When setting up a predictive maintenance program, the two most important variables to watch are temperature and pressure. In some cases, vibration is another variable that can be useful. These variables are very important in spotting breakdowns in the compressed air system's efficiency. A decrease in pressure may indicate reduced compressor performance or increased system leakage. In addition to temperature and pressure, another important variable to monitor is differential pressure.
Pressure drops are a result of air moving across a filter.
Therefore, differential pressure exists wherever a filter element is found. The one thing to keep in mind is, with time, these pressure differentials will increase. For this reason, it's a good practice to replace the filter elements before the cost of increasing pressure drop exceeds the cost of a replacement element. Another critical concern is that these filter elements must be able to maintain the air quality required for the compressed air system's application. Replacing the filter elements will help avoid unscheduled downtime and costly repairs.