The oil content of compressed air is not only related to the oil core, but also related to the design of the oil distribution tank, the load of the air compressor, the type of oil temperature and lubricating oil. The oil content of the air compressor is related to the design of the oil distribution tank, and the air flow of the air compressor needs to match the processing capacity of the oil distribution core. Under normal circumstances, the air compressor selection matching oil core must be greater than or equal to the air compressor output flow. Different end users require different final pressure differences.

In actual use, the final pressure difference of the oil core used by the air compressor is 0.6-1bar, and the dirt gathered on the oil core will increase at a higher oil flow rate, which can be measured by the amount of pollution. Therefore, the service life of the oil core can not be measured by time, only the final pressure difference of the oil core is used to determine the life. Air inlet filtration can extend the service life of downstream filter components (i.e. lubricating oil filter and oil and gas separation core). Impurities in dust and other particles are the main factors limiting the service life of lubricating oil filters and oil and gas separation cores. The oil core is limited by solid particles on the surface (oxide of the oil, worn particles, etc.), which ultimately leads to an increase in pressure differential. The selection of oil has an impact on the service time of the oil core, and only those lubricants that are tested, antioxidant and water-insensitive can be used.

In the oil-gas mixture formed by compressed air and lubricating oil, the lubricating oil exists in two forms: gas phase and liquid phase. The oil in the gas phase is produced by the evaporation of the oil in the liquid phase, and the amount depends on the temperature and pressure of the oil and gas mixture, but also related to the saturated vapor pressure of the oil. The higher the temperature and pressure of the oil and gas mixture, the more oil in the gas phase. Obviously, the most effective way to reduce the oil content of compressed air is to reduce the exhaust temperature. However, in the oil injection screw air compressor, the exhaust temperature is not allowed to be low to the extent that water vapor will be condensed, another way to reduce the content of gaseous oil is to use lubricating oil with low saturated vapor pressure, synthetic oil and semi-synthetic oil often have quite low saturated vapor pressure and high surface tension. The low load of the air compressor sometimes causes the oil temperature to be lower than 80 ° C, the compressed air water content will be relatively high, and too much water on the oil core filter material will make the filter material expand and shrink, reducing the effective separation area of the oil core, resulting in increased resistance of the oil core and advanced blockage.