Installation Guide

 Installation  Testing  Maintenance Instructions
INSTALLATION INSTRUCTIONS
CAUTION: Installation of Backow Preventers must be performed by qualied, licensed
personnel. The installer should be sure the proper device has been selected for the
particular installation. Faulty installation could result in an improperly functioning device.
ZURN WILKINS Model 475 Series Reduced Pressure Principle assemblies are for use
on potable water lines where a health hazard exists in the event of a backow situation.
Damage to the device could result wherever water hammer and/or water thermal expan-
sion could create excessive line pressure. Where this could occur, shock arrestors, check
valves and/or pressure relief valves should be installed downstream of the device.
If installation is in a pit or vault, the Backow Preventer must never be submerged in
water because this could cause a cross-connection. Make sure that the pit or vault always
remains dry by providing ample drainage. (Consult local codes.)
1. Before installing a Model 475 Series Backow Preventer, ush the line thoroughly
to remove all debris, chips and other foreign matter. If required, a strainer
should be placed upstream of the Backow Preventer. CAUTION: Do not use a
strainer in seldom used emergency waterlines such as re lines.
2. Provide adequate space around the installed unit so that the test cocks will be
accessible for testing and servicing.
3. Install valve at least 6 inches above surrounding ood level.
4. Always consult local codes for installation methods, approvals and guidance.
INDOOR INSTALLATION
Indoor installation is preferred in areas that
are subject to freezing conditions. All the
basic installation instructions apply to such
installations. CAUTION: An adequately
sized drain is required to prevent pos-
sible water damage due to relief valve
discharge.
OUTDOOR INSTALLATION
The Model 475 Series Backow Preventer
may be installed outdoors only if the device
is protected against freezing conditions.
Exposure to freezing conditions will result
in improper function or damage to the
device. The installation location must be
kept above 32°F. All the basic installation
instructions apply.
PLACING THE MODEL 475 IN SERVICE
1. Start with both shut-off valves closed.
Slowly open the inlet shut-off valve until the
Backow Preventer is completely pressu-
rized. A brief discharge from the relief valve
may occur while the device is pressurizing.
The discharge should cease by the time the
shut-off valve is fully open. If the discharge
does not stop, refer to "MAINTENANCE
INSTRUCTIONS" for repair procedures.
2. After the device has been pressurized,
vent all trapped air by slightly opening each
of the four test cocks.
3. Slowly open the downstream shut-off
valve. The Model 475 Series Reduced
Pressure Principle Backow Preventer is
now in service.
4. If spitting or intermittent discharges
from the relief valve are noted, it could be
a result of pressure uctuation and/or a
water hammer condition in the system. If
such conditions exist, install water pressure
reducing valves or water hammer shock
arrestors in compliance with industry
standards as needed.
5. After the Model 475 has been pro-
perly installed, test the device (see "TEST
PROCEDURES"). If the device fails the
test, remove the rst and second check
valves and thoroughly ush the device. If
the relief valve fails to operate properly,
inspect the sensing passage for clogging
(see "MAINTENANCE INSTRUCTIONS").
Clean rubber seals of all debris and place
unit back in service.
(Patent No. 5,913,331
)
Model 475, 475V, 475DA & 475DAV
Reduced Pressure Principle Assembly (Size, 4" & 6")
Reduced Pressure Detector Assembly (Size, 4" & 6")
6" MIN.
ZURN WILKINS VALVE
SETTER
DIRECTION OF FLOW
PROTECTIVE
ENCLOSURE
A1
AIR GAP
DIRECTION OF FLOW
DRAIN
AIR
GAP
TYPICAL HORIZONTAL ORIENTATION
TYPICAL VERTICAL ORIENTATION
VERTICAL INSTALLATION
Vertical Installation is acceptable in applica-
tions where inlet and outlet piping are ow-
ing vertically upwards. All the basic installa-
tion instructions apply to such installations.
Consult factory for approval status.
®
*This product contains a weighted average lead content less than 0.25% for wetted surfaces.
LEAD-FREE*
WARNING: This product contains a chemical known to the State of California to cause cancer, birth defects and other reproductive harm
ADVERTENCIA: Este producto contiene una sustancia química que el Estado de California como causante de cáncer, defectos de nacimiento
y otros daños reproductivos