BS ISO 4406:2021 PDF Download

BS ISO 4406:2021 is a standard that describes a method for coding the level of contamination by solid particles in fluids used in hydraulic fluid power systems. The standard provides a code that defines the quantity of solid particles present in the fluid in the form of a three-part number. The first number indicates the number of particles with a size equal to or greater than 4 microns, the second number represents the number of particles with a size equal to or greater than 6 microns, and the third number indicates the number of particles with a size equal to or greater than 14 microns.

The standard is useful in helping engineers and maintenance personnel to monitor the level of contamination in hydraulic fluid power systems and assess the level of cleanliness of the fluid used in these systems. Furthermore, the standard provides a uniform coding system that is widely recognized, making it easier to implement and communicate the level of contamination in hydraulic fluid power systems across different industries and countries.