A seal is a component that impedes the flow of fluid through a given system. The word "impede" holds emphasis as there is no such thing as a zero leakage seal. All dynamic seals must leak, even if it is as low as 1 mm^3 per year and referred to as "emission".
This is a publication from the International Aircraft Cabin Air Conference 2021 (Online, 15-18 March 2021)
