To supply the town of Mbujimayi with drinking water, REGIDESO has organized its distribution network into three pressure zones: the low-pressure zone, the medium-pressure zone and the high-pressure zone. Each zone has its own topographical characteristics: the low-pressure zone is supplied by gravity, while the other 2 zones necessarily require electrical energy to power the motor-driven pumps used to convey the fluids. This gives rise to the need for shock wave protection in the event of load shedding, to protect electromechanical equipment, accessories, buildings, etc. Two methods are used to size protection tanks, one analytical and the other graphical. First, we'll use the concepts developed by Evans and Crawfort to read the abacuses, then we'll compare and verify them by plotting Louis Bergeron's lines using the characteristics of each pressure zone.