
- 10 -
6.1 Removal, installation and inspecting the anti-pollution check valve (refer to Figure 4)
1. Close cut-off valves 1 and 2.
2. Reduce pressure by opening ball valves 3, 4, and 5.
3. Take off cover.
4. Remove the anti-pollution check-valve.
For DN 65-150, first unscrew the discharge anti-pollution check valve and then the supply anti-pollution check valve.
You can obtain an assembly tool as an accessory.
Danger of injury! The anti-pollution check-valve is spring preloaded.
5. Check for leakproofness by filling water from the rear.
Leaky anti-pollution check-valves must be replaced. Repair is not possible.
6. Assemble in the reverse sequence.
For DN 65-150: - grease O-ring and thread well on the anti-pollution check valve with Unisilikon 250.
Do not damage the O-ring when installing.
The tightening torque for the anti-pollution check-valve is 100-120 Nm.
7. Close the ball valves.
8. Open the cut-off valves.
9. Vent the system through the ball valves.
10. Check the backflow preventer, see Chapters 5.1 to 5.3.
11. Connect the dust plugs to the ball valves.
7. Important information instructions for your safety
Use the device solely in a technically flawless condition and as intended for use, safety and hazard aware while complying
with the installation and operating instructions. Have all malfunctions that could impair safety repaired immediately.
The BA Backflow Preventer, Figure 361, is intended solely for the application areas named in these installation and
operating instructions. Any different use or use beyond and above that is considered non-intended usage.
8. Troubleshooting
Errors Possible causes Remedy
Other Strong pressure fluctuations in the
water network.
Install a water surge (hammer) damper
behind the backflow preventer
Fluctuating admission pressure Install a pressure reducer before the
backflow preventer
Supply-side anti-pollution check valve
or drain valve
is soiled
Remove and clean anti-pollution check
valve
Leaky supply anti-pollution check valve Remove the anti-pollution check valve
Drain valve does not close Deposits on the valve seat Remove the drain valve
Damaged O-rings Remove drain valve and replace O-ring
Leaky drain valve Remove the drain valve
Drain valve does not open Clogged pressure control line Remove and clean the pressure control
line
Table 4: Troubleshooting
9. Technical data
Total pressure drop: max. 1.0 bar at nominal flow
Flow media: Water at 60 °C
Operating pressure: max. 10 bar
Minimum supply pressure: 1.5 bar
Ball valve connection: G ½ with connection size DN 65-150
Connection sizes Weight ca. in kg Total length in mm Nominal flow rate in m³/h
DN 65 32 559 45
DN 80 32.5 559 54
DN 100 33 559 85
DN 150 57 695 191
Table 5: Technical data