13. Replacing the impeller
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The following operations can only be carried out by DRENO POMPE qualified personnel. In order to replace
the impeller, the following operations must be carried out in the order shown.
A) Unscrew the 4 socket screws that connect the pump body with the motor holder.
B) Remove the pump body from the motor holder.
C) Using an appropriate spanner, unscrew the screw securing the impeller.
D) Easily remove the impeller from the motor shaft.
Before fitting a new impeller, ensure that the end of the shaft is clean and free of any imperfections.
E) Fit the new impeller and tighten the screws with a torque of 25Nm ±10%
F) Replace the pump body in its position, and tighten the screws with a torque of 25Nm ±10%
14. Replacing the mechanical seals
These series of electric pumps are supplied with two mechanical seals.
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Motor side mechanical seal;
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Impeller side mechanical seal;
Both seals consist of two parts, a rotating section, and a fixed ring.
Before fitting the new seals, ensure that the faces in contact are not damaged.
14.1 Replacing the lower mechanical seal
The following operations can only be carried out by DRENO POMPE qualified personnel. In order to replace
the mechanical seal, the following operations must be carried out in the order shown.
A) Empty the seal lubrication oil tank as indicated in paragraph 10.6.
B) Before replacing the mechanical seal, uncouple the impeller as indicated in paragraph 13.
C) Using two flat screwdrivers, remove the old seal, first working on the rotating part, and then on the fixed ring,
paying attention to position the pump so that no oil comes out from the tank.
D) Before fitting the new seal, ensure that the housings are clean, without burring or scores that may damage
it, or in any case compromise the perfect seal to the shaft.
WARNING: It is recommended to avoid seizing that could cause the break of the fixed ring. After its insertion,
insert the rotating part of the seal itself.
E) Replace the impeller and the pump body as described in paragraph 13.
F) Refill the oil tank with the oil quantity indicated in paragraph 10.6.
14.2 Replacing the upper mechanical seal
The following operations can only be carried out by DRENO POMPE qualified personnel.
In order to replace top the mechanical seal, the following operations must be carried out in the order shown.
A) Empty the seal lubrication oil tank as indicated in paragraph 10.6.
B) Remove the impeller as described in paragraph 13.
C) Remove the lower mechanical seal as described in paragraph 14.1.
D) Unscrew the screw securing the motor holder to the motor casing.
E) Remove the motor holder.
F) Remove the Seeger ring and the AVP ring on the shaft in front of the mechanical seal using Seeger pliers.
G) Remove the mechanical seal from the shaft.
H) Fit the new mechanical seal.
I) Replace the Seeger ring and the AVP ring on the shaft.
L) Check the condition of the O-Ring between the motor holder and the motor casing. Replace if necessary.
M) Reinsert the motor holder, making sure not to damage the O-Ring.
N) Tighten the 4 screws securing the motor holder to the motor casing.
O) Replace the impeller and the pump body as described in paragraph 13.
Check that the electric power supply is disconnected, and that the pump cannot
restart, not even accidentally, before starting any work on the same.
To avoid biological contamination, ensure that the pump has been carefully washed
with water and non aggressive detergents that will not compromise the integrity of
the same.
The electric pump can only be disassembled by DRENO POMPE qualified personnel,
ensuring that the parts are handled using working gloves.
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