Maintenance
7-8
WILO EMU 3.0
Repairs
The following repairs can be carried out on this machine:
- Changing the impeller and pump unit
- Changing the impeller and stationary wear rings
When carrying out repair work, the following information should always be noted:
- Round sealing rings as well as existing seals should always be replaced.
- Screw fixings such as spring washers or the self-locking Nord-Lock screw fixing should
always be replaced.
- If no self-locking Nord-Lock screw fixing is used as a locking screw or it is not possible to use
these, then no dacromet-coated screw should be used. In this case, screws made from the
material A2 or A4 must be used. The correct torques must be observed.
- Never use brute force during this work.
In general, the following applies to repairs:
Switch off the machine, disconnect it from the mains (have this done by
an electrician), clean it and place it on a solid base in a horizontal posi-
tion. Secure it from falling over and/or slipping. For certain housing
coatings (e.g. Ceram C0) the plugs are protected with plastic covers.
These must be removed and put back on after a successful lubricant
change. They must be lined with an acid-resistant sealant (such as
SIKAFLEX 11FC).
The following applies when using a self-locking Nord-Lock screw fixing:
- Do not use any rustproof screws
- Only use with dacromet-coated screws (strength level 10.9)
Changing the impeller and
pump unit
There are two ways to change the impeller. With the first version, the pump housing is dismantled
first, so that the impeller can then be changed.
With the second version, the intake port on the pump housing is dismantled. Version two is used
when the impeller is wider than the flange connection on the pump housing. In this version, the
impeller must be dismantled before the pump unit is changed.
Version 1 (see illustration)
1
Loosen and remove the hexagon nuts.
2
Secure and remove the pump housing from the sealing housing with suitable equipment,
e.g. hoisting gear. Place on a secure base.
3
Fasten the impeller with suitable equipment, loosen and remove the fastening screw.
Pay attention to the locking screw.
4
Remove the impeller from the shaft using a suitable extractor.
5
Clean the shaft.
6
Attach a new impeller to the shaft.
Make sure that the sliding surfaces do not become damaged.
7
Apply the screw fixing to the new fastening bolt and screw it into the shaft. Fasten the
impeller and tighten the fastening screw with the correct torque (see table).
8
Place the pump unit on the sealing housing and fasten it with hexagon nuts (1).
9
It must be possible to turn the impeller by hand.
