St. Nicholas/Volume 40/Number 5/Nature and Science/Valve

A water-valve nine feet in diameter

This nine-foot valve is one of five built for the Ontario Power Company of Niagara Falls, Canada. They are used to control hydraulic turbines generating 12,000 horse-power each. The valves are operated by a fifteen-horse-power electric motor, arranged to be controlled from a distant station. The diameter of the waterway is nine feet. In each of these giant valves there are 4000 pounds of bronze, 18,000 pounds of steel plug, and 110,000 pounds of cast-iron. The motor operates the gears, which raise the two bronze spindles that pull the plug or gate up into the top of the valve, called the “cap” or “bonnet.”
A valve larger than an automobile.

The small, sixteen-inch valve on the side of the large valve is what we call a by-pass valve, and which, when opened, relieves the pressure, so that the large gate can be opened more easily.

The opening of these great valves is so large that, if a floor were laid inside it, a forty-horse- power automobile could run into or through it.