A beta value of 200 means the filter element maintains a stable particle removal efficiency of 99.5% for particles of the corresponding size. Though the basic filtration efficiency is identical, filters with different micron ratings differ greatly in practical performance and applicable scenarios.
First, they vary in particle interception range. A 5 μm filter effectively traps solid particles of 5 μm and larger. It provides comprehensive protection for precision hydraulic components such as servo valves and proportional valves, and keeps fluid cleanliness steadily at NAS Class 5-6, making it the mainstream option for high-precision hydraulic systems. A 10 μm filter mainly captures particles above 10 μm and is less effective against fine contaminants. It is more suitable for ordinary piston pumps and standard valve assemblies, maintaining fluid cleanliness at NAS Class 7-8 to meet the demands of most industrial equipment. A 20 μm filter only works on large particles and allows fine contaminants to pass through. It is mostly used in return lines and low-pressure circuits for gear pump systems with low cleanliness requirements.
Second, they differ in flow resistance and differential pressure. Higher filtration accuracy means denser fiber arrangement of the filter media and greater flow resistance. Under the same working conditions, the 5 μm filter has a higher initial differential pressure. Its differential pressure rises rapidly as contaminants accumulate, leading to a shorter replacement cycle. In contrast, the 20 μm filter features larger pores, superior flow capacity and a slowly increasing differential pressure, thus enjoying a longer service life.
Besides, their dirt holding capacities are different. Low-accuracy filters have larger overall space to hold more contaminants. When selecting filters, do not merely refer to the beta value. Choose fine micron ratings for precision circuits and medium accuracy for regular oil lines to balance filtration performance and operating costs, and avoid extra energy consumption and frequent replacements caused by overfine filters.
