Water Hammer, Pipe Shock, Fast Surge Deceleration
Water hammer, Shock, and pipeline surge prevention equipment; For more information please make use of our RFQ form. Select a country to send your information to via email: United Kingdom, USA, Germany.
Water hammer is the repeated reflection of a pressure wave in a liquid. The most common of liquids being water, the hammering sound is most often heard in water systems, and hence the name.
Typically, in a hard walled pipe the pressure wave of water hammer travels to reflection point and back at a velocity in the order of 1440 meters per second. That is similar to saying that if you change the pressure at the end of a pipe, it can be read one mile away one second later. Therefore the rapidity of the hammering sound is dependent on the length of the pipe.
Also, the frequency depends on the effective hardness of the system. Therefore the waterhammer frequency will be lower if the pipe is for example soft plastic. Frequencies in hot liquid systems are lower because hot liquids are more compressible, so the frequency is lower.
The time that it take for water hammer to die away, depends how much pressure energy is lost by pressure drop against the pipe wall. Whilst it is generally believed that the larger the pipe the better, that is for preventing the generation of the initial shock wave, once a shock wave does occur, the occurance will last longer because a large pipe dissipates very little of the pressure of the wave.
A 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 caused to stop or change direction suddenly. The movement of liquid mass in a pipe is kinetic energy, which is proportional to the mass of liquid times the square of the velocity . For this reason, most pipe sizing charts recommend keeping the flow velocity at or below 5 ft/s (1.5 m/s).
Water hammer is a sudden increase in the pressure of a liquid due to an instantaneous conversion of momentum to pressure. This is caused by a very rapidly moving pressure wave in a closed conduit, usually resulting from a sudden stoppage or change in the mass velocity.
Water-hammer can be a tapping sound in a water pipe which may occur when a tap is suddenly closed, causing the water column to vibrate. The noise and vibration experienced by piping systems as a result of rapid deceleration of liquid flow - Such as that introduced by a the fast closing action of a solenoid valve. The most common occurrence of this is the water inlet solenoid valve of a washing machine.
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. This is most commonly caused by fast closing valves and/or high velocity water flow.
A "hammering" noise, created by a liquid surge or rapid flow change of the liquid water, or in a steam system due to the sudden collapse, or phase change from steam to water. 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.
Surge and Shock Absorbers / Absorber