Installation Guide

ManualsBrandsZurn ManualsGarden Center1/2 in. Double Check Backflow Preventer Regulator

PROTECTIVE

ENCLOSURE

DIRECTION OF FLOW

12" MIN.

30" MAX.

OPTIONAL LEAD-FREE STRAINER

(MODEL SXL)

Model 950XLT2 LEAD-FREE*

Double Check Valve Assembly (3/4”, 1”, 1 1/4”, 1 1/2” & 2”)

*This product contains a weighted average lead content less than 0.25% for wetted surfaces.

*Meets the requirements of NSF/ANSI 61

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

particular installation. Faulty installation could result in an improperly functioning device.

ZURN WILKINS Model 950XLT2 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 ex-

pansion 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 950XLT2 Backow Preventer, ush the line thoroughly to

remove all debris, chips and other foreign matter. If required, a lead-free strainer

should be placed upstream of the Backow Preventer. CAUTION: Do not use a

lead-free 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 ac-

cessible 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.

ZURN WILKINS

1747 Commerce Way, Paso Robles, CA 93446 Phone:855-663-9876 Fax:805-238-5766

 Installation  Testing  Maintenance Instructions

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 950XLT2 Backow 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.

PLACING THE MODEL 950XLT2 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 pressurized,

vent any trapped air by slightly open-

ing each of the four test cocks.

3. Slowly open the downstream shut-off

valve. The Model 950XLT2 Double

Check Valve assembly is now in

service.

4. After the Model 950XLT2 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.

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 instal-

lations. Consult factory for approval status.

DIRECTION OF FLOW

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DIRECTION OF FLOW

Summary of content (4 pages)

PAGE 1
Model 950XLT2 LEAD-FREE* ® Double Check Valve Assembly (3/4”, 1”, 1 1/4”, 1 1/2” & 2”) *This product contains a weighted average lead content less than 0.25% for wetted surfaces. *Meets the requirements of NSF/ANSI 61  Installation  Testing  Maintenance Instructions INSTALLATION INSTRUCTIONS 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.
PAGE 2
Testing Procedures MODEL 950XLT2 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.
PAGE 3
Maintenance Instructions SERVICING CHECK VALVES SEAL RING 1. Close inlet and outlet shut-off valves. 2. Open No. 2, No. 3 and No. 4 test cocks to release pressure from valve. SCREW 3. Unscrew check valve cover using appropriate sized wrench. CAUTION: COVER IS SPRING LOADED. To avoid injury, hold cover down firmly with one hand while unscrewing. SEAL RETAINER 4. Remove cover, spring and poppet assembly. POPPET 5. Inspect the rubber seal ring for cuts or embedded debris. 6.
PAGE 4
Troubleshooting PROBLEM POSSIBLE CAUSES CORRECTIVE ACTION 1. LEAKING CHECK VALVES 1. 2. 3. Debris on seat or seal ring Damaged seat Damaged seat o-ring 1. 2. 3. Clean seat and seal ring area Replace seat Replace seat o-ring 2. LOW OR NO FLOW 1. 2. Device installed backwards Shut-off valves or valve upstream may not be fully open Low supply pressure 1. 2. Verify flow direction arrow Turn handles counterclockwise 3. Attach pressure gauge to test cock #1 and verify pressure 3.