What is water hammer?
Water hammer occurs when water, accelerated by steam pressure or a low-pressure void, is suddenly stopped by impact on a valve or fitting, such as bend or tee, or on a pipe surface. Water velocities can be much higher than the normal steam velocity in the pipe, especially when the water hammer is occurring at startup. When these velocities are destroyed by impact, the kinetic energy in the water is converted into pressure energy, and a pressure shock is applied to the obstruction. In mild cases, there is noise and perhaps movement of the pipe. More severe cases lead to fracture of the pipe or fittings with almost explosive effect and consequent escape of live steam at the fracture. Fracturing of pipes or steam system components can propel fragments that can cause injury or loss of life. There are two types of water hammer: a steam-flow-driven water hammer and condensate-induced water hammer. A steam-flow-driven water hammer is an impact event, where a slug of rapidly moving water strik
