Zurn Wilkins 375 - User Manual

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375 REDUCED PRESSURE PRINCIPLE

1. Start with both shut-off valves closed.

Slowly open the inlet shut-off valve un-

til the backow preventer is completely

pressurized. A brief discharge from the

relief valve may occur while the device

is pressurizing. The discharge should

cease by the time the shut-off valve

is fully open. Device should function

properly. If the discharge does not

stop, refer to "MAINTENANCE IN-

STRUCTIONS" for repair procedures.

2. After the device has been pressurized,

vent all trapped air from both check

valves by slightly opening each of the

four test cocks.

3. Slowly open the downstream shut-off

valve. The Model 375 Reduced Pres-

sure Principle Backow Preventer is

now in service.

4. If "spitting" or intermittent discharges

from the relief valve are noted, it could

be a result of pressure uctuation and/

or a water hammer condition in the

system. If such conditions exist, install

a ZURN WILKINS water pressure

reducing valve, a Model 40XL2 check

valve, or a Model 1250XL water ham-

mer shock arrester in compliance with

industry standards as needed.

5. After the Model 375 has been prop-

erly installed, test the device (see

"TEST PROCEDURES"). If the de-

vice fails the test, remove the rst and

second check valves and thoroughly

ush the device. If the relief valve

fails to operate properly, inspect the

sensing passage for clogging (see

"MAINTENANCE INSTRUCTIONS").

Clean rubber seals of all debris and

place unit back in service.

 Installation  Testing  Maintenance Instructions

INLET SHUT OFF

DIRECTION OF FLOW

30" MAX.

12" MIN.

ENCLOSURE

AIR GAP

OPTIONAL

WATER METER

FLOOR

DRAIN

OPTIONAL

LEAD-FREE STRAINER

MODEL SXL

WILKINS

PROTECTIVE

2" PIPE (DRAIN LINE CAN BE ANY

STANDARD PIPING MATERIAL)

4. Install valve at least 12 inches above

surrounding ood level.

5. Always consult local codes for installa-

tion methods, approvals and guidance.

OUTDOOR INSTALLATION

Model 375 Backow Preventers 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.

If installation is in a pit or vault, the Back-

ow Preventer must never be submerged

in water because this will cause a cross-

connection. Make sure that the pit or vault

always remains dry by providing ample

drainage.

INDOOR INSTALLATION

Indoor installation is preferred in areas

that are subject to freezing conditions. All

the basic installation instructions apply to

such installations.

PARALLEL INSTALLATION

Where uninterrupted service from a single

meter connection must be maintained, two

or more Backow Preventers may be con-

nected in parallel. All the basic installation

instructions apply to parallel installation.

Be sure to allow adequate room between

the units for testing and repair.

PLACING THE DEVICE IN SERVICE

After the installation of a Model 375 has

been completed, place the unit in service

as follows:

CAUTION: Installation of Backow Pre-

venters 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 375 Reduced

Pressure Principle Backow Preventers

are for use on water lines where a health

hazard could exist if a backow situation

were to occur.

Proper performance is dependent upon

following these installation instructions and

prevailing governmental and industry stan-

dards and codes. Failure to do so, according

to ZURN WILKINS Limited Warranty "...

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.

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

and/or pressure relief valves should be

installed downstream of the device.

1. Before installing a Model 375 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 sel-

dom 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. WARNING: If installation of a

Model 375 is in a building, a suit-

able drain arrangement MUST

be provided to drain off spillage

from the relief valve. An air gap

at least two times the pipe diame-

ter must be provided between the

relief valve and the drain piping

to prevent a cross-connection.

Air Gap AG-11 not intended to

support weight of drain pipe.

CAUTION: Do not pipe the relief valve

solidly to a oor drain, sewer or sump.

CAUTION: An adequately sized drain

is required to prevent possible water

damage due to relief valve discharge.

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.

! 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

Model 375, 375B

Reduced Pressure Principle (1/2" - 1")

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Summary

Installation Instructions

Installation Safety and Precautions

Important safety warnings and precautions for installing the Model 375.

Installation Steps and Space Requirements

Steps for flushing, providing access space, and ensuring proper installation.

Drainage and Air Gap Requirements

Guidelines for providing adequate drainage and air gaps for relief valve discharge.

Special Installation Types

Outdoor Installation Considerations

Requirements for installing the device outdoors, focusing on freeze protection.

Indoor Installation Preference

Preference for indoor installation in freezing conditions and basic instruction applicability.

Parallel Installation Method

Guidelines for connecting two or more devices in parallel for uninterrupted service.

Placing the Device in Service

Initial Pressurization Procedure

Steps for slowly opening shut-off valves to pressurize the backflow preventer.

Venting and Finalization Steps

Venting trapped air and opening the downstream shut-off valve to put the device in service.

Service Troubleshooting and Testing

Addressing spitting discharges and post-installation testing requirements.

Testing Procedures

Test No. 1: Check Valve Tightness

Procedure to test the #2 check valve's tightness against reverse flow.

Test No. 2: #1 Check Valve Pressure Drop

Procedure to test the #1 check valve's tightness and record pressure drop.

Test No. 3: Relief Valve Operation

Procedure to test the differential relief valve's operation.

Maintenance Instructions

General Maintenance Guidelines

Requirements for inspection, maintenance frequency, and using genuine parts.

Servicing Check Valves

Detailed steps for disassembling, inspecting, and reassembling check valves.

Maintenance and Troubleshooting

Servicing Relief Valve

Steps for disassembling, inspecting, and reassembling the relief valve.

Troubleshooting Spitting;Drips

Diagnosing and correcting sudden spitting or light intermittent drips.

Troubleshooting Continuous Discharge

Diagnosing and correcting continuous discharge from the relief valve.

Device Specifications

Technical specifications including working pressure, temperature, and connections.

Freeze Protection Procedures

System Blow Out Procedure

Steps to blow out the system for freeze protection, including fitting replacement.

System Flush Procedure

Steps to flush the system during installation to remove debris.

Performance Characteristics Data

Graphs and tables detailing relief valve discharge rates and repair kits.