Knowledge Center

Unveiling the Power of Air Compressor Filters

air compressor filters

In modern industrial production, air compressors, as a key equipment, play an important role in converting atmospheric air into high-quality compressed air. However, in order to ensure that the air is free of impurities, oil mist and solid particles, air compressor filters become a vital component. This article will delve into the functions, types and replacement methods of air compressor filters, laying the foundation for ensuring clean and efficient compressed air for industrial production.

What are air compressor filters

The function of Air compressor filters is to enter the oil-containing compressed air generated by the host into the cooler, mechanically separate it into the oil and gas filter element for filtration, intercept and aggregate the oil mist in the gas, and form oil droplets concentrated at the bottom of the filter element and return to the compressor through the oil return pipe. The machine lubrication system enables the compressor to discharge purer, high quality compressed air; simply speaking. It is a device that removes solid dust, oil and gas particles and liquid substances in the compressed air.

air compressor filters

Types of Air compressor filters

Air compressor filters include air filters, oil filters, oil filters, precision filters, etc.

1. Air filter element (air filter):

The air filter is the primary line of defense in an air compressor. Its main function is to filter solid particles, dust and other impurities in the atmosphere to ensure that the air is clean when it enters the compressor system. This helps reduce mechanical wear, improves air quality, and protects subsequent filters and the entire compressor system.

2. Oil filter element (oil filter):

The oil filter element is a key component responsible for filtering the oil mist discharged from the compressor. Through the action of mechanical separation and filter material, the oil filter element can effectively intercept oil droplets, concentrate them at the bottom of the filter element. Then return them to the lubrication system of the compressor through the oil return pipe. This ensures that the discharged compressed air is purer and of higher quality.

3. Oil filter element :

The oil filter element further filters the liquid oil to ensure the purity of the lubricating oil in the compressor system. It can effectively separate and remove tiny oil droplets and oil components, further improving system reliability and long-term operation stability.

4. Precision filter element:

Precision filter elements usually use micron-grade glass fiber filter materials, which are mainly used to filter tiny oil droplets in the air. The function of this filter element is to filter small suspended oil droplets to ensure that the discharged air does not contain tiny oil mist. The correct selection of fiberglass diameter and thickness is crucial to maintaining filtration effect. Making the compressed air cleaner and improving the efficiency of the entire system.

The principle of Air compressor filters

Air compressor filters are a key component that determines the quality of compressed air discharged from an oil-injected screw compressor. With correct installation, use and good maintenance. The quality of compressed air and the service life of the filter element can be ensured.

The air compressed from the screw compressor host head carries oil droplets of different sizes. Large oil droplets are easy to separate through the oil and gas separation tank. Filter the small oil droplets through the micron-grade glass fiber filter material of the oil and gas separation filter element.

The correct selection of glass fiber diameter and thickness is an important factor in ensuring filtration effect.

After the oil mist is intercepted, diffused and aggregated by the filter material, the small oil droplets quickly aggregate into large oil droplets, pass through the filter layer under the action of pneumatic force and gravity, and settle at the bottom of the filter element. The oil passes through oil return pipe inlet at the bottom of the filter and continuously returns to lubrication system. Allowing the compressor to discharge relatively pure, high-quality compressed air.

How to replace Air compressor filters

When the lubricating oil consumption of the air compressor increases greatly, check whether the air compressor filters, pipelines, oil return pipes, etc. are blocked and clean them. If the oil consumption is still very large, generally the air compressor filters have deteriorated and need to be replaced in time. 

Replace air compressor filters when the pressure difference between both ends reaches 0.15MPA. When the pressure difference is 0, it indicates that the filter is faulty or the air flow has been short circuited. And the filter element should also be replaced at this time. The general replacement time is 3000 to 4000 hours. Poor environmental conditions will shorten its usage time. The replacement steps are as follows:

External model

The external model is relatively simple. Stop the air compressor, close the air pressure outlet, open the drain valve, confirm that there is no pressure in the system, remove the old air compressor filters and replace them with new ones.

Built-in model

Follow these steps to properly replace air compressor filters:

1. Stop the air compressor, close the air pressure outlet, open the drain valve, and confirm that there is no pressure in the system.

2. Disassemble the pipeline above the oil and gas barrel. At the same time remove the pipeline from the outlet of the pressure maintenance valve to the cooler.

3. Remove the oil return pipe.

4. Remove the fixing bolts of the oil and gas barrel cover, and remove the upper cover of the oil and gas barrel.

5. Remove the air compressor filters and replace them with new oil and gas separators.

6. Install in the reverse order of disassembly.


When installing the oil return pipe, ensure to insert the pipe into the bottom of the filter. When replacing air compressor filters, pay attention to electrostatic discharge and connect the inner metal mesh to the outer shell of the oil drum. Thoroughly staple about 5 staples to each of the upper and lower pads to prevent the accumulation of static electricity and the risk of ignition and explosion. It’s necessary to prevent unclean materials from falling into the oil drum to avoid affecting the operation of the compressor.


In the process of ensuring the stable operation of the air compressor system and output of high quality compressed air. It is crucial to choose the appropriate filter element. To meet this need, we recommend Btlas air compressor filters. Btlas actively delivers outstanding filtration solutions to industrial customers. Its air compressor filters use advanced materials and technology to ensure excellent filtration effects and long service life.

Reference blog :Why Air Compressor Air Oil Separators are Burned Out. Air oil separators in a Compressor.Understanding Air Compressor Air Oil Separator.

Related Posts

Leave a Reply