5
Servicing First and Second Checks
Sizes: 2
1
⁄
2
" – 10"
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
1
⁄
2
", all the
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
1
⁄
2
" – 3", turn the seat by one quarter to remove it.
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
1
⁄
2
" – 4", remove the retaining nut.
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.
*Disc & Spring
As sem bly
Seat
Seat O-ring
Cover O-ring
*Disc & Spring
As sem bly
Retainer wire
Seat O-ring
Cover O-ring
Sizes
4" – 10"
Lower Stem
O-ring (6" only)
Seat
Disc
No special tools
required to service
Series 909/LF909-FS
First and second checks
are not interchangeable
First
Check
Second
Check
Relief
Valve
909/LF909-OSY-FS
WARNING
!
*Spring as sem bly is factory assembled. DO NOT DIS AS SEM BLE.
Figure 5.
Disc & Spring Assembly by Valve Size
Sizes
2
1
⁄
2
" – 3"
Flood
Sensor