Specification

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Zurn Industries, LLC | Wilkins
1747 Commerce Way, Paso Robles, CA U.S.A. 93446 Ph. 855-663-9876, Fax [phone]
In Canada | Zurn Industries Limited
7900 Goreway Drive, Unit 10, Brampton, Ontario L6T 5W6, 877-892-5216
www.zurn.com
All ZURN WILKINS Model 48 Gate Valves must be inspected and maintained by qualified, 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.
Servicing Wedge and Bonnet Seal:
1. Shut off main water supply. If servicing a gate valve attached to the downstream side of a backflow
preventer, the upstream shut-off valve may be closed instead of the main water supply.
2. Relieve line pressure.
3. Remove bonnet nuts and bolts.
4. Slowly lift and remove bonnet assembly and wedge from valve body.
5. Clean all parts thoroughly after disassembly.
6. Carefully inspect bonnet seal and wedge for wear or damage. Replace if worn or damaged.
7. Carefully inspect body interior seating surface for coating damage and foreign debris.
Clean seating surface or replace valve if necessary.
8. Reinstall wedge and bonnet assembly.
9. Tighten down bonnet nuts and bolts evenly. Do not over tighten.
Servicing Gland Stuffing Box (OS&Y):
1. Make sure gate valve is fully open.
2. Remove gland nuts.
3. Raise gland and gland bushing.
4. Remove packing rings from stuffing box using a small pick or similar device.
5. Replace worn or damaged packing rings.
6. Lower gland and gland bushing and lightly tighten gland nuts.
7. Cycle valve fully closed to fully open.
8. If there is stem leakage, tighten gland nuts until leakage stops.
Servicing Stem Seals (NRS):
1. Shut off main water supply and relieve line pressure.
2. Remove the bolt and washer retaining the operating nut/handwheel.
3. Remove operating nut/handwheel.
4. Remove gland flange bolts and gland flange.
5. Remove stem by turning stem clockwise.
6. Replace stem o-rings, gland flange o-ring, wiper ring, and thrust washers if necessary.
7. Reassemble in reverse order.
Troubleshooting
Maintenance Instructions
PROBLEM POSSIBLE CAUSES CORRECTIVE ACTION
1. Body Leakage 1. Loose bonnet bolts 1. Tighten bolts
2. Dirty or damaged bonnet seal 2. Inspect bonnet seal. Clean or replace if
necessary
2. Seat Leakage 1. Foreign debris between seat and 1. Cycle valve and flush line
wedge
2. Dirty/corroded seat 2. Flush line or disassemble and clean
3. Damaged seat or wedge 3. Repair or replace valve
3. Stem Leakage 1. Packing nuts loose 1. Tighten nuts
2. Stem o-rings worn (NRS) 2. Replace stem o-rings
3. Packing rings worn (OS&Y) 3. Replace packing rings