ZURN NR3XL Pressure Reducing Valve with Integral By-pass User Manual

Model NR3XL
LEAD-FREE Pressure Reducing Valve with Integral By-pass
(1/2″, 3/4″, 1″, 1-1/4″ 1-1/2″ & 2″)

Installation

Annual inspection and maintenance are required of all plumbing system components. To ensure proper performance and maximum life, this product must be subject to regular visual inspection and pressure testing, with cleaning or repair as needed. If the end-user is not qualified to perform periodic inspection and maintenance, a qualified licensed plumber must be contacted for assistance. It is also recommended that a suitable strainer be installed upstream of the valve. Anytime a pressure-reducing valve is adjusted, a
pressure gauge must be used downstream to verify the correct pressure setting. Do not bottom out adjustment bolt-on bell housing. Where the desired pressure reduction is more than a 3 to 1 ratio (i.e. 225psi to 75psi), or inlet pressure is above 150 PSI multiple regulators in series are recommended to be installed to prolong valve life.

Installation Instructions

1. This valve should be installed by a qualified licensed plumber.

2. The flush supply line to remove loose dirt and scale which may damage the seal ring and seat.

3. Install valve in-line with an arrow on valve body pointing in the direction of flow. The valve shall be installed in an accessible location and may be installed in any orientation.

4. All valves are factory set to approximately 50 PSI, adjust the regulator to the desired outlet set pressure by turning the adjustment bolt clockwise (into bell housing) to raise pressure or counterclockwise (out of bell housing) to reduce pressure.
   NOTE: When reducing pressure open a downstream faucet to relieve pressure and use a pressure gauge(Zurn Wilkins Model HGI-25) to verify the correct pressure setting.

5. Tighten locknut when desired pressure is achieved and test valve to confirm proper operation.

Inspection and Maintenance Instructions

Tools Required:

• Hose Bibb Pressure gauge (Zurn Wilkins Model HGI-25)
• 9/16” wrench for bolt adjustment
• Pliers for cartridge removal
• Crescent wrench for bell removal
• Silicone-based food grade o-ring grease

Testing:

1. If available, determine the incoming supply pressure for reference.
2. Install the pressure gauge
3. Open a downstream fixture inside the dwelling to start flow through the valve.
4. Record the reading on the pressure gauge for reference. This is the reduced flowing pressure.
5. Close the inside faucet or fixture and immediately record the reading on the pressure gauge. This is the reduced static pressure and outlet set point of the valve.
6. Observe the gauge for 10 minutes.

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 the 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
ADVERTENCIA: Cáncer y daño reproductivo – www.P65Warnings.ca.gov
AVERTISSEMENT: Cancer et néfastes sur la reproduction – www.P65Warnings.ca.gov

1.  Criteria:
   a.If the outlet pressure is maintained for 10 minutes without increasing, the valve is working properly and no further action is required.
   b.If outlet pressure increases immediately and is equal to supply pressure from step 1, the valve may be severely fouled, damaged, or defective and should be repaired or replaced. Proceed to the Repair Instruction steps below.
   c.If pressure slowly creeps up within 10 minutes the valve may be fouled and should be cleaned and retested. Proceed to the Maintenance and Cleaning steps below. If you are retesting a cleaned cartridge and it still has pressure creep, proceed to repair the valve.
   d.If there is any external leakage from the body the valve should be replaced. If there is any leakage observed from the bell, the valve should be repaired.

Maintenance and Cleaning

1. Close shutoff valve upstream of the pressure reducing valve.
2. Open a faucet in-dwelling to remove line pressure.
3. Note and record the height that the adjustment bolt protrudes from the bell housing. Loosen locknut on adjustment bolt, then turn adjustment bolt out of bell housing to remove spring tension.
4. Using a wrench, remove bell housing by turning counterclockwise and remove spring, spring disc, and friction ring.
5. Remove the cartridge from the regulator by a gripping retaining bolt with pliers and pulling outwards away from the body.
6. While disassembled, open the upstream shutoff valve to flush out the valve body and service line of debris.
7. Visually inspect internal machined surfaces in the body where the o-rings of the cartridge seal, looking for cuts or gouges in the body.
8. Clean the screen by removing it from the cartridge. Ensure both upper and lower o-rings remain in place. Remove all debris from the screen.
9. Visually inspect both sides of the diaphragm for cuts or tears, or material degradation and clean as needed.
10. Visually inspect the seal ring for cuts, tears, or debris on the seating face and clean as needed.
11. Visually inspect the seat for nicks, cuts, or other damage and clean as needed.
12. Criteria:
    a.If there is no visible damage observed, reinstall the cleaned cartridge following steps 2-9 of the Repair Instruction below and retest the valve.
    b.If there is any visible damage to the diaphragm, seal ring, or seat, the valve should be repaired.
    c.If there is any visible damage or corrosion to the bronze body, the valve should be replaced.

Repair Instructions

Repair kits and instruction videos are available at zurn.com
Call 1-855-663-9876 to order

SEALED CAGE WARNING: Loosen lock washer at adjustment bolt slowly. Look for any trapped water pressure under the sealed cage washer. Relieve pressure before removing the bell.

1. Follow maintenance and cleaning steps 1-6 above and discard the old cartridge.

2. Apply silicone grease to cartridge o-rings and push the new cartridge into the bore in the body making sure o-rings seal tight against both the cartridge and body.

