Fluid transients in pipes. Pressure surge following pump trip in rising mains and other similar discharge lines. Suppression using air vessels

ESDU 84038 gives a graphical method for estimating the maximum and minimum surge heads, following pump trip, at four points in a single pipe discharge line. Plotting these results on a blank chart provided and comparing the heads with the head profile of the pipeline assists in interpreting the results to establish regions of concern. The effects on the surge heads of altering the system parameters such as pump inertia or flow rate are readily studied. If the pipeline needs protection, data are given to enable the size of the air vessel, situated just downstream of the pump, to be selected. A practical worked example illustrates the use of the method.