Page 99 - Microsoft Word -Cow Book 10-06-09 final update.doc

BACK SIPHONAGE PROTECTION DEVICES

TYPE & DESCRIPTION APPLICATION EXAMPLES
PURPOSE

Atmospheric Single float and Cross connections not Properly designed faucets
or other non pressure
subject to backpressure or
Type Vacuum disc with large continuous pressure. applications. (must be
atmospheric port
fixture rim.
Breaker Install at least 6" above installed downstream from
last shut-off valve)

Hose Single check with Installed directly on hose Hose bibbs over wash
vats, hose bibbs on wall or
bibbs, utensil sinks and
Connection atmospheric wall faucets. Not for outside of buildings,
hydrants
continuous pressure.
vacuum breaker
Vacuum vent
Breakers

Pressure Type Spring loaded Designed for installation in Livestock water systems,
a continuous pressure
lawn sprinklers, chemical
Vacuum single float and line. To be installed 12" tanks, cooling towers
disc with
Breakers independent 1st above the highest line and
point of use downstream
check. Supplied from the device and point
of usage. Protection
with shut-off valves against back siphonage
only
and ball type test
cocks

Specialty Type Two independent For use in low hazard Dairy equipment,
cross connections in small
residential use, any low
Back Flow check valves with pipes under continuous hazard cross connection
with continuous pressure
pressure.
intermediate
Preventer vacuum breaker
and relief valve

Reduced Two independent For use on continuous Processing tanks, cooling
pressure situations
towers, sewerage
Pressure Zone check valves with subject to back pressure treatment, boilers, toxic
chemical applications.
intermediate relief
Back Flow valve. Supplied or
back-siphonage where a
Preventer with shut-off valves high potential health
hazard exists.
and ball type test
cocks.

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