EXAIR Products: The Importance of Oil Removal Filters

Oil Removal Filter
Oil Removal Filters

EXAIR’s Intelligent Compressed Air Products have no moving parts and require no maintenance. Most EXAIR products require no direct maintenance, and will continue to require no maintenance if the supplied air is clean. Keeping air clean, in EXAIR’s case, can be done with a simple water/dirt or oil filter separator close to the application of the product – usually within 10 feet. The reason for the filters is that many products have very tight orifices that could get clogged from contaminants such as particulate, condensate, and lubricant.

Oil is commonly present in a compressed air supply, whether that’s intentional or not. Many air compressors are lubricated by a constant supply of oil, inevitably some of this oil ends up in the air supply. As the compressor wears, more oil is permitted to pass and ends up in the distribution system. While this is kept to a minimum with proper maintenance, it is impossible to prevent unless using an oil-free compressor.

Sometimes oil is present in the air supply intentionally. Many pneumatic devices require a precise amount of oil to keep the internal moving parts lubricated. In the case of EXAIR Intelligent Compressed Air Products, we recommend particulate-free, moisture-free, and oil-free air.

EXAIR offers a line of Oil Removal Filters. These coalescing style filters are used to remove very fine water vapor as well as any residual oil. These filters are highly recommended to be installed just prior to dryers that contain a media that would be compromised by 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 filter bowl. With a coalescing filter, the most common cause of pressure drop increase is due to particulate clogging the element. Because of this, a particulate filter should always be installed just prior to coalescing filters. Check out this video demonstrating an Auto-Drain Filter and Oil-Removal Filter in action:

Without filtration, oil in the air supply will pass through the point of use device and into your product or process. The elimination of this problem is such a simple solution. Don’t neglect your compressed air system and ensure you’re delivering clean, dry, oil-free air to all of your EXAIR Intelligent Compressed Air Products.

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

Compressed Air Quality and ISO 8573-1 Purity Classes

Airborne particles surround us everywhere.   In a general work environment, nearly four million particles per cubic foot is floating around us at any given time.  When a compressor compresses this air, the concentration increases substantially.  So, compressed air is not only expensive to make, but very dirty.  As the air exits your air compressor and travels into your pneumatic system, there is so much contamination that the International Standard Organization, ISO, created an Air Quality chart with Purity Classes.


This chart is easy to follow and can be found in the ISO8573-1 standard for Air Quality.  It is used to select a cleanliness level for your compressed air system.  The contamination is categorized into three areas; Particles, Water, and Oil (reference above).  A Class is associated with a number for each category ranging from 0 (most stringent) to 9 (most relaxed).  As an example, an Air Quality value of ISO8573-1:2010 [1.2.4] has a Class 1 for Particles, Class 2 for Water, and Class 4 for Oil.  These Class values will show the maximum value in each category.

To define the categories in more detail, I will separate the three to discuss the origins and solutions.

  • Particles: For solid particles, this part comes from many different areas.  The surrounding ambient air that is being drawn into the air compressor is filtered; but the intake filter will only remove large diameter particles.  The smaller diameter particles will go through the filter and into the compressed air system.  Another part is rust particles that occur from steel air pipes and receiver tanks.  Over time, rust will flake off and create particles that can affect pneumatic equipment.  Other particles can come from components inside the air compressor, valves, etc., that wear and breakdown.  In the ISO column for Particles, it is separated into three different micron ranges and concentrations.  The removal of particles from the compressed air is done by traps and compressed air filters.  EXAIR offers two types; Filter Separators with 5-micron filtration and Oil Removal Filters with 0.03-micron filtration.  There are other types of filtration systems depending on your ISO requirement.
  • Water:  Humidity is a natural occurrence as water vapor in the surrounding air.  It can be measured as a dew point temperature.  This is the temperature at which water will condense and make rain.  Inside an air compressor, the air is ‘squeezed”, and the amount of space for water vapor is reduced.  So, it will condense into liquid form as “rain” inside the pipes.  Air that comes out from an air compressor will always be saturated with water.  To remove liquid water, a mechanical device can be used.  Inside a Filter Separator, a centrifugal separator will spin the air and remove the liquid water.  To remove water vapor, a compressed air dryer is required like a refrigerant, desiccant, deliquescent, or membrane type.  Each type will have a dew point range that they can reach.  As an example, a refrigerant type will reduce the dew point near 37 oF (3 oC).  That means that water will not condense until the temperature reaches below 37 oF (3 oC).
  • Oil: This category can be found as a liquid, aerosol or vapor, and it includes more than just oil. It contains small hydrocarbons, CO, CO2, SO2, and NOX.  Oil mainly comes from inside an oil-flooded air compressor.  As the air passes through the compressor, it will pick up remnants of oil aerosols and carry it downstream.  With high temperatures inside the air compressor, some of the oil will vaporize.  Even with oil-less type air compressors, carbon vapor can still be an issue.  Small hydrocarbons can come through the air intake and condense inside the system like water vapor above.  To remove the liquid and aerosol type of oil, Oil Removal Filters can be used.  They are designed to “coalesce” the small particles into larger particles for gravity to remove.  Oil vapor requires an activated carbon to remove.  These types of filter units will adsorb the vapor.  This helps to remove odors as well as dangerous chemical vapors that may be in the compressed air line.

