Vibration Analysis of Pump Discharge Lines

Cause and possible solution of the vibrations in pump discharge lines are described. A method is presented to determine the minimum natural frequency of a thin cylindrical shell (pump discharge lines) containing fluid under pressure. In determining the minimum natural frequency of the shell, many existing analyses do not include hydrostatic pressure which is a very significant factor. The method presented herein includes all such factors affecting the natural frequency of the shell. A computer program to accomplish the necessary computations is developed. In addition, using the appropriate dimensionless parameters, graphs were plotted which can be utilized to determine the natural frequency of the pipe under water pressure. This analysis was used for several major pumping plants of the California State Water Project.