... , factory and mine.PrincipleYou should fill the pump with water before start, then the impeller ... and impact the useful life of the pump.Direct coupled type pump units:the chassis must remain stable, ... hydraulic discharge descend etc.),and attention the bearing heat up, the temperature can’t exceed 75°C ... ,the rotate speed is too high1,adjust2,pump shaft bended2,adjust or replace3,bearing wear ...