There are a variety of pneumatic systems that use the ISO8573-1 standard.  This will include breathing air operations, food and beverage, pharmaceutical, and the electronic industries.  If you need stringent requirement for your compressed air system, the Air Quality standard should be used by referring to the Class numbers above.  This helps to dictate the types of filtration and air dryers that should be used within your pneumatic system.  If you have any questions about your compressed air system, an Application Engineer at EXAIR can help.

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


ISO 8573-1 Chart by Compressed Air Best Practice.

Compressed Air Accessories for Clean Air, Quiet Air, and Adjustability

In this blog, I would like to turn your attention to our accessories that support our Intelligent Compressed Air® Products.  EXAIR products use compressed air to coat, conserve, cool, convey and clean.  To maximize the performance, it is important to have the controls and options to increase their “flexibility”.  EXAIR offers these items as Accessories.  Pneumatic applications come in many variations and forms, and Accessories can help you to adapt to your application and to remove any “guess work”.

Here are the different categories and explanations of each item that EXAIR recommends for our products.  With their defined functions, they can help you in different areas to enhance your pneumatic experience.


  • Filter Separators remove bulk liquid and contamination from the compressed air stream. EXAIR stocks a range of sizes from ¼” NPT ports to 1 ¼” NPT ports.  They use a 5-micron filter and a mechanical baffle to remove slugs of liquid from your compressed air system.  Most Filter Separators have an auto-drain to automatically remove the buildup of liquid inside the bowl.   I would consider the Filter Separator as a minimum level of protection required to protect your EXAIR products.
  • The Oil Removal Filters remove very small particles of dirt and oil from the compressed air; making it even cleaner. The 0.03-micron media of the Oil Removal Filter will “coalesce” the fine liquid particles into large droplets.  Thus, allowing gravity to remove it from the compressed air stream.  EXAIR offers different sizes ranging from ¼” NPT to 1 ½” NPT ports.  As a note, Oil Removal Filters are great for removing very fine particles, but if you have a system with lots of water, I would recommend a Filter Separator upstream of the Oil Removal Filter for optimal filtration.
  • Pressure Regulators control the amount of air pressure being supplied to your EXAIR products. This is important if you are trying to save compressed air, control the force, or convey material.  EXAIR, being a leader in compressed air savings, recommends to use the minimum amount of air pressure to do the job.  This will save compressed air and save you money.  Regulators have a characteristic called “droop”.  Droop is the amount of air pressure that it drops downstream when you start flowing compressed air.  If the regulator is not sized properly, you can “starve” your pneumatic component, causing loss of function.  EXAIR properly sizes our regulators in our kits to make sure that you won’t “starve” our product.
  • EXAIR also offers Mounting Brackets for the regulators and the filters to help support them to a wall or structure. To connect filters and regulators together without a pipe nipple, we also have Coupling Kits for sizes up to ¾” NPT.  And for combination kits which includes a filter and a regulator, we offer the Mounting Bracket and Coupling Kit together for a set.

