Watts 909 Series Instruction, Installation, Maintenance And Repair Manual page 5

Servicing First and Second Checks
Sizes: 2 ⁄ " – 10"
1
2
CAUTION
!
The spring assembly is an essential part of a check unit. Use care
when servicing the first and second checks. The units are factory
assembled and should never be disassembled in a field installation.
1. Remove the hatch cover bolts. Series 909/LF909-FS is
designed so that when the bolts are loosened by
spring load is re leased from the cover and retained by the check
module. Verify this before removing all the bolts.
2. Lift the check valve module straight out taking care not to hit
and damage the seating.
3. Remove and replace the seat ring as directed by size:
Sizes 4" – 10", pull out the two wire retainers.
Sizes 2 ⁄ " – 3", turn the seat by one quarter to remove it.
1
2
One wire is drawn out clockwise; the other, counterclockwise.
4. Lift the seat ring straight up to remove it.
5. To replace the disc on sizes 2
For sizes 6" – 10", remove the Allen head socket screws.
Reverse this procedure to install the new disc.
For further details contact your tech ni cal sales representative.
1 ⁄ ", all the
2
1 ⁄ " – 4", remove the retaining nut.
2
No special tools
required to service
Series 909/LF909-FS
First
Check
909/LF909-OSY-FS
Figure 5. Disc & Spring Assembly by Valve Size
Sizes
2 1 ⁄ " – 3"
2
Sizes
4" – 10"
*Disc & Spring
As sem bly
Seat
WARNING
!
*Spring as sem bly is factory assembled. DO NOT DIS AS SEM BLE.
First and second checks
are not interchangeable
Second
Relief Check
Valve
Flood
Sensor
*Disc & Spring
As sem bly
Seat
Seat O-ring
Cover O-ring
Disc
Lower Stem
O-ring (6" only)
Retainer wire
Seat O-ring
Cover O-ring
5