cause system damage relative to the size of the orifice or clearance of system components such as between a piston and cylinder wall, or filter porosity. The usual system clearances available in hydraulic systems show the importance of maintaining hydraulic cleanliness Visualize these clearances consider the size of some common objects: •Yeast Cell- 1 Micron •Red Blood Cell- 6 Microns • White Blood Cell- 24 Microns • Human Hair- 70 Microns • Grain of Table Salt - 100 Microns
August 2016
How Do Contaminants Get Into Hydraulic Systems? There are many ways contaminants can get into hydraulic systems. During assembly, operation, maintenance and repairs. During assembly the contaminants can come from a number of sources including hydraulic reservoir, valves, pumps, hoses, tubes and hydraulic oil. System components need to be cleaned before installation into a hydraulic system. Components can have material left over from the manufacturing process that can contaminate the hydraulic oil. For components such as hoses
assemblies, the contamination gains access to the inside of the hose while cutting it to length with a saw or skiving the hose before assembly. These processes generate clouds of dust particles that can flow into the open ends of the hose. Once cleaned the components need have any opening capped or plugged to prevent contamination during storage. New oil should be filtered before adding it in to a hydraulic system. New hydraulic oil cleanliness can vary from container to container, so it is best to use a filter during the fill process to prevent contamination. Minimizing Contamination And
Its Harmful Effects To minimize contamination and reduce the harmful effects it can have on a system, there are some steps to follow. Have an understanding of your hydraulic system and cleanliness requirements. By understanding the cleanliness requirements of the system you can set a target level to maximize system life. To select a target cleanliness level, review the system components for the most sensitive to contamination. Most hydraulic component manufactures have guidelines to flow when it comes to hydraulic oil cleanliness. This may even affect the warranty coverage from the manufacturer.
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