Zurn Wilkins 950XLTDABF User manual

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 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 backow
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 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 950XLTDABF Backow Preventer, ush the line thor-
oughly 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 950XLTDABF Backow 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 backow 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 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 ap-
plications where inlet and outlet piping
are owing 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 buttery valve shut-off valves.
The Model 950XLTDABFSS incorporates a supervisory switch with each buttery valve shut-off valve.
Unless otherwise noted, the following instructions apply to both Models.
Installation Testing Maintenance Instructions
DIRECTION OF FLOW
WILKINS
175 PSI
180˚F
2”
ASSE 1048
950 XLTDA
DCDA
WILKINS 350 3/4” DC
DIRECTION OF FLOW
12” MIN.
30” MAX.
PROTECTIVE
ENCLOSURE
950XLTDA
DCDA
WILKINS
180˚ F
175 PSI
2”
DIRECTION OF FLOW
WILKINS
950XLTDA
DCDA
175 PSI
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.

#3 TEST COCK
#4 TEST COCK
#2 SHUT-OFF
VALVE
LOW SIDE BLEED
NEEDLE VALVE
LOW SIDE HOSE
NOTE: BY-PASS OMITTED FOR CLARITY
(FOR BY-PASS TESTING REFER TO MAINTENANCE
INSTRUCTIONS FOR MODEL 350D)
#2 TEST COCK
#1 TEST COCK
(ON OPPOSITE
SIDE OF VALVE)
#1 SHUT-OFF
VALVE
HIGH SIDE BLEED
NEEDLE VALVE
HIGH SIDE HOSE
VENT HOSE
TEST NO. 2 - TIGHTNESS OF #2 CHECK VALVE
REQUIREMENT:
The static pressure drop across check valve #2 shall be at
least 1.0 psid. If test cock #4 is not at the highest point of
the check valve body, then a vertical tube must be installed
on test cock #4 so that it rises to the top of the check valve
body.
PROCEDURE:
1. Attach hose from the high side of the test kit to the #3
test cock.
2. Open test cock #3 and bleed all air from the hose
and gauge by opening the high side bleed needle
valve. Close high side bleed needle valve. If a tube is
attached to test cock #4, open test cock #4 to ll the
tube. Close test cock #4. Close #1 shut-off valve.
3. Hold gauge at same level as test cock #4 or water
level in tube. Slowly open test cock #4. Record the
static pressure drop across check valve #2 after
gauge reading stabilizes and water stops running out
of test cock #4.
4. Close all test cocks, slowly open shut-off valve #1 &
#2 and remove test equipment.
2
MODEL 950XLTDABF Double Check Detector Assembly
Testing Procedures
Equipment Required: Differential pressure gauge test kit.
TEST NO. 1 - TIGHTNESS OF #1 CHECK VALVE
REQUIREMENT:
The static pressure drop across check valve #1 shall be at
least 1.0 psid. If test cock #3 is not at the highest point of
the check valve body, then a vertical tube must be installed
on test cock #3 so that it rises to the top of the check valve
body.
PROCEDURE:
1. Slowly open all 4 test cocks to remove any foreign
material and attach ttings.
2. Attach hose from the high side of the test kit to the #2
test cock.
3. Open test cock #2 and bleed all air from the hose
and gauge by opening the high side bleed needle
valve. Close high side bleed needle valve. If a tube is
attached to test cock #3, open test cock #3 to ll the
tube. Close test cock #3. Close #2 shut-off valve then
close the #1 shut-off valve.
4. Hold gauge at same level as test cock #3 or water
level in tube. Slowly open test cock #3. Record the
static pressure drop across check valve #1 after
gauge reading stabilizes and water stops running out
of test cock #3.
5. Close all test cocks, open shut-off valve #1 and re-
move test equipment.
ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
®
www.zurn.com

