Tag: oil change

The Importance Of Planned Maintenance

Published on by Russ BowmanLeave a comment

“If it ain’t broke, don’t fix it” is a common phase that we’ve all heard. It’s also a recipe for disaster. Think about it:

  • Corrective maintenance is ALWAYS more expensive. An oil change in your car might set you back $50 and an hour or so, but when (not if) emulsified, contaminated oil causes your engine to seize, that’s a four (if not five) figure repair bill.
  • Corrective maintenance is also ALWAYS more inconvenient. “If you don’t schedule time for maintenance, your equipment will schedule it for you.” ’nuff said.

Anything with moving parts is going to live its best life if you maintain it properly, and your air compressor has a LOT of moving parts that are CONSTANTLY under a good deal of mechanical stress. Your compressor’s manufacturer almost certainly has a published list of recommended maintenance items, with a schedule of when they should be performed. While that list is going to vary, depending on the type of compressor you have, some of the more common items include:

  • Intake Filter: This is what removes environmental contamination from the air that the compressor is drawing in. When (not if) it gets dirty, your compressor works harder. That means higher power consumption, which means higher operating costs. It also means more heat is generated, which can wear machinery out WAY faster than it should.
  • Lubricating Oil: If your compressor is oil lubed, that oil needs to be changed periodically. The schedule for this is always going to be a certain number of hours of operation, or a certain period of time, whichever comes first. That first one is because the amount of particulate contamination is going to be roughly proportional to the amount of time the lubricated parts spend in motion. The latter is because oil just loses some of its critical lubricating properties over time.
  • Drive Equipment: The two main methods of connecting a motor to a compressor are direct drive shaft coupling, or a system of pulleys and belts. Making sure they stay aligned is critical to their operation. Depending on the nature of the drive, lubrication, tension, and physical condition are all important maintenance points as well.
  • Safety (Pressure Relief) Valve: This valve releases excess pressure if the pressure switch fails and the compressor keeps running. At the very least, this keeps your operating costs in line — the higher the discharge pressure, the higher the power consumption. And, worst case, it makes sure you don’t over pressurize the system. If your receiver tank blows up, that’s a bad day.
  • Receiver Tank Condensate Drain: While there are a number of automatic condensate drains available for industrial air compressors, many owners choose to manually drain condensate from the wet receiver. This should be done AT LEAST once a day, with some manufacturers recommending it more frequently than that. This is critical because standing water can corrode the tank from the inside over time. It can also lead to moisture carryover into the header, and it reduces the volume of available air storage in the tank.
  • Keep Clean To Keep Cool: Air compressors generate heat, both from the friction between the moving parts, and the compression itself (Gay-Lussac’s Law states that the pressure of a given mass of gas is directly proportional to its temperature as long as the volume is constant.) Some compressors are air cooled; others are water cooled. Whichever yours is, keep the heat transfer surfaces — like the fins on the air end housing (air cooled) or fins of the heat exchanger (water cooled) — clean & free of debris to maximize the heat transfer, keeping your compressor as cool as possible.

Again, these are just some of the more common maintenance items for an air compressor. If you want yours to live its best life, keep up with the manufacturer’s recommendations. Oftentimes, maintenance records are required for warranty consideration, should something fail. If you have questions about getting the most out of your compressed air system, give me a call.

Russ Bowman, CCASS

Application Engineer
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Air Compressors: Maintenance and Optimization

Published on by John BallLeave a comment

In one of my previous jobs, I was responsible for the operation of the facility, and one of my biggest jobs was the operation of our air compressor.  Like with many industries, the compressor system is the lifeblood of the company.  If the compressor fails, the whole facility will stop.  In this blog, I will share some maintenance items and schedules for air compressors.

Because the cost to make compressed air is expensive, the compressed air system is considered to be a fourth utility.  With such an important investment, you would like to keep it operating as long and efficiently as possible.  To do this, it is recommended to get your air compressor a “checkup” every so often.  I will cover some important items to check.  Depending on the size and type, some items may or may not apply.  But please, always check with the manufacturer of your air compressor.

Intake filter: The intake filter is used to clean the air that is being drawn into the air compressor.  Better filtration results in less debris getting into your system.  Particles can damage the air pump mechanisms over time as well as plug filters and heat exchangers downstream.  If they are not properly monitored and cleaned, the air flow can be restricted.  This will cause the compressor motor to operate harder and hotter.

Compressor Oil: This would be for flooded screws and reciprocating compressors that use oil to lubricate the bearings and sleeves in the air pump.  Most systems have an oil sight to verify levels.  The oil can also be checked for acidity, which will tell the degree at which the oil is breaking down.  Just like the motor oil in your car, you will have to replace it after so many hours of operation.

Belts & couplings: These items transmit the power from the motor to the air pump.  Check their alignment, condition, and tension (belts only) as specified by the manufacturer.  You should have spares on hand in case of any failures.

