The leakage rate of a working mechanical seal is conditional on the design, fabrication and installation of the mechanical seal, hut most especially on the operating conditions. Main factors of influence are

• roughness and waviness of the sliding faces when new and after the running-in period
• changes in the flatness of the sliding faces due to constant or alternating deformations under the effect of pressure and temperature
• vibration characteristics of the machine to be sealed
• machine- or process-induced axial and radial displacements of the sliding faces
• mode of plant operation
• characteristics of the medium to be sealed
• type of pressurization and constructional design of the mechanical seal
• degree of conformily between the design data and the operating data