Grundfos CM series, Service Instructions Manual

Page: 10 / 30

5. Dismantling and assembly
5.1 General information
DANGER
Electric shock
Death or serious personal injury
‐
Before starting any work on the product, make sure
that the power supply has been switched off and that it
cannot be accidentally switched on.
WARNING
Corrosive liquids
Death or serious personal injury
‐
Wear personal protective equipment.
WARNING
Toxic liquids
Death or serious personal injury
‐
Wear personal protective equipment.
WARNING
Hot liquid
Death or serious personal injury
‐
The pumped liquid may be scalding hot and under
high pressure. Before any removal or dismantling of
the pump, the system must therefore be drained, or
the isolating valves on either side of the pump must be
closed.
CAUTION
Hot or cold liquid
Minor or moderate personal injury
‐
Wear personal protective equipment.
CAUTION
Back injury
Minor or moderate personal injury
‐
Use lifting equipment which is approved for the weight
of the product.
‐
Use a lifting method suitable for the weight of the prod-
uct.
‐
Wear personal protective equipment.
If it is necessary to dismantle the pump, either because it is choked
or damaged, please follow the instructions in the following sections.
Position numbers of parts (digits) refer to the section on Drawings;
position numbers of tools (letters) refer to the section on Service
tools.
Before dismantling the pump
• Disconnect the electricity supply to the motor.
• Close the isolating valves, if fitted, to avoid draining the system.
• Remove the electric cable in accordance with local regulations.
Before assembly
• Clean and check all parts.
• Replace defective parts by new parts.
• Order the necessary service kits.
• Gaskets and O-rings should always be replaced when the pump
is overhauled.
• See the section on replacement of impellers and spacing pipes
before replacing an impeller or spacing pipe.
During assembly
• Lubricate and tighten screws and nuts to correct torque. See the
section on tightening torques and lubricants.
Related information
3. Tightening torques and lubricants
4. Service tools
5.9 Replacement of impellers and spacing pipes
7.1 CM 1, 3, 5
7.2 CM 10, 15, 25
5.2 CM 1, 3, 5, cast iron
5.2.1 Dismantling
1. Remove staybolts (pos. 26).
2. Remove inlet part (pos. 6).
3. Remove gasket (pos. 139b) and chamber (pos. 4e).
4. Hold clamp (pos. 64c), and remove nut (pos. 67).
5. Remove lock washers (pos. 66) and clamp (pos. 64c).
6. Remove impeller (pos. 49).
7. Remove bearing ring (pos. 47a) and short spacing pipe (pos.
64a).
Step 7 applies only to pumps with eight stages.
8. Remove chamber for bearing (pos. 4a), gasket (pos. 139b),
impeller (pos. 49) and spacing pipe (pos. 64).
Step 8 applies only to pumps with eight stages.
9. Continue the dismantling until shaft seal (pos. 105).
10. Remove shaft seal (pos. 105). See the figure below.
TM044327
Exploded view of shaft seal
Dismantling of MG 71 and MG 80, see the section on dis-
mantling.
Dismantling of MG 90 and MG 100, see the section on
dismantling.
It is advisable always to replace wear rings (pos. 45) and
wear ring retainers (pos. 65). See the section on checking
and replacing impellers and chambers.
Related information
5.6.1 Dismantling
5.7.1 Dismantling
5.8 Checking and replacing impellers and chambers
10
English (GB)