Warning
Gloves and other suitable personal protection
equipment must be used in accordance with local
regulations.
Observe local regulations on exposure to
wastewater.
If natural light is insufficient, the maintenance
Note
staff must use lamps.
Fig. 28 Lifting a pump on auto coupling for service
16
1
2
12.1 Repairing a non-return valve
Warning
Make sure that the escaping water does not
cause injury to persons or damage to the
equipment.
Warning
Before starting work on the non-return valves,
make sure that the fuses have been removed or
the main switch has been switched off.
Make sure that the power supply cannot be
accidentally switched on.
Warning
Make sure that the isolating valves cannot be
accidentally opened.
When entering the valve chamber, do not step on
Caution
pipes or valves.
1. Open the valve chamber drainage valve by means of the
valve handle in the pit in order to empty the sump of the valve
chamber. See fig. 29.
Valve handle
Drainage valve
Drainage pipe
Fig. 29 Draining the valve chamber
2. Close the isolating valves. See fig. 11.
3. Remove the two screws on the non-return valve cover. See
fig. 30.
Non-return valve
Fig. 30 Non-return valve
4. Replace worn-out valve balls and clean valves inside.
5. Close the valve cover and tighten the screws.
6. Open the isolating valves. See fig. 11.
7. Close the drainage valve inside the pit. See fig. 29.
Exploded view