Watts 909 Serie Manuel D'installation, D'entretien Et De Réparation page 6

Servicing the Relief Valve
CAUTION
!
Use the clearance recommendations referenced below for servicing
relief valve assemblies according to valve size. Figure 6 shows the
differences between the assemblies by valve size.
1. Remove the relief valve cover bolts. Series 909/LF909 is designed
so that when the bolts are loosened by
spring load is retained by the bottom plug spring module. Verify
this before removing all the bolts.
2. Remove the cover and diaphragm. The relief valve piston assembly
can be lifted straight up and out.
3. Replace the wiper seal and piston O-ring and apply grease to
the O-ring.
4. To replace the relief valve disc, hold the upper guide fin and
unscrew the diaphragm pressure plate. If necessary, lightly tap
the cast webs and the pressure plate to loosen. Replace with
a new disc holder assembly and O-ring. The disc rubber is molded
into the disc holder and supplied as a disc holder assembly.
5. Inspect the bottom plug and spring assembly. During normal field
service there is no need to remove this assembly other than
inspection. Unscrew the assembly with a large pipe wrench.
CAUTION
!
The spring is retained on the bottom plug and is highly loaded. NO
attempt should be made in the field to disassemble the bottom plug
and spring piston assembly. For replacement, a complete bottom
plug assembly must be obtained from the factory.
For further details contact your technical sales representative.
Clearance Recommended for Servicing
Relief Module
6
1 ⁄ " all the relief valve
2
CLEARANCE REQUIRED FOR SERVICING
Valve Size Clearance
2 1 ⁄ " – 3" 11"
2
4" 14"
6" 16"
8" 21"
10" 21"
Figure 6. Relief Valve Assemblies by Valve Size
Adapter O-ring
Diaphragm
Relief Valve Disc
Relief Valve Piston
Assembly
Piston O-Ring
Seat
O-ring
2 ⁄ " – 3"
1
2
Adapter O-ring
Diaphragm
Relief Valve Assembly
Seat
O-ring
8", 10"
Plug & Spring Piston
Assembly
Air Gap
Adapter O-ring
Diaphragm
Relief Valve Piston
Assembly
Piston seal
O-ring
4", 6"
8"M1, 10"M1
Spring Piston
Assembly
Relief Valve
Flood Sensor
Activation Module
Module Cable
Relief valve with flood sensor
Seat
Plug &