Seal Compatibility Decision Tree (Interactive PDF)

Seal compatibility is critical in multi-function gearboxes—such as those used in wind turbines, mobile hydraulics, or aerospace actuators—where a single gearbox may host multiple lubrication zones (e.g., gear oil, servo fluid, grease) operating under divergent thermal, pressure, and chemical conditions. Incompatibility between seal elastomers (e.g., NBR, FKM, HNBR, EPDM) and lubricants (mineral oils, PAOs, esters, polyglycols) can lead to accelerated aging, loss of sealing force, leakage, or catastrophic system contamination. The decision tree codifies empirical and standardized test data into a hierarchical diagnostic workflow: users begin by selecting seal material type, then input lubricant chemistry class, maximum continuous operating temperature, exposure duration, and dynamic vs. static service mode. Each node applies pass/fail thresholds derived from immersion testing (volume change ≤ ±15%, hardness change ≤ ±10 IRHD, tensile strength retention ≥ 70%) and real-world field validation. The interactive PDF enhances usability through embedded tooltips referencing ASTM/ISO test methods, hyperlinked material datasheets, and auto-generated compliance reports—enabling traceable, auditable decisions without requiring offline databases or specialist software. This approach bridges the gap between generic material compatibility charts and application-specific engineering judgment, significantly reducing trial-and-error during design, retrofit, or lubricant changeover.