Formation reason: the equipment itself coupling axial, radial deviation. Pump flange bolt is too large and uneven force. The natural vibration frequency of the pump and pipeline is close to the resonance.

改进措施：调整联轴器的轴向、径向偏差。调整水泵与管道间的固有振动频率，加装相关软接部件。更换法兰并使地脚螺栓受力均匀。

Improvement measures: adjusting the axial and radial deviation of the coupling. Adjust the natural vibration frequency between the pump and the pipe, and install the related soft parts. Replace the flange and bolt the uniform stress.