Watson's water hammer pulse

Have you ever played with a rubber ball and bounced it really hard on the ground, and heard the "boing" sound it makes? Now imagine we have a tube that has water flowing through it like a river, and the water is moving very fast. Suddenly, we close a valve on the tube really fast, just like pressing the ball onto the ground really hard.

When we close the valve really fast, it creates a shockwave, just like the "boing" sound the ball made. This shockwave travels really fast through the water in the tube and hits the end of the tube, making a loud noise like a big clap.

The shockwave is called the water hammer pulse, because it sounds like a hammer hitting the tube. It happens because the water is moving very fast and has a lot of energy, so when we stop it suddenly, that energy has to go somewhere and it creates the shockwave.

So, we have to be careful when we manipulate the water in a tube or pipe, because if we close valves too quickly, we can create a water hammer pulse which can damage the tube and be really loud and disruptive. It's like playing with the ball, we have to be careful not to bounce it too hard or it can break something.