Compressed Air Filters: How to Choose the Right One for Your System

Posted on January 17th, 2022

Compressed air does not mean clean air. No matter what industry you are in, your compressed air stream will contain many contaminants from the surrounding environment that need to be removed to ensure your system runs efficiently.

Whether these contaminants are oil, water vapor, dust or other particles, removing them from the compressed air stream is an important step. By utilizing compressed air filters, you can protect your equipment and your end product from contamination, component wear and spoilage.

Below are the most important considerations for choosing the right compressed air filter for your system.

1. What are Micron Ratings and Why Do They Matter?

Compressed air filter elements are rated by the size of the particles they trap. The smaller the micron rating, the smaller the particles it captures. The size of the particles that need to be removed from your compressed air stream depends on how clean your air needs to be. For instance, food applications and medical-grade air need to be cleaner than many manufacturing applications.

Standard universal air filters, such as Walker Filtration’s X5 filter grade, will remove particles that are larger than 5 microns. However, there are high efficiency filters, such as our 0.01 micron element, that can remove particles larger than 0.01 micron in size. These elements are often a necessity in the food and medical industries. But each application is unique, so it is good to consult with the equipment manufacturer or system installer to determine the exact filtration requirements.

In general, do not opt for a higher efficiency filtration grade than necessary. The larger the micron rating, the less pressure loss that occurs within the filter. For example, using a 1 micron filter when a 5 micron will suffice will unnecessarily increase energy consumption, the overall operating expenses and frequency of change out intervals.

2. Can My System be Damaged by Lubricants, Such as Oil?

Like other particles, oil in your compressed air system can compromise the air quality and cause equipment failure. In addition, there is an opportunity for oil and other vapours to enter your airstream by aerosols in the ambient air or from an oil-injected compressor.

If your application is sensitive to oil, the only way to fully protect your end product and equipment from corrosion and contamination caused by oil aerosol is by installing a coalescing filter or activated carbon filter, which removes oil vapor particles and odours. Walker Filtration has an extensive range of coalescing filters to remove oil aerosols, water vapor and dust particles from your compressed air line.

3. How Can I Determine the Correct Flow Rate for My System?

When choosing the correct compressed air filter for your system, it is essential to consider the airflow demand of the application. Since compressed air and gas filters are available in many sizes, first, you must determine your application’s inlet pressure and calculate the maximum pressure drop of the filter.

Most manufacturers supply flow vs. pressure drop curves for their filters in their literature. The pressure loss curve often gives several estimates based on different inlet pressures to help you calculate and select the correct filter for your requirements. If the flow rate is too low, choose a larger port or filter size. If it is too large, select a smaller filter unit to obtain the flow you require.

4. What Kind of Drain Valve is Most Effective?

If your compressed air system is frequently in use, an automatic drain valve may be the best choice because it reduces the need for manual intervention to the drain. Also, automatic drain valves are often the preferred option if the location of the filter makes access for servicing difficult, the equipment is in continual use, or the filter is being used in an application where large quantities of water can accumulate.

Manual drains, often called low flow drain valves, are often beneficial in smaller systems where the compressor capacity is not large enough to close a standard automatic drain or when there is minimal moisture and oil vapor present in the system – for example, after a compressed air dryer.

5. Can The Filter Withstand the System’s Operating Temperature?

Compressed air filters that do not withstand a high enough operating temperature run the risk of damage. In extreme cases, the filter could melt or explode. However, in a more likely case, the hot air could carry on through the system, damaging other equipment or the end product.

Walker Filtration’s Alpha and PRO XF Filter Ranges are suitable for temperatures up to 248°F (120°C) with a manual drain valve and our High Temperature Compressed Air Filters are ideal for operating temperatures up to 250°C (450°F).

6. Do I Need to Consider a Compressed Air Filters Compliance?

Selecting the correct air filter that meets your industry or government standards is essential. Without ensuring compliance, you may risk whether or not your end product will meet your set criteria.

The most established compressed air purity standard is ISO 8573-1:2010, which specifies the purity of compressed air for the presence of solid particles, water and oil. Therefore, when choosing the correct air filter, it would be wise to consider whether it meets any necessary standards imposed on your industry.

7. How Important is a Filter’s Energy Efficiency?

Suppose you are looking to reduce your carbon footprint, minimize your energy bills and limit the cost of running your business. In that case, you may also want to consider the energy efficiency of your air filter. The more energy efficient the compressed air and gas filter, the lower your power bills.

Walker Filtration’s High efficiency filters can produce clean air in line with the highest air purity standards while minimizing the pressure drop in your system and delivering maximum efficiencies. A low pressure drop across your filter element means you avoid the need for the system to work harder to produce more air, therefore, saving energy and money.

8. Who Can I Speak to if I need Assistance Selecting a Filter?

At Walker Filtration, we are the experts in developing, manufacturing and supplying high-quality Compressed Air and Gas Filtration. We have a wide range of compressed air filters for breathing air, food, manufacturing and other industrial applications.

Contact us at for further advice on choosing the right air filter for your compressed air system.

Alternatively you can view our complete range of Compressed Air and Gas Filtration Solutions.

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