Cavitation

The video below captures the phenomenon of cavitation following the rapid closure of an upstream valve. The footage was recorded at 250fps, with playback at 30fps.

Damping effect of leaks on Transients

The following two videos show the damping effect of leaks on transients. In the first the leak point is not attached and the transients propagates around the system for a significant amount of times (seen by the number of oscillations before decay). In the second video the leak is present and the wave is damped quickly, the water intruded into the pipe can also be seen in the measuring cylinder.