6 Basic Steps for Good Air Compressor Maintenance (And When to Do Them)

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. (Air Force photo by Ron Mullan)

In one of my previous jobs, I was responsible for the operation of the facility.  One of my biggest responsibilities was the air compressor because it supplied pressurized air though out the facility to feed the pneumatic systems.  Like with many industries, the compressor system is the life blood of the company.  If the compressor fails, the whole facility will stop.  In this blog, I will share some preventative maintenance items and schedules for your air compressors.

Because the cost to make compressed air is so expensive, compressed air systems are considered to be a fourth utility.  And with any 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 as well as a recommended schedule for checking.  Depending on the size of your air compressors, some items may or may not apply.

1. Intake filter:  The intake filter is used to clean the air that is being drawn into the air compressor.  Particles can damage the air pump mechanisms, so it is important to have the proper filtration level.  But, as the intake filter builds up with debris, the pressure drop will increase.  If they are not properly monitored and cleaned, the air flow will be restricted.  This can cause the motors to operate harder and hotter as well as reduce the efficiency of the air compressor.

2. Compressor Oil:  This would be for flooded screws and reciprocating compressors that use oil to operate the air pump.  Most systems will have an oil sight gauge to verify proper levels.  In larger systems, the oil can be checked for acidity which will tell you the level at which the oil is breaking down.  The oil, like in your car, has to be changed after so many hours of operation.  This is critical to keep the air pump running smoothly without service interruptions.

3. Belts and 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.

4. 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 or gets damaged, excess oil will travel downstream.  Not only will the air pump lose the required oil level, but it will also affect the performance of downstream parts like your air dryer and after cooler.

5. Internal filters:  Some air compressors will come with an attached refrigerated air dryer.   With these types of air compressors, 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 air pressure.  Some filters come with a pressure drop indicator which can help you to determine the life of the internal filter element.

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

Preventative maintenance is very important, and checks need to be performed periodically.  As for a schedule, I created a rough sequence to verify, change, or clean certain items that are important to your air compressor.  You can also check with your local compressor representative for a more detailed maintenance schedule.

Daily:

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

Monthly:

  • Inspect cooling fins on air pump. Clean if necessary
  • Inspect 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.

Yearly:

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

Keeping your air compressor running optimally is very important for pneumatic operations and energy savings.  I shared some important information above to assist.  Another area to check would be your pneumatic system downstream of the air compressor.  EXAIR manufactures engineered products that can reduce air consumption rates.  You can contact an Application Engineer to discuss further on how we can save you energy, money, and your air compressor.

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

 

Reduce Sound Level in your Factory, Improve Worker Safety and Comfort

Checking the sound level in your processes is an important aspect of ensuring a safe working environment for your employees. Loud noises and the exposure time can lead to significant health concerns. Permanent hearing loss, increased stress levels due to the uncomfortable work environment, and potential injury due to lack of concentration or inability to hear the surroundings are all examples of some risks associated with a noisy environment.

The Occupational Safety and Health Administration, known by most simply as OSHA, introduced Standard 29 CFR 1910.95(a) as a means of protecting operators from injury associated with high noise levels. The chart below indicates maximum allowable exposure time based on different noise levels. At just 90 dBA, an operator can operate safely for 8 hours. Open end pipe blowoffs and some air guns fitted with cross drilled relief holes will often result in noise levels in excess of 100 dBA. At 110 dBA, permanent hearing loss can be experienced in just 30 minutes!

OSHA Chart

The first step to lowering your sound level is to take a baseline reading of your various processes and devices that are causing the noise. EXAIR’s Sound Level Meter, Model 9104, is an easy to use instrument that provides a digital readout of the sound level. They come with an NIST traceable calibration certificate and will allow you to determine what processes and areas are causing the most trouble.

SoundMeter_new_nist225

From there, EXAIR has a wide range of Intelligent Compressed Air Products® that are designed to reduce compressed air consumption as well as sound levels. For noisy blowoffs where you’re currently using an open-ended pipe or a loud cross-drilled nozzle, EXAIR’s Super Air Nozzles are the ideal solution. Not only will they pay for themselves over time due to compressed air savings, but your operators will thank you when they’re able to hear later on in life!!

Drilled pipe is another common culprit of high noise levels. Rather than purchasing an engineered solution, the idea is that a simple drilled pipe is just as effective right? Not at all!! Not only does a drilled pipe produce exceptionally high sound levels, but the amount of compressed air used is also very inefficient. EXAIR’s Super Air Knife is available in lengths ranging from 3”-108” and has a sound level of just 69 dBA at 80 PSIG. At this sound level, operators won’t even require hearing protection at all!