Silencing Mufflers:

  • Reclassifying Mufflers are designed to have two functions. They can reduce noise levels by 35 dB and remove oil mist from the exhaust air.  Cylinders and valves that exhaust pressurized air may have oil in the line to keep the seals from sticking.  When exhausted, it can create a fine mist which is dangerous for operators.  The Reclassifying Mufflers can reduce the loud noise as well as collect any contamination from the exhaust air.
  • Sintered Bronze Mufflers are simple in design, cost effective, and easy to install. They have a minimal back pressure to not restrict operations of the pneumatic device.  They come in sizes from #10-32 thread to 1-1/2 NPT.  For a quick and simple way to reduce noise, the Sintered Bronze Mufflers are in stock for fast delivery.
  • Straight-Through Mufflers offer a way to reduce noise levels without worrying about clogging. They have an aluminum shell lined with sound absorbing foam, and they can reduce the noise level by 20 dB.  EXAIR offers them with two ports from ¼” NPT to ¾” NPT.  This can allow you to connect other items like blowing hose kits while reducing noise.
  • Heavy Duty Mufflers have an outer aluminum shell with an internal stainless steel screen that can protect the components from environmental contamination, and can also keep contaminant like rust from being ejected at high speed into the work area. They have a typical noise reduction of 14 dB.

Pneumatic Valves:

  • Manual Valves allow for operators to turn on and off their system by hand. The full-flow ball valves range from ¼” NPT to 1 1/4” NPT in size and will not restrict flow.  EXAIR also offers a manual foot pedal valve for hands-free operations.  This ¼” NPT Foot Valve has a 3-way operation and works great if the operator has to use both hands in their process.
  • Solenoid Valves are a way to turn on and off the supply of compressed air electrically for automated systems. We offer solenoids in three different voltages; 110Vac, 240Vac, and 24Vdc.  EXAIR has a large range of flows with ports ranging from ¼” NPT to 1” NPT.  All models are UL listed and are CE and RoHS compliant.


  • Swivel Fittings are a great way to securely install and aim EXAIR nozzles. They are dynamic as they can be adjusted and set to a flow direction with 50-degrees of movement.  They are made from 303SS or 316SS for corrosion resistance with ports ranging from 4mm to 1” NPT.
  • Compressed Air Fittings are a nice arrangement to connect different compressed air items together. We offer a range of hex and close nipples, couplings, reducers, tees, elbows, crosses and bulk head fittings.  If you need a quick way to connect directly to your pneumatic system, we may have it on the shelf.
  • Magnetic Bases are designed for a solid mount to steel surfaces and for easy portability of your blow-off system to different locations. It has a 100 lb. (45.5Kg) pulling force to keep the blowing device attached firmly until you want to move it.  They can be mounted in a vertical or horizontal position.  EXAIR offers a single outlet Magnetic Base (for one blow-off device); a dual outlet Magnetic Base (for multiple blowing products); and a single outlet Swivel Magnetic Base (to offer more flexibility to orientation).  The bases come with a ¼ turn shut-off valve to easily turn on and off the compressed air to the EXAIR products.
  • Receiver Tanks are used to store compressed air. They can be used at the air compressor or as secondary reservoirs for intermittent demand.  They help your compressed air system with pressure variations and high demand loads.  EXAIR offers a model 9500-60 Receiver Tank that has a capacity of 60 gallons, is rated to 200 psig, and meets ASME pressure vessel code.



  • Conveying Hoses are used with our Air Operated Conveyors or Line Vacs. The hoses are made from a durable PVC semi-flexible hose with six different diameters from ¾” I.D. up to 3” I.D.  The conveyance hoses can slip easily to the ends of the Line Vacs or to tubes for an easy transition.  EXAIR can cut-to-length Conveying Hoses up to 50 feet (15m); in increments of 10 feet (3m).
  • Coiled Hoses get compressed air from the piping system to the EXAIR product. They are made of a durable abrasion-resistant nylon material that is 12 feet long (3.6 meters).  They have swivel fittings at the end to allow for easy uncoiling, and a spring strain relief to keep the hose from kinking.  The coiled design makes it easy to reach around the work area and retract back to the substation.  This will help to keep the hose off the ground where potential dangers could occur.  We offer 3 different connection sizes; 1/8” NPT, ¼” NPT, and 3/8” NPT.
  • Compressed Air Hoses is another way to supply EXAIR products. They are useful if you need to reach from overhead sources or around equipment.   They are made from a reinforced synthetic rubber in 3/8” I.D. and 1/2” I.D. diameters.  We can make specific lengths up to 50 feet (15m).  They are rated for 250 PSIG (17 bar) air pressure, and the hose material works well for long-lasting protection against ozone, weathering and temperatures up to 158oF (70oC).  They come standard with two male ends in ¼” NPT or ½” NPT.

