The sounds
of leaks in pressurized water pipes can travel for hundreds
(even thousands) of feet in every direction down the mains
and services. If there is no evidence of the leak, then compare
the loudness of the leak sounds at the meters, valves, and
hydrants:
When
you have found the two meters, valves, or hydrants with
the loudest
leak sounds, you are ready to begin the final “pinpointing”.
First, mark the exact location of the pipe between the two
loudest valves, meters, hydrants, etc. with a pipe locator.
Then listen every 2-3 feet directly over the pipe.
Different
pipe materials and different pipe diameters transmit leak
sounds down their pipe walls very differently:
Iron
Pipe
6
inch
1000 — 1200
ft
Iron
Pipe
12
inch
800 — 1000
ft
Iron
Pipe
24
inch
600 — 800
ft
AC
Pipe
6
inch
800 — 1000
ft
AC
Pipe
12
inch
700 — 900
ft
AC
Pipe
24
inch
400 — 600
ft
PVC
Pipe
6
inch
400 — 600
ft
PVC
Pipe
12
inch
200 — 300
ft
PVC
Pipe
24
inch
100— 150
ft
*For
5 gal/min leak at 60 psi pressure
Water leak
surveying at meters is often performed using a long contact
rod:
Touch the tip of the rod on the brass shut off valve.
Listen
and use the meter display
to compare the loudness at different locations.
Use your
hearing and the meter display to determine exactly where
the leak sound is loudest:
For
water leak pinpointing, attach the base plate to the sensor’s
magnet and listen directly over the pipe:
Press
the
Mute Switch
only when the
base plate is
sitting firmly
on
the street.
Listen
and move the sensor every
few feet directly over the pipe.
The Long
Contact Rods are NOT digging bars or probe rods. The sensor
can be broken if the rod is pounded into the ground.
