Comparisons between Experimental and Theoretical Results of the Waterhammer with Water Column Separations

The laboratory equipment used in association with the pumping plant of the cooling-water supply for steam electric stations was made in order to give validity to the analysis of the previous paper. In this experiment, water column separations were caused by the negative pressure surge at two positions, just after the valve and at the middle of the conduit. In this paper are shown the effects of : the time of gate closure : normal head of the pump : and normal velocity on the first or the second pressure rise due to the rejoining, and the relationship between the time of the maximum pressure rise and the normal velocity. The theoretical results on the assumption that the boundary between the vapor void and the water column is a free surface agreed well with the test results over the range in which the second pressure rise is caused.