Electric Motors: A mechanical device that turns electric energy into rotational energy.  It is the main component that uses a lot of energy to make compressed air.  So, some checks are required to foresee any potential issues and major shutdowns.  For the windings inside, the resistance should be measured with a multi-meter, and it should fall within the motor’s specifications.  Another check should be on the start capacitor.  The start capacitor stores energy to give the motor a powerful boost to get it turning.  One other item is the centrifugal switch.  Just like the name states, it will disconnect the start capacitor when the motor starts spinning.  One other item for large electric motors is the phase converter.  These are typically capacitors, and they are designed to keep the direction of three-phase motors going in the correct rotation.  Both types of capacitors can be checked with a multi-meter.

Air/Oil Separators: This filter removes as much oil from the compressed air before it travels downstream.  It returns the oil back to the sump of the air compressor.  If the Air/Oil Separator builds too much pressure drop, excess oil can travel downstream.  Not only will the air pump lose the required oil level, but it will affect the performance of downstream parts like air dryers and after-coolers.  Also, the pressure drop is a waste and can rob your air system of workable energy. 

Internal filters: Many air compressors will come with an attached refrigerated air dryer.   With this type of air compressor, they will place coalescing filters to remove any residual oil.  These filters should be checked for pressure drop.  If the pressure drop gets too high, then it will rob your compressed air system of pressure, and you will not get the required performance.  Some filters come with a pressure drop indicator which can help you to determine the time to change the element.   

Unloader valve: When the air compressor unloads, this valve helps to remove any of the compressed air that is trapped in the cavity.  When the air compressor restarts, it does not have to “work” against this air pressure.  If they do not fully unload, the air compressor will have to work harder to start, wasting energy.

Preventative maintenance is very important.  As for a schedule, I created a rough sequence to check, change, or clean certain items that are important to your air compressor.  You should also check with your local compressor representative for a more detailed maintenance schedule.

Daily:

  • After stopping, remove any condensate from the receiver tank.
  • Check the oil level.

Monthly:

  • Inspect the cooling fins on the air pumps.  Clean if necessary
  • Inspect the oil cooler. Clean if necessary

Quarterly:

  • Inspect the inlet air filter.  Clean or replace if necessary.
  • Check the belt for tension and cracks.  Tighten or replace.
  • Check differential pressure indicators on outlet compressed air filters.
  • Ohm check on the electric motor

Yearly:

  • Replace Air Inlet Filter
  • Replace the air-oil separator
  • Test safety valves and un-loader valve
  • Replace compressed air filters
  • Change oil
  • Grease bearings if required

Keeping your air compressor running optimally is very important for pneumatic operations.  But there is much more than an air compressor in your system.  To help, there are steps that can be used on the demand side.  EXAIR created a Webinar – “Optimizing Your Compressed Air System In 6 Simple Steps”.  With this combination, you can keep a healthy compressed air system.  You can always contact an Application Engineer at EXAIR to see how much money can be saved by energy reduction, safety, and monitoring.  

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

Image courtesy of Compressor1 – Creative commons license

Any Machine Is A Smoke Machine If You Operate It Wrong Enough

Published on by Russ BowmanLeave a comment

While most folks think this old adage applies only to personnel not being familiar with the OPERATION of machinery, it’s also a reminder that ‘operating it right’ necessarily includes keeping up with regularly scheduled preventive maintenance. This includes pretty much anything with moving parts and components in a system that fluids might flow through. But today, I’m going to focus on certain parts of a typical industrial compressed air system. Failing to change oil in an industrial air compressor, for example, will “let the smoke out” just as fast (and sometimes faster) than anything a day-to-day operator can do to it.

The folks at Compressed Air Challenge are dedicated to (and this is right from their website) “helping you enjoy the benefits of improved performance of your compressed air system.” Their “Best Practices For Compressed Air Systems” stresses the importance of:

  • Proper maintenance as a means to ensure operational efficiencies and systems reliability.
  • Continuous checks for preventive maintenance items.
  • Implementing a detailed system maintenance program, including schedules of required maintenance, and records of its performance.

And that’s just from the introduction. It goes on to list the major components that should be included in this program: the compressor, heat exchanger surfaces, lubricant, lubricant filter, air inlet filter, motors, belts, and air/oil separators. The steps for properly maintaining these components range from standard housekeeping practices, to mechanical operations that are typically performed by trained operators, to services that might be best handled by qualified manufacturer’s representatives:

  • Cleaning: The air compressor itself, and any heat transfer surfaces, have to be kept clean & free of contaminants. Moving parts generate heat, and dirt, scale, corrosion, etc. are essentially insulation that’ll prevent that heat from being dissipated.
  • Lubrication: It’s critical to service the lubricant & any lubricant filtration per the manufacturer’s specifications. Again – not doing this is one of the best ways to “let the smoke out” of any machine.
  • Power transmission components: Regular inspection, including alignment checks, of belts & couplings is probably the 2nd best way (next to lubrication maintenance) of keeping the moving parts of the air compressor, and its drive, in good working order.
  • Intake filter: An air compressor will try to compress anything that’s drawn in with its air intake. If it pulls in particulate, that can damage internal surfaces, especially moving parts with tight tolerances to each other, like pistons & cylinders, scrolls & casings, rotary screws & chambers, impellers & volutes, etc., depending on the type of compressor. Plus, anything that makes its way into your compressed air header will also have a chance to foul up your pneumatic tools & devices, and get on anything that you use compressed air to blow off.
  • Motors & drives: Simply put, if you can’t turn the shaft of the compressor, it won’t compress any air. Periodic checks of electric motor windings, bearings, ‘soft start’ capacitors, phase converters, etc., are among the basic maintenance items that operators can inspect.

