As the important accessories of seawater pipes system, seawater pump and valve usually made of tin bronze and silicon brass were not able to meet the high reliability requirement for seawater pipes, because they were liable to serious electric coupling corrosion as they were coupled with the currently popularized B10 alloy in sea water.

Through the diagnosis of breakdown of the seawater pump on the FPS in south China sea, the damnification process of corrupt fatigue and selectivity electrochemistry corrupting are analyzed for GG25 material in flowing sea water.

This paper analyzed the motion track of the wobble-plate mechanism in detail and derived its motion equations, and applied them to the design of the high-power seawater pumps according to the motion characteristics of the mechanism.

Properties of seawater and different corrosions in seawater pump are introduced, its features and protection countermeasures are described, quantitative values of corrosion problems are acquired by border factor numerical value analytics.

The initial cavitation of sea water pump was tested.

The causes of the damage and failure of the impellers of sea water pumps of 316 stainless steel were analyzed,some methods of extending the service life of the impellers were discussed.

The impeller vane of sea water pump was fractured just after two months.