Working Principle of a Mechanical Seal

The working principle of a mechanical seal lies in its unique sealing device design. It consists of two mating sealing surfaces, which are flat and perpendicular to the axis of rotation and rotate relative to each other. A resilient element, such as a spring or bellows, and the pressure of the sealing medium work together to generate an appropriate compressive force, keeping the contact ends of the rotating ring (rotating with the shaft) and the stationary ring (non-rotating) in close contact. In this tight fit, only a very thin film of liquid remains between the end faces, achieving an efficient seal.