Understanding and Preventing Water Hammer
Water hammer is not just “noise in the pipe.” It’s a pressure surge that occurs when steam and liquid water interact in ways the system wasn’t designed to handle. Steam moves fast. Condensate does not compress. When a slug of condensate sits in a pipe and steam accelerates into it, the condensate becomes a moving mass. That mass can reach high speed and then collide with an elbow, valve, reducer, or dead end. The collision sends a shockwave through the piping.
Two things make this especially destructive:
Condensate is dense and incompressible. Even a small volume carries huge kinetic energy when moving at steam velocity.
Steam systems are full of direction changes and flow restrictions. Every elbow, control valve, and tee is a potential impact point.
The characteristic symptoms—sharp hammering or banging, pipes “jumping,” vibration, and fluctuating pressure—are warnings that the system is experiencing forces far beyond normal design loads.
Continue reading to learn more about the causes, various types, how to avoid it, troubleshooting, early warning signs, and what to do if it occurs.