nas 1683and iso4406[一]清洁度标准.pdfVIP

GreenOil Standard Technical Paper 004 Particle Contamination ISO4406 and NAS1638 Date: 15-12-2005 Saved as: Technical Paper 004 Page 1 af 3 Working with ISO4406 and NAS 1638 Particle contamination in oil is specified from particle count. Many factors influence lifetime and demands to fluid quality. Two basic standards the ISO and NAS systems are com- High reliability systems enhance demands to quality, and monly used as contamination reference. The two cleanliness high pressure systems and heavy bearing load increase de- standards can not be directly compared or converted, as the mands. basic principles within the two systems differ to much. This The last three columns of the tables indicate the range of the is explained in the next pages. GreenOil filter system. Although the filters may be put into However, the following tables gives some rough guidelines service in many application, parameters as fluid volume and of common practice for setting targets of cleanliness levels in viscosity should be taken into consideration before expecta- different systems. As seen both ISO 4406 and NAS 1638 are tions to contamination limits are set. represented. These guidelines are minimum fluid cleanliness levels required for an acceptable lifetime of equipment and components. Hydraulic Equipment and Components Minimum GreenOil Pressure Range Class Requirement Filter Inserts