How to filter hydraulic oil for reuse？

Filtering hydraulic oil for reuse involves removing contaminants such as dirt, water, and wear particles to restore the oil's quality. Here are some steps and techniques to filter hydraulic oil effectively:

 1. Oil Analysis

   - Before starting, conduct an oil analysis to determine the level of contamination. This helps to understand the type and amount of contaminants present and decide on the appropriate filtration method.

 2. Pre-Filtration (Coarse Filtration)

   - Use a coarse filter to remove larger particles and debris. This step typically involves filters with a higher micron rating (e.g., 25-40 microns). A suction strainer can also be used before the pump to capture large contaminants.

 3. Fine Filtration

   - For finer particles, use high-efficiency filters with a micron rating of 3-10 microns. These filters help remove smaller particles that can cause damage to the hydraulic system. Inline or offline filtration units can be used depending on the system setup.

 4. Water Removal

   - Water contamination can be addressed using techniques like vacuum dehydration, which applies heat and vacuum to evaporate the water from the oil, or centrifugal separation, which uses high-speed rotation to separate water from the oil based on density differences.

 5. Oil De-aeration

   - To remove air and gases dissolved in the hydraulic oil, use a vacuum degassing unit. This process improves the oil’s ability to lubricate and prevents cavitation.

 6. Use of Portable Filtration Units

   - Portable oil filtration carts or trolleys can be used to filter oil in multiple hydraulic systems. These units are typically equipped with a combination of coarse and fine filters, water separators, and sometimes vacuum dehydration capabilities.

 7. Filter Maintenance and Monitoring

   - Regularly monitor the condition of the filters used in the system. ｒｅｐｌａｃｅ or clean filters as needed, based on pressure ｄｒｏｐ indicators or scheduled maintenance intervals.

 8. Re-testing the Oil

   - After filtration, conduct another oil analysis to ensure the oil meets cleanliness standards for reuse. The recommended cleanliness levels are often based on ISO cleanliness codes, specific to the equipment being serviced.

Following these steps can help maintain oil quality and extend the life of both the hydraulic oil and the hydraulic system components.