3. Replace friction ring, spring, spring disc, and bell housing. (Make sure friction ring is installed with raised edge facing up).

4. Tighten bell housing onto the body by threading clockwise.

5. Turn adjustment bolt into bell housing and adjust to height recorded from Maintenance and Cleaning step 3 above.

6. Enter the dwelling and turn on several fixtures.

7. Open upstream shutoff valve slowly to turn on water service. Let the water run for several seconds or as long as needed until the air is purged from the system, then turn off fixtures in the dwelling.

8. Adjust the regulator to the desired outlet set pressure by turning adjustment bolt clockwise (into bell housing) to raise pressure or counterclockwise (out of bell housing) to lower pressure.
   NOTE: When reducing pressure open a downstream faucet to relieve pressure and use a pressure gauge (Zurn Wilkins Model HGI-25) to verify the correct pressure setting.

9. Tighten locknut when desired pressure is achieved and retest valve to confirm proper operation.

Troubleshooting

Pipelines in a water supply system must be of sufficient carrying capacity to maintain adequate pressure at the most remote or highest fixture. Under the maximum probable fixture use, minimum adequate pressure is generally 8 to 15 PSI but maybe more, depending on the equipment being supplied. Relatively high service pressures which can create high water velocities in pipelines would allow the use of smaller pipes to satisfy fixture use. However, high velocity tends to cause whistling and humming. Reduction of pressure by the use of a pressure reducing valve, in an attempt to eliminate such a condition, may reduce pipeline capacities below that which is adequate for maximum probable use. When high service pressures are in effect, either continuously or periodically, the application of a pressure-reducing valve will be successful only when the installed pipeline is of adequate size to satisfy the system demand at the lower pressure. When actual water demands are unknown, the valve size should be no less than the existing pipe size.

1. Pressure periodically builds up in system above the outlet sets the pressure of the pressure-reducing valve.
   a. Cause: Thermal expansion of water as it is being heated.

i.Solution: This is a natural consequence. It may happen each time that the heater runs.  Pressure will be relieved the next time a fixture is opened until the next time the heater turns on. An expansion control relief valve (Zurn Wilkins model BVECXL) properly piped to a suitable drain or expansion tank (Zurn Wilkins model XT) set at the pressure reducing valve outlet set pressure must be installed. This will not prevent pressure rise but should limit it to a safe level.

2. Pressure builds up in the system above the outlet set pressure of the pressure reducing valve.
   a. Cause: Debris on the sealing face of the seal ring.

i.Solution: Flush the reducing valve by opening multiple fixture outlets wide open. If this does not correct the problem, remove the cartridge for inspection and cleaning.

b. Cause: Cut or worn seal ring or stem o-ring.

i.Solution: Repair the valve with a Zurn Wilkins repair kit.

3. Fixture Pressure and flow is unsteady or inadequate.
   a. Cause: Low water supply pressure in mains.

i.Solution: This is a water department problem. It is due to the mains being inadequate for the demands made on them during certain periods of the day.

b. Cause Heavy periodic demands by appliances in the house or inadequate line size.

i.Solution: House service lines may at times be inadequate for certain fixtures. The size of some pipelines may need to be increased. Increasing the house service mains might be necessary if the inadequate flow is general at all fixtures. Contact a qualified licensed plumber for assistance to determine if pipeline sizes need to be increased.
ii. Solution: Pressure setting of reducing valve may be too low. Try increasing the setting of the reducing valve gradually to increase flow at the fixtures. Caution: Do not bottom out adjustment bolt-on the bell housing.

c. Cause: Screen clogged with debris.

i.Solution: Follow the maintenance and cleaning steps above.

4. Valve appears to be noisy; chatters, hums, whistles.
   a. Cause: High velocity of flow in pipelines causing vibration.

i.Solution: The valve or the pipelines could be undersized. Pipes and valves being undersized would accentuate this condition. Contact a qualified licensed plumber for assistance to determine if the valve size or pipe size should be increased.

b. Cause Worn seat washer or loosely installed seal ring.

i.Solution: Follow the maintenance and cleaning steps above. If a deep channel appears on the seal ring face, repair the valve with a Zurn Wilkins repair kit.

c. Cause: Pressure reduction is greater than 3 to 1

i.Solution: increase set pressure temporarily to see if the noise goes away, adding a second valve in series may be required to achieve desired pressure setting without noise.

ZURN WILKINS
1747 Commerce Way, Paso Robles, CA 93446 Phone:855-663-9876 Fax:805-238-5766
www.zurn.com

ISNR3XL (REV. G 5/21)

Documents / Resources

| ZURN NR3XL Pressure Reducing Valve with Integral By- pass [pdf] User Manual
Pressure Reducing Valve with Integral By-pass, NR3XL
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| ZURN NR3XL Pressure Reducing Valve [pdf] Installation Guide
NR3XL Pressure Reducing Valve, NR3XL, Pressure Reducing Valve, Reducing Valve, Valve
| ZURN NR3XL Pressure Reducing Valve with Integral By Pass [pdf] Instruction Manual
NR3XL, Pressure Reducing Valve with Integral By Pass, NR3XL Pressure Reducing Valve with Integral By Pass, Pressure Reducing Valve

References

• P65Warnings.ca.gov
• Engineered Water Solutions | Zurn
• Engineered Water Solutions | Zurn

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