Zurn-Wilkins 2-350XL Installation Guide

Model 350
®
Double Check Valve Assembly (1-1/4”- 2”)
 Installation  Testing  Maintenance Instructions
INSTALLATION INSTRUCTIONS
PLACING THE MODEL 350 IN SERVICE
CAUTION: Installation of Backflow Preventers must be performed by qualified, 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.
1. Start with both shut-off valves closed.
Slowly open the inlet shut-off valve until the
backflow preventer is completely pressurized.
ZURN WILKINS Model 350 Double Check Valve 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 arresters, 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 350 Backflow Preventer, flush the line thoroughly 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 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 Double Check Valve
assembly is now in service.
4. After the Model 350 has been properly installed, test the device (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.
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.
2
DIRECTION OF FLOW
PROTECTIVE
ENCLOSURE
OPTIONAL STRAINER
(MODEL SXL)
2
2
12" MIN.
30" MAX.
2
DIRECTION OF FLOW
DIRECTION OF FLOW
VERTICAL INSTALLATION
INDOOR INSTALLATION
OUTDOOR INSTALLATION
Vertical installation is acceptable in applications where inlet and outlet piping are flowing vertically upwards. All the basic installation instructions apply to such installations.
Consult factory for approval status.
Indoor installation is preferred in areas
that are subject to freezing conditions. All
the basic installation instructions apply to
such installations.
The Model 350 Backflow 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.
Proposition 65 Warning This product contains chemicals known to the State of California to cause cancer
or birth defects or other reproductive harm.
In accordance with U.S. Federal Safe Drinking Water Act Lead-Free requirements, as of January 4, 2014, this product can only be used in water
systems considered non-potable. Please contact your local water utility for further requirements.
Testing Procedures
MODEL 350 DOUBLE CHECK VALVE ASSEMBLY
Equipment Required: Differential pressure gauge test kit.
TEST NO. 1 - TIGHTNESS OF #1 CHECK VALVE
TEST NO. 2 - TIGHTNESS OF #2 CHECK VALVE
REQUIREMENT:
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.
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:
PROCEDURE:
1. Slowly open all 4 test cocks to remove any foreign material
and attach fittings.
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 fill 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 remove
test equipment.
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 fill 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 TEST COCK
#3 TEST COCK
#4 TEST COCK
#1 TEST COCK
350 DC
FLOW
ZURN
FLOW
WILKINS
175 PSIG 180◦ F
#2 SHUT-OFF
VALVE
#1 SHUT-OFF
VALVE
HIGH SIDE BLEED
NEEDLE VALVE
HIGH SIDE HOSE
LOW SIDE BLEED
NEEDLE VALVE
LOW SIDE HOSE
VENT HOSE
2
ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:855-663-9876 Fax:805-238-5766
www.zurn.com
®
Maintenance Instructions
All Model 350 Double Check Valve Backflow Preventers
must be inspected and maintained by licensed personnel
at least once a year or more frequently as specified by local
codes. Replacement of worn or damaged parts must only
be made with genuine “ZURN WILKINS” parts.
O-RING
GENERAL MAINTENANCE
1.
2.
3.
SEAT, #2
Clean all parts thoroughly with water after disassembly.
Carefully inspect rubber seal rings and o-rings for damage.
Test unit after reassembly for proper operation (refer to “TESTING PROCEDURES”).
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
SEAL
RETAINER
SPRING
O-RING
POPPET
BOLT
SEAT, #1
SERVICING CHECK VALVES
SEAL
WASHER
BOLT
SEAL
WASHER
SEAL
RETAINER
SPRING
Close inlet and outlet shut-off valves.
Open No. 2, No. 3 and No. 4 test cocks to release pressure from valve.
Unscrew the 4 bolts (1/4-20 UNC Hex Flange) holding the housing in place. Lift housing up to remove.
Twist and remove sleeve from body. Using finger or blunt object, push in outlet end of body, both checks
should slide out the body inlet. A short object like a
socket can be placed on a flat surface. Place body
over object so it pushes into valve outlet and push
down on body.
Twist spring retainers counter-clockwise to remove
from seats and access poppets.
Inspect the rubber seal ring for cuts or embedded debris. To remove seal ring, remove screw and seal ring
retainer. If the reverse side of the seal ring is unused,
it is possible to invert the seal ring. This will be consi-
dered a temporary solution to fixing a fouled check and should be replaced with a new seal ring as soon as possible.
Inspect seat surface for nicks or dings and replace if necessary. Use fingernail to check for dings.
Re-grease seat o-rings.
Inspect seat o-ring sealing areas in body and wipe clean.
Reverse the above procedures to reinstall check valve
assembly. Drop #2 check assembly in body. Then drop
#1 check assembly in and turn until #1 spring retainer
lines up with #2 seat. Then push both assemblies into
body. Insert sleeve against checks. (Place sleeve down
against flat surface and push on body with rocking motion.)
Lightly grease face of o-rings on housing and reinstall into
body following the above procedures in revers order.
Rock body side to side to help o-rings slide in. If it does
not drop in completely, do not use screws to force it.
An overly greased o-ring might slide out of groove at top of ball valve. Use a screw driver to push o-ring
back in groove, then push body down in.
SPRING
RETAINER, #2
SPRING
RETAINER, #1
POPPET
CHECK ASSEMBLY
TEST COCKS
BOLT
BOLT
O-RING
O-RING
SLEEVE
HOUSING
O-RING
Note: When installing housing, match slight taper on the outlet
of the housing with corresponding taper in body.
®
ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:855-663-9876 Fax:805-238-5766
www.zurn.com
3
Troubleshooting
POSSIBLE CAUSES
PROBLEM
1. LEAKING CHECK VALVES
1.
2.
3.
4.
Debris on seat or seal ring
Damaged seat Damaged seal ring
Damaged check o-ring
2. LOW OR NO FLOW
1. Device installed backwards
2. Shut-off valves or valve upstream may not be fully open
3. Low supply pressure
CORRECTIVE ACTION
1.
2.
3.
4.
Clean seat and seal ring area Replace seat
Replace poppet
Replace check o-ring
Performance Characteristics
Flow Characteristics
MODEL 350 1-1/4", 1-1/2" & 2" (STANDARD & METRIC)
0.0
3.2
6.3
FLOW RATES (l/s)
9.5
12.6
15.8
103
2" (50mm)
1-1/4" (32mm)
10
PRESSURE LOSS
(kpa)
PRESSURE LOSS
(PSIG)
15
69
1-1/2" (40mm)
5
34
0
0
50
100
150
FLOW RATES (GPM)
200
0
250
⃟ Rated Flow (Established by approval agencies)
Capacity thru Schedule 40 Pipe
Pipe size 5 ft/sec 7.5 ft/sec 10 ft/sec 15 ft/sec
1/2"
5
7
9
14
3/4"
8
12
17
25
1"
13
20
27
40
1 1/4"
23
35
47
70
1 1/2"
32
48
63
95
2"
52
78
105
167
SPECIFICATIONS
Maximum working water pressure: 175 PSI
Maximum working water temperature: 180°F
Hydrostatic test pressure: 350 PSI
End connections: Threaded ANSI B1.20.1
Proper performance is dependent upon licensed, qualified personnel performing regular, periodic testing according
to ZURN WILKINS’ specifications 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.
®
ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:855-663-9876 Fax:805-238-5766
IS350-114-2 (REV. 4/13)
www.zurn.com
4