The performance of a gasket depends on its ability to form an effective seal for a reasonable length of time. It should not be affected by the chemical composition, or the temperature, of the gas or liquid that it contains. It should not contaminate the gas or liquid and must be easy to remove, clean and replace.
Gaskets are commonly made from cork, paper, rubber, silicon and soft, malleable metal. It is important that a gasket deforms enough to fill any imperfections in the surfaces that it is clamped between.
One common example of a gasket is the o-ring that is used to seal the gear shifting lever in a motor vehicle. Another is the oil pan gasket in the engine transmission, which seals the joint between the engine block and the oil pan to prevent leaks.
A gasket is a static, mechanical seal between matched machine parts or wrapped around pipe joints. Its purpose is to prevent the escape of gas or liquid from the joint.