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What is the difference between pre-filter and post-filter?

Mobile Diesel Screw Air Compressor


In the air compressor system, the pre-filter and post-filter play a key role. They have different functions and filtration precision, and together they make the air output by the air compressor clean and dry. So what is the difference between the pre-filter and the post-filter of the air compressor?


  1. Pre-filter

The pre-filter is located between the air tank and the refrigeration dryer. Its main task is to perform preliminary filtration before the air enters the cold dryer. The pre-filter can remove moisture, oil and larger impurities from the air. This helps protect the dryer from damage or poor performance due to excess impurities.


The filtration precision of the pre-filter is usually lower, such as 1-5 microns. This means it can capture particles larger than 1-5 microns in diameter. Although the pre-filter has a lower filtration accuracy, it is still very important in the entire air compressor system because it can protect subsequent equipment and reduce its burden.


2.Post filter


The post filter is located after the refrigeration dryer. The function of a cold dryer is to reduce the moisture in the air to a very low level, making the air drier. However, even after being processed by a cold dryer, there may still be some fine impurities in the air. At this time, the post-filter comes into play to further remove these fine impurities, making the output air clean, dry, and oil-free.


The filtration accuracy of the post-filter is usually 0.01-1 micron. This means it can capture particles larger than 0.01-1 micron in diameter. The post-filter plays a key role in the entire air compressor system because it allows the output air to meet the required quality standards and meet the requirements of various industrial applications.


  1. The pre-filter and post-filter cooperate with each other.


Pre-filters and post-filters work together in the air compressor system to improve the quality of the output air. The pre-filter is responsible for preliminary filtration and protection of the cold dryer; the post-filter is responsible for further improving air quality to meet the needs of different application scenarios. When choosing an air compressor system, we need to choose the appropriate pre-filter and post-filter based on actual needs and application scenarios. For example, in situations with higher air quality requirements, such as the food, pharmaceutical and electronic industries, we should choose post-filters with higher filtration accuracy to improve the air quality in the production process.


For continued performance and air quality of your air compressor system, we recommend regular filter inspection and replacement. This not only extends the service life of the equipment, but also outputs high-quality compressed air. Our professional team will provide you with detailed maintenance advice and services to keep your air compressor system in optimal condition.

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