman
Application Engineer
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Image courtesy of U.S. Naval Forces Central Command/U.S. Fifth Fleet, Creative Commons License 

High Temperature Application Needs High Temperature Filtration

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Two 42″ stainless steel Super Air Knives in need of proper filtration of the compressed air supply

In an undisclosed application, two 42” stainless steel Super Air Knives (shown above) are positioned to provide a needed blowoff function.  The exact purpose of the blowoff wasn’t revealed, but this OEM requested various shims for these knives along with suitable filtration.  Shims, which can be field installed into the knife to adjust the air gap and air flow due to different thicknesses, will directly affect the volume of air and force out of the knife. Determining model numbers and pricing for the requested shims is straightforward, but providing the required filtration proved to be a bit more challenging.

Whenever considering filtration, the first step in product selection is to consider what needs to be filtered from the air; for example, water, dirt, or oil.  This customer needed a method to remove both water and dirt, as well as oil particulate from the compressed air.

The next step is to consider the potential greatest flow (required by the knives) through the filters, which, in turn, requires having knowledge of the intended operating pressure for the application and the air gap set by the shims.  These knives are to be operated at a maximum pressure of 87 PSIG, creating a maximum flow potential of about 260-520 SCFM depending on the chosen shim.  (3.1 SCFM per inch of length for each knife when operating at 87 PSIG * 42 inches per knife * 2 knives = ~260 SCFM;  6.2 SCFM per inch of length for each knife when operating at 87 PSIG and having the additional shims installed * 42 inches per knife * 2 knives = ~520 SCFM)

Lastly, we have to give consideration to the environment into which the filters will be installed.  For example, will the filters be exposed to any kind of wash-down process using specific chemicals; and, what is the ambient temperature in the environment?  The purpose of these questions is to uncover any environmental specifications or limitations.

In this application, those questions uncovered a need to place these filters into a hot environment with temperatures up to 300°F.  Given that our stock filter options have maximum operating temperatures of 120°F, we needed to explore an application-specific solution.

So, the Engineering team at EXAIR sprung into gear to find a suitable, high temperature option, which we in turn presented to the OEM user, offering a specific solution for their specific application.  The high temperature filters for this application are suitable for temperatures up to 450°F with flow rates as high as 600 SCFM at 100 PSIG – a perfect fit!

If you have application-specific needs, we’re happy to discuss and brainstorm potential solutions.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

Step 2 of Optimizing Your Compressed Air System, Find & Fix Leaks

Over the past handful of blog posts I have blogged about topics like understanding the demand on your compressor, creating a system pressure profile,  and the effectiveness of filtering your compressed air.  These are all critical steps in ensuring your compressed air system is optimized for maximum efficiency.   These can also all fall into place with our Six Steps To Compressed Air Optimization.

EXAIR Six Steps To Optimizing Your Compressed Air System

EXAIR Six Steps To Optimizing Your Compressed Air System

Another factor in the six steps is identifying and addressing leaks within your system.   Finding leaks in your compressed air system can be done several ways, one of the oldest methods is to use a soap and water mixture to spray on every joint and see if there is a leak that causes bubbles.   The next method would be to use ball valves and pressure gauges to test each run of pipe to ensure they are holding their pressure over a period of time, similar to a leak down test.  The final method, and by far the easiest, would be to utilize our Ultrasonic Leak Detector.

This can be used to sense leaks in compressed air systems up to 20′ away and can also pin point a leak by closely monitoring each joint.  Neal Raker made a great video on how to use the Ultrasonic Leak Detector a while back and it is shown below.

If you have any questions on how to find leaks or how to optimize your compressed air system, give us a call.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

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