Water hammer in a steam system is not a minor sound annoyance. It’s a high-pressure battering ram.
When low-pressure steam travels through cold iron pipes, a portion of the vapor inevitably condenses into liquid water. If that liquid cooled water is allowed to pool in low spots or level runs, the high-speed steam rushing behind it sweeps the water into a solid, high-thickness slug.
Traveling at sixty miles per hour through a six-inch pipe, an eight-pound slug of boiling water hits the first ninety-degree elbow with the striking force of a cannonball, generating transient pressure spikes exceeding five hundred pounds of pressure.
Inside the basement of Tenement Block 12, the heavy steam header was shaking wildly.
BANG! CLANG! BANG!
With every bone-shaking shock, the iron pipe hangers groaned against the granite foundation walls, and dust showered down from the timber floor beams.
Giles stood on the damp cellar floor with his 24-inch pipe wrench resting on his shoulder, shining his brass lantern onto the shivering six-inch steam riser.
Behind his eyes, the test model screen was mapping the fluid velocities and water drops rates along the district main.
