Abstract
The transient pressure in a pipe network with different sources of transient is investigated in this study. Hammer and AFT Impulse softwares were employed to accomplish the transient flow behavior analysis. The outputs from both softwares are agreed very well and they compared with the available published results for the same conditions. In a case study, the characteristics of the network components such as valve type, valve closing rate, pipe material, friction model and surge protection device, are found to be highly affecting the amount of pressure surge in the network. The results showed that using butterfly valves in such case lowered the maximum transient pressure head by 33% compared to that when gate valves are employed. Using two stage valve closing rates with short duration time of the first stage lowered the maximum pressure head by 41% relative to that for sudden closure. Using pipes with low elasticity, PVC pipes, decreases the maximum pressure by 30%, however, the minimum pressure is increased where the column separation is avoided. The studied case results confirm that using unsteady frictional model leads to less oscillated pressure compared to steady frictional model. Installation of an air chamber ata short distance from the pump discharge reduces the oscillation of pressure as that produced due to using variable speed pump when the static head of the pump is relatively low due to higher pump elevation