Preventative Maintenance for EXAIR Filters

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

I read a white paper from Parker Hannifin about compressed air filters.  The idea behind the paper was to remember your filter replacements.  Compressed air can be dirty with water, oil, pipe scale, etc.  As the filters capture the contamination, it will start to build pressure drop.  Remember, pressure drop is a waste of energy in your compressed air system.

Majority of EXAIR products use compressed air for cleaning, cooling, conveying, static elimination, coating and more.  To help keep them running efficiently, it is important to supply them with clean, dry, pressurized air.  EXAIR offers a line of Filter Separators and Oil Removal Filters to supply quality air to your equipment.  In this blog, I will explain the two types of filters that we carry and the maintenance requirements.  Filters and preventative measures can play an important part in your compressed air system.

Filter Separators are used to remove bulk liquid and contamination from the compressed air stream.  They utilize a 5-micron filter with a mechanical separation to help remove large amounts of dirt and water.  This type of filter would be considered the minimum requirement for filtration.  Most of the Filter Separators come with an auto-drain to automatically dispense the collection of oil and water.  EXAIR offers a variety of port sizes and flow ranges to meet your pneumatic flow requirement.  For maintenance, the filter elements should be changed once a year or when the pressure drop reaches 10 PSID (0.7 bar), whichever comes first.  I created a list in Table 1 below showing the correct replacement element kits for each model number.  And for any reason, if the bowl or internal components get damaged, we also have Rebuild Kits as well.  Just remember, the air quality is very important for longevity and functionality of your pneumatic systems and even for EXAIR products.

The Oil Removal Filters can make your compressed air even cleaner.  They work great at removing very small particles of dirt and oil.  They are made from glass fibers and can remove particles down to 0.03 micron.  They are designed to collect small particles and to coalesce the liquid particles into a large droplet for gravity to remove.  Because of the fine matrix, Oil Removal Filters are not great for bulk separation.  If you have a system with lots of oil and water, I would recommend to use the Filter Separator upstream of the Oil Removal Filter.  As with the Filter Separator, the filter element should be changed once a year or at a pressure drop of 10 PSID (0.7 bar).  EXAIR also offers a variety of port sizes and flow ranges.  Table 1 below shows the replacement Element Kits as well as the Rebuild Kits.  If the application requires very clean compressed air, the Oil Removal Filter should be used.

Table 1

By using EXAIR filters, they will clean your compressed air to prevent contamination on parts, performance issues, and premature failures.  As an ounce of prevention, you should add the replacement elements in stock and enter them in your preventative maintenance program.  With quality air, your pneumatic system and EXAIR products will provide you with effective, long-lasting performance without any maintenance downtime.  If you would like to discuss the correct type of filters to use in your application, you can speak with an Application Engineer.  We will be happy to help you.

John Ball
Application Engineer
Twitter: @EXAIR_jb

Comparing the Different Styles of Compressed Air Filters

Most of EXAIR’s line of Intelligent Compressed Air Products have no moving parts and require no maintenance. The caveat to the “no maintenance” aspect is proper filtration at the point of use. Many products have very tight orifices that could get clogged from any contaminants such as particulate, condensate, and lubricant. EXAIR recommends point of use filtration to be installed just upstream of any EXAIR Product for this purpose.

There are three primary types of compressed air filters: particulate, coalescing, and adsorption. Each have their own inherent characteristics and can be used in conjunction with one another. Each style is used to handle a different form of contaminant that’s present within the distribution system of your compressed air supply.

EXAIR Model 9001 Auto-Drain Filter

Particulate filters – Particulate filters are available with different filtering mechanisms that allow you to control the particulate size that will be filtered out. The higher the level of filtration, the greater the pressure drop you’ll experience at the outlet of the filter. Styles are also available with either a polycarbonate bowl or metal bowls, depending on the application and environment.

Any filter with a polycarbonate bowl should have a metal guard on the outside to provide protection for personnel should a failure occur. In these styles of filters, compressed air is forced through a filter element that blocks any particulate contained within the air supply.

These filter elements are generally a sintered bronze material with filtration levels from 40-5 micron possible. Over time, the filter elements can clog and increase the pressure drop at the discharge of the filter. They’re relatively inexpensive and should be replaced yearly to maintain optimum performance and mitigate pressure drop. They also remove liquid drops as well from the air supply, containing them within the bowl. Styles with both manual-drains and automatic-drains are available that will drain the bowl of excess moisture automatically through the bottom of the filter.

EXAIR Model 9005 Oil Removal Filter

Coalescing Filters – The coalescing filter is used to remove very fine water vapor as well as any residual oil. These filters are highly recommended to be installed just prior to any dryer that contains a media that would be compromised by any lubricant passing through it. Coalescing filters utilize an element typically made up of glass fibers that “coalesce”, or combine, the fine water vapor and oil aerosols until the droplet size becomes large enough that it drops off into the bowl or filter housing. With a coalescing filter, the most common cause of pressure drop increase is due to particulate clogging the filter element. Because of this, a particulate filter should always be installed just prior to any coalescing filters.

Adsorption Filters – The final type of compressed air filter is the adsorption filter. Where the particulate filters can remove the majority of contaminants and the coalescing filters the residual oil, they are not capable of removing lubricant vapors or oil. That’s where the adsorption filter comes in. In addition to removing the finest oil vapors, they also can eliminate odors from the compressed air supply. The oil vapors and odors adhere to activated carbon within the filter, removing them from the air supply. These filters are commonly found within the food processing industry, where any contaminants in the air supply could impact the integrity of the product.

EXAIR has a line of Automatic Drain Filter Separators and Oil Removal Filters, available from stock, to make sure the quality of your air supply is sufficient for proper operation of any EXAIR product. Feel free to give us a call and any of our Application Engineers will be happy to assist you.

Tyler Daniel
Application Engineer
Twitter: @EXAIR_TD