ZURN 710 Pressure Vacuum Breaker Instruction Manual

: June 10, 2024
: ZURN

Table of Contents

INSTALLATION INSTRUCTIONS
Maintenance
Testing Procedures
Troubleshooting
References
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ZURN 710 Pressure Vacuum Breaker Instruction Manual

INSTALLATION INSTRUCTIONS

CAUTION: Installation of Pressure Vacuum breakers must be performed by qualified, licensed personnel. Faulty installation could result in an improperly functioning device. The installer should be sure the proper device has been selected for the particular installation. ZURN WILKINS Model 710 Pressure Vacuum Breakers are for use on irrigation, industrial, and other non- potable services where a health hazard could exist if a backsiphonage situation were to occur. They must not be installed where backpressure may occur. Proper performance depends upon following these installation instructions and prevailing governmental and industry standards and codes. 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.

Always consult local codes for installation methods, approvals, and guidance. It is recommended that system supply pressure be at least 20psi (138 kPa).
Before installing the ZURN WILKINS Model 710 Pressure Vacuum Breaker, flush the lines thoroughly to remove all debris, chips and other foreign matter.
The Model 710 must be installed in a vertical position (see Fig. 1) to provide proper operation of the air inlet valve.
Provide adequate space around the installed unit so that the test cocks will be accessible for testing and servicing.
CAUTION: If installation of a Model 710 unit is in a building, provide a suitable drain arrangement to drain off spillage from the air vent.
Install valve at least 12 inches above the highest piping or water outlet downstream of the Model 710 Pressure Vacuum Breaker.
The Model 710 Pressure Vacuum Breaker may be installed outdoors only if the device is protected against any freezing conditions. Warning: do not block air vent opening with insulation. Exposure to freezing conditions will result in improper function or damage to the device. The installation location must be kept above 32°F.

PLACING THE DEVICE IN SERVICE
After the installation of a Model 710 Pressure Vacuum Breaker has been completed, place the unit in service as follows:

Start with both shut-off valves and test cocks closed. Slowly open the inlet shut-off valve until water starts to discharge from bonnet then quickly open to pressurize valve.
The discharge should cease by the time the shut-off valve is in the full open position.
If the discharge does not stop, refer to “MAINTENANCE INSTRUCTIONS”.
Repressurize device as in Step 1. Device should function properly.
Slowly open the No. 2 shut-off valve. The Model 710 is now in service.
NOTE: The downstream pressure must be maintained above 5psi (34 kPa) to keep the spring loaded air inlet poppet closed.
After the Model 710 has been properly installed, test the device. If the device fails the test, refer to “MAINTENANCE INSTRUCTIONS”

Drain Procedure for Freeze Protection

Turn off main shut-off (1) that supplies water to the system.
Open both inlet and outlet drain valves in the system (2 & 6). Open inlet and outlet shut-off valves on the pressure vacuum breaker (3 & 5) and all of the test cocks. Leave all valves and test cocks in the half open/half closed (45°) position to allow full drainage of the ball valves and test cocks.
If you “blow out” the system downstream of the pressure vacuum breaker, make sure the outlet drain valve (6) is open and the pressure vacuum breaker shut-off valve (5) is closed.
Connect an air hose to the outlet drain valve (6) and inject an adequate volume of air to remove all water from the downstream portion of the system.
CAUTION: Open outlet shut-off valve to the pressure vacuum breaker (5) and outlet drain valve (6) to the half open/ half closed (45°) position after “blow out” process is completed.
If drain valves (2 & 6) are not part of the system, and if air pressure is not used to “blow out” the system, the internal components of the pressure vacuum breaker should be removed for the duration of the winter.
Leave all drain valves (2 & 6), shut-off valves (3 & 5) and test cocks in the half open/half closed position (45°) for the duration of the winter to prevent freezing. Caution: Be certain that main shut-off (1) remains tightly closed to prevent refilling of the system. Also, the main shut-off valve must be resilient seated to insure no leakage of water into the system.

WARRANTY: ZURN WILKINS Valves are guaranteed against defects of material or workmanship when used for the services recommended. If in any recommended service, a defect develops due to material or workmanship, and the device is returned, freight prepaid, to ZURN WILKINS within 12 months from date of purchase, it will be repaired or replaced free of charge. ZURN WILKINS’ liability shall be limited to our agreement to repair or replace the valve only.

WARNING: Cancer and Reproductive Harm – 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.

Maintenance

Close inlet and outlet shut-off valves before disassembling device.
Remove canopy screws counterclockwise and remove canopy.
Bleed off pressure by opening the No. 2 test cock.
Unscrew the bonnet from the body by turning counterclockwise.
Remove the float spring, plunger, spring retainer, check spring, and poppet.
Clean all parts with clean water only.
After completing inspection, replace necessary parts and reassemble. Repair kits are available from your supplier. 8. Retest according to “TEST PROCEDURES”.

Testing Procedures

TEST NO. 1

Purpose: To test the opening pressure differential of the air inlet valve. Requirement: The air inlet valve shall open when the pressure in the body is no less than 1.0 psi above atmospheric pressure. The air inlet valve shall be fully open when the water drains from the body.

STEPS:

Bleed water through both test cocks to eliminate foreign material.
Install appropriate fittings for test kit hoses.
Remove air inlet valve canopy.
Install the high side hose of the differential pressure gauge to test cock #2. Open test cock #2 and bleed air from hose and gauge.
Close #2 shut-off valve then close #1 shut-off valve.
Slowly open the high side bleed needle valve being especially careful not to drop the pressure differential too fast. Record the pressure differential at which the air inlet valve opens. 7
Close test cock #2 and remove equipment.
Open #1 shut-off valve.

TEST NO. 2
Purpose: To test the check valve for tightness in the direction of flow.
Requirement: The check valve shall be driptight in the normal direction of fl ow when the inlet pressure is 1.0 psi and the outlet pressure is atmospheric.

STEPS:

Attach high side hose of differential gauge to test cock #1. Open test cock #1 and bleed all air from the hose and the gauge by opening high side bleed needle valve. Close high side bleed needle valve.
Close #1 shut-off valve. 3
Open test cock #2. The air inlet valve will open and the water in the body will drain out through test cock #2. When this flow of water stops, the differential pressure indicated by the gauge after it has settled will be the pressure drop across the check valve. This value must be 1.0 psi or greater. Record this value. If water continues to flow out of test cock #2, then the #1 shut-off valve is leaking.
Close test cocks #1 and #2 and remove equipment.
Replace air inlet valve canopy.
Open #1 shut-off valve, then #2 shut-off valve.

Troubleshooting

PROBLEM
Air inlet valve does not open as gauge drops to 0.0 psid.
Air inlet valve does not open and diff erential on gauge will not drop.
Air inlet opens below 1.0 psid.
Check valve opens below 1.0 psid

POSSIBLE CAUSES

1. Air inlet o-ring stuck to bonnet. Clean o-ring and bonnet.
2. Broken or missing fl oat spring
1. Leaking No. 1 shut-off valve.
2. Parallel installation with leaky No. 2 shut-off valve.
1. Dirty or damaged air inlet o-ring.
2. Scale buildup on bonnet.
1. Dirty or damaged check seal or seat o-ring.
2. Damaged seat