Definition: In general, elements or designs that prevent the unintended material transfer from one point to another are referred to as gasket. Examples include the gasket in the valve of a tire or in a shut-off faucet. In fluid handling, a distinction must be made between static and dynamic gaskets: The former do not make any movements relative to each other, while the latter move relative to each other. Static gaskets include, for example, fiber gaskets and O-rings. An example of a dynamic gasket is the mechanical seal in which a rotating shaft seals against a wall. Gaskets are used in pumps to prevent leakages. Even if absolute leakproofness is not assured, it is still referred to as a gasket, such as in the case of a throttle gap. In fluid handling, gaskets are also required outside of the pump unit, for example, for valves and piping connections.