In addition to the compressor itself, the air distribution system should be properly maintained as well:

  • Filtration: The intake filter is there primarily to protect the compressor. Many times, the aforementioned tight tolerances between the moving parts in the air end will result in (hopefully) small amounts of particulate being carried over into the compressor discharge. There’s usually a main particulate filter, along with a dryer (for entrained moisture – the intake filter won’t do anything about that either), and possibly even a coalescing filter for oil & oil vapor. Good engineering practice calls for servicing those filters when the differential pressure across them reaches a certain value (5psid is a common one), but those elements, being relatively inexpensive, can also be replaced during regularly scheduled downtime as well.
  • Leak detection & repair: Leaks make the compressor run harder, so any reduction in the amount of compressed air leakage will, by definition, reduce the wear & tear on the compressor. EXAIR makes it easy to find them with the Ultrasonic Leak Detector.
  • Filtration Part 2: Don’t forget about contaminants that can enter the system downstream of the compressor, too. Iron pipe headers are subject to internal corrosion, which can result in rust particulate. Environmental pollution can enter if flanges or fittings are broken & made up during maintenance. Point of use filtration, like EXAIR Automatic Drain Filter Separators, can keep this debris (and any moisture that’s not removed by the compressor’s dryer) out of your pneumatic tools & products.
EXAIR has a number of Accessories and Optimization Products to help you get the most out of your compressed air system.

Compressed air is expensive enough without throwing in a bunch of easily preventable repair costs. Schedule time for maintenance, or it’ll schedule the time for you…and it may even send you a ‘smoke signal’ when it’s ready. If you’ve got questions about getting the most out of your compressed air system, we’ve got answers.

Russ Bowman, CCASS

Application Engineer
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The Importance Of Preventative Maintenance

Published on by Russ BowmanLeave a comment

The first brand-new car I ever bought was a 1995 Ford Escort wagon. I was playing in a band pretty much every weekend (and the occasional weeknight), and my digital piano case fit perfectly in the back – I took it with me to make sure when I went to test drive it. Over eleven years, I put just shy of 200,000 miles on it, and, aside from gas, oil, and tires, had a little under $1,000 in repair costs.

There used to a legendary warning about not buying a car made on a Monday (since the auto workers were presumably recovering from the weekend) or a Friday (since they were equally presumably distracted by getting ready for the weekend). Some folks only buy a particular make of automobile (or shun another) because that’s the make their favorite race car driver (or least favorite) drives. I don’t know what day of the week that Escort was made, and I couldn’t tell you which race car drivers are loyal to the Ford Motor Company, but I CAN tell you that I followed the manufacturer’s recommended maintenance schedule to a “T”. And I’m pretty sure that had a LOT more to do with that little red wagon’s longevity than a bunch of auto workers’ attention to detail (or lack thereof) or who’s popular on the NASCAR circuit.

The same is true for many components that make up your compressed air system. You’re going to want to change the lubricating oil in your compressor on a regular basis (as recommended by the manufacturer) for the exact same reasons you change the oil in your car’s engine. You need to replace particulate elements in compressed air filters, same as you need to periodically replace your car’s air filter.

For point-of-use devices – like most EXAIR compressed air products – preventative maintenance largely comes down to replacing those particulate elements in your filters. Products like our Air Knives, Air Wipes, Air Amplifiers, E-Vac Vacuum Generators, Reversible Drum Vacs, and Vortex Tubes all have relatively small passages that the air has to flow through, so it’s critical to their performance to supply them with clean air. In fact, if you DO supply these products with clean air, they’ll run darn near indefinitely, maintenance free. That’s why all of our product Kits include a Filter Separator with a 5 micron particulate element, and a centrifugal element for moisture removal.

Good engineering practice calls for point of use filtration and moisture removal, such as that provided by EXAIR Filter Separators.

One question we get on a pretty regular basis is, how often do you have to change the particulate element in our Filter Separators. Good engineering practice calls for replacing that element when the differential pressure across the filter reaches 5psi. Now, you can measure the pressure on either side of the Filter Separator and change the element when the outlet pressure drops 5psi from the inlet. If you can shut down long enough to do so, that’s an efficient way to do it – that ensures you get the most ‘bang for your buck’ from that element.

Of course, those elements don’t cost all that much – but shutting down a production line, for even the few minutes it takes to replace an element, can get VERY costly. Facilities that run 24/7 will usually plan some downtime for periodic maintenance on SOMETHING…and they’ll just replace their Filter Separator’s particulate elements during those downtimes.

If you’ve got questions about getting the most out of our products – and, by extension, your compressed air system – give me a call.

Russ Bowman, CCASS

Application Engineer
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