A sharp hammer-like blow from a steep-fronted pressure wave in water caused by the sudden stoppage of flow in a long pipe when a valve is closed sufficiently rapidly. Occurs also when a steam valve is suddenly opened to a cold pipe.

Knocking noises caused by vibration in pipes which is caused by fluctuating water pressure.

A sudden increase in pressure of water due to an instantaneous conversion of momentum to pressure.

A tremendous force produced by rapid interruption of linear flow of a non-compressible fluid. Most commonly occurs when fast acting valves are closed in a high flow liquid system.

The surging of pressure which occurs when a control valve is suddenly closed. In extreme conditions, this surging will cause the pipes to vibrate or create a pounding noise. Water hammer is most commonly caused by fast closing valves and/or high velocity water flow.

A series of water surges in piping caused by a fast closing valve. The magnitude and frequency is dependent on the velocity of flow, size, length and material of the pipe.

A shock wave or series of waves produced by the abrupt acceleration or deceleration of water flow, due to inertia. Water hammer may produce instantaneous pressures many times the normal pressure.

A banging sound in water supply lines caused by the sudden stopping of the water flow.

A occurrence caused when flowing water in a system is immediately stopped due to a valve or hydrant being closed too quickly, which sends a sudden pressure wave down the water line, shocking the pipes.

the banging sound of steam in pipes

a sudden pressure change or a slug of water like the one that can rattle your household pipes when turning off a water faucet

a shock wave created by a fast closing valve throughout the entire irrigation zone piping.

The sound like someone hammering on a pipe that occurs when a valve is opened or closed very rapidly. When a valve position is changed quickly, the water pressure in a pipe will increase and decrease back and forth very quickly. This rise and fall in pressures can do serious damage to the system.

Mechanical stress on membrane element in pressure vessel that occurs when feed flow and pressure are increased too sharply. May cause telescoping and cracking of element outer wrap.

A knocking in water pipes caused by a sudden change in pressure after a faucet or water valve shuts off.

The term used to describe the destructive forces, audible pounding and vibration which develop in a piping system when a column of non-compressible liquid flowing through a pipe line at a given pressure and velocity is abruptly stopped.

Shock waves in plumbing generally due to high velocity water being shut off quickly. This is mainly caused by undersizing of pipes and faucets or valves that are shut off fast. Sometimes installing water hammer arrestors can help alleviate or lessen water hammer. Best is to increase water pipe sizes (thereby slowing velocity).

A destructive, high-pressure surge in a water supply piping system accompanying the quick closure of valves or faucets on the system. The surge causes a shock wave which vibrates the pipes causing them to bang, knock or "hammer" against the wall or floor.

Sound of water under pressure coming to an abrupt halt within a piping system.

The shock wave or series of waves produced by the abrupt acceleration or deceleration of water flow through a pipe, caused by inertia.

A shock wave in the piping system usually created by excessive flow velocity and/or a fast closing valve.

A very rapidly moving pressure wave in a closed conduit, usually resulting from a sudden stoppage or change in the flow.

A loud banging noise caused by the hydraulic shock of suddenly shutting off a water supply, where water moves against the side of containing pipe or vessel. Not caused by the basement monster.

Energy transmitted from a sudden stoppage in the flow of water out of the pump.

The sudden spike in water pressure observed when moving water is stopped suddenly. This occurs when the kinetic energy in the moving water is converted into potential energy. Pressure spikes due to water hammer are larger when schedule 40 pipe is used as opposed to SDR ("class") pipe. This is primarily because the inside diameter of SDR pipe of a given nominal size is larger than the inside diameter of schedule 40 pipe, resulting in a lower water velocity, and therefore less kinetic energy. A secondary reason is that SDR pipe is more elastic than schedule 40 pipe (since it has a thinner wall thickness in the common sizes) and absorbs the kinetic energy, reducing the maximum pressure during the water hammer spike. Back to glossary index.

The sudden rise in pressure that occurs when a valve is closed and or power is shut and a column of moving liquid is suddenly halted.

The shock wave or series of waves caused by the resistance of inertia to an abrupt change (acceleration or deceleration) of water flow through a water piping system.

A loud noise caused by a sudden stop in the flow of water, which causes pipes to repeatedly hit up against a nearby framing member. Home Improvement Encyclopedia

A loud pressure pulse that occurs when valves close fast.

Noise, created by a water surge or rapid flow change of water, in a steam system. When a change of direction is reached, by water being carried along in air, both at the same velocity, it cannot smoothly turn the corner due to its mass. When it strikes the pipe, it makes a hammering noise.

Large, damaging shock wave in a water supply system caused by shutting a valve quickly.

The loud thump of water in a pipe when a valve or faucet is suddenly closed.

The damaging water pressure in the hoseline or pumps resulting from sudden stopping of the flow of water through fire hose or pipe; force created by the rapid deceleration of water; results from closing a valve or nozzle too quickly.

Water hammer (or, more generally, fluid hammer) is a pressure surge or wave caused by the kinetic energy of a fluid in motion when it is forced to stop or change direction suddenly. It depends on the fluid compressibility where there are sudden changes in pressure. For example, if a valve is closed suddenly at an end of a pipeline system a water hammer wave propagates in the pipe.