The bearings of centrifugal pumps should be replaced when they have the following defects:
1. There are scratches and cracks on the inner and outer ring raceways of the bearing;
2. The ball holder is damaged, and there are marks on the balls;
3. There is excessive looseness of the ball, and the noise is large when rotating;
4. The surface of the bearing inner and outer rings is worn;
Impellers with the following defects should be replaced:
1. There is a crack on the impeller;
2. Due to cavitation and other reasons, many holes are formed on the surface of the impeller, which cannot be repaired;
3. The impeller wall is thinned due to long-term liquid erosion and its mechanical strength is affected;
4. The impeller cover and blade are defective;
5. Excessive wear at the entrance of the impeller or serious unilateral wear;