    Flexible and durable, EXAIR Stay Set Hoses come in lengths from 6″ to 36″.
  • Stay Set Hoses give you that possibility of manually adjusting or re-adjusting Super Air Nozzles. The hose has a “memory” function; so, it will not creep or droop until you physically move it.  They work well to direct air flows in unique ways at specific target areas.  They can be used with Super Air Nozzles, Safety Air Guns and Blow-off Kits.  The Stay Set Hoses come in lengths from 6” (15cm) to 36” (91cm), and they are offered with ¼” NPT male on both ends or with a 1/8” NPT female and a ¼” NPT male connections.  These hoses are rated for 250 PSIG (17 bar) and are made from reinforced synthetic rubber.

Temperature Accessories:

  • The ETC, or Electronic Temperature Control, is a digital temperature controller with a LED screen for precision monitoring and adjusting temperatures in a Cabinet Cooler System. The controller has easy-to-use buttons to raise or lower the desired internal cabinet temperature.  Once set, the ETC will hold the temperature to +/- 1 oF (+/- 0.5 oC).  The LED displays the internal temperature for continuous monitoring.  The ETC comes complete with the controller and a solenoid valve in two different voltages, 120Vac and 240Vac.
  • The thermostat is a way to control a solenoid valve electrically to turn on/off a Cabinet Cooler System at a set temperature. It is preset at 95°F (35°C), but it can be adjusted to other desired temperatures.  It has an accuracy to hold the set temperature within +/- 2 °F (1 °C).  It can handle voltages from 24V to 240V, AC (50/60 Hz) or DC.  They are UL Recognized and CSA certified.

In todays fast-paced world, there is a need to get your devices operating as quickly as possible.  With EXAIR Accessories, they can help you to do that.  Not only will you have confidence, as you are using the items from the manufacturer, but it will minimize downtime, setup, and malfunctions that can occur if using other types of accessories.  If you would like to discuss the proper options with your EXAIR products, an Application Engineer will be happy to help you.

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

The Importance of Compressed Air Filtration

In this blog, I would like to turn your attention to our accessories that support our Intelligent Compressed Air® Products; the Filter Separator and the Oil Removing Filter.  EXAIR products use compressed air to coat, conserve, cool, convey and clean.  So, to keep our products running properly and efficiently, we need to supply them with clean, pressurized air.  If we look at the two types of filters that we offer, we can see how they can play an important part in your compressed air system.

Filter Separators

Filter separators are used to remove bulk liquid and contamination from the compressed air stream.  They have a 5-micron filter and work very well if you get a slug of liquid in your compressed air system.  They use mechanical separation to remove the large particles of dirt and water from the air stream.

Most facilities use some type of compressed air dryer in their system to dry and condition the compressed air.  But, if a system failure occurs, then water, oil, and dirt can be pushed into the compressed air lines and perhaps into your EXAIR products.

Even if you have good quality air, it is still important to keep your products protected.  I would consider the Filter Separator as a minimum level of protection that should be used.

Oil Removal Filters

The Oil Removal Filters are used to keep the compressed air even cleaner yet.  They work great at removing very small particles of dirt and oil.  The 0.03-micron media of the Oil Removal Filter is designed to “coalesce” the fine liquid particles into large droplets.

Thus, allowing gravity to remove it from the compressed air stream.  Some common issues allow for dirt and oil particles to collect in “dead” zones within the air lines.  As it piles up and grows, portions can break off and get into the air stream affecting pneumatic devices.

The Oil Removal Filter will be able to help eliminate this long-term problem in your compressed air system.  As a note, Oil Removal Filters are not great for bulk separation.  If you have a system with lots of water, you should use a Filter Separator in front of the Oil Removal Filter to optimize the filtration.

Now that we went through each type, how do we use them together to get the best supply of compressed air?  We always want them to be installed upstream of a Regulator.  This is because the velocity is lower at higher pressures.

