Wear mechanism and leakage failure analysis of the mechanical seal end face of an oil transfer pump

Abstract

The John Crane 48 V mechanical seal is a long-distance oil transfer pump station shaft end seal; its sealing effect directly affects pipeline production safety. However, it has been found that there is oil leakage at the shaft end of the pump station. In order to explore the oil transfer pump mechanical seal abnormal leakage failure causes, to ensure the safety and stability of production, the end face of the 48 V mechanical seal was analyzed by white light interference and scanning electron microscope technology. The failure mechanism of the 48 V mechanical seal was explored from the perspective of the wear mechanism of moving and stationary rings. Results showed that the wear mechanism of the 48 V mechanical seal stationary ring was mainly abrasive wear, and substantial furrows, bulges, and depressions existed on the wear surface. The material removal mechanism was brittle spalling, and the roughness of the wear surface increased with the increase in wear depth and decreased with the increase in wear average width. Uneven wear occurred on the end face of the stationary ring of the mechanical seal, resulting in the leakage of the sealing medium from the end cover of the mechanical seal. The working condition could be improved by adding a spring compensation device to the stationary ring or increasing the gap between the stationary ring and the shaft sleeve.