The efficiency of your operation, longevity of your hydraulic systems and life of hydraulic oil often hinge on one simple factor – oil cleanliness. Contaminants in hydraulic systems can have disastrous effects, leading to increased wear on pumps, causing valves to stick and causing equipment failure and expensive downtime. Dirty oil may also hamper the efficiency of the system, reducing its overall performance and productivity. Clean hydraulic oil is crucial for your equipment, optimizing its lifespan and reducing maintenance costs.
Clean hydraulic oil benefits:
- Improved performance – Reduces friction, runs cooler, and provides efficiency.
- Reduced wear – Fewer wear-causing contaminants that damage your equipment.
- Less downtime – Reduces valve sticking and wear that cause system failures.
- Lower maintenance costs – Extends component and oil service life for fewer repairs.
Maintaining the cleanliness of hydraulic oil is critical for optimal performance and prolonging the life of your hydraulic equipment. Cleanliness is measured using the ISO 4406 standard, where each three-digit ISO code represents a range of particles of different sizes in the oil. For example, an ISO code of 16/14/11 indicates:
- ISO code 16 means 1ml of oil contains 321 to 640 particles 4 microns or larger.
- ISO code 14 means 1ml oil contains 81 to 160 particles 6 microns or larger.
- ISO code 11 means 1ml oil contains 11 to 20 particles 14 microns or larger.
The maximum number of particles doubles for every single digit increase in ISO code. For example, an ISO code of 17/15/12 indicates an effective doubling of particles from ISO code 16/14/11. This effect compounds, so dirty oil with an ISO code of 21/19/16 has up to 32 times the maximum particle counts of ISO code 16/14/11.
Different types of pumps (gear, piston, vane) and control valves (directional, proportional, servo) have specific oil cleanliness requirements. Hydraulic pump cleanliness requirements are shown in the chart below.