Product Manual

Figure 4-6 Leak Survey at a Hydrant
As previously discussed, knowledge of the pipe material and pipe diameter is
important in order to know whether a thorough survey can be performed only by
listening at hydrants and valves that are 500 to 600 feet apart.
During the water leak survey, if the sounds of a possible water leak are heard at a
hydrant or valve, the LD-12 user then checks at every immediate, nearby lateral
valve, hydrant valve, and residential or commercial service line. At the valve or
other location where the leak sound is the loudest is where the final leak "pin-
pointing" usually begins.
Water Leak Pinpointing
The "pinpointed" location refers to the exact spot on the street's surface directly
above the water leak. This spot is almost always the location of the maximum
intensity or maximum loudness of the leak sounds (see Figure 4-7).
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