What is commonly used to provide a seal between two pieces of mechanical equipment?

In mechanical engineering, a seal is crucial for preventing leaks and ensuring the efficiency and longevity of equipment. Packing is typically used in applications where a dynamic or static sealing is required between two surfaces, often where there is movement or vibration. This material fills the space between the equipment components, compressing under pressure to create a tight seal that can effectively handle various fluids or gases while minimizing leakage.

Packing's versatility makes it suitable for a variety of applications, including pumps, valves, and rotating shafts. It can be made from materials such as graphite, PTFE, or fiber, allowing it to withstand different temperatures, pressures, and chemical environments, which is essential for effective sealing.

In contrast, O-rings and sealing washers serve specific purposes and may not be as universally applicable in all mechanical contexts. O-rings are typically used in static applications or situations with minimal movement, while sealing washers are often designed for use in flanged connections or as a backup to other sealing methods. Silicone sealant is generally for more general-purpose sealing in non-pressured situations, often in construction or assembly rather than mechanical equipment interfaces.