Water Hammer

Water hammer (also known as fluid hammer, hydraulic shock, or surge) is a pressure surge or shock wave that occurs in a piping system when a fluid (usually liquid, most commonly water) in motion is suddenly forced to stop or change direction rapidly.

This sudden change creates a high-pressure wave that travels back and forth through the pipe at the speed of sound in the fluid, often producing loud banging noises (like a hammer hitting the pipe) and potentially causing serious damage.