8
EN
4. Troubleshooting
PROBLEM
POSSIBLE CAUSE
ACTION
1. Rapid discharge of water through the
relief valve followed by normal operation
Pressure fluctuation in the upstream water supply
network
None
2. Continuous discharge of water
through the relief valve in the course of
normal operation
The relief valve is dirty or damaged
Clean or replace the relief valve module
3. Continuous discharge of water
through the relief valve in safe mode
(normal flow or no flow)
a. The upstream valve is dirty or damaged
b. The piston seal of the relief valve is dirty or damaged
c. The downstream valve is dirty or damaged
a. Clean or replace the upstream valve
b. Clean or replace the relief valve module
c. Clean or replace the downstream valve
D
E
A
B
C
F
Repair kits for BA4760 backflow preventer
Modules
/ kits
Items
DN
DN65 *
DN80
DN100
DN150
DN200
DN250
Ref BA 4760
149B3486
149B3097
149B3098
149B3400
149B3401
149B3402
Serial number
"I 01000
SI 000000"
"K 01000
SK 000000"
"L 01000
SL 000000"
"M 01000
SM 000000"
"N 01000
SN 000000"
"P 01000
SP 000000"
A
5-6-7-10-12-
13-14-15-22
Relief valve module
Upstream check valve and retainer
149B055379 149B055380 149B055381 149B055382
149B055383
B
8-9
First check valve module
Downstream check valve and retainer
149B055301 149B055370 149B055371 149B055372
149B055373
C
11-9
Second check valve module
Draining valve assembly, head, seat and
cover, membrane, seals
149B055374 149B055375 149B055376 149B055377
149B055378
D
15-16-18-19-
20-21
Complete cover module
Cover, draining valve seat, cover, test
cocks and screws
149B055305 149B055384 149B055386 149B055387
149B055388
E
2-3-4
Drain kit
Funnel and screws
149B055389
149B055406
F
18-21
Kit 3 Test cocks with caps
149B055410
A+B+C
5-6-7-8-9-10-
11-12-13-14-
15-22
Complete kit
149B19
149B20
149B21
149F017922
149B25
* For former BA4760 DN65 Nr 149B3096, serie Nr J01000, please refer to DN 80.
