May 16th, 2011
Municipalities across the country are getting into the exercise movement to ensure the health of their water valves. That’s right -- water valves. These hidden, but important, devices lie beneath the city streets and their health is important to our overall security in stopping the potential of contaminants from entering the water supply.
In many cases these water valves have been neglected, but a Homeland Security directive as a result of the 9/11 attacks has raised the importance of these often unnoticed valves. They need to be in top working order should a municipality need to shut off water valves quickly to contain contaminated water flow and prevent it from spreading throughout a community.
Because of this concern, cities must have the ability to reach the valves quickly to shut the water flow off. However, some of these valves may not have been paid much attention for years and thus the water valve boxes may be filled with compacted sediment, making them hard to reach, and taking several hours to clean by hand.
First, some background about water valve boxes. A water valve box is an eight-inch diameter tube that stretches from the ground surface down to an underground valve, which can be eight-feet below the surface, depending on the freeze line. When it rains, water and sediment flow into the box and over time the sediment becomes compacted. In the event of a water main break or contaminated water, a sediment filled valve box slows down the process of reaching and closing the valve.
Valve exercising is a maintenance activity. So a valve exercising equipment that turns fast is ideal, but it should not exert too much torque. Excessive torque can damage a valve leading to an unexpected repair. If the valve will not open or close, then it likely needs to be replaced and putting too much torque on the valve could lead to additional repair issues that need to be resolved immediately versus scheduling the repair.
For example, a six-inch valve may require 19 rotations to open and 19 to close. If fewer rotations are taken to open and close the valve, then the city may not be receiving all of their water flow and valves need to be exercised further to break up sediment inside until they reach their full rotation.
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