Water hammer, also known as steam hammer, is a violent flow transient in piping that derives its name from the loud banging that it generates.

Water hammer can affect just about any fluid system that experiences rapidly changing flows, including power-plant piping, water-supply systems, pumped storage facilities, oil pipelines and hydraulic and general fluid-handling lines.

More than a mere nuisance, water hammer can uproot anchors, permanently deform supports or overload connections to adjacent equipment. In some cases, pipes can ram the surrounding structures or equipment.

The antidotes to water hammer include well-designed restraints, slowing valve openings and eliminating entrapped air.

For more, read "Taming Water Hammer" in sister publication Machine Design.