Abstract: The seawater lift pump equipped by the Offshore Oil FPSO is a large-flow single-stage centrifugal pump,and its main function is to provide cooling seawater and fire-fighting water for offshore oil facilities. Due to the large amount of impurities in seawater and the strong electrochemical corrosion of seawater to metals,the mechanical seal of the seawater lift pump frequently leaks,and the seawater enters the bearing chamber along the direction of the pump shaft,causing the bearing to be damaged. This paper takes the transformation of the seawater lift pump as the background,and conducts research by changing the mechanical seal form,redesigning and installing the bearing water retaining plate,etc.,and finally optimizes the maintenance procedure,increases the bearing service life,and improves the reliability of the whole pump.

Key words: seawater lift pump, mechanical seal, bearing, reliability