Design Charts for Air Chamber on Pump Pipe Lines

A set of comprehensive design charts for sizing air chambers used in hydraulic systems for the purpose of surge protection is presented. The analysis considers friction loss distributed along the pipeline as well as head loss at the chamber orifice. The maximum and minimum pressure during the transients at any location along the pipeline can be computed from the charts. The fact that the maximum downsurge pressure inside the chamber is less than that outside the chamber (due to orifice loss) is also considered. In addition, the charts can be used to determine the magnitude of the maximum flow into the chamber and its time of occurence as well as the time of maximum and minimum pressure at the pump. The time to restart the pump after power failure can also be determined from the charts. A numerical example is presented to demonstrate the application of the charts.