INSTALLATION INSTRUCTIONS
CAUTION: Installation of Backflow Preventers must be performed by qualified,
licensed personnel. The installer should be sure the proper device has been se-
lected for the particular installation. Faulty installation could result in an improperly
functioning device.
ZURN WILKINS Model 950XLTDABF Double Check Detector Assemblies are for
use on water lines where a health hazard does not exist in the event of a backflow
situation.
Damage to the device could result wherever water hammer and/or water thermal
expansion could create excessive line pressure. Where this could occur, shock ar-
resters, check valves and/or pressure relief valves should be installed downstream
of the device.
If installation is in a pit or vault, the Backflow 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 950XLTDABF Backflow Preventer, flush the line thor-
oughly to remove all debris, chips and other foreign matter. If required, a strainer
should be placed upstream of the Backflow Preventer. CAUTION: Do not use a
strainer in seldom used emergency waterlines such as fire 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 flood 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 950XLTDABF Backflow Pre-
venter may be installed outdoors only if
the device is protected against freezing
conditions. Exposure to freezing condi-
tions 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 950XLTDABF
IN SERVICE
1. Start with both shut-off valves closed.
Slowly open the inlet shut-off valve
until the backflow preventer is com-
pletely pressurized.
2. When the unit has been pressur-
ized, vent any trapped air by slightly
opening each of the four test cocks.
3. Slowly open the downstream shut-
off valve. The Model 950XLTDABF
Double Check Detector Assembly is
now in service.
4. After the Model 950XLTDABF has
been properly installed, test the de-
vice (see “TEST PROCEDURES”).
If the device fails the test, remove
the first and second check valves
and thoroughly flush the device.
Clean rubber and seats of all debris
and place unit back in service.
VERTICAL INSTALLATION
Vertical installation is acceptable in ap-
plications where inlet and outlet piping
are flowing vertically upwards. All the
basic installation instructions apply to
such installations. Consult factory for
approval status.
Model 950XLTDABF & 950XLTDABFSS
Double Check Detector Assembly (2”)
The Model 950XLTDABF is a Double Check Detector Assembly with butterfly valve shut-off valves.
The Model 950XLTDABFSS incorporates a supervisory switch with each butterfly valve shut-off valve.
Unless otherwise noted, the following instructions apply to both Models.
Installation
Testing
Maintenance Instructions
DIRECTION OF FLOW
WILK
IN
S
175 PS
I
180˚
F
2”
ASSE 1048
950 XL
TD
A
DCD
A
WILKINS 35
0
3/4” DC
DIRECTION OF FLOW
12” MIN.
30” MAX.
PROTECTIVE
ENCLOSURE
950X
LTDA
DCDA
WILKIN
S
180˚
F
175 P
SI
2”
DIRECTION OF FLOW
WILKIN
S
950X
LTD
A
DCDA
175 PS
I
180º
F
2”
®
!
WARNING:
Cancer and Reproductive Harm - www.P65Warnings.ca.gov
!
ADVERTENCIA:
Cáncer y daño reproductivo - www.P65Warnings.ca.gov
!
AVERTISSEMENT:
Cancer et néfastes sur la reproduction - www.P65Warnings.ca.gov
WARNING: This product is NOT Lead Free in accordance with U.S. Federal Law and is illegal in the U.S. for use in potable
services or to install in water systems anticipated for human consumption.
