Mismatch between hydraulic seal materials and hydraulic fluid is one of the most common hidden causes of premature hydraulic system failure. Chemical incompatibility may trigger seal swelling, hardening, cracking or volume deformation, further resulting in fluid leakage, pressure loss and unexpected equipment downtime. Proper material-fluid matching is critical to stable long-term operation.

Mineral-based hydraulic oils As the most widely-used working fluid, mineral oils show good compatibility with NBR nitrile rubber. For high-temperature working conditions, FKM fluoroelastomer delivers more reliable performance. Avoid materials prone to swelling when exposed to petroleum-base fluids.

Synthetic hydraulic oils Synthetic formulations offer superior temperature and oxidation resistance yet carry stronger chemical aggressiveness. FKM and PTFE-composite seals are preferred options. Standard NBR often fails to resist special synthetic additives, which will accelerate seal aging.

Biodegradable bio-hydraulic oils Bio-oils are environmentally friendly but have unique ester-based properties. HNBR hydrogenated nitrile rubber and specific FKM grades are recommended. Ordinary rubber materials risk hydrolysis and rapid performance degradation in bio-oil environments.

Final tip: Always verify chemical compatibility before configuration. Even well-manufactured seals will fail early if paired with incompatible hydraulic fluid. Matching seals and fluid as a complete set effectively cuts maintenance costs and maximizes your hydraulic system service life.