Install Instructions

Model 350, 350A, 350DA & 350ADA
Double Check Valve Assembly (2-1/2", 3", 4" & 6")
Model 450
Double Check Valve Assembly (2-1/2" & 3")
 Installation  Testing  Maintenance Instructions
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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 par-
ticular installation. Faulty installation could result in an improperly functioning device.
WILKINS Model 350/450 Series Assemblies are for use on potable water lines where a
health hazard does not exist 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.
1. Before installing a Model 350/450 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 12 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.
OUTDOOR INSTALLATION
The Model 350/450 Series Backow Pre-
venter may be installed outdoors only if the
device is protected against freezing condi-
tions. 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 DEVICE IN SERVICE
1. Start with both shut-off valves closed.
Slowly open the inlet shut-off valve until the
backow preventer is completely pressur-
ized.
2. When the unit has been pressurized,
vent any trapped air by slightly opening
each of the four test cocks.
3. Slowly open the downstream shut-off
valve. The Model 350/450 Series Assembly
is now in service.
4. After the Model 350/450 Series has
been properly 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.
Clean rubber and seats of all debris and
place unit back in service.
(Patent No. 5,913,331)
OUTDOOR INSTALLATION
Model 450 (2 1/2” & 3”)
OUTDOOR INSTALLATION
Model 350
PROTECTIVE
ENCLOSURE
DIRECTION OF FLOW
PROTECTIVE
ENCLOSURE
DIRECTION OF FLOW
12" MIN.
30" MAX.
WILKINS, a ZURN Company
1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
Proposition 65 Warning This product contains chemicals known to the State of California to cause cancer and birth defects or other
reproductive harm.
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.
DIRECTION OF FLOW
INDOOR INSTALLATION
Model 350ADABGVIC