Installation and operating instructions Wilo-RexaBloc RE/Rexa BLOC 47
MAINTENANCE AND REPAIR English
Fig. 5.: Screw plug
L- Drain hole screw plug
1. If you can place a tank beneath the hydraulics to collect
the operating fluids, you do not need to remove the
hydraulics.
2. Place a collector tank underneath the screw plug (L-).
3. Carefully and slowly unscrew the screw plug (L-) and
allow the operating fluid to drain out. Dispose of the
operating fluid in accordance with the requirements in
the “Disposal” section.
4. Clean the screw plug (L-), renew the seal ring and screw
it back in.
8.3.5. Complete overhaul
In a general overhaul, the normal maintenance work is car-
ried out, and in addition, the shaft seals, O-rings and shaft
bearings are checked and replaced if necessary. This work
may only be performed by the manufacturer or an authorised
service centre.
8.4.
Repairs
DANGER due to toxic substances!
Hydraulics that pump liquids hazardous to
health must always be decontaminated before
undertaking any other work! Otherwise there
is a risk of fatal injury! Wear the necessary
protective clothing!
WARNING! Sharp edges!
Sharp edges can form on the impeller and the
opening on the suction port. There is a risk of
injury! Wear the necessary protective cloth-
ing, such as protective gloves.
CAUTION! Risk of burns!
The housing parts can heat up to well above
40 °C. There is a risk of burns!
• Never touch parts of the housing with your
bare hands.
• After switching them off, let the hydraulics
cool down to ambient temperature.
• Wear heat-resistant protective gloves.
Before carrying out repairs:
•
Have a qualified electrician disconnect the motor’s
power supply cable on the motor and secure it against
being switched on inadvertently.
• Allow the hydraulics and motor to cool down and clean
them thoroughly.
• Make sure that all the operationally relevant parts are in
good condition.
• Always replace O-rings, gaskets and screw locking
devices (spring lock washers, Nord-Lock washers).
•
The specified tightening torques must be complied with.
• Never use force when carrying out this work!
8.4.1. Use of screw locking
Screw locking is used on all screws. This must always be
renewed after dismantling.
The screw locking can be applied in different ways:
• Liquid thread-locking compound, e.g. Loctite 243
• Mechanical screw locking with Nord-Lock washer
Thread-locking fluid
Thread-locking fluid can be unfastened by applying
increased force. If this is not possible, the connection must
be heated to about 300 °C in order to be released. The
affected components must be thoroughly cleaned and, on
assembly, once again have the thread-locking fluid applied
to them.
Mechanical screw locking device
The Nord-Lock washer is only used on bolts with strength
class 10.9 which have been coated with Geomet.
The Nord-Lock washer must not be used for screw locking
with rust-free screws!
8.4.2. Which repair work is allowed to be performed?
• Impeller change
• Changing the mechanical seal
• Change of hydraulics
• Change of motor
8.4.3. Impeller change
The bearing bracket and housing cover, impeller and motor
are constructed in “back pull-out” design. This means that
these components can be removed as a complete unit. The
hydraulics housing remains installed in the pipeline system.
Fig. 6.: Removal of the impeller
1 Hydraulics housing
7 Washer
2 “Back pull-out” unit
8 Screw locking device
3 Support
9 Impeller
4 Fastening screw for
support
10 Shaft
5 Fastening nuts for back
pull-out unit
11 Key
6
Impeller fixation
12 O-ring
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 fixation 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! Pull the back pull-out unit off the stud
bolts slowly and wear suitable protective gloves.
5. Secure the impeller (9) with suitable means, unscrew and
remove the fastening screw (6). Note the washer (7) and
the screw locking device (8).
Warning! Sharp edges!
Sharp edges can form on the impeller. There is a risk of
injury! Wear the necessary protective clothing, such as
protective gloves.
