Install Instructions

#1 check is fouled Remove and Clean #1 check
Relief valve discharges water Relief valve does not properly close Service relief valve
while system is not flowing
Municipal water pressure is fluctuating Install check valve upstream
of backflow assembly
Fouled relief valve seat Service relief valve
Relief valve does not Incorrectly installed diaphragm Remove diaphragm and
shut off properly correctly install
Damaged rubber surface on piston Replace with new piston
Damaged or plugged pressure hose Repair or replace hose.
7
Series 957, 957RPDA, LF957RPDA
Troubleshooting Guide
ORDERING NO. SIzE MODEL
in. mm
Relief Valve Total Kit
0899232 2
1
⁄2 - 10 65-250 RK 957/957RPDA VT
Kit consists of: Complete relief valve assembly
Relief Valve Rubber Parts Kit
0899236 2
1
⁄2 - 10 65-250 RK 957/957RPDA RV
Kit consists of: Diaphragm, Inlet coupler O-ring and Piston assembly
ORDERING NO. SIzE MODEL
in. mm
Air Gap
0111764 2
1
⁄2 – 10 65-250 957AG
0111815 2
1
⁄2 – 10 65-250 957AG Splash Guard
O-ring, Inlet Coupler
Spider Bushing
Spring
Piston Assembly
Screw, Cover
Relief Valve Assembly
Body
Diaphragm
Cover Plate
Assembly
Series 957, 957N, 957Z,
957RPDA, LF957RPDA, 957NRPDA,
LF957NRPDA, 957ZRPDA, LF957ZRPDA
Relief Valve Kits
ORDERING NO. USE FOR MODEL
Relief Valve Hose
0298120 2
1
⁄2" – 4" (65-100mm) 957, 957RPDA
1
⁄2 x
1
⁄2 CFC-S-CFx20
0298121 2
1
⁄2" & 3" (65,80mm) 957,
1
⁄2 x
1
⁄2 CFC-S-CFx24
957RPDA N & Z
0298122 6" (150mm) 957, 4" 957N
1
⁄2 x
1
⁄2 CFC-S-CFx30
2
1
⁄2", 3", 4" (65,80,100mm) 957Z
6", 8" (150,200mm) 957RPDA
4", 6", 8" (100,150,200mm) 957RPDA N & Z
2
1
⁄2", 3", 4" (65,80,100mm) 957RPDA BFG
2
1
⁄2", 3", 4", 6" (65,80,100,150mm)
957RPDA BFG N & Z
0298123 8" & 10" (200 & 250mm) 957
1
⁄2 x
1
⁄2 CFC-S-CFx36
6", 8", 10" (150, 200, 250mm) 957 N & Z
10" (250mm) 957RPDA N & Z
6" & 8" (150, 200mm) 957RPDABFG N & Z