In this seal configuration, the liquid to be contained is inside the sealing surfaces. The stationary ring must be axially locked to prevent misalignment caused by the hydraulic thrust of the liquid on it.
The rotating part of the seal is designed to limit components in contact with the process.
When it is used:
The external seal is used in applications where internal installation is difficult or when it is crucial to limit contact between the process and the mechanical seal materials themselves. Some examples of use are:
- Chemically aggressive fluids
- Top entry agitators
- Industrial fans
- Positive displacement pumps for food or sanitary applications, where the external seal is suitable for periodic washing and meets the requirements of regulations related to the Food & Pharma markets: FDA, EHEDG