How to Collapse a Pipe by Closing a Valve

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!