Watts LF007 IOT Manual De Instalación página 3

Servicing the First and Second Check Valves
No special tools are required to service the assembly.
1. Remove cover bolts and cover.
2. Remove the retainer from the body bore. The check valve
modules can now be removed from the valve by hand or with
a screwdriver.
3. The check seats are attached to the cage with a bayonet type
locking arrangement. Holding the cage in one hand, push the
seat inward and rotate counterclockwise against the cage.
The seat, spring cage, spring, and disc assembly are now
individual components.
4. Clean and reassemble the disc assembly. Or depending on
its condition, discard or replace with a new assembly from the
repair kit. O-rings should be cleaned or replaced as necessary.
For more information, refer to repair parts price list PL-RP-BPD.
5. Reassemble the check valve modules. Check modules are
installed in the valve body with the seats facing the valve inlet.
The modules must be securely in place before the retainer can
be replaced.
Troubleshooting
SYMPTOM
Check valve fails to hold
1.0 PSID minimum
Chatter during flow conditions
Low flows passing through
mainline valve
CAUSE
Debris on check disc sealing surface
Leaking gate valve
Damaged seat disc or seat O-ring
Damaged guide holding check open
Weak or broken spring
Worn, damaged or defective guide
Mainline check fouled
Meter strainer plugged
Damaged mainline seat disc or seat
Broken mainline spring
Seat
Disc
Seat
O-ring
Assembly
Check Assemblies
Cover
Cover O-ring
Retainer
SOLUTION
Disassemble and clean
Disassemble and clean or repair
Disassemble and replace
Disassemble and clean or replace
Disassemble and replace spring
Disassemble and repair or replace guide
Disassemble and clean
Disassemble and clean
Disassemble and replace
Disassemble and replace
Caps/
Spring Retainer
Seat
Body
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