In this work, a water hammer problem was investigated. First, the theoretical assumptions and definitions of important items of the water hammer are given and an example of an analytical model is presented. Then the measurement was done in the laboratory and a physical model was made. Finally, based on the physical model, a hydraulic model was created in ALLIEVI, where stationary and transitional states were calculated. The analytical calculation of the pressure increase was based on the Žukovsky water hammer, while the pressure increase in the physical model was measured on the pressure gauges mounted on the air chamber and valve. Observations were made visually so that slight discrepancies in the results were possible. The modeling in ALLIEVI was based on the method of characteristics and it was necessary to calibrate the given hydraulic model. The length and diameter of the pipe, the roughness and the material were adjusted. The supply pipe to the air kettle is made of steel, while the other PE pipes. The results of all three methods were compared and the pressure (flow rate) increased. The highest pressure increase was observed for case 1 when the initial state on the valve was 1.1 bar, while for cases 2 and 3, where the initial state was 2 and 3 bars, the pressure increase was lower.