Water hammer can work in both directions, and I only discussed one of those in the previous video (https://youtu.be/xoLmVFAFjn4). This episode revisits that demonstration to show how water hammer can form a vacuum pressure in a pipe. Momentum carrying fluid away from a valve wants to keep going even after the valve is closed. This generates a negative pressure than can cause major damage!
Hydraulic transients (also known as water hammer) can seem innocuous in a residential setting, but these spikes in pressure can cause major damage to large pipelines and industrial pipe networks. In this video, we briefly discuss how water hammer occurs and how engineers mitigate the effect.