In high-temperature environments, specialtygreases may experience flow issues or coking, potentially affecting equipmentperformance. This article explores the common problems of grease under highheat and provides effective solutions.
Why Does Grease Flow at HighTemperatures?
Low Dropping Point – When the operating temperature exceeds the grease’s dropping point, it melts and starts to leak.
Poor Mechanical Stability – Some greases cannot retain their original consistency after repeated shear stress, making them thinner and more prone to flowing.
Weak Colloidal Stability – Oxidation or shear stress may cause base oil separation, reducing lubrication efficiency.
Causes of Grease Coking Under HighTemperatures
Base Oil Oxidation – The lighter components of the base oil evaporate quickly under high temperatures, while the heavier components undergo oxidation, carbonization, and shrink into coke under high pressure and catalytic effects of metals.
Poor Sealing or Prolonged Use – External dust and contaminants mix with grease, forming hard oxidation layers or abrasive particles under heat and pressure.
Thickener and Base Oil Interaction – When the light fractions evaporate, the heavier components combine with inorganic thickeners or solid additives, causing hardening.
How to Prevent Grease Flow and Coking atHigh Temperatures?
Choose the Right Grease – The dropping point should be at least 30°C higher than the operating temperature, with excellent mechanical and colloidal stability.
Use Synthetic Base Oils – Opting for synthetic-based greases improves high-temperature resistance.
Regular Lubrication Maintenance – Implement a scientific lubrication plan with periodic replenishment or replacement to ensure optimal system performance.
Conclusion:By selecting the appropriate grease type and following proper maintenancepractices, you can significantly enhance equipment reliability and lifespan inhigh-temperature environments.