SAK vs drilled pipe
EXAIR’s Super Air Knife is the ideal solution for replacing noisy, inefficient drilled pipe

With all of these products available in stock, EXAIR has the tools you need to reduce sound level in your processes. If you’d like to talk to an Application Engineer about any applications that you feel could benefit from a sound reduction, give us a call.

Tyler Daniel
Application Engineer
E-mail: TylerDaniel@EXAIR.com
Twitter: @EXAIR_TD

The Case For Desiccant Compressed Air Dryers

Most people are familiar with desiccant from the small packets we find enclosed with a new pair of shoes, in a bag of beef jerky, or in some medication bottles.  These packets almost always say “Do Not Eat,” and I get that for the ones in the beef jerky or the pill bottles, but I just don’t understand why they put it on the desiccant packets bound for a shoe box…

Anyway, desiccant (in MUCH larger volumes than the household examples above) are also used to get water vapor out of compressed air.  Desiccant dryers are popular because they’re effective and reliable.  The most common design consists of two vertical tanks, or towers, filled with desiccant media – usually activated alumina or silica gel.

These materials are prone to adsorption (similar to absorption, only it’s a physical process instead of a chemical one) which means they’re good at trapping, and holding, water.  In operation, one of these towers has air coming in it straight from the compressor (after it’s become pressurized, remember, it still has just as much water vapor in it as it did when it was drawn in…up to 5% of the total gas volume.)

When that tower’s desiccant has adsorbed water vapor for long enough (it’s usually controlled by a timer,) the dryer controls will port the air through the other tower, and commence a restoration cycle on the first tower.  So, one is always working, and the other is always getting ready for work.

There are three methods by which the desiccant media can be restored:

  • Regenerative Desiccant Dryers send a purge flow of dry air (fresh from the operating tower’s discharge) through the off-line tower’s desiccant bed.  This dry air flow reverses the adsorption process, and carries the water away as it’s exhausted from the dryer.  This is simple and effective, but it DOES use a certain amount of your compressed air.
  • Heat Of Compression Desiccant Dryers use the heat from pressurized air straight from the compressor(s).  This hot air is directed through one tower, where it removes moisture from the desiccant.  It then flows through a heat exchanger where it’s cooled, condensing the moisture, before it flows through the other tower to remove any remaining moisture.  This method doesn’t add to your compressed air usage, but it only works with oil-free compressors.
  • The third method uses a hot air blower to flow heated air through the off-line desiccant bed.  It’s similar to the Regenerative type, but it doesn’t use compressed air.  However, they DO require a certain amount of wattage for the heater…remember, electricity isn’t cheap either.

As an EXAIR Application Engineer, it’s my job to help you get the most out of our products, and your compressed air system.  If you have questions about compressed air, call me.

Russ Bowman
Application Engineer
EXAIR Corporation
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About Air Compressors: Air Intake Best Practices

Take a second and think about where the air compressor is located within your facility.  It is more than likely not a major focal point displayed prominently in the floor layout. There is a better chance it is tucked away in a corner of the facility where operators seldom travel.  No matter the type of air compressor, it still has an intake where it pulls in the ambient air from around the compressor then sends it through some process and on the demand side of your compressed air system.  These intakes can easily be placed out of sight and out of mind especially in older facilities that were designed when compressors were loud and the piping layout kept them away from operators due to sound level restrictions.

Air Compressor
Antique Air Compressor (Not safe for use!)

That’s why your compressor manufacturer supplies a specific grade of air 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. It’s just like changing the air filter on your car, your car needs clean air to run correctly, so does your compressor and the entire demand side of your compressed air system.

According to the Compressed Air Challenge, as a compressor inlet filter becomes dirty, the pressure drop across the inlet increases, this is very similar to the point of use compressed air filters.  The inlet filter on the compressor is the only path the compressor has to pull in the air, when restricted the compressor can begin to starve for air very similar to if you only had a small straw to breath through and told to run a marathon.  A clogged inlet filter can give false symptoms to compressor technicians as well.

The effects can mimic inlet valve modulation which result in increased compression ratios. If we were to form an example based on a compressor with a positive displacement, if the filter pressure drop increases by 20″ H2O, a 5% reduction of the mass flow of air will be present without a reduction in the power being drawn by the compressor. This all leads to inefficiency which easily amounts to more than the cost to replace the depleted inlet air filter.

compressor
Compressed Air System

Where you place the filter is just as important as how often you replace it.  There are some tips to be used when mounting the inlet filter.

  1. The filter can be placed on the compressor, but the inlet pipe should be coming from an external area to the compressor room or even the building if possible. The inlet should be free from any contaminants as well.  Some examples that are easy to overlook are nearby condensate discharges, other system exhausts and precipitation.
  2. Depending on the type of compressor being used, a lower intake air temperature can increase the mass flow of air due to the air density.  A compressor that is lubricant injected is not susceptible to this due to the air mixing with the warmer lubricant before being compressed.

