Which component is designed to prevent leakage in a dynamic seal?

The correct choice identifies packings as the component designed to prevent leakage in a dynamic seal. Packings are specifically used in rotating or reciprocating applications, serving to create a tight seal around a moving element such as a shaft or piston. They are typically made of materials that can withstand wear and temperature changes while maintaining their sealing properties against fluids or gases.

Dynamic seals, which are essential for machines that involve moving parts, require materials that can not only compress to fill the space between two surfaces but also allow for movement without losing effectiveness. Packings achieve this by often being made from soft materials like rubber, or by using braided fibers that can conform to the shaft or casing, ensuring a continuous barrier against leaks.

While gaskets, seals, and felts do provide sealing functions, they serve different contexts and applications. Gaskets are mainly used for static applications, providing a seal between two flat surfaces, while seals can refer to various static and dynamic sealing mechanisms, depending on use cases. Felts, although they can absorb some fluids, are generally not employed as sealing components in mechanical design. This specificity in the application makes packings the most suitable option for preventing leakage in dynamic sealing situations.