Installation Guide

ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
OUTDOOR INSTALLATION
The Model 350XL Backow Preventer may
be installed outdoors only if the device is pro-
tected against freezing conditions. Exposure
to freezing conditions will result in improper
function or damage to the device. The instal-
lation location must be kept above 32°F. All
the basic installation instructions apply.
 Installation  Testing  Maintenance Instructions
1
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.
ZURN WILKINS Model 350XL Double Check Valve 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 arresters, 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 350XL 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.
PLACING THE MODEL 350XL 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 350XL Double Check
Valve assembly is now in service.
4. After the Model 350XL has been prop-
erly 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.
VERTICAL INSTALLATION
Vertical installation is acceptable in appli-
cations where inlet and outlet piping are
owing vertically upwards. All the basic
installation instructions apply to such
installations. Consult factory for approval
status.
Model 350XL LEAD-FREE*
Double Check Valve Assembly (3/4” & 1”)
*This product contains a weighted average lead content less than 0.25% for wetted surfaces.
*Certied to NSF/ANSI 61-G
DIRECTION OF FLOW
WILKINS 350XL
DIRECTION OF FLOW
WILKINS 350XL
DIRECTION OF FLOW
WILKINS 350XL
PROTECTIVE
ENCLOSURE
DIRECTION OF FLOW
12" MIN.
30" MAX.
OPTIONAL LEAD-FREE STRAINER
(MODEL SXL)
WILKINS 350XL
®
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®