Repair Of Non-Return Valve - Grundfos PUST04 Montage- Und Betriebsanleitung

Warning
If the top opening is up to ∅1000, normal
precaution will be sufficient. Openings larger
than ∅1000 must be equipped with safety
barriers or other safety measures.
Warning
Pumps can be lifted by means of a crane, using
lifting points.
Proper slings or chains, approved for lifting must
be used.
Warning
Gloves and other suitable personal protection
equipment must be used in accordance with local
regulations.
Local regulations on exposure to wastewater
must be regarded.
If natural light is insufficient, the maintenance
Note
staff must use lamps.
Fig. 34 Lifting a free-standing pump for service
Fig. 35 Lifting a pump on auto coupling for service
16

11.1 Repair of 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 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. 36.
2. Close the isolating valves. See fig. 20.
3. Loosen and remove the two screws on the non-return valve
cover. See fig. 37.
4. Replace worn-out valve balls and clean valves inside.
5. Close valve cover and tighten screws.
6. Open isolating valves. See fig. 20.
7. Close the drainage valve inside the pit. See fig. 36.
Valve handle
Drainage valve
Fig. 36 Drainage valve
Non-return valve
Fig. 37 Non-return valve
Non-return valve,
exploded view