Brochure

Installation Testing
Double Check Valve
In these figures, the double
check assembly is shown on
the service connection, it can
also be used for internal pro-
tection as well. The minimum
and the maximum distances
are the same as they are for
the RP device.
Dual Check
The dual check is usually
installed immediately down-
stream of the water meter in
residential installations (not
shown).
Pressure Vacuum
Breaker
The pressure vacuum breaker
cannot be installed where there
can be backpressure. It should
only be used where there may
be backsiphonage. The pres-
sure vacuum breaker can have
shutoff valves downstream of
the device. The PVB must be
installed at least 12" above the
highest outlet or, if it is feed-
ing an open tank, at least 12"
above the highest overflow rim
of the tank. The following figure
shows a typical installation on a
sprinkler system.
Atmospheric Vacuum
Breaker
Just as the pressure vacuum
breaker, the atmospheric vacu-
um breaker cannot be installed
where there can be backpres-
sure, only where there can be
backsiphonage. The atmo-
spheric vacuum breaker cannot
have any shutoff valves down-
stream of it. It also must be
installed at least 6" above the
highest outlet or the topmost
overflow rim of a nonpressure
tank. The following illustration
shows the AVB on a sprinkler
system.
All mechanical devices should
be inspected on a regular basis
to ensure they are working
correctly. Pressure vacuum
breakers, double check and
reduced pressure principle
assemblies should be tested
at time of initial installation and
annually thereafter. Acceptable
test procedures are published
by The University of Southern
California (USC), The American
Water Works Association
(AWWA), The American Society
of Sanitary Engineering (ASSE
Series 5000), and The Canadian
Standards Association (CAN/
CSA B64.10). Please consult the
regulatory authority in your area
for more specific information.
Side View
Protective
Enclosure
30" Max
12" Min
12" Min
Water Meter
Water Meter
Top View
Flow
Hose Bib
24" Min
12" Minimum Above
Highest Outlet
NOTE: Unit Cannot Have Any
Shutoff Downstream of it
Flow
6" Minimum Above
Highest Outlet
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