How does water hammer occur in a pipeline system?

Water hammer occurs when the flow of water within a pipeline system is suddenly stopped or changed in direction. This abrupt alteration in velocity creates a pressure surge or shock wave that travels through the pipe, resulting in a loud banging sound or a physical concussion against the pipe walls.1

This phenomenon is a critical concern in engineering because the resulting pressure spikes can significantly exceed the normal operating pressure of the system, potentially leading to pipe bursts, joint failures, or damage to valves and pumps. To protect infrastructure, engineers often implement surge control devices, such as pressure relief valves or surge tanks, to dissipate the energy generated by these sudden changes in flow.