Lower velocities mean lower pressure drops which is great for supplying the proper amount of compressed air to EXAIR products.  If you are using a combination of both filters, the Filter Separator will be upstream of the Oil Removal Filter.  The Filter Separator will knock down the large particles and liquid slugs allowing the Oil Removal Filter to remove the smaller droplets and particles.

EXAIR offers a range of sizes to help support our products.  They range from ¼” NPT ports up to 1 ½” NPT ports.  The size of the ports determines the flow rating for each unit.  EXAIR also has Mounting Brackets to mount the filters to walls or frames.

To support each type of filter, we have replacement elements and bowl kits.  Since the function of the filter is to remove debris, we recommend to change the filter element once a year or when it reaches 10 PSID pressure drop; whichever comes first.

If we can analyze the compressed air systems, I would like to categorize it into a good and premium quality.  For the good quality of compressed air, you can have the compressed air run through the Filter Separator.  For the premium quality of compressed air, you can have your compressed air run through the Filter Separator and then through the Oil Removal Filter.

With clean quality air, your EXAIR products will provide you with effective, long-lasting performance without maintenance downtime.

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

Compressed Air Demand Preventative Maintenance

Preventative maintenance for compressed air demand products is a simple as keeping the compressed air clean and condensate free. It is simple because all it takes is a filter and keeping the filter element clean, just like you do for your home furnace and/or air conditioner.

I received a phone call from a customer that needed replacement elements for EXAIR filters.  They were using four different models of Filter Separators and Oil Removal Filters.  The filters had been in service for one year, and the internal elements needed to be changed.  They requested a quote to replenish the replacement elements that they stocked as a preventative measurement.  What an idea!

Majority of EXAIR products use compressed air for cleaning, cooling, conveying, static elimination, coating and more.  To help keep your EXAIR products 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.  The 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, whichever comes first.  I created a list in Table 1 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 for pneumatic products 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 0.01 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.  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 cross contamination, performance issues, and premature failures.  As an ounce of prevention, you can add the replacement elements in stock and enter them in your preventative maintenance program.  With clean quality air, your pneumatic system and EXAIR products will provide you with effective, long-lasting performance without 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
Email: johnball@exair.com
Twitter: @EXAIR_jb

Compressed Air Filtration – Particulate, Coalescing, and Adsorption Types

Compressed air systems will contain contaminants that can lead to issues and increased costs through contamination of product, damage to the air operated devices, and air line clogging and restriction. Proper air preparation is critical to optimizing performance throughout the plant operations.

Because there are different types of contaminants, including solid particles, liquid water, and vapors of water and oil, there are different methods of filtration, each best suited for maximum efficiency in contaminant removal.

Particulate Filters – The compressed air flows from outside to inside of the filter element. The compressed air first passes through a baffle arrangement which causes centrifugal separation of the largest particles and liquid drops (but not liquid vapors), and then the air passes through the filter element.  The filter element is usually a sintered material such as bronze.  The filter elements are inexpensive and easy to replace. Filtration down to 40-5 micron is possible.

Particulate Type Filter with Sintered Bronze Element

Coalescing Filters – This type operates differently from the particulate type.  The compressed air flows from inside to outside through a coalescing media. The very fine water and oil aerosols come into contact with fibers in the filter media, and as they collect, they coalesce (combine) to form larger droplets towards the outside of the filter element. When the droplet size is enough the drops fall off and collect at the bottom of the filter housing.  The filter element is typically made up of some type glass fibers.  The coalescing filter elements are also relatively inexpensive and easy to replace. Filtration down to 0.01 micron at 99.999% efficiency is possible.

Coalescing Type Filter with Borosilicate Glass Fiber Element

Adsorption Filters – In this type of filtration, activated carbon is typically used, and the finest oil vapors, hydrocarbon residues, and odors can be be removed.  The mechanism of filtration is that the molecules of the gas or liquid adhere to the surface of the activated carbon.  This is usually the final stage of filtration, and is only required for certain applications where the product would be affected such as blow molding or food processing.

When you work with us in selecting an EXAIR product, such as a Super Air Knife, Super Air Amplifier, or Vortex Tube, your application engineer can recommend the appropriate type of filtration needed to keep the EXAIR product operating at maximum efficiency with minimal disruption due to contaminant build up and unnecessary cleaning.

If you have questions regarding compressed air filtration or any EXAIR Intelligent Compressed Air® Product, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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