If you would like to discuss improving your compressed air efficiency or any of EXAIR’s engineered solutions, I would enjoy hearing from you…give me a call.

Jordan Shouse
Application Engineer
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Images Courtesy of  the Compressed Air Challenge and thomasjackson1345 Creative Commons.

Six Steps to Optimization, Step 4 – Turn Off Your Compressed Air When Not in Use

Step 4 of the Six Steps To Optimizing Your Compressed Air System is ‘Turn off the compressed air when it isn’t in use.’  Click on the link above for a good summary of the all the steps.

6 Steps from Catalog

Two basic methods to set up a compressed air operation for turning off is the ball valve and the solenoid valve. Of the two, the simplest is the ball valve. It is a quarter turn, manually operated valve that stops the flow of the compressed air when the handle is rotated 90°. It is best for operations where the compressed air is needed for a long duration, and shut off is infrequent, such as at the end of the shift.

manual_valves (2)
Manual Ball Valves, from 1/4 NPT to 1-1/4 NPT

The solenoid valve offers more flexibility. A solenoid valve is an electro-mechanical valve that uses electric current to produce a magnetic field which moves a mechanism to control the flow of air. A solenoid can be wired to simple push button station, for turning the air flow on and off – similar to the manual valve in that relies on a person to remember to turn the air off when not needed.

wa_solvalv
A Wide Array of Solenoid Valve Offerings for Various Flows and Voltage Requirements

Another way to use a solenoid valve is to wire it in conjunction with a PLC or machine control system. Through simple programming, the solenoid can be set to turn on/off whenever certain parameters are met. An example would be to energize the solenoid to supply an air knife when a conveyor is running to blow off parts when they pass under. When the conveyor is stopped, the solenoid would close and the air would stop blowing.

The EXAIR EFC (Electronic Flow Control) is a stand alone solenoid control system. The EFC combines a photoelectric sensor with a timer control that turns the air on and off based on the presence (or lack of presence) of an object in front of the sensor. There are 8 programmable on/off modes for different process requirements. The use of the EFC provides the highest level of compressed air usage control. The air is turned on only when an object is present and turned off when the object has passed by.

efcapp
EFC Used To Control Bin Blow Off Operation

By turning off the air when not needed, whether by a manual ball valve, a solenoid valve integrated into the PLC machine control or the EXAIR EFC, compressed air usage will be minimized and operation costs reduced.

If you have questions about the EFC, solenoid valves, ball valves or any of the 15 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer
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The EXAIR Chip Trapper™ System Extends Machine Coolant Life

Have you realized that you spend too much time cleaning out your CNC machine?  Do you find that It is messy and backbreaking work?  Do you spend too much money replacing the coolant in your system?  If you answer yes to any of these, EXAIR has a product for you; the Chip Trapper System.

EXAIR created this product to reduce the down time and extend the life of your coolant.  This device will save you money and time with productivity, coolant, and repairs.  In this blog, I will go over some of the features and benefits with the Chip Trapper Systems.

EXAIR offers two types, the Chip Trapper and the High Lift Chip Trapper.  They are designed to move fluid into the drum to be filtered, and to allow the clean fluid to be placed back into the sump.  The Chip Trapper works great for quick coolant cleaning at the floor level.  The High Lift Chip Trapper is ideal for cleaning viscous fluids as well as for reservoirs below the floor level.

Both types use a pneumatic two-way pump to move the fluid.  They come in three different drum sizes, 30 Gallon (114L), 55 Gallon (208L), and 110 Gallon (418L). So, you can clean large sump tanks with only one cycle through the cleaning system.  They come standard with a 5-micron bag filter that can hold over 5 gallons of material.

EXAIR can also offer filter bags in 5 other micron ranges from 1 micron up to 200 micron.  And if you are not sure on the other filtration ranges, EXAIR offers a filter sample pack, model 901060-SP, that includes one of each type.

Chip Trapper Cut Away

The Chip Trapper System includes the drum, the two-way pneumatic pump, a drum dolly, a directional flow valve, 10 feet (3m) of vacuum hose, 20 feet (6m) of compressed air hose, a chip wand, a shut off valve, and two additional filter bags.  All you need to do is to attach the Chip Trapper System to a filtered compressed air source.

The High Lift Chip Trapper offers a more powerful pneumatic pump which can fill a 55 gallon (208L) drum in 85 second from 15 feet (4.5m) below.  And, instead of the 10 feet (3m) vacuum hose, it will come with a  20 feet (6m) vacuum hose.

