Replacing The Mechanical Seal - Wilo RexaBloc RE Notice De Montage Et De Mise En Service

English
Fig. 6: Removal of the impeller
1 Hydraulics housing
2 "Back pull out" unit
3 Support
Fastening screw for
4
support
Fastening nuts for "back
5
pull out" unit
6 Impeller fixation
1. Fasten the lifting equipment to the marked
attachment points.
2. Loosen the fastening screw (4) on the support (3)
and remove it.
3. Loosen and remove the hexagon nuts (5) for fixa-
tion of the "back pull out" unit (2).
4. Slowly and carefully pull the "back pull out" unit
(2) off the hydraulics housing (1).
Warning: Danger of crushing!
When the "back pull out" unit is pulled off
the stud bolts, it can fall suddenly. Limbs may
be crushed between the impeller and flange.
Slowly pull the "back pull out" unit off the stud
bolts and wear suitable protective gloves.
5. Secure the impeller (9) with suitable means, un-
screw and remove the fastening screw (6). Note
the washer (7) and the screw locking device (8).
Beware of sharp edges!
Sharp edges can form on the impeller. There is
a risk of injury! Wear the necessary protective
clothing, such as protective gloves.
6. Carefully pull the impeller (9) off the shaft (10).
Make sure that the key (11) remains in the groove.
7. Clean the shaft (10) and key (11).
8. Push a new impeller (9) onto the shaft (10). Make
sure that the sliding surfaces are not damaged
and that the key (11) is pushed into the groove on
the impeller (9).
9. Fit a new screw locking device (8) and a new
washer (7) to a new fastening screw (6). Screw
the fastening screw (6) back in. Secure the impel-
ler (9) and tighten the fastening screw (6) tightly.
10. Change the O-ring (12) on the bearing bracket of
the "back pull out" unit.
11. Push the "back pull out" unit back onto the stud
bolts on the hydraulics housing and secure it with
the hexagon nuts (5).
12. Secure the support (3) to the flange again with
the fastening screw (4).
13. Test: It must be possible to turn the impeller by
hand.
Beware of sharp edges!
Sharp edges can form on the opening on the
suction port. There is a risk of injury! Wear the
necessary protective clothing, such as protec-
tive gloves.

8.4.4. Replacing the mechanical seal

Great care must be taken during this task. The
mechanical seal is a very sensitive component
44
7 Washer
8 Screw locking device
9 Impeller
10 Shaft
11 Key
12 O-ring (265x4)
that will be destroyed if incorrect forces are
applied to it. This work must be carried out by
trained personnel or Wilo customer service.
Fig. 7: Component overview
10 Shaft
11 Key
13 Bearing bracket cover
1. Drain the oil from the sealing chamber – see sec-
tion "Oil change in sealing chamber"
2. Dismantle the impeller – see section "Impeller
change"
3. Remove the key (11).
4. Carefully and slowly pull the rubber bellows and
spring (14) (rotating part of the mechanical seal)
off the shaft (10).
Caution!
Avoid tilting! Otherwise the shaft may be
damaged.
5. Loosen the four fastening screws (16) on the
bearing bracket cover and completely unscrew
them.
6. Carefully and slowly pull the bearing bracket
cover (13) off the shaft.
Caution!
Avoid tilting! Otherwise the shaft may be
damaged.
7. Press the stationary ring with angle collar (15)
(stationary part of the mechanical seal) out of its
seat in the bearing bracket cover (13).
8. Clean the shaft (10) and bearing bracket cover
(13) thoroughly and check for wear and corrosion.
If the components are damaged, please contact
Wilo customer service.
9. Unpack the new mechanical seal and check for
damage.
Faulty parts must not be installed!
10. To reduce friction during installation, lubricate
the shaft, the seat on the bearing bracket cover
and the two components of the mechanical seal
with low surface tension water (with dishwashing
detergent added) or pure dishwashing detergent.
Caution!
Never use oil or grease as lubricants!
11. Applying an even distribution of pressure, press
the stationary ring with angle collar (15) into its
seat in the bearing bracket cover (13).
12. Fit a new O-ring (17) to the bearing bracket cover
(13), carefully and slowly push it onto the shaft
(10) and secure it again with the four fastening
screws (16).
Caution!
Avoid tilting! Otherwise the shaft or sliding sur-
face of the mechanical seal may be damaged.
MAINTENANCE AND REPAIR
Rubber bellows with
14
spring
Stationary ring with
15
angle collar
Fastening screws for
16
bearing bracket cover
WILO SE 12-2015 V05 DIN A4