Seals are simple or complex systems that keep a fluid or gas separated from another, or that maintain a fluid or gas at a different pressure than its surroundings. Surface texture plays a critical role in how well a seal will function, both when it leaves the factory and after years of service.

In this module we discuss various types of sealing systems and show how surface texture impacts their function. We show how waviness (as opposed to surface roughness) impacts sealing, and we review surface texture parameters that can be used to quantify both roughness and waviness in sealing applications. We introduce morphological filtering, a technique for analyzing how well a gasket material will conform to a mating surface. We also revisit the Bearing Ratio (or Material Ratio) curve, which was introduced earlier in this course, and show how it can be applied in the case of engine piston seals. Finally, we review a number of sealing materials and discuss their applications.

This is Module 9 of the Surface Texture and Tribology Short Course. The full course is available on udemy, or you can select the individual course modules of interest to you. Enter "surface roughness texture tribology" in the udemy search bar to browse the full course and modules.