Describe the phenomenon of 'water hammer' in a piping system and how to mitigate it.

Water hammer is a pressure surge or wave that occurs in a piping system when a fluid in motion is suddenly forced to stop or change direction. This sudden change in momentum creates a pressure wave that propagates through the piping system, often with considerable force. The most common cause is the rapid closure of a valve, but it can also be caused by the sudden starting or stopping of a pump. When a valve closes quickly, the fluid immediately upstre....