Watts LF919 - Manual (Page 6)

6
Servicing First & Second Check Valves
Series 919 and LF919
1 ⁄
4
" – 2" (8 – 50mm)
NOTES: 1. No special tools are required to service the Series 919 and LF919
1 ⁄
4
" - 2" (8 – 50mm).
2. Before servicing, make sure the water is turned off or
shutoff valves are closed.
1. Close shutoff valves up and downstream of the valve.
2. Using an appropriate sized wrench, loosen the check valve
cover. Unscrew the check valve cover and lift it off.
3. Remove the spring.
4. Lift out the disc holder assembly from the body of the valve.
5. To reverse the seat disc, unscrew the disc screw and disassemble
the disc washer and disc rubber from the disc holder assembly.
Reverse the disc rubber so the opposite face is showing.
6. Assemble the disc screw through the disc washer and
disc rubber, and screw it into the disc holder.
7. To replace the seat module, pull the seat module
out of the body by gripping at the reinforcement
ring. Replace the seat module with the new seat
by placing it into the body seat bore.
NOTE: When you tighten the cover in Step 12, the
cover will engage the seat module properly.
8. Insert the disc holder assembly back into the seat module.
9. Replace the spring ensuring that it seats properly on the
disc holder.
WARNING:
The first check valve has a heavy weight spring. The second check valve
has a lighter weight spring. When reassembling the check valves, make
sure you install the correct spring into the correct check valve.
10. Place the cover onto the spring with the internal guide on the cover
positioned inside the end coil.
11. Screw the cover onto the valve body.
12. Tighten the cover using the appropriate sized wrench.
13. Service the second check valve using Steps 2 through 12.
14. Slowly open shutoff valves.
Check Disc Washer
Check Disc Screw
Check Seat
Check Seat
O-ring
Cover
Cover O-ring
Check Spring
Check Disc Rubber
Check Disc Holder
Check Assembly