In drilling motors, Downhole Seal Stacks like Kalsi rotary designs use hydrodynamic lips for lubricant retention amid 500 RPM and abrasives. Wavy edges trap oil, excluding mud at 10,000 PSI. Patented for mud motors, they cut shaft wear by 70%. HNBR jackets enhance RGD safety. Permian deployments extend run times to 300 hours. https://globalsealstech.com/media/