Аннотация:In the following research mathematical model, describing pipeline flows within boiled liquid phase sections, is provided. The numerical method for calculating this model is developed. By mathematical modeling it is demonstrated, that in case of boiled liquid phase sections occurrence, ignoring them can lead to hundreds percent errors, especially considering waves travel time. This allows us to conclude, that for adequate water hammer description accounting boiling occurrence is obligatory for obtaining correct and complete characteristic of the flow.