Why is Hydraulic Oil Cleanliness Important?
Posted by Hamid Shakouri on 3rd Sep 2024
Ensuring an optimal level of cleanliness is crucial for the successful operation of hydraulic systems in any hydraulic equipment. Contamination in hydraulic fluid stands out as the most critical factor affecting the system's reliability, with approximately 50 to 70% of all hydraulic system failures attributed to contamination issues.
The ISO Cleanliness Code, ISO 4406:1987, stands out as one of the most widely utilized international standards for indicating the particle contamination level in industrial fluid power systems. Under ISO 4406, cleanliness is denoted by a two-number code, such as 16/13. This code is determined based on the quantity of particles exceeding 5 µm and 15 µm, respectively, in a known volume of fluid. Some manufacturers have extended the code to three numbers by incorporating a code indicating the number of particles greater than 2 µm, for example, 18/16/13.
Utilizing the ISO particle count table, an oil with a cleanliness rating of 18/16/13 would imply the presence of:
1300 to 2500 particles larger than 2 microns
320 to 640 particles larger than 5 microns
40 to 80 particles larger than 15 microns
