Small bore polymer tubing easily absorbs movement, but many conventional piping systems in steel or other rigid materials are still widely used for fluid transport. Yet they too need a way of sealing the system reliably in the face of vibration, especially where they join dissimilar materials. The answer is to close the system with a flexible polymer, and seals are of great importance in all engines and machines with moving parts (1). Sealants serve a similar purpose where gaps in a building, for example, must be closed against ingress of rainwater.
Seals have been critical parts of engines ever since the invention of the steam engine by Savery, Newcomen and Watt in the early part of the Industrial Revolution, ...