The unique features with the Chip trappers are the abilities to clean the CNC sump very quickly and with less mess.  Also, by using compressed air to pump the coolant in and out of the drum, it will aerate the coolant.  This will reduce bacteria growth and extend the life of the coolant. Thus, saving you money with those more expensive coolants.

Another benefit is that the pneumatic pump does not have any moving parts to wear out.  So, it will last you a long time without worrying about motor failures or loud noises.

You can watch the video of the operation here:

A list of some benefits that you will see if you purchase the Chip Trapper System is as follows:

  • The number of complete coolant change-outs are reduced.
  • The speed to get the CNC machines back operational to make parts.
  • Reduce the number of barrels of coolant concentrate per year.
  • Bacterial growth dramatically reduced as the Chip Trapper aerates the coolant.
  • Filter bags will remove the chip fines and some tramp oils keeping the coolant fresh.
  • Quiet and long lasting
  • A complete system that is easy to use.

As an added note, some CNC machines come with a spindle coolant feature.  This new technology helps in the need to increase speeds and feed rates.  The coolant is pumped to the top of the machine and fed directly through the spindle.  This type of spindle uses a rotary union which allows the coolant to the spindle as it spins at a high rate of speed.  The rotary unions are very expensive and costly to replace.

These spindles are very susceptible to dirty coolant.  If a seal within the rotary union begins to leak inside the machine, you will not be able to diagnose the problem until they have a machine failure.  The Chip Trapper with help eliminate this chance and keep your machine from an extreme expensive breakdown.

When your machine is not operating, your productivity is lost.  The EXAIR Chip Trapper Systems can be that product for you to get you back up and running is a short period of time, extend your coolant life, and keep the area clean and safe.  A win-win proposition in saving money and time.

For U.S. and Canadian customers, EXAIR offers a 30-day unconditional guarantee to try.  And, for a limited time.  an end-user will get a free EXAIR Vac-u-Gun, a $112.00 value, with any purchase of a Chip Trapper or High Lift Chip Trapper.

If you want to learn more about the EXAIR Industrial Housekeeping Products, you can contact an Application Engineer.  We will be happy to help you.

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

 

EXAIR’s Powerful Chip Vac for Keeping Your Plant Clean and Safe

March brings with it the first day of spring and April seems to have brought that first day where I believe spring could actually be here consistently. I don’t know about you, but boy am I ready for some warmer temperatures!! Naturally, spring is the time of year that we roll up our sleeves and do some of the deep-cleaning we’ve been putting off all winter.

Though, for any manufacturer or processor, “spring cleaning” is a year round affair.

Lucky for you, EXAIR has an entire line of Industrial Housekeeping Products that’ll get your shop tidied up for spring. In this blog, I’d like to dive into the Chip Vac. With its powerful suction, it’s an ideal solution for fast and efficient cleaning.

premcv400
Chip Vac cleaning up a floor spill

EXAIR’s Chip Vac is a compressed air operated industrial duty vacuum designed specifically for vacuuming up chips and shavings. The powerful vacuum is suitable for use with metal, wood, or plastic chips and is designed to thread into the 2” NPT bung on standard drum lids. The Chip Vac can handle dry or wet chips from fixtures, floors and work surfaces of machining centers, lathes, saws, mills, and a variety of other industrial equipment.

Electrically powered vacuums or shop vacs are not designed to be operated in a rugged industrial environment. Filters clog, motors wear out, and you find yourself frequently replacing them. EXAIR’s Chip Vac has NO moving parts to wear out, doesn’t require maintenance, and needs nothing but a source of compressed air to operate. In addition, the sound level produced is half of that produced by an electric vacuum.

The Chip Vac is sold in systems both with and without the drum. EXAIR has 5, 30, 55, and 110 gallon systems available for a wide range of applications. If you already have spare drums in your facility, the Chip Vac is also available with just the lid assembly, Chip Vac, 10’ hose, tools, and filter bag to attach to the top of your own drums.

All systems will include a drum lid with a locking ring that easily fits onto the top of a standard open top drum. It’s easy to remove and place onto another drum so that different materials can be easily kept separate for recycling. Recycling companies will pay a premium price for pre-sorted chips and shavings. With the Chip Vac, it’s as easy as removing the lid and placing it onto a new drum in between jobs.

Don’t waste your time this spring fooling with and replacing electrical vacuums. Get yourself a vacuum designed for the job. One that’ll last year after year! With these systems in stock, ready to ship with an order by 3:00 ET, an unconditional 30 day guarantee and backed up by our 5-Year Warranty, there’s no reason not to give one a try!

Tyler Daniel
Application Engineer
E-mail: TylerDaniel@EXAIR.com
Twitter: @EXAIR_TD