Compressed Air Filter: Surface Filtering

How does surface filtering work?

A surface filter is used to separate unwanted particles from compressed air. When compressed air comes to a surface filter, the idea is that the compressed air passes through, while the particles and pollutants are blocked and collected.

This works because there are holes in a surface filter. The actual size of these holes depends on the filter. Any particle bigger than the holes will be blocked.

What size filter?

If you want to block particles of incredibly small size, you’re best using a number of filters, with progressively smaller holes on each filter. Why not just start with the smallest holes? The filter will soon become blocked, and the compressed air will lose pressure or even be stopped from travelling through the filter. But by starting with larger holes and working your way down, you’ll capture larger particles first, while still allowing smaller particles to pass and be trapped by subsequent filters.

If a surface filter is blocked? Remove it and, depending on the type of filter, clean it or replace it. 

What size filter do you need?

The level of quality you need in your compressed air will decide the filter you need. The higher the quality required, the smaller the holes in your filter to ensure you filter out those tiny particles.

You may also need an air dryer to help remove water vapour from your compressed air. Once again, this will depend on what you’re using the compressed air for. 

Would you like a hand choosing the right filtration system for your system? Do you want to know more about air dryers? Great! There is nothing we would rather chat about. Get in touch today! 


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Who we are and how Ash Air can help your business!

Ash Air has been around in New Zealand since 1979, and we’ve grown into a nationwide company with international support and a reputation for quality and reliability.We look after all things compressed air for your business!

  • Rotary Screw and Piston Air Compressors
  • Vacuum Pumps and Blowers
  • Nitrogen Generation
  • An extensive line of Air Treatment components
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  • Mobile Compressors, Generators, and Light Towers

Ash Air's range of Chicago Pneumatic, ALUP, Pneumatech, and Atlas Copco products are used extensively around the world in industries ranging from oil and gas to food, automotive and farming, and we bring you these world-class compressors here in the land of the long white cloud.Our technicians are compressed air equipment experts and are dedicated to addressing customer needs. Supported with nationwide coverage, Ash Air offers one of the widest selections of compressed air, vacuum pump, and industrial gas equipment and parts available today in New Zealand.

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With Ash Air, you can count on reliability and high performance for even the most demanding applications. We focus our efforts on the following:

  • Increasing uptime
  • Reducing unexpected repairs
  • Reducing energy consumption and meeting our sustainability goals
  • Improving the cleanliness of compressed air


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