Point-of-use filters, coalescing filters, or particulate filters downstream of the compressor are clogged and creating a restriction.

What you'll see

Pressure drop across specific inline filters. Good pressure before the filter, lower pressure after. The drop gets worse over time as the filter clogs. Many inline filters have a differential pressure indicator -- check it.
Before you assume this is the problem

See all causes of pressure drop →

How to diagnose

  1. Check differential across each filter

    Measure or read the pressure before and after each inline filter. A new filter has minimal drop. A clogged filter can have 0.5-1+ bar drop.

    Result: High differential = clogged element.

How to fix it

  1. Replace filter elements

    Install new elements. Consider buying filters one size too big -- lower velocity means less pressure drop and longer element life. The small upfront cost pays for itself in energy savings.

Common mistakes

Don't forget about filters that 'someone installed years ago' -- they may be hiding behind a panel, forgotten, and clogged solid.

Parts & tools

Replacement filter elements. Pressure gauges for checking differential.

Review safety precautions before starting →

This issue can also cause

  • High Energy Use Excessive power consumption or unexpectedly high electricity bills, often caused by control problems, air leak...