SCREW
SEAL RING
RETAINER
SEAL RING
POPPET
CHECK SEAT
SEAT O-RING
ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
POPPET ASSEMBLY
#1 SPRING
#2 SPRING
POPPET ASSEMBLY
SCREW
SEAL RING
SEAL RETAINER
POPPET
#2 TEST COCK
#3 TEST COCK
#4 TEST COCK
COVER O-RING
NO. 1 CHECK
VALVE COVER
COVER O-RING
NO. 2 CHECK
VALVE COVER
#1 TEST COCK
FIGURE 3
3
CHECK ASSEMBLY
FIGURE 1
FIGURE 2
Maintenance Instructions
All Model 950XLTDABF Double Check Detector Backow
Preventers must be inspected and maintained by licensed
personnel at least once a year or more frequently as
specied by local codes. Replacement of worn or damaged
parts must only be made with genuine "ZURN WILKINS"
parts.
GENERAL MAINTENANCE
1. Clean all parts thoroughly with water after disassembly.
2. Carefully inspect rubber seal rings and o-rings for damage.
3. Test unit after reassembly for proper operation (refer to
"TESTING PROCEDURES").
SERVICING CHECK VALVES
1. Close inlet and outlet shut-off valves.
2. Open No.2, No.3 and No.4 test cocks to release pres-
sure from valve.
3. Unscrew check valve cover using appropriate sized
wrench.
CAUTION: COVER IS SPRING LOADED!
To avoid injury, hold cover down rmly with one hand
while unscrewing.
4. Remove cover, spring and poppet assembly.
5. Inspect the rubber seal ring for cuts or embedded
debris.
6. To remove seal ring, remove screw and seal retainer.
7. If the reverse side of the seal ring is unused, it is
possible to invert the seal ring. This would be consid-
ered a temporary solution to xing a fouled check and
should be replaced with a new seal ring as soon as
possible.
8. Inspect the valve cavity and seating area. Remove
any debris.
9. If necessary, unscrew seat from body and replace with
new seat and lightly greased o-ring (For seat removal
assistance, contact factory).
10. Reverse the above procedures to reinstall check
valve assemblies and access cover, making sure
the 3 test cocks remain open.
®
www.zurn.com

IS950XLTDABF (REV. D 5/18)
ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:[phone] Fax:[phone]
SPECIFICATIONS
Maximum working water pressure: 175 PSI Hydrostatic test pressure: 350 PSI
Maximum working water temperature: 180°F End connections: Threaded ANSI B1.20.1
PROBLEM
1. LEAKING CHECK VALVES
2. LOW OR NO FLOW
CORRECTIVE ACTION
1. Clean seat and seal ring area
2. Replace seat
3. Replace seat o-ring
1. Verify ow direction arrow
2. Turn handles counterclockwise
3. Attach pressure gauge to test cock
#1 and verify pressure
POSSIBLE CAUSES
1. Debris on seat or seal ring
2. Damaged seat
3. Damaged seat o-ring
1. Device installed backwards
2. Shut-off valves or valve upstream
may not be fully open
3. Low supply pressure
Proper performance is dependent upon licensed, qualied personnel performing regular, periodic testing according
to ZURN WILKINS’ specications and prevailing governmental & industry standards and codes and upon following
these installation instructions. Failure to do so releases ZURN WILKINS of any liability that it might otherwise have
with respect to that device. Such failure could also result in an improperly functioning device.
Rated Flow (Established by approval agencies)
Troubleshooting
Performance Characteristics
BLACK
(SWITCH POSITION VALVE FULL OPEN)
SWITCH 1: DUAL LEADS
RED
WHITE
LISTED FIRE ALARM
CONTROL PANEL
SUPERVISORY CIRCUIT
NC
COM
NO
TO NEXT INDICATOR
OR
END OF LINE RESISTOR
Green Lead provided is ground for switch housing
Switch Rating: 10AMP/ 115 VAC
.5AMP/28 VDC
Cap unused leads with wire nuts and tuck inside junction box (not provided)
NOTE: Supervisory tamper switches are for indoor and outdoor use.
SWITCH 2: SINGLE LEADS
AUXILIARY
EQUIPMENT
ORANGE
YELLOW
BLUE
COM
NC
NO
VOLTAGE
SOURCE
Wiring Diagram for 950XLTDABFSS Only
4
®
www.zurn.com
0
34
69
103
138
0.0 3.2 6.3 9.5 12.6 15.8
0
5
10
15
20
050 100 150 200 250
PRESSURE LOSS (kPa)
FLOW RATE (l/s)
PRESSURE LOSS (PSIG)
FLOW RATE (GPM)
MODEL 950XLTDABF 2" (STANDARD & METRIC)