1. In the operation of the equipment in the process of personal failure or sudden rupture of a part of the unit.
2. Centrifugal pump body or bearing a high fever of more than the maximum limit.
3. Motor running current, voltage suddenly increased or decreased more than the specified limits, or equipment on fire, the motor has burnt smell, etc..
4. Pump vaporization heat or violent vibration.
5. The pump has a serious friction and impact sound, or moving more than 2~3mm.
6. With the operation of the centrifugal pump is associated with the process of pipeline and container